CAN DIET AFFECT PREMENSTRUAL SYNDROME?
It is believed that no less than half, and perhaps as many as 90%, of all women suffer from PMS to some degree during their childbearing years and that upward of one out of every five women are so severely afflicted it interferes with their normal functioning. It has been suggested that numerous dietary factors influence the severity of PMS symptoms. Yet there is no clear-cut scientific explanation for the fact that dietary modifications work in one case and not in another. Despite the uncertainty, there has been an explosion of nutrition-related theories on the origins of PMS accompanied by a host of nutrition-related "solutions." What follows is a look at the most popular ones. They range from the harmless but unproven to the expensive but unproven to the out-and-out dangerous. 
Perhaps the most widely held nutritional theory regarding premenstrual syndrome is that it results from a lack of vitamin B-6. Advocates of this theory say that a deficiency of B-6 is somehow related to hormonal imbalance, particularly to an imbalance of estrogen, which in turn leads to depression or dramatic mood swings. To treat the "problem," a number of "practitioners" have been prescribing megadoses of vitamin B-6, also known as pyridoxine. In some instances, the recommended levels have been as high as 1,000 times the RDA of 1.3 milligrams-based on the belief that any excess of B-6, a water-soluble vitamin, would simply be excreted in urine and therefore could not harm the body. However, it has become clear that even much lower doses can cause damage to the nervous system, resulting in numbness, tingling, difficulty in walking and spinal problems. Such symptoms have developed in women who have taken as little as 500 milligrams a day. For this reason, the tolerable upper limit for vitamin B-6 has been set at 100 mg per day. From a scientific point of view, supplements of B-6 have never proven to be more effective than a placebo (sugar pill) in treating PMS, despite their continued popularity.
Some believe that women who suffer from PMS do not have enough of the enzyme needed to produce a fatty acid called gamma linolenic acid, which supposedly leads to a deficiency of a very active biochemical called prostaglandin E-1. That deficiency, they claim, is evening primrose oil, sometimes sold as Enfamil, which contains the "missing" fatty acid and allows the balance to be restored. Besides the fact that evening primrose oil, widely available in health food stores, is expensive, it has never been demonstrated that a prostaglandin deficiency is what causes PMS symptoms or that any oil given in supplemental form will turn such a deficiency around. And as with B-6 supplements, evening primrose oil has never been clinically proven to decrease the emotional mood swings of premenstrual syndrome. It can, however, cause gastric irritation if taken on an empty stomach. Once of evening primrose's greatest fans, by the way, is David Horrobin, formerly of the University of Montreal, who is affiliated with a manufacturer of evening primrose oil supplements.
Too Much Calcium, Too Little Magnesium A physician named Guy Abraham has observed that some women with premenstrual symptoms have lower levels of the mineral magnesium than women who do not suffer from PMS, and out of that observation has grown the theory that PMS may have something to do with a magnesium deficiency. According to the theory, the deficiency develops in part because of too much calcium consumption in the form of dairy products. This forces calcium to compete with magnesium for absorption and leaves a woman with a magnesium shortfall. The "solution" is to take a magnesium supplement. The hitch is that although some of the women with PMS had lower levels of magnesium in their blood cells than symptom-free women, their levels were still within normal range. The real problem in taking megadoses of magnesium is that a woman can, in fact, impair her absorption of calcium-a hazardous thing to do since it is now widely believed that adequate consumption of calcium helps guard against osteoporosis. Furthermore, women should be aware of the fact that in very high doses, magnesium can be toxic. And magnesium salts like those in Milk of Magnesia will act as laxative-even if you're not looking for that effect.
Some people, including Dr. Abraham, subscribe to the notion that women afflicted with PMS may be deficient in a wide range of nutrients, including vitamins A, C, E, B-6 and other B vitamins as well as magnesium, iron, and zinc. Based on that assumption, this physician has developed a nutritional supplement called Optivite, which if taken six times a day, as advised, contains up to 15,000 percent of the U.S. Recommended Daily Allowance for vitamin B-6, vitamin C, thiamin, riboflavin, vitamins A and E, pantothenic acid, niacin and zinc. The increasing popularity of this supplement has given rise to some Optivite "clones" that are identical or nearly identical to the original and can be found in health food stores next to the evening primrose oil. The six tablets can cost up to about a dollar a day depending on the brand. Needless to say, the safety of taking megadoses of so many nutrients for any length of time is questionable at best and quite dangerous at worst. It should also be pointed out that in a study recently published in the American Journal of Clinical Nutrition, in which the levels or activity of zinc, vitamins A and E, thiamin, and B-6 were compared in PMS sufferers and non-PMS sufferers, "no evidence was found to support the hypothesis that premenstrual symptoms are caused by absolute or relative nutritional deficiencies."
Unfortunately, there are no well-conducted clinical trials to prove that what a woman eats has anything to do with whether she develops-or gets over-PMS. However, one theory supports the fact that victims of PMS and hypoglycemia sometimes suffer some of the same symptoms: fatigue, weakness, irritability and overall malaise (although they may suffer from hypoglycemic-like problems, women with PMS do not have abnormal blood sugar levels). Thus, health care professionals are advising those who experience PMS to follow a modified version of the diet generally recommended for people who have hypoglycemia, along with regular exercise. Non-clinical testimonials from women suggest this regime does appear to help relieve the symptoms of premenstrual syndrome in a significant number of cases. The eight-point diet calls for:
Source: Connie Roberts, R.D., Tufts University Diet and Nutrition Letter |
Updated December 9, 2002