Thursday, December 31, 2009

Minerals for Seniors

Diminished digestion and ABSORPTION can lead to deficiencies of MAGNESIUM, IRON,
ZINC, COPPER, and CALCIUM. Older persons probably need more than the current calcium RDA of 800 mg because the ability of the intestine to absorb adequate calcium declines progressively with age. The common experience is that the bodies of elderly women and men remove calcium from their bones to meet their calcium needs. Supplementation with calcium and VITAMIN D, or calcium with low-dose ESTROGEN for post-menopausal women, seems to be more effective in slowing bone losses than supplementation with calcium alone. Normally, iron stores increase throughout adult life in men and in women after menopause. However, blood loss due to chronic ASPIRIN use and bleeding ulcers can cause iron deficiency; 5 percent of elderly men are iron deficient in the United States. CHROMIUM stores in the body decline steadily with age and this may contribute to the decline in the regulation of blood sugar. Chromium assists in insulin action and helps blood sugar regulation in some diabetics. Low chromium is correlated with elevated blood cholesterol levels.

Nutrient Needs During Aging

Elderly persons are prone to MALNUTRITION for several reasons. They are more likely to eat alone and so take less interest in meal preparation, and they are more often disabled and immobile. Thus, they are less likely to eat properly. More than 30 percent of homebound older individuals may have difficulty in preparing their own meals. Low-fiber, high-carbohydrate meals typify the diets of many elderly persons. They use more LAXATIVES and medications for long periods. Furthermore, many elderly persons have periodontal disease and poor teeth. Their senses of smell, taste, and sight decline, making eating less appealing, and STOMACH ACID production gradually drops, decreasing nutrient uptake even with an adequate diet.
Evidence indicates that superior nutrition may prevent unnecessary illness and disability from shortening a productive life. Therefore, experts recommend the following health decisions:
  • Avoiding excess calories and ALCOHOL. Surplus calories regardless of their source are converted to fat. Excessive body fat contributes to the risk of heart disease, hypertension, and some forms of cancer. Besides carrying a risk of addiction, excessive alcohol can damage the liver, pancreas, and brain, in addition to depleting the body of nutrients.
  • Medical testing of stomach acid production. Low stomach acid production sets the stage for inadequate digestion of nutrients.
  • Making informed choices regarding nutritional supplements. They can affect the quality of health of those who are nutrient deficient, though eating wisely.
  • Choosing a diet based on DIETARY GUIDELINES FOR AMERICANS as a foundation. A BALANCED DIET, one that provides adequate amounts of all nutrients and FIBER from varied, minimally processed foods without excessive calories and FAT, is of paramount importance.

Understanding Aflatoxin

A mycotoxin, a family of toxic compounds derived from molds growing on foods and on grains used for animal feed. Aflatoxin is produced by ASPERGILLUS, a storage mold that often infests damp grains and nuts. Nuts such as PISTACHIOS, ALMONDS, WALNUTS, PECANS, and PEANUTS are susceptible to MOLD. Very low levels of aflatoxin often contaminate PEANUT BUTTER. Spot checks have shown that this contamination is usually below the U.S. Food and Drug Administration limit. In the 1970s and again in the 1980s, hot drought conditions caused outbreaks of mold in corn and, consequently, widespread aflatoxin contamination.
Concern has focused on aflatoxin because it is a potent liver CARCINOGEN. The amount of aflatoxin permitted by the U.S. FDA is 15 parts per billion, although levels as low as one part per billion can cause liver cancer in certain species of experimental animals. As yet there is no compelling evidence that aflatoxin consumption in the low amounts usually encountered in Western nations causes cancer. In regions of Africa where peanut consumption and consequently aflatoxin intake is very high, population studies suggest a correlation with liver cancer in humans. Recent epidemiological studies have shown that ingestion of aflatoxin B-1 increases the risk of developing liver cancer. The risk is even higher for people who are infected with hepatitis B. In addition to increasing the risk of chronic diseases such as cancer, ingestion of aflatoxin B-1 can cause acute symptoms of aflatoxicosis, including vomiting, abdominal pain, and even death.
Consumers should avoid moldy, discolored, or off-flavor nuts. Molds and fungi send out microscopic filaments beyond the immediate, visibly moldy area and cannot be easily removed. Furthermore, aflatoxin is not completely destroyed by cooking. Therefore moldy food (except cheese) should be discarded, rather than cutting out the mold.

Monday, November 30, 2009

Understanding Food Advertising

Billions of dollars are spent each year on advertising food, and much of this is focused on specific markets. Food ads for breakfast cereals and junk food, for example, focus largely on the children’s market. Toys, comic books, giveaways, and polished commercials can hinder young people from making independent judgments on how to eat a balanced diet. Instead, their choices may rely on the direction of advertisers. TV advertising plays a prominent role, where cartoons featuring food commercials dominate children’s programming. Most of these emphasize PROCESSED FOODS—low in nutrients and high in CALORIES, SUGAR, SALT, and FAT. The American Academy of Pediatrics (AAP) discovered that less than 3 percent of advertising during children’s programs focuses on healthful food, such as fruit and milk. The AAP concluded that there is a direct link between commercials promoting high-calorie food and health problems, and in 1991 recommended a ban on food commercials geared toward children.
The Better Business Bureau’s Children’s Advertising Review Unit was founded in 1972. Composed of representatives from the media, ad agencies, and others, its goal is to monitor truth in advertising in radio, TV, and the printed word for children up to the age of 12, according to self-regulating guidelines. It will review material before it is publicized upon request. The group provides a forum for information exchange and relies on a panel of academic professionals to provide expertise on the impact of images on children.

Understanding Adulterated Food

A food is classified as adulterated if it contains extraneous material, dangerous amounts of poisons or filth, or if it has been processed or stored under unsanitary conditions. In terms of food for interstate commerce, the U.S. Food and Drug Administration monitors environmental contaminants, toxins from microorganisms, bacterial levels, and potentially harmful substances. Since it is impossible for food to be 100 percent pure, tolerances have been set for each type of contaminant. Very hazardous materials can be ruled so dangerous that no amount should be detected (a “zero tolerance”).

