You may have seen the headlines that exploded across the headlines in February, in referece to the results of two studies considering the connection between dietary fat and health: The Women’s Health Initiative Study and the Nurses Health Study
“Low Fat Diets do not cut the risk of breast cancer”
“Low-fat diets not as effective as expected: Little change in cancer, heart disease risk”
“Low-Fat Diets Disappoint for Cancer and Heart Disease”
But what is the skinny on these corpulent quotes packed with controversy? Could it be that we need to re-think of using hot fudge and fatty steaks medicinally? I’m not so sure that’s the whole story. So let’s take a look at some alternative views, maybe there’s some cream to be skimmed from this after all? It’s almost Summer and while food is fun, what we eat is important to our health.
Let’s take a look at a letter that was originally sent out by Dr. T. Colin Cambell. Dr. Cambell co-authored the first ever study on the connection between dietary fat and health in 1982 during his time at the National Academy of Sciences. Dr. Cambell’s letter was submitted widely to major newspapers but rejected by each one. You can read the full letter at this link HERE But here are some excerpts. In referring to both studies, Dr. Campbell states that:
Both studies were prompted by a major 1982 National Academy of Sciences (NAS) report that was the first major document to recommend cutting fat consumption from 40% of calories to 30% to prevent cancer risk, a report that I co-authored. But the researchers who subsequently organized these two very large studies misinterpreted our report’s findings, then designed studies that were seriously flawed, despite recommendations to the contrary. Aside from their recommendation on fat, the committee also advocated increased consumption of “fruits, vegetables, and whole grain cereal products” but cautioned that this did not apply to the effects of individual nutrients. They made clear that the 30% fat recommendation was arbitrary and was only meant as a “practical target” to monitor dietary change, adding that the evidence on fat even suggested, “the[sic] data could be used to justify an even greater reduction”. Together, these recommendations emphasized the effect of whole foods on cancer risk, not the effects of individual nutrients.
Dr. Campbell has more to say regarding the results of his original work on this topic compared with the current studies:
The available evidence for our NAS committee showed that the association of dietary fat with breast and other cancers was attributed to the consumption of animal protein, reflecting excessive consumption of animal based foods, perhaps also inadequate consumption of plant based foods. Laboratory evidence, including our own, also was showing that consuming animal protein had multiple adverse health effects. It could markedly increase cancer development, elevate blood cholesterol and atherosclerotic plaque and induce loss of calcium needed for strong bones. But all of this evidence was minimized and ignored, and continues even today. This also was a personal challenge for me. I was raised on a dairy farm milking cows, then started my research career at Cornell University attempting to promote more not less animal protein consumption. This negation of the evidence has had serious consequences. For example, the vast majority of subjects in both of these recently reported studies used diets rich in animal protein, total fat and animal based foods, leaving virtually no opportunity to experimentally investigate the effects of a diet of whole plant based foods naturally low in fat. Women who consumed less fat, actually consumed more animal protein. Indeed, they were urged and coached to do this. At best, these women only made minor changes in fat consumption, leaving intact their imbalanced consumption of foods likely to make the most difference.
It strikes me as a real injustice to the public, and women in particular, that evidence to the contrary was ignored regarding the link of dietary fat and breast cancer.
Besides Dr. Campbell’s commentary, is there any evidence that might be to the contrary? Well, turns out there is. The University of California published a report in the Journal of the National Cancer Institute. The researches did an analysis of 13 studies on diet and breast cancer between the years 1966 and 1998. What they found was that reducing fat intake below 20% of calories will reduce breast cancer risk. You can read the report’s abstract at the Journal of the National Cancer Institute HERE.
But there’s not just that report, Dr. Dean Ornish, one of the most influential researchers on low fat diets and health has this to say regarding another study that alleges no link to breast cancer and low fat diets:
One study from Dr. Michelle Holmes of the Harvard School of Public Health was widely quoted to have found no relationship between dietary fat and breast cancer, but the group of women who ate the most fat before being diagnosed had a 70% greater risk of death than the women who ate the least fat. Also, they found that women who ate the most vegetables were less likely to die from breast cancer.
It’s not just a question or reducing the amount of dietary fat but also increasing consumption of fruits, vegetables, grains, and legumes, especially soy products. There are at least 1,000 substances that have anticancer properties, and with few exceptions these are found in fruits, vegetables, grains, and beans.
You can read Dr. Ornish’s full statement on breast cancer and low fat diets at this link HERE
You can read a news article on this controversy at SFGate.com at this link HERE
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