The Feb. 9 lead editorial in the New York Times said it all: "The more we learn about nutrition, the less we seem to know." The editorial was commenting on a $415 million study on the effects of low-fat diets. If anything, the study involving 40,000 women who were tracked for eight years proved that the much-publicized benefits of this diet cannot be proven.
The "war against fats was mostly in vain," the Times concludes. The 20,000 or so women on the low-fat diet had essentially the same occurrence of breast cancer, colorectal cancer, heart disease and stroke as the 20,000 women who followed their normal eating patterns.
So much for all the verbiage extolling the positives about low-fat diets. The results of the study surprised the investigators and could end the belief that reducing the percentage of total fat in the diet is vital for good health. But some nutrition experts still feel that benefits would have been found if some conditions of the study were changed. Letters to the editor in the same edition of the Times that carried the editorial also for the most part refuted the findings of the low-fat study. These were from physicians who are still convinced that a low-fat diet is important.
This low-fat-diet study is typical of many others, particularly those involving health concerns. The results often undermine long-held beliefs. And, as in this study, they frequently do not change long-held beliefs of those who are unwavering in their opinions.
The study was part of a federally funded effort by the National Heart, Lung and Blood Institute of the National Institutes of Health. About 40 percent of the women were assigned to a low-fat diet and the rest continued on their normal diet.
The low-fat group was asked to eat no more than about 20 percent of their total calories daily in fat and to strive to eat five servings daily of fruits and vegetables and six servings of grains. The control group wasn't instructed how or what to eat. The study did show that women in the low-fat group had a 9 percent lower risk of getting breast cancer, but the researchers said that finding wasn't statistically significant and could have been due to chance.
The research team did learn that people find it difficult to cut way back on fat calories. The study urged the low-fat dieters to reduce fat intake to 20 percent of their calories but the best they could do was 24 percent the first year and 29 percent after that. It proved that most people would not be able to follow an extremely low-fat diet.
Nutrition experts who followed the study now say it is not the amount of fat an individual consumes that is important but rather the kind of fat. Many recommend that people limit their intake of the so-called bad facts like saturated fats and trans fats and increase their consumption of the "good" fats like those in vegetables and fish oils.
When another study is made of individuals whose intake of these kinds of fats is dominant, the results will be very interesting. Would it be consistent with the beliefs of the nutritionists? If not, what next?
I would suggest that additional studies must be done. One is most certainly not conclusive, particularly when many so-called experts question its findings. It's a subject of great interest to many dieters and non-dieters, and all should get definitive answers to dispel the doubts that this test has left in the minds of all involved.
Murray B. Light is the former editor of The Buffalo News.