Understanding Adipose tissue (body fat, depot fat)

Fat storage is A specialized function of adipose tissue, and it represents The major fuel depot of the body; it is as Essential to normal function as any other tissue. Body fat serves other important functions: It insulates The body against low environmental temperatures And serves as a shock absorber. Typically, fat Stored in adipose tissue represents 15 percent to 20 Percent of men’s weight and 20 percent to 25 percent Of women’s average weight. Women usually Have more fat than men because fat is an important Energy reserve during pregnancy and lactation. Adipose tissue synthesizes fat after a high carbohydrate Meal in response to the hormone INSULIN. During FASTING, STARVATION, or STRESS, a second Hormone EPINEPHRINE (adrenaline) signals ADIPOCYTES (fat cells) to break down stored fat into FATTY ACIDS, which are released into the bloodstream. They are rapidly absorbed and oxidized for energy By muscles. In contrast, the brain relies on blood Sugar to meet its energy needs.
The fact that an adult can consume approximately Two pounds of food a day (or 700 pounds of Food a year) with only small changes in body fat Indicates how well the body regulates weight when The calorie intake matches the total body requirements. Of course, common experience suggests that Body fat can increase. For example, fat accumulation Often accounts for the weight gain of middleaged Americans. Older people tend to EXERCISE less And the metabolic rate slows with aging. An individual’s Optimal body fat at any age depends upon Many factors, including inheritance, body build, Sex, and age. Standard HEIGHT/WEIGHT TABLES or the BODY MASS INDEX can be used to estimate an appropriate Body weight for an individual.
Excessive body fat is not healthy for many reasons.
OBESITY carries with it the increased risk of CARDIOVASCULAR DISEASE, HYPERTENSION, and some Forms of CANCER. It is interesting to note that the Distribution of body fat plays a role in defining the Risk for heart disease. Abdominal fat (the “spare Tire” profile) carries a greater risk for cardiovascular Disease than fat accumulated around hips and Thighs (the “pear” profile).
The general approach to losing fat stored in adipose Tissue is exercising and eating low-fat, highadipose Fiber meals, while decreasing caloric intake. Dieting Without exercise decreases muscle mass (not desirable) As well as the fat in adipose tissue, and the Weight regained after a crash diet is mostly fat (also Not desired). Cycles of dieting and not dieting also Cause loss of muscle mass. Muscle burns more ENERGY per pound than fat, so DIET cycling may Increase the difficulty of losing weight permanently. The number of fat cells in adipose tissue—
The storage bags themselves—cannot be lost by Dieting or exercise. The only way to lose fat cells of Adipose tissue is by LIPOSUCTION, a surgical procedure.

Thursday, October 29, 2009

Understanding Sugar Addiction

Addiction to refined CARBOHYDRATES in general and to sucrose (table sugar) specifically is a controversial topic. Proponents believe that sugar has no effect on behavior, and that it has little effect on health other than promoting tooth decay. A government task force concluded in 1986 that typical sugar consumption does not generally pose a health hazard. Critics contend that sugar addiction is a common phenomenon. Preferring sugar and sweets seems to be programmed at infancy. A craving for sweets often develops later in life, and in this sense sugar may be psychologically addicting. Compounding the problem of defining sugar addiction is the general observation that related symptoms are rather vague, including a change in mood or feeling shaky when abstaining from sugary foods.
One hypothesis proposes that addicted persons have a drive to achieve a sense of well-being and to overcome depression. Some addicted persons seem to have an abnormal metabolism of NEUROTRANSMITTERS, chemicals that carry signals from one nerve cell to another cell. A primary example is the link between depression and low levels of the brain chemical serotonin and the correlation between high-sugar, high-fat diets, and high brain serotonin levels. Evidence suggests that eating certain sugary foods stimulates the production of brain peptides (ENDORPHINS), which trigger pleasant feelings. It has been hypothesized that the formation of endorphins may be abnormal in some individuals,
possibly triggering compulsive eating behavior like BULIMIA NERVOSA. (See also APPETITE; BLOOD SUGAR; NATURAL SWEETENERS.)

Understanding Addiction

A chronic condition characterized by CRAVINGS for and uncontrollable use of a substance (often drugs or alcohol) despite negative physical, mental, or social consequences. People who suffer from drug or alcohol addiction are often malnourished and may be either overweight due to an increased consumption of foods high in refined CARBOHYDRATES or underweight due to a loss of APPETITE.
Nutrition offers a powerful adjunct to recovery and restoring the body’s biochemical balance. A nutritional program for a recovering addict might advise:
  • establishing new eating patterns, including eating frequent small meals to stabilize blood sugar (GLUCOSE) and prevent HYPOGLYCEMIA
  • avoiding foods high in sugar or refined carbohydrates eating a varied, balanced diet of VEGETABLES, whole GRAINS, LEGUMES, FRUITS, lean MEAT, POULTRY, and FISH
  • avoiding or eliminating foods that contain CAFFEINE
  • taking daily supplements of certain VITAMINS and MINERALS, such as GLUTAMINE, VITAMIN C, and NIACINAMIDE.

Acrylamide and Human Health

A chemical used in making plastics, textiles, and dyes and in purifying drinking water. Short-term exposure above safe limits (maximum contaminant levels) set by the Environmental Protection Agency (EPA) causes damage to the central nervous system. Long-term exposure can cause paralysis and possibly cancer. The chemical has been shown to cause cancer in laboratory animals. In 2002 the World Health Organization (WHO) convened an emergency meeting of food safety and health experts after a team of Swedish scientists reported that some starch-based foods, like potato CHIPS, FRENCH FRIES, and some BREAKFAST CEREALS and BREADS, contain high levels of acrylamide. The amount of the chemical found in a large order of fast-food french fries was at least 300 times above EPA safe limits for drinking water. Additional studies in Norway, Great Britain, Switzerland, and the United States reached similar results.
Acrylamide apparently forms in some starchy foods when they are baked or fried at high temperatures. Raw or boiled samples of these foods, such as potatoes, test negative for the chemical. Research on the health effects of acrylamide in food is ongoing. For the time being, most health experts have stopped short of advising consumers to avoid the risky foods or change their cooking methods.

Monday, September 28, 2009

Understanding Acidosis

The acidification of the blood and other body fluids. This condition can be due to acid accumulation or to the loss of bicarbonate buffering capacity from kidney disease. The pH of blood is tightly regulated; the normal range is between pH 7.3 and 7.4. A drop in blood pH below pH 7.3, which corresponds to increased hydrogen ion concentration, could signal excessive acidity of the blood (ACIDEMIA). Homeostatic mechanisms (the body’s regulatory system of checks and balances) help prevent acidosis. Bicarbonate and serum proteins take up hydrogen ions to neutralize excessive acid rapidly, while the kidneys more slowly compensate for acid production by excreting surplus hydrogen ions. Prolonged acidosis requires medical attention because it slows down many vital functions, including nerve transmission and heart muscle contraction. Symptoms of acidosis include nausea, vomiting, DIARRHEA, headache, rapid breathing, and, eventually, convulsions.
Two forms of acidosis are recognized: metabolic and respiratory. Metabolic acidosis can occur when metabolic acids accumulate excessively. For example, when the body burns FAT at a high rate, the liver converts FATTY ACIDS to KETONE BODIES, acidic substances. This condition may occur during crash DIETING and FASTING or in a person suffering from uncontrolled DIABETES MELLITUS or chronic ALCOHOLISM.
Excessive ingestion of acids, such as in aspirin poisoning, also causes acidosis. Metabolic acidosis can also result from vomiting or diarrhea, which cause excessive loss of ELECTROLYTES like BICARBONATE and upset the acid/base balance.
Renal disease may prevent the kidneys from adequately correcting acid production.
Respiratory acidosis can occur when breathing does not adequately remove carbon dioxide. Shallow breathing, associated with respiratory disease, can cause excessive CARBON DIOXIDE in the lungs, in turn causing carbon dioxide blood levels to rise and upset the bicarbonate buffer system of the blood.

