Winter Maladies: Natural Approaches
June Russell's Health FactsCaveats: Conflicting Reports on Vitamins and Minerals[Vitamins] [Minerals] [Related Links] Vitamins--- Antioxidants: Beta-carotene and Vitamins A and E ---There was the popular Finnish study a few years ago on smokers and beta-carotene (vitamin A), and not only was it reported that the supplement offered no protection but actually increased the risk of lung cancer. The media neglected to report that synthetic beta-carotene was used, and the risk was only among those who smoked more than a pack of cigarettes a day and/or drank a daily drink (or more) of alcohol. There was no increased risk for lighter smokers or former smokers. The Finns have one of the highest rates of alcohol consumption by smokers, and alcohol consumption interferes with the utilization of vitamins, both vitamin E and beta-carotene. Beta-carotene needs vitamins E and C to produce its antioxidant effect, and the smoker's vitamin C is used up inactivating the free radials from the cigarette smoke, so there is little left. The combination of smoking and alcohol use results in toxic damage to the liver and 15 times the rate of cancer. It has been suggested that a carcinogenic dye had been used in the coating of the beta-carotene used in the study. The study was described by many to be 'badly flawed,' and criticisms abound. Here are a few: (1)the study used 1/8th to 1/40th the dosage of vitamin E that had been shown by more than 20 previous studies to lower the risk of lung cancer in smokers; (2) it used 1/10th the dosage of beta-carotene recommended for the treatment of lung cancer in long-term smokers; and (3) it used as subjects people living in Finland, despite the fact that both the British Medical Journal and the American Journal of Clinical Nutrition consider it one of the least desirable countries in the world for cancer/nutrition studies. The Finns have one of the highest rates of per capita alcohol consumption by smokers, and alcohol interferes with the utilization of vitamin E and beta-carotene. Also Finland's soil has extremely low levels of selenium (which acts preventively against cancer in combination with vitamin E). The Finnish study appeared in a publication that is heavily dependent on pharmaceutical advertising support and shows a bias against vitamin supplementation. The more potent vitamin C was curiously absent from the study, and the dietary intake of the water-soluble nutrients: vitamin C, folic acid, and B vitamins are extremely low in Finland. The molecular mechanism by which beta-carotene and vitamin E protect against lung cancer in smokers depends on adequate levels of water-soluble nutrients. Men who had adequate levels of beta-carotene or vitamin E were intentionally excluded from this Finnish study, which meant that only men with very high risk factors for developing lung cancer (poor diets and heavy smoking) were allowed to participate. This distorted the real value of proper nutrition for cancer prevention. This highly questionable study was funded by the National Cancer Institute (NCI), using tax dollars provided by the American public.
Current smokers tend to drink more alcohol than former smokers or nonsmokers. In smokers who also consume alcohol, beta-carotene supplementation promotes pulmonary cancer and, possibly cardiovascular. Everyone knows that smoking causes lung disease, yet here are missing links in this equation because so many smokers never develop lung cancer. A study shows that alcohol boosts smoking's harm, and smokers who drink regularly are twice as likely to have a certain type of genetic mutation associated with lung cancer as smokers who do not drink alcohol. The researchers suspect that alcohol interferes with the body's ability to convert carcinogenic chemicals in smoke into more benign substances than it can eliminate. Alcohol may also disrupt the body's ability to repair DNA that has been damaged by carcinogens.
A study by Israeli researchers has proven that a natural beta-carotene supplement acts as a powerful antioxidant in humans, but synthetic beta-carotene does not. With these facts the study takes on a different value. Note that the Physician's Health Study of over 22,000 physicians showed no benefit or harm from beta-carotene supplementation of 50 mg of synthetic beta-carotene every other day. This was consistent for the 11% who smoked and the 51% who were former smokers. Note also that physicians pay more attention to their health and have exceptional access to health care, according to Jeffrey Blumberg, PhD, a leading antioxidant researcher and associate director of the USDA Center for Human Nutrition and Aging at Tufts University. "People who take good care of themselves are less likely to have dramatic health benefits." more than 200 scientific studies have shown that antioxidants, including beta-carotene, play a major role in preventing cancer and heart disease. The Journal of the American Medical Association stated that long-term consumption of a diet high in vitamin A can increase the risk of hip fractures in post-menopausal women. When vitamin A from supplements was considered separately, there was no statistically significant association with fracture risk, although there was a trend toward increasing the risk with increasing levels of supplementation. Beta-carotene was not included in the analysis. While vitamin A toxicity does adversely affect bone, the amounts required to produce such effects are extremely large (33,300 IU's per day). Some or all of the foods high in vitamin A can promote the development of osteoporosis for reasons unrelated to vitamin A. Breakfast cereals contain a lot of sugar which has been shown to increase calcium excretion in humans and causes bone loss in animals. Margarine delivers vitamin A but also contains high quantities of trans-fatty acids, which can create a deficiency of nutrients necessary for bone health. Liver is a key source of vitamin A but is also known to carry environmental toxins such as lead and cadmium, both of which contribute to osteoporosis. Although milk's calcium content is high, it is not very good for bones because it is a major source of dietary phosphorus, which has been known to compromise bone health. The classic Nurse's study concluded that women who drank two or more glasses of milk per day actually increased their risk of fractures when compared with women who drank less that one glass per week. The recommendation by Allan Spreen, MD, HSI Panelist, is 10,000 IU's of vitamin A (not synthetic). Studies suggest that a safe level of vitamin A is 25,000 for most healthy adults and 15,000 IU's for individuals over the age of 65. Taking large amounts of beta-carotene does not lead to vitamin A toxicity because there is a limit to the amount that can be converted to vitamin A.
Charles Lieber, MD, a scientist who has been studying beta-carotene and alcohol consumption at the Bronx Veterans Affairs Medical Center, says moderate drinkers who take in more than 15 mg of beta-carotene a day may be placing themselves at an increased risk for liver damage because of an interaction between the alcohol and the vitamin A. Minerals--- Zinc ---
For adults, the evidence from the dozen or so published clinical trials of zinc lozenges is split evenly pro and con. A study in the Aug. 15, 2000, Annals of Internal Medicine showed zinc worked to reduce the severity of cold symptoms by four days. The positive test results have come when people started taking the lozenges in the first 24 to 48 hours after symptoms appeared, and the subjects in this study sucked on a lozenge every 2 to 3 hours for several days — popping one now and then may not do much good. One of the largest negative studies of zinc used a 4.5 mg lozenge, which was probably too low to be a fair test. Also zinc gluconate is the compound found in most lozenges, but zinc acetate may be more biologically active, so trial results would be different. Related Links about Supplements |