Monday, August 2, 2010


News of a study upending the conventional wisdom of calcium as lifesaver (or quality of life crutch) for post-menopausal women (and older men) brought yet another reminder that medicine is very much an inexact science.

University of Auckland medical researchers discovered a 30% increase risk for heart attack among people older than 40 who take calcium supplements. Dr. Ian Reid, lead researcher, said the study reviewed results of already published studies involving almost 12,000 people. He told BusinessWeek:
"The extent of that increased risk is enough to completely counterbalance the small beneficial effect that calcium tablets have on numbers of fractures."

A similar report by the LA Times noted:
“…recent studies have shown that the pills provide little benefit: Even though they may increase bone density, they do not reduce the risk of fractures or of death. Now, some researchers are becoming convinced that the supplements not only provide no benefit, but that they can even be harmful, increasing the risk of heart attacks by nearly a third.”

The news raised a small frisson of anger in me – and some relief at not having yet plunked down hard-earned money for imported “extra-strength” calcium supplements.

I am a breast cancer survivor, having undergone modified radical mastectomy of the left breast and a complete chemotherapy course. While no cancer has since been detected in regular tests, I am taking daily anti-cancer medication for five years. This drug, which I chose over a cheaper medicine that increases (slightly) the risk of uterine cancer, hikes the risk for osteoporosis – which runs in our family. To stave this off, you get bone density tests and then get an injection if results show brittleness indicating a degenerative state. Everybody else recommends calcium supplements, especially since my stomach cannot stand milk in its pure form.

Nasty shocks

It can be maddening, this regular debunking of conventional wisdom. One day you’re thinking about five, maybe ten, more years to live hale and well; the next you’re being told that an erstwhile miracle drug has turned out to be yet another Trojan horse bearing deadly gifts.

Take estrogen. The naturally occurring hormone, which plays a major role in the reproductive cycle, is also what gives the oomph in women. The onset of menopause, which is caused partly because the body’s supply of estrogen dwindles, can lead to a host of symptoms: hot flashes, a sudden drop in libido, severe mood swings, increase in body and facial hair and a propensity for brittle bones.

The danger to bones was especially troubling. Other medical breakthroughs and higher living standards in developed nations meant longer life expectancy. Brittle bones significantly lessen the quality of that “bonus time”.

Hormone replacement therapy was seen as a major boon for women. It was touted to increase bone density, lower the incidence heart disease and stroke, and delay the onset of dementia. It was marketed as the perfect “cure” for “female problems” at a time women were being told that menopause was no reason to retreat from life’s pleasures, sex included.

Then in 2002, the Journal of the American Medical Association said women who take estrogen for many years may be at increased risk for ovarian cancer.

“In a study known as the Women's Health Initiative, researchers at the National Cancer Institute used patient interviews and medical records to track the history of hormone use and cancer among 44,241 women. Overall, women who took only estrogen were 60 percent more likely to develop ovarian cancer than women who didn't take any hormones. Among women who took estrogen for 20 years or more, the risk of the disease was roughly three times higher than average.”

This was followed by the National Institutes of Health 2004 report that cited estrogen-only therapy as increasing the risk of stroke and deep vein thrombosis in women. That finding prompted the Women’s Health Initiative to call a premature halt to a study with 16,000 subjects – by 2007 a new study by the group said the risk of stroke was around 32% across all age groups.

Anger was still bubbling among the millions of women who’d received estrogen-replacement therapy when news broke out of clear links between the procedure and increased risk of breast cancer. Worse, the study found that HRT provided no benefit against heart disease and stroke.

Nature is best

Moderation is often junked in the chase for health. Vitamin E, for example, has once hailed as effective against the effects of aging, cataracts, and helpful in preventing cancer and heart disease.

The UC Berkeley wellness guide to dietary supplements describes the fat-soluble vitamin, discovered at the famous university more than 80 years ago, as a star among nutrients for at least 25 years.

“Vitamin E is an important antioxidant that exists in several forms, the most potent of which is alpha tocopherol, the form usually found in Vitamin E supplements. Like other antioxidants, Vitamin E protects cells against the effects of free radicals, which are potentially damaging by-products of life processes. Free radicals can damage cells and may contribute to the development of heart disease and cancer. Vitamin E may play a role in immune function. The RDA for vitamin E is just 15 milligrams (about 23 IU) a day. The upper limit is 1,000 milligrams (about 1,500 IU) a day.”

But the wellness letter admits that, “after reviewing subsequent clinical trials that had yielded disappointing or conflicting results, we softened our endorsement of vitamin E supplements.”

It cited the 2004 meta-analysis from Johns Hopkins Medical Institutions, which concluded that “high doses of vitamin E (more than 400 IU a day) taken long term may slightly increase the overall risk of dying—by about 4%. Lower doses of vitamin E (200 IU or less) did not increase the risk.” It also acknowledged the absence of clinical research showing that vitamin E supplements are beneficial.

The confession ends:
“Nearly all the clinical trials on vitamin E from the past few years have yielded negative, inconclusive, or neutral results. Get vitamin E from foods—nuts, seeds, vegetable oils, whole grains, and leafy greens. There is no reason to take vitamin E supplements.”

Indeed, in 2007 the Journal of the American Medical Association published the results of a University of Copenhagen meta-study on 67 placebo-controlled trials that covered around 232,000 test subjects.

Their conclusion:
“Vitamin supplements taken by millions of people every day for their health could be increasing their risk of death.”

That doesn’t mean vitamins are dangerous to our health. It means we’re better off getting these from food rather than gulping down handfuls of pills.

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