Acidophilus (Lactobacillus acidophilus) and Nutrition

A species of the bacterium Lactobacillus that produces lactic acid by fermenting LACTOSE (milk sugar). This organism in the upper intestinal tract forms a symbiotic relationship with its human host. Other acid producing bacteria, including BIFIDOBACTERIA, are predominant in the lower intestine. Acidophilus is a member of the normal intestinal microflora, the so-called friendly bacteria that produce nutrients like BIOTIN and VITAMIN K. Acidophilus and other Lactobacillus species help balance the digestive system by maintaining conditions that inhibit the growth of yeasts like CANDIDA ALBICANS, as well as potentially dangerous bacterial species. Without beneficial bacteria to control them, such opportunistic microorganisms can multiply rapidly, leading to a full-blown infection.
A variety of conditions can drastically lower or eliminate the intestinal acidophilus population.
Treatment with broad-spectrum antibiotics (such as tetracycline) imbalances gut microecology because these antibiotics destroy both benign and disease producing bacteria. More generally, an unhealthful lifestyle and a diet high in SUGAR and PROCESSED FOODS also adversely affect beneficial intestinal bacteria.
Acidophilus is a common food supplement that may help repopulate the gut with beneficial bacteria to prevent hard-to-control yeast infections; to break down milk sugar for those with LACTASE DEFICIENCY; to control travelers’ DIARRHEA; to relieve CONSTIPATION; to treat vaginitis (when administered as acidophilus douches); and to decrease the production of potential CARCINOGENS by certain bacteria populating the gut.

Food and acid indigestion (heartburn, esophageal reflux, gastric reflux)

A condition characterized by a burning pain near the stomach. Typically, this occurs an hour or so after a heavy (fatty) meal and is often relieved by taking ANTACIDS or by drinking MILK. Acid indigestion is the most common gastrointestinal complaint in the United States; one in 10 Americans suffer daily attacks. The pain associated with acid indigestion is caused by STOMACH ACID backing up into the ESOPHAGUS, the region of the throat connecting the mouth with the stomach. Acid indigestion can be caused by air gulped when swallowing large bites of food, which can keep the passageway open. Some food allergies and food sensitivities may trigger acid indigestion by relaxing the sphincter muscles that normally seal off the stomach juices from the esophagus after eating. Although the stomach lining is protected from acid by mucus, the unprotected esophagus is irritated by repeated exposure to acid.
To prevent acid indigestion, patients should eat slowly and chew food thoroughly, avoiding foods and beverages that cause adverse reactions. Common examples include fatty foods, CHOCOLATE, COFFEE, CITRUS FRUIT, and alcoholic beverages. Also
patients should consult a physician for any chronic stomach pain because what feels like acid indigestion may actually be inadequate stomach acid (HYPOCHLORHYDRIA). Patients should seek immediate medical attention if experiencing a crushing pain in the middle of the chest that extends to the left arm, since these symptoms could indicate a heart attack.

Saturday, August 29, 2009

Understanding acidifiers

Common additives that increase the acidity (lower the pH) of foods and beverages. Acidifiers provide tartness and enhance flavors of processed foods. The increased acidity inhibits the growth of microorganisms; thus acidifiers act as preservatives. Certain acidifiers can also retard spoilage by acting as antioxidants, preventing chemical changes due to oxygen. This group of additives includes ADIPIC ACID (adipate), TARTARIC ACID (tartrate), benzoic acid (benzoate), and CITRIC ACID (citrate).

Understanding acid-forming foods

Foods that create acidic residues after they have been broken down by the body. Protein-rich food, such as EGGS, MEAT, and poultry, produce acidic residues when oxidized for energy. The combustion of sulfur-containing amino acids tends to acidify the body (acidic residue). In contrast, fruits and vegetables make the body more alkaline or basic. They contain magnesium, calcium, and potassium salts of organic acids, which yield an alkaline residue when oxidized. Fruits are accordingly classified as alkali-forming foods, even though juices and fruit taste acidic (sour). Excretion of organic acids (potential renal acid load) can be calculated for various foods based on their content of sodium, potassium, calcium, magnesium, chloride, phosphorus, and sulfur. Choosing more alkaline foods may ameliorate osteoporosis, autoimmune conditions such as rheumatoid arthritis, and chronic inflammation.

Acid and human health

A large family of compounds that taste sour and can neutralize bases to create salts. Strong acids like hydrochloric acid (STOMACH ACID) and sulfuric acid (battery acid) give up all of their protons in water and lower the pH, the effective hydrogen ion concentration. A pH of 7.0 is neutral, that is, neither acidic nor basic, while pH values less than 7.0 are considered acidic. Exposure to strong acids tends to damage cells and tissues. The stomach is the only organ normally exposed to strong acids, but it is protected from injury by a heavy mucous layer.
In contrast to strong acids, organic acids are classified as weak acids because they donate only a portion of their hydrogen ions, lower the pH to a lesser degree, and are less dangerous to tissues.
Many compounds in foods are weak acids, including CITRIC ACID, ACETIC ACID, and TARTARIC ACID. Several weak acids are used as FOOD ADDITIVES, including benzoic acid, CARBONIC ACID, and alginic acid. As food additives and recipe ingredients, weak acids add tartness to foods. Weak acids are common intermediates, products of cellular processes that sustain life, including LACTIC ACID, KETONE BODIES, PYRUVIC ACID, acetic acid, FATTY ACIDS, SUCCINIC ACID, citric acid, even the nucleic acids DNA and RNA. GLUTAMIC ACID and ASPARTIC ACID (two common AMINO ACIDS) are classified as acidic amino acids, and are more acid than most.
In the body, weak acids characteristically have lost all their hydrogen ions and exist as a family of anions (negatively charged ions) classified as “conjugate bases” because they have been completely neutralized by the buffer systems of blood. In the blood, lactic acid exists as its anion, lactate; acetoacetic acid (a ketone body) as acetoacetate; citric acid as citrate, and so on. Often the names of acids and their anions are interchanged in nutrition literature.

Tuesday, July 28, 2009

What is achlorhydria?

A condition resulting from the lack of STOMACH ACID. DIARRHEA, stomach discomfort, and bloating are common symptoms of achlorhydria, which has serious effects. It can lead to MALNUTRITION, even when the diet is well balanced, because achlorhydria drastically reduces the efficiency of DIGESTION. A chronic MALABSORPTION syndrome leads to deficiencies of VITAMIN B12, CALCIUM, IRON, and other nutrients and sets the stage for chronic FATIGUE, OSTEOPOROSIS, ANEMIA, and serious infections. Although causes of achlorhydria are unknown, lowered stomach acid production is associated with anemia, stomach inflammation, CELIAC DISEASE, diabetes, lupus, myasthenia gravis, rheumatoid ARTHRITIS, and some forms of cancer. Limited stomach acid production, not the absence of stomach acid, is termed HYPOCHLORHYDRIA. It is not as severe a condition as achlorhydria, although unless corrected, the ensuing malabsorption syndrome can have similar, detrimental longrange effects on health. In either situation patients may be advised to take supplemental hydrochloric acid in the form of BETAINE HYDROCHLORIDE or glutamic acid hydrochloride with meals to enhance digestion. These supplements should be used with medical supervision because of the danger of overdosing.

