People: Walter Willett
WALTER WILLETT: YOU ARE WHAT YOU EAT
One fascinating area in medicine is nutritional epidemiology--the impact of diet on health. By general consensus, the world's foremost expert is Walter Willett, '66, chairman of the nutrition department at the Harvard School of Public Health. Twelve years ago, he and his team of researchers launched a study involving 121,700 female nurses, the world's largest such study. Recently he launched two more, with 300,000 being studied. To date, he has debunked many dietary myths--in the process angering many special interests.
- Is decaf coffee better? Caffeine does not hurt the heart, Willett has found, but decaf might.
- Is alcohol bad? Consumed moderately, it lowers the risk of heart attack (but among women it raises the risk of breast cancer).
- Red meat? Give it up, says Willett, to the chagrin of 'a couple of big tall Texans who came strolling in.'
- Margarine is associated with increased risk of heart disease, says Willett.
What makes Walter such a national authority goes beyond his 396-tome on the subject, Nutritional Epidemiology (1990). The reason is that Willett's conclusions are backed by scientific research. 'A lot of what we hear,' Walter notes, 'is based not on science but on speculation.'
For example, the American Heart Association's recommendation that no more than 30 percent of calories come from fat is not based on any evidence. Eat fewer eggs? 'You would think there would be a handful of studies showing that people who ate more eggs have more heart attacks,' he notes, 'but there aren't any.'
Although his is mild-mannered, he is unafraid to speak his mind. And he is gaining power and influence as a result. He recently helped convince the Food and Drug Administration to the national food supply be fortified with folic acid--since evidence shows it helps prevent birth defects. In the future, as more evidence is gathered, you will continue to hear from what one writer calls 'the myth-basher from Harvard Square.'
