OOPS, Wrong Again!
Well, the latest research on the relation between nutrition and health has just been released and the fur is flying. Turns out the largest study ever done to asses the impact of a low fat diet on some of our major killer diseases has found that the diet hasno effect – no effect on heart disease, no effect on stroke, no effect on breast cancer and no effect on colon cancer.
These less than impressive findings come from the impressive sounding (and very expensive to the tune of about $415 million) Women’s Health Initiative Randomized Controlled Dietary Modification Trial. They were published this week in the prestigious Journal of the American Medical Association. Almost 50,000nurses ages 50-79 were followed for more than eight years. Those assigned to a low-fat diet had the same disease rates as those who were not.
As is usually the case with such elaborate, expensive and emotionally charged findings, spin-meisters on both sides of the issue responded immediately. One expert exclaimed, “these studies are revolutionary…They should put a stop to this era of thinking that we have all the information we need to change the whole national diet and make everybody healthy.” Towing the same line another called it “the Rolls-Royce of studies and said it was likely to be the “final word.”
Others took a very different view. One long time advocate of the benefits of low-fat eating claimed the results were inconclusive because the women did not lower their fat intake enough, ate too few fruits and vegetables and were not followed for a long enough period of time. Another concluded that “It would be a huge misinterpretation to believe that it doesn’t matter what we eat to prevent heart disease and cancer.” He went on to say that the evidence from this study was “quite strong” that “eating more fruits and vegetables as well as less saturated and trans fats cuts the risk of heart disease and cancer.
If the experts can’t make up their minds about this research and the issues involved, it is quite likely that the general public won’t know what to do with it either. This is especially true for a general public still reeling from the effects of the now receding low-carb mania of the last few years, which of course replaced the low-fat mania of the decade before.
However, it would be wrong to claim that this study constitutes a complete waste of our $415 million hard-earned dollars. In fact there are a number of important lessons to be learned from this research including the following:
1.No matter what health-related research claims, if there is any wiggle room at all (and there usually is quite a bit when dealing with human beings) scientistswill put their spins and biases on it in an effort to support what they believe to be true. This is not necessarily a bad thing but it is something that people often forget in trying to decide what the findings really mean.
2.When it comes to the causes of complex, multifactorial diseases like all of those examined by this research, we know much less than we think we do about why certain people get them while others don’t. While nutrition may play a role, it is only one of many, many potential contributing factors