What is acetoacetic acid (acetoacetate)

The most prevalent of the KETONE BODIES, which are acids produced by the liver. Acetoacetic acid is a useful fuel; it is readily oxidized by the heart and brain for the production of ATP, the energy currency of cells.
Though small amounts of ketone bodies are normally produced by liver metabolism, an excessive buildup of acetoacetic acid and its derivative, BETA HYDROXYBUTYRIC ACID, in the blood (ketonemia) can occur during excessive fat breakdown, when the liver cannot completely oxidize massive amounts of fatty acids released from fat (ADIPOSE TISSUE). Conditions conducive to excessive acetoacetic acid production include STARVATION (prolonged FASTING), crash DIETING, uncontrolled DIABETES MELLITUS, and chronic ALCOHOLISM.
Ketone body production serves an important role in the physiologic adaptation to starvation. With prolonged starvation, the blood levels of ketone bodies rise, and more of them cross the BLOOD-BRAIN BARRIER to be taken up by nerve tissue, where they are burned for energy. Consequently, the brain requires less blood glucose (blood sugar) for energy at a time when this fuel is at a premium. The sustained build-up of acetoacetic acid in the blood (KETOSIS) can acidify the blood, leading to metabolic ACIDOSIS, and alter the acid-base balance of the body, a potentially dangerous condition.

What is acetic acid?

During fermentation, certain bacteria produce acetic acid by oxidizing alcohol when exposed to air. VINEGAR contains 4 percent to 6 percent acetic acid, which gives vinegar its characteristic sour taste. As vinegar, acetic acid is a common ingredient in food preparation.
One of the simplest organic acids, acetic acid contains only two carbon atoms. It is classified as a weak acid because it is only partially ionized, unlike strong mineral acids, such as hydrochloric acid.
Acetic acid plays a pivotal role in metabolism. To be metabolized, acetic acid must be activated as acetyl CoA, in which acetic acid is bound to a carrier molecule, COENZYME A, which is in turn derived from the B vitamin PANTOTHENIC ACID. Metabolic pathways that oxidize fatty acids, carbohydrate, and amino acids for energy, all yield acetyl CoA, the common intermediate by which carbons from these fuels enter the KREB’S CYCLE to be oxidized to carbon dioxide. Alternatively, acetyl CoA can be used as a building block. It forms saturated fatty acids, cholesterol, and ketone bodies. Nerve cells can use it to form the NEUROTRANSMITTER, ACETYLCHOLINE. Tissues combine acetic acid with amino sugars to form a family of sugar derivatives like Nacetylglucosamine and N-acetylgalactosamine that help define recognition sites on the surface of cells and blood group specificities, such as the A, B, O, and Lewis blood groups used in blood typing.

Sunday, June 28, 2009

Acesulfame-K (acesulfame potassium; Sunett)

This non-caloric, ARTIFICIAL SWEETENER tastes approximately 200 times sweeter than table sugar (SUCROSE) and lacks the bitter aftertaste of SACCHARIN. The United Nations Food and Agriculture Organization endorsed acesulfame-K as a satisfactory artificial sweetener in 1983. Acesulfame-K was approved in 1988 by the U.S. FDA as a sugar substitute to be used in packets or as tablets and now is approved for use in chewing gum and in powdered drink mixes. Unlike ASPARTAME, acesulfame-K can be used in cooking because it does not break down at oven temperatures. Blending Sunett with other low-calorie sweeteners creates a beverage with a more sugarlike taste than one sweetened with any single low-calorie sweetener.
The Center for Science in the Public Interest has raised questions about Sunett’s safety, saying a few tests on rats indicated a possibility of cancer, although this was not proof that the sweetener could cause cancer. The Calorie Control Council counters that the safety of acesulfame potassium has been confirmed by more than 90 studies, and it is endorsed by a committee of the World Health Organization. Theoretically, it would not be expected to be absorbed by the body. Nonetheless, some studies suggest that large doses raise blood CHOLESTEROL levels in diabetic laboratory animals and increase the number of lung and mammary tumors in other animals.

Acerola (acerola cherry, acerola berry) Acerola

fruit is a product from the Caribbean and is one of the richest natural source of VITAMIN C. Acerola juice contains nearly 40 times more vitamin C than orange juice. Acerola extract is sometimes added to natural vitamin C supplements. Because of its very limited availability, the amount added to supplements is usually very small; an acerola-enriched vitamin C preparation may contain as little as a tablespoon of acerola extract per barrel of vitamin C powder.

What is Food absorption?

Generally, the passage of liquids into solid materials and of gases into liquids and solids. In terms of nutrition, absorption refers to the passage of substances into body fluids and tissues.
Digestion is only the first step in the assimilation of nutrients. This chemical breakdown of food particles releases AMINO ACIDS, GLUCOSE, FATTY ACIDS, VITAMINS, and MINERALS, which must then be absorbed by the intestine in order to be used by the body. Nutrients enter cells lining the intestine (the intestinal mucosa) and then are drawn into underlying cells, where they may enter either the lymph or bloodstream for distribution to tissues throughout the body. Tissues absorb nutrients from blood via capillaries, the smallest blood vessels. Gases, too, are absorbed. Blood becomes oxygenated in the lungs by absorbing oxygen from inhaled air and releasing carbon dioxide that was absorbed from tissues.
Absorption requires a disproportionately large surface area to meet the body’s needs. Consider the total area of the small intestine, which is a highly specialized absorptive organ. Though this tube is only about 20 feet long, it has a highly convoluted surface. Furthermore, the cells lining the surface, VILLI, are covered with microscopic, hairlike projections (MICROVILLI) that dramatically increase the absorptive area to a quarter the size of a football field. The microvilli move constantly, to trap nutrients and partially digested food, which is further digested. The upper regions of the small intestine, the lower DUODENUM, and upper ILEUM, are most active in absorbing nutrients. Other regions of the gastrointestinal tract carry out limited absorption:
The stomach absorbs some ALCOHOL, glucose, ions, and water, and the colon absorbs primarily water and minerals.

Friday, May 29, 2009

Maintaining the Right Amount of Water in Your Body

As much as three-quarters of the water in your body is in intracellular fluid, the liquid inside body cells. The rest is in extracellular fluid, which is all the other body liquids, such as
  • Interstitial fluid (the fluid between cells)
  • Blood plasma (the clear liquid in blood)
  • Lymph (a clear, slightly yellow fluid collected from body tissues that flows through your lymph nodes and eventually into your blood vessels)
  • Bodily secretions such as sweat, seminal fluid, and vaginal fluids
  • Urine A healthy body has just the right amount of fluid inside and outside each cell, a situation medical folk call fluid balance. Maintaining your fluid balance is essential to life. If too little water is inside a cell, it shrivels and dies. If there’s too much water, the cell bursts.

Investigating the Many Ways Your Body Uses Water

Water is a solvent. It dissolves other substances and carries nutrients and
other material (such as blood cells) around the body, making it possible for
every organ to do its job. You need water to
  • Digest food, dissolving nutrients so that they can pass through the intestinal cell walls into your bloodstream, and move food along throughyour intestinal tract
  • Carry waste products out of your body
  • Provide a medium in which biochemical reactions such as metabolism (digesting food, producing energy, and building tissue) occur
  • Send electrical messages between cells so that your muscles can move, your eyes can see, your brain can think, and so on
  • Regulate body temperature — cooling your body with moisture (perspiration) that evaporates on your skin
  • Lubricate your moving parts

Phytochemicals Future

Yes, I know that misspelling forecasting as “phorecasting” and future as “phuture” is gross. Yes, I know I already named this chapter “Phabulous Phytochemicals” and that should have been enough, but I just couldn’t resist the tempting play on words.
Please don’t let my lack of semantic restraint turn you away from the fact that phytochemical research is serious stuff that eventually should enable people to identify biochemical reactions that trigger — or prevent — specific medical conditions.
While you’re waiting for final analyses, the best nutrition advice is to dig into those veggies, fruits, and grains — and turn to Chapter 13 to find out why you need to wash them down with plenty of cold, clear water.

Monday, April 27, 2009

Dietary fiber in foods

Dietary fiber is a special bonus found only in plant foods. You can’t get it from meat or fish or poultry or eggs or dairy foods. Soluble dietary fiber, such as the pectins in apples and the gums in beans, mops up cholesterol and lowers your risk of heart disease. Insoluble dietary fiber, such as the cellulose in fruit skins, bulks up stool and prevents constipation, moving food more quickly through your gut so there’s less time for food to create substances thought to trigger the growth of cancerous cells.

Sulfur compounds in your foods

Slide an apple pie in the oven, and soon the kitchen fills with a yummy aroma that makes your mouth water and your digestive juices flow. But boil some cabbage and — yuck! What is that awful smell? It’s sulfur, the same chemical that identifies rotten eggs.
Cruciferous vegetables (named for the Latin word for “cross,” in reference to
their x-shaped blossoms) — such as broccoli, Brussels sprouts, cauliflower,
kale, kohlrabi, mustard seed, radishes, rutabaga, turnips, and watercress — all
contain stinky sulfur compounds, such as sulforaphane glucosinolate (SGSD),
glucobrassicin, gluconapin, gluconasturtin, neoglucobrassicin, and sinigrin, that
seem to tell your body to rev up its production of enzymes that inactivate and help eliminate carcinogens.
These smelly sulfurs may be one reason why people who eat lots of cruciferous veggies generally have a lower risk of cancer. In animal studies at Johns Hopkins University School of Medicine, rats given chemicals known to cause breast tumors were less likely to develop tumors when they were given broccoli sprouts, a food that’s unusually high in sulforaphane. In 2005, a human trial conducted in China by researchers from Johns Hopkins, Qidong Liver Cancer Institute, Jiao Tong University (Shanghai), and the University of Minnesota Cancer Center showed that the sulforaphane-rich sprouts appear to help the body defang aflatoxins produced by molds that grow on grains such as rice. Aflatoxins, which damage cells and raise the risk of cancer, may be linked to the high incidence of stomach and liver cancer in China. Further studies are in the planning phases. (But of course.)

Hormonelike compounds

Many plants contain compounds that behave like estrogens, the female sex hormones. Because only animal bodies can produce true hormones, these plant chemicals are called hormonelike compounds or phytoestrogens (plant estrogen). Seems fair.
The three kinds of phytoestrogens are
  • Isoflavones, in fruits, vegetables, and beans
  • Lignans, in grains
  • Coumestans, in sprouts and alfalfa
The most-studied phytoestrogens are the isoflavones known as daidzein and genistein (found in soy), two compounds with a chemical structure similar to estradiol, which is the estrogen produced by mammalian ovaries. Like natural or synthetic estrogens, daidzein and genistein hook onto sensitive spots in reproductive tissue (breast, ovary, uterus, prostate) called estrogen receptors. But phytoestrogens have weaker estrogenic effects than natural or synthetic estrogens. It takes about 100,000 molecules of daidzein or genistein to produce the same estrogenic effect as one molecule of estradiol. Every phytoestrogen molecule that hooks onto an estrogen receptor displaces a stronger estrogen molecule. As a result, researchers suggested that consuming isoflavone-rich foods such as soy products may provide post-menopausal women with the benefits of estrogen (stronger bones and relief from hot flashes) without the higher risk of reproductive cancers (of the breast, ovary, or uterus) associated with hormone replacement therapy (HRT). The theory was supported by the fact that the incidence of breast and uterine cancer, heart disease, osteoporosis, and menopausal discomfort is lower in countries where soy — a primary source of phytoestrogens — is a significant part of the diet.
However, recent animal and human studies offer conflicting evidence. On the one hand, these studies
  • Raise questions about the safety of phytoestrogen-rich foods for women with hormone-sensitive tumors
  • Show that phytoestrogen may stimulate tumor growth in animals whose ovaries have been removed
  • Demonstrate that isoflavone-rich foods have only modest effects on preserving bone and relieving “hot flashes” at menopause One the other hand, including isoflavone-rich soy foods such as tofu, miso, tempeh, soy milk, soy flour, and soy protein in a healthful diet
  • May reduce total cholesterol, lower LDL (“bad cholesterol”), and maintain or even increase blood levels of HDL (“good cholesterol”). In 2005, researchers at the Johns Hopkins University School of Nursing announced the results of a 216-woman study funded by the National Heart, Lung, and Blood Institute in which women consuming 20 grams of soy proteins per day had significant decreases in LDLs, while women who were given the same amount of milk protein did not.
  • Helps people feel full longer so they can stick to a lower-calorie diet for managing weight loss. Bottom Line? According to the International Food Information Council, “Further clinical studies will continue to increase understanding of the role of soy in maintaining and improving health.” Couldn’t have said it better myself.

Sunday, March 29, 2009

Understanding Antioxidants

Antioxidants are named for their ability to prevent a chemical reaction called oxidation, which enables molecular fragments called free radicals to join together, forming potentially carcinogenic (cancer-causing) compounds in your body.
Antioxidants also slow the normal wear-and-tear on body cells, so some researchers noted that a diet rich in plant foods (fruits, vegetables, grains, and beans) seems likely to reduce the risk of heart disease and maybe reduce the risk of some kinds of cancer. For example, consuming lots of lycopene (the red carotenoid in tomatoes) has been linked to a lower risk of prostate cancer — as long as the tomatoes are mixed with a dab of oil, which makes the lycopene easy to absorb.
However (you knew this was coming, right?), recent studies show that although a diet rich in fruits and veggies is healthful as all get-out, stuffing yourself with the antioxidant vitamins A and C has ab-so-lute-ly no effect on the risk of heart disease.

Phytochemicals Are Everywhere

Did you take French literature in high school or college? If your answer is no, you may as well skip to the third sentence in the paragraph that follows. But if your answer’s yes, then you’re probably familiar with Molière’s The Bourgeois Gentleman. The bourgeois gentleman is a lovable but pompous character who’s surprised to discover he’s been speaking prose all his life without knowing it.
Your relationship with phytochemicals is probably something like that. You’ve been eating them all your life without knowing it. The following are all phytochemicals:
  • Carotenoids, the pigments that make fruits and vegetables orange, red, and yellow (dark green vegetables and fruits like kiwi contain these pigments, too, but green chlorophyll masks the carotenoids’ colors)
  • Thiocyanates, the smelly sulfur compounds that make you turn up your nose at the aroma of boiling cabbage
  • Daidzein and genistein, hormonelike compounds in many fruits and vegetables
  • Dietary fiber
These and other phytochemicals, such as vitamins (yes, vitamins), perform beneficial housekeeping chores in your body. They
  • Keep your cells healthy
  • Help prevent the formation of carcinogens (cancer-producing substances)
  • Reduce cholesterol levels
  • Help move food through your intestinal tract
The undeniable value of phytochemicals is one reason the U.S. Department of Agriculture/Health and Human Services Dietary Guidelines for Americans urges you to have at least five servings of fruits and vegetables and several servings of grains every day.
Did you notice that no minerals appear in the list of phytochemicals? The omission is deliberate. Plants don’t manufacture minerals; they absorb them from the soil. Therefore, minerals aren’t phytochemicals.

Wow — You think that was a hot flash?

Then you need extra calcium. Both men and women produce the sex hormones testosterone and estrogen, although men make proportionately more testosterone and women, more estrogen. Testosterone builds bone; estrogen preserves it.
At menopause, a woman’s production of estrogen drops precipitously, and her bones rapidly become less dense. As men age and their testosterone levels drop, they’re also at risk of losing bone tissue, but the loss is less rapid and dramatic than a woman’s.
For both men and woman, severe loss of bone density can lead to osteoporosis and an increased risk of bone fractures, a condition more common among women of Caucasian and Asian ancestry. Estrogen supplements can help a woman maintain bone tissue, but taking the hormone may have serious side effects, including an increased risk of breast cancer. Twenty years ago, nutritionists thought it impossible to stop age-related loss of bone density — that your body ceased to absorb calcium when you passed your mid-20s. Today, medications such as alendronate (Fosamax) protect an aging woman’s bones without estrogen’s potentially harmful effects. Increasing your consumption of calcium plus vitamin D may also be helpful, regardless of your gender. But the most recent studies says the value of extra calcium may not be as high as once believed. What can I say? Stay tuned for more on this one.

Thursday, February 26, 2009

Calcium supplements: What kind of calcium is in that pill?

Calcium-rich foods give you calcium paired with natural organic acids, a combination that your body easily digests and absorbs.
The form of calcium most commonly found in supplements, however, is calcium carbonate, the kind of calcium that occurs naturally in limestone and oyster shells.
Calcium carbonate is a versatile compound. Not only does it build strong bones and teeth, but it also neutralizes stomach acid and relieves heartburn. Calcium carbonate antacids can be used as calcium supplements. They’re nutritionally sound and generally cost less than products designed solely as nutritional supplements. Some calcium supplements contain compounds that mix calcium with an organic acid. Calcium lactate is calcium plus lactic acid, the combination that occurs naturally in milk. Calcium citrate is calcium plus citric acid, an acid found in fruits. These compounds are easier to digest, but they’re sometimes more expensive than calcium carbonate products. Calcium carbonate is nearly half calcium, a very high percentage. But unless your stomach is very acidic, it’s hard for your digestive system to break the compound open and get at the elemental calcium (the kind of calcium your body can use). You can increase your absorption of calcium from calcium carbonate by taking the tablets with meals.
Because different calcium compounds yield different amounts of elemental calcium, the label lists both the calcium compound and the amount of elemental calcium provided, like this:
Calcium carbonate, 500 milligrams, providing 200 milligrams elemental calcium. Whenever you see the word calcium alone, it stands for elemental calcium.
The human body absorbs calcium most efficiently in amounts of 500 milligrams or less. You get more calcium from one 500-milligram calcium tablet twice a day than one 1,000-milligram tablet. If the 1,000-milligram tablets are a better buy, break them in half.
Warning: Not all antacids double as dietary supplements. Antacids containing magnesium or aluminum compounds are safe for neutralizing stomach acid, but they won’t work as supplements.
In fact, just the opposite is true. Taking magnesium antacids reduces your absorption of calcium, and taking aluminum antacids reduces your absorption of phosphorus. Because manufacturers sometimes change the ingredients in their products without notice, you always need to read the product label before assuming that an antacid can double as a calcium supplement

I’m looking for an iron supplement. What’s this “ferrous” stuff?

The iron in iron supplements comes in several different forms, each one composed of elemental iron (the kind of iron your body actually uses) coupled with an organic acid that makes the iron easy to absorb.
The iron compounds commonly found in iron supplements are:
  • Ferrous citrate (iron plus citric acid)
  • Ferrous fumarate (iron plus fumaric acid)
  • Ferrous gluconate (iron plus a sugar derivative)
  • Ferrous lactate (iron plus lactic acid, an acid formed in the fermentation of milk)
  • Ferrous succinate (iron plus succinic acid)
  • Ferrous sulfate (iron plus a sulfuric acid derivative)
In your stomach, these compounds dissolve at different rates, yielding different amounts of elemental iron. So supplement labels list the compound and the amount of elemental iron it provides, like this:

Ferrous gluconate 300 milligrams
Elemental iron 34 milligrams

This tells you that the supplement has 300 milligrams of the iron compound ferrous gluconate, which gives you 34 milligrams of usable elemental iron. If the label just says “iron,” that’s shorthand for elemental iron. The elemental iron number is what you look for in judging the iron content of a vitamin/mineral supplement.

People who need extra minerals

If your diet provides enough minerals to meet the RDAs, you’re in pretty good shape most of the time. But a restrictive diet, the circumstances of your reproductive life, and just plain getting older can increase your need for minerals. Here are some scenarios.

You’re a strict vegetarian
Vegetarians who pass up fish, meat, and poultry must get their iron either from fortified grain products such as breakfast cereals or commercial breads or naturally from foods such as seeds, nuts, blackstrap molasses, raisins, prune juice, potato skins, green leafy vegetables, tofu, miso, or brewer’s yeast. Because iron in plant foods is bound into compounds that are difficult for the human body to absorb, iron supplements are pretty much standard fare. Vegans — vegetarians who avoid all foods from animals, including dairy products — have a similar problem getting the calcium they need. Calcium is in vegetables, but it, like iron, is bound into hard-to-absorb compounds. So vegans need calcium-rich substitutes. Good food choices are soybean milk fortified with calcium, orange juice with added calcium, and tofu processed with calcium sulfate.

You live inland, away from the ocean
Now here’s a story of 20th century nutritional success. Seafood and plants grown near the ocean are exposed to iodine-rich seawater. Freshwater fish, plants grown far from the sea, and the animals that feed on these fish and plants are not exposed to iodine. So people who live inland and get all their food from local gardens and farms cannot get the iodine they need from food. American savvy and technology rode to the rescue in 1924 with the introduction of iodized salt. Then came refrigerated railroad cars and trucks to carry food from both coasts to every inland city and state. Together, modern salt and efficient shipment virtually eliminated goiter, the iodine deficiency disease, in this country. Nonetheless, millions of people worldwide still suffer from chronic iodine deficiency.

You’re a man
Just as women lose iron during menstrual bleeding, men lose zinc at ejaculation. Men who are extremely active sexually may need extra zinc. The trouble is, no one has ever written down standards for what constitutes “extremely active.” Check this one out with your doctor.
Men who take a daily supplement of 200 micrograms selenium seem to cut their risk of prostate cancer by two-thirds. The selenium supplement also produces an overall drop in cancer mortality, plus a significantly lower risk of prostate cancer, colon cancer, and lung cancer in both men and women.

You’re a woman
The average woman loses about 2 to 3 teaspoons of blood during each menstrual period, a loss of 1.4 milligrams of iron. Women whose periods are very heavy lose more blood and more iron. Because getting the iron you need from a diet providing fewer than 2,000 calories a day may be virtually impossible, you may develop a mild iron deficiency. To remedy this, some doctors prescribe a daily iron supplement.
Women who use an intrauterine device (IUD) may also be given a prescription for iron supplements because IUDs irritate the lining of the uterus and cause a small but significant loss of blood and iron.

You’re pregnant
The news about pregnancy is that women may not need extra calcium. This finding, released late in 1998, is so surprising that it probably pays to stay tuned for more — and definitely check with your own doctor. Meanwhile, pregnant women still need supplements to build not only fetal tissues but also new tissues and blood vessels in their own bodies. Animal studies suggest (but don’t prove) that you may also need extra copper to protect nerve cells in the fetal brain. Nutritional supplements for pregnant women are specifically formulated to provide the extra nutrients they need.

You’re breast-feeding
Nursing mothers need extra calcium, phosphorus, magnesium, iron, zinc, and selenium to protect their own bodies while producing nutritious breast milk. The same supplements that provide extra nutrients for pregnant women will meet a nursing mother’s needs.

Wow — You think that was a hot flash?
Then you need extra calcium. Both men and women produce the sex hormones testosterone and estrogen, although men make proportionately more testosterone and women, more estrogen. Testosterone builds bone; estrogen preserves it.
At menopause, a woman’s production of estrogen drops precipitously, and her bones rapidly become less dense. As men age and their testosterone levels drop, they’re also at risk of losing bone tissue, but the loss is less rapid and dramatic than a woman’s.

For both men and woman, severe loss of bone density can lead to osteoporosis and an increased risk of bone fractures, a condition more common among women of Caucasian and Asian ancestry. Estrogen supplements can help a woman maintain bone tissue, but taking the hormone may have serious side effects, including an increased risk of breast cancer. Twenty years ago, nutritionists thought it impossible to stop age-related loss of bone density — that your body ceased to absorb calcium when you passed your mid-20s. Today, medications such as alendronate (Fosamax) protect an aging woman’s bones without estrogen’s potentially harmful effects. Increasing your consumption of calcium plus vitamin D may also be helpful, regardless of your gender. But the most recent studies — by which I mean the study released in February 2006 as I am typing these words — says the value of extra calcium may not be as high as once believed. What can I say? Stay tuned for more on this one.

Wednesday, January 28, 2009

Knowing how much mineral is too much

Like some vitamins, some minerals are potentially toxic in large doses:
  • Calcium: Though clearly beneficial in amounts higher than the current RDAs, calcium is not problem-free:
• Constipation, bloating, nausea, and intestinal gas are common side effects among healthy people taking supplements equal to 1,500 to 4,000 milligrams of calcium a day.
• Doses higher than 4,000 milligrams a day may be linked to kidney damage.
• Megadoses of calcium can bind with iron and zinc, making it harder for your body to absorb these two essential trace elements.
  • Phosphorus: Too much phosphorus can lower your body stores of calcium.
  • Magnesium: Megadoses of magnesium appear safe for healthy people, but if you have kidney disease, the magnesium overload can cause weak muscles, breathing difficulty, irregular heartbeat and/or cardiac arrest (your heart stops beating).
  • Iron: Overdosing on iron supplements can be deadly, especially for young children. The lethal dose for a young child may be as low as 3 grams (3,000 milligrams) elemental iron at one time. This is the amount in 60 tablets with 50 milligrams elemental iron each. For adults, the lethal dose is estimated to be 200 to 250 milligrams elemental iron per kilogram (2.2 pounds) of body weight. That’s about 13,600 milligrams for a 150-pound person — the amount you’d get in 292 tablets with 50 milligrams elemental iron each. New FDA rules require individual blister packaging for supplements containing more than 30 milligrams iron to foil tiny fingers and prevent accidental overdoses.
  • Zinc: Moderately high doses of zinc (up to 25 milligrams a day) may slow your body’s absorption of copper. Doses 27 to 37 times the RDA (11 mg/males; 8 mg/females) may interfere with your immune function and make you more susceptible to infection, the very thing that normal doses of zinc protect against. Gram doses (2,000 milligrams/2 grams) of zinc cause symptoms of zinc poisoning: vomiting, gastric upset, and irritation of the stomach lining.
  • Iodine: Overdoses of iodine cause exactly the same problems as iodine deficiency: goiter. How can that be? When you consume very large amounts of iodine, the mineral stimulates your thyroid gland, which swells in a furious attempt to step up its production of thyroid hormones. This reaction may occur among people who eat lots of dried seaweed for long periods of time.
  • Selenium: In China, nutrition researchers have linked doses as high as 5 milligrams of selenium a day (90 times the RDA) to thickened but fragile nails, hair loss, and perspiration with a garlicky odor. In the United States, a small group of people who had accidentally gotten a supplement that mistakenly contained 27.3 milligrams selenium (436 times the RDA) fell victim to selenium intoxication — fatigue, abdominal pain, nausea and diarrhea, and nerve damage. The longer they used the supplements, the worse their symptoms were.
  • Fluoride: Despite decades of argument, no scientific proof exists that the fluorides in drinking water increase the risk of cancer in human beings. But there’s no question that large doses of fluoride — which you’re unlikely to consume unless you drink well or groundwater in the western United States — causes fluorosis (brown patches on your teeth), brittle bones, fatigue, and muscle weakness. Over long periods of time, high doses of fluoride may also cause outcroppings (little bumps) of bone on the spine. Fluoride levels higher than 6 milligrams a day are considered hazardous.
  • Molybdenum: Doses of molybdenum two to seven times the Adequate Intake (AI) (45 micrograms) may increase the amount of copper you excrete in urine.

Avoiding mineral deficiency

What happens if you don’t get enough minerals and trace elements? Some minerals, such as phosphorus and magnesium, are so widely available in food that deficiencies are rare to nonexistent. No nutrition scientist has yet been able to identify a naturally occurring deficiency of sulfur, manganese, chromium, or molybdenum in human beings who follow a sensible diet. Most drinking water contains adequate fluoride, and Americans get so much copper (can it be from chocolate bars?) that deficiency is practically unheard of in the United States.
But other minerals are more problematic:
  • Calcium: Without enough calcium, a child’s bones and teeth don’t grow strong and straight, and an adult’s bones lose minerals and weaken. Calcium is a team player. To protect against deficiency, you also need adequate amounts of vitamin D, the nutrient that allows you to absorb the calcium you get from food or supplements. Milk fortified with vitamin D has done much to eliminate rickets.
  • Iron: Iron deficiency anemia is not just an old advertising slogan. Lacking sufficient iron, your body can’t make the hemoglobin it requires to carry energy-sustaining oxygen to every tissue. As a result, you’re often tired and feel weak. Mild iron deficiency may also inhibit intellectual performance. In one Johns Hopkins study, high school girls scored higher verbal, memory, and learning test scores when they took supplements providing Recommended Dietary Amounts of iron. Check with your doctor before downing iron supplements or cereals fortified with 100 percent of your daily iron requirement, the Environmental Nutrition newsletter warns. Hemochromatosis, a common but often-undiagnosed genetic defect affecting one in every 250 Americans, can lead to iron overload, an increased absorption of the mineral linked to arthritis, heart disease, and diabetes, as well as an increased risk of infectious diseases and cancer (viruses and cancer cells thrive in iron-rich blood).
  • Zinc: An adequate supply of zinc is vital for making testosterone and healthy sperm. Men who don’t get enough zinc may be temporarily infertile. Zinc deprivation can make you lose your appetite and your ability to taste food. It may also weaken your immune system, increasing your risk of infections. Wounds heal more slowly when you don’t get enough zinc.That includes the tissue damage caused by working out. In plain language: If you don’t get the zinc you need, your charley horse may linger longer. And, yes, zinc may fight the symptoms of the common cold. To date, several studies have confirmed that sucking on lozenges containing one form of zinc (zinc gluconate) shortens a cold — by a day or two. Others show no differences. Your choice. These results are for adults, not children, and the zinc tablets are meant just for the several days of your cold.
  • Iodine: A moderate iodine deficiency leads to goiter (a swollen thyroid gland) and reduced production of thyroid hormones. A more severe deficiency early in life may cause a form of mental and physical retardation called cretinism.
  • Selenium: Not enough selenium in your diet? Watch out for muscle pain or weakness. To protect against selenium problems, make sure that you get plenty of vitamin E. Some animal studies show that a selenium deficiency responds to vitamin E supplements. And vice versa.


Molybdenum (pronounced mo-lib-de-num) is part of several enzymes that metabolize proteins. You get molybdenum from beans and grains. Cows eat grains, so milk and cheese have some molybdenum. Molybdenum also leeches into drinking water from surrounding soil. The molybdenum content of plants and drinking water depends entirely on how much molybdenum is in the soil.

Tuesday, January 13, 2009

Benefits of chromium

Very small amounts of trivalent chromium, a digestible form of the very same metallic element that decorates your car and household appliances, are essential for several enzymes that you need to metabolize fat. Chromium is also a necessary partner for glucose tolerance factor (GTF), a group of chemicals that enables insulin (an enzyme from the pancreas) to regulate your use of glucose, the end product of metabolism and the basic fuel for every body cell. In a recent joint study by USDA and the Beijing Medical University, adults with noninsulin-dependent diabetes who took chromium supplements had lower blood levels of sugar, protein, and cholesterol, which are all good signs for people with diabetes. In a related study, chromium reduced blood pressure in laboratory rats bred to develop hypertension (high blood pressure), a common complication in diabetes. Right now, little information exists about the precise amounts of chromium in specific foods. Nonetheless, yeast, calves’ liver, American cheese, wheat germ, and broccoli are regarded as valuable sources of this trace element.

Benefits of Fluoride

Fluoride is the form of fluorine (an element) in drinking water. Your body stores fluoride in bones and teeth. Although researchers still have some questions about whether fluoride is an essential nutrient, it’s clear that it hardens dental enamel, reducing your risk of getting cavities. In addition, some nutrition researchers suspect (but cannot prove) that some forms of fluoride strengthen bones.
Small amounts of fluoride are in all soil, water, plants, and animal tissues. You also get a steady supply of fluoride from fluoridated drinking water.

Benefits of Manganese

Most of the manganese in your body is in glands (pituitary, mammary, pancreas), organs (liver, kidneys, intestines), and bones. Manganese is an essential constituent of the enzymes that metabolize carbohydrates and synthesize fats (including cholesterol). Manganese is important for a healthy reproductive system. During pregnancy, manganese speeds the proper growth of fetal tissue, particularly bones and cartilage.
You get manganese from whole grains, cereal products, fruits, and vegetables. Tea is also a good source of manganese.

Benefits of Copper

Copper is an antioxidant found in enzymes that deactivate free radicals (pieces of molecules that can link up to form compounds that damage body tissues) and make it possible for your body to use iron. Copper also may play a role in slowing the aging process by decreasing the incidence of protein glycation, a reaction in which sugar molecules (gly = sugar) hook up with protein molecules in your bloodstream, twist the protein molecules out of shape, and make them unusable. Protein glycation may result in bone loss, high cholesterol, cardiac abnormalities, and a slew of other unpleasantries. In people with diabetes, excess protein glycation may also be one factor involved in complications such as loss of vision.
In addition, copper
  • Promotes the growth of strong bones
  • Protects the health of nerve tissue
  • Prevents your hair from turning gray prematurely
But, no no, a thousand times, no: Large amounts of copper absolutely, and I repeat, absolutely will not turn gray hair back to its original color. Besides, megadoses of copper are potentially toxic. You can get the copper you need from organ meats (such as liver and heart), seafood, nuts, and dried beans, including cacao beans (the beans used to make chocolate).

Benefits of Selenium

Selenium was identified as an essential human nutrient in 1979 when Chinese nutrition researchers discovered that people with low body stores of selenium were at increased risk of Keshan disease, a disorder of the heart muscle with symptoms that include rapid heartbeat, enlarged heart, and (in severe cases) heart failure, a consequence most common among young children and women of childbearing age.
How does selenium protect your heart? One possibility is that it works as an antioxidant in tandem with vitamin E. A second possibility, raised by U.S. Department of Agriculture studies with laboratory rats, is that it prevents viruses from attacking heart muscle.
Here’s some exciting news: The results of a four-year study involving 1,312 patients previously treated for skin cancer strongly suggests that daily doses of selenium in amounts 3.8 times the current recommended daily allowance (RDA) (55 micrograms) may reduce the incidence of cancers of the lung, prostate, colon, and rectum. The University of Arizona study was designed to see whether taking selenium lowered the risk of skin cancer. It didn’t. But among the patients who got selenium rather than a placebo, 45 percent fewer lung cancers, 58 percent fewer colon and rectal cancers, 63 percent fewer prostate cancers, and a 50 percent lower death rate from cancer overall were recorded. Now a follow-up study will determine whether these results hold up. Although fruits and vegetables grown in selenium-rich soils are themselves rich in this mineral, the best sources of selenium are seafood, meat and organ meats (liver, kidney), eggs, and dairy products.