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» BEYOND THE HEADLINES: IS THE NEWS ABOUT LOW-FAT DIETS ALL BAD?
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NUTRITION NEWS
Beyond the Headlines: Is the news about low-fat diets all bad?“Was [the Women’s Health Initiative] a waste of time, asking women to aim for an impossible goal?"More than a decade ago, I stood in front of my class of nutrition students lecturing about the Women’s Health Initiative (WHI). I wanted them to be as excited as I was. This huge, $415 million effort was planned to test the hypothesis that a low-fat diet rich in vegetables, fruits and grains would reduce heart disease as well as breast and colorectal cancer in women. I explained that the study was long overdue—because in the past most of the large, government-funded trials had been directed at men. Finally we were going to have the massive numbers we needed to get to the bottom of some women’s health issues. Beginning in the mid-1990s, the WHI recruited 48,835 women between the ages of 50 and 79 and randomly assigned them to either a low-fat diet group, which received regular nutrition counseling, or to a control group, and followed their progress over time. But as the decade passed and I continued to mention the WHI in my lectures, I became increasingly anxious. After all, the study volunteers were instructed to reduce their total fat intake to 20 percent of total calories with no specific advice about the type; olive oil and lard were lumped in the same category. And even though nearly three-quarters of the women were overweight, they were not given guidance to lose weight. When the WHI researchers released their long-awaited findings earlier this year, the headlines screamed failure. Colleagues were stunned by the news that a low-fat, fruit- and vegetable-rich diet seemed to have no effect: there were no significant differences in the risk of cancer or heart disease between the low-fat diet group and the control. One colleague said to me, “It makes me so mad—why does the press do this?” “Do what?” I thought to myself. “Report the truth?” It shows how badly we want our beliefs confirmed and how disappointed we are when science doesn’t give us the answers we expect. Wanting to dig beneath the headlines, I called one of my former dietetic students, Buff—a WHI nutrition educator who had been based in Hawaii in the late ’90s. Buff had been charged with instructing the women to cut their fat intake to just 22 to 28 grams per day (equivalent to about 2 tablespoons of oil) and to get at least five servings of vegetables and fruit, and at least six servings of grains daily. (The control group participants were not asked to make any dietary changes.) After hearing repeatedly how difficult it was to adhere to the diet, Buff tried it herself. “I had the hardest time,” she recalled. “I found the fat allotment way too low to sustain for more than a few days.” In fact, relatively few women in the low-fat group met their dietary target; 31 percent at year one and only 14 percent at year six. Clearly knowledge isn’t everything, and translating what we know into long-lasting behavior change eludes many of us. Was this trial a waste of time, asking women to aim for an impossible goal? I don’t think so. If you read the papers closely, there are some intriguing findings when you tease out smaller subgroups of the women in the study. Among those who reported eating less saturated fat and trans fat, there were trends toward greater reductions in cholesterol and heart disease risk. The women who started with the highest fat intake—and reduced their fat intake the most—showed the strongest evidence for reduction in their breast cancer risk. In other words, those women who successfully made dietary changes did lower their risk of breast cancer and heart disease. And since cancers take years to develop, we may see very different results at the next reporting, in 2010. I love the science of nutrition. There is always something new to be learned. The WHI is just one piece of the massive puzzle we are slowly piecing together about the role of diet in health. I’m not giving up the conviction that we will eventually learn how to make it easier for people to live healthy lives. In the meantime, I’ll stick with what nutrition experts agree on: exercise regularly, maintain a healthy weight, eat plenty of vegetables, fruits and whole grains, and watch the amount and type of fat. I don’t expect any one future study to pronounce these the definitive answer to good health—but I look forward to the questions that arise along the way. ew -Rachel Johnson is senior nutrition advisor to EatingWell and dean of the University of Vermont College of Agriculture & Life Sciences. 
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