food facts

fluoride:Fluoride is one of the elements in water removed by most filters. Although the science is overwhelmingly in support of fluoridation to reduce the incidence of dental caries significantly and to reduce the incidence of osteoporosis slightly, this issue is probably the most emotional surrounding water safety. Your Advisor is at a loss to understand the heat generated by this. This has been a hot button issue for people since fluoridation began in Grand Rapids, Michigan in 1945. There have been numerous claims of health problems from opponents of fluoridation but, to date, not one study published in peer-reviewed medical literature has supported these claims. When the science has not supported people who want to ban fluoride, they have resorted to arguments that it was a Communist plot to poison our water supply or that they have rights not to be fluoridated. Since tax dollars pay for a significant part of medical and dental bills, the government has rights to reduce unnecessary medical and dental costs. If you don't want fluoride in your water, buy a filter or drink bottled water but be ready to visit your dentist more often.

biotin:Biotin is a cofactor in a number of enzymatic reactions involved in metabolism of proteins, carbohydrates, and fats. Because biotin is so widely distributed in foods, deficiency is extremely rare and is usually associated with long term intravenous feeding or consumption of large amounts of uncooked egg whites. Egg white contains a chemical called avidin which binds biotin and prevents its absorption. Cooking inactivates avidin, so cooked eggs have no effect on biotin. Symptoms of deficiency include skin rash, lethargy, extreme sensitivity to touch, muscle aches, and a number of other signs. There is no RDA set for biotin but there is an adequate intake (AI) estimate of 30 micrograms (mcg or millionths of a gram) per day for adults. The AI may be used as a goal for individual intake but lack of data prevent the degree of certainty that accompanies an RDA. Rich sources of biotin include egg yolks, liver, kidneys, soybeans and peas. Most foods contain some biotin, except that biotin found in wheat is not absorbable because it is complexed to another chemical. Little is known about effects of large daily doses from supplements.

vitamin E: Vitamin E is well known to many people as alpha-tocopherol. Actually, there are eight chemical forms of vitamin E: four tocopherols and four tocotrienols. Alpha-tocopherol in the "d" isomer has the most vitamin activity of these compounds, which can vary in vitamin activity by a difference of 100-fold. But all have significant biological activity, and their benefits are probably not due completely to their functions as a vitamin. Vitamin E is popular now primarily because it is an antioxidant. It is also fat soluble, so it can prevent damage to the cell membranes (which are primarily lipid). The RDA for adults is 10 mg/day (milligram or thousandths of a gram) for men and 8 mg/day for women. This is easily achieved in a balanced diet. The biggest sources in the normal diet are vegetable oils and margarine. Other good sources of vitamin E include nuts, seeds, shrimp, wheat germ, cabbage, sweet potatoes, asparagus, and some fortified breakfast cereals.

vitamin C: The richest sources of vitamin C are sweet peppers, black currants, broccoli, Brussel sprouts, kale, and turnip greens. Moderate sources are citrus fruits, cabbage, cauliflower, beet greens, spinach and watercress. Good sources include tomatoes, potatoes, onions and peas. Cooking does decrease the content of vitamin C in foods, but the extent of this has been overplayed in many media reports. Reductions from cooking are quite variable: fried and baked potatoes lose 20% of their vitamin C. Boiling causes the loss of up to 45%, but stir frying only loses 5% from greens. The longer time and more water used contribute to larger decreases. Cooked foods are a significant source of vitamin C in the typical diet, but many in the list above can be enjoyed raw.

vitamin D:Vitamin D's major role is in the formation of strong bones. However, recent studies indicate that this vitamin has a number of other functions in the body. It is important for absorption of calcium and regulation of its level in the bloodstream. It is also thought to play an important role in the differentiation, or maturation, of a variety of cells in the body. There is research suggestive of a preventive role of vitamin D in colon and breast cancer. Prevention indicates that vitamin D from either diet or sun exposure is related to reduced breast cancer incidence. At this time, this is only a reason to do more research; the data are not strong enough to take vitamin D or sit out in the sun to prevent cancer. Don't forget there is convincing evidence that too much sun causes skin cancer.

calcium: Bioavailability is simply the amount of a nutrient the body absorbs and uses from a food. Many people believe that plant foods are good sources of calcium, but all the available data are against this concept. A glass of milk contains 315 mg of calcium, and 101 mg is actually absorbed. While a serving of spinach contains 129 mg, only 7 mg are absorbable. Kale (49 mg in a serving) has the highest percentage of calcium absorbed, but a half-cup yields only 26 mg. Broccoli contains 38 mg in a serving, but 20 are absorbed. Beans are even worse, with kidney beans supplying only 9 mg from a total of 52 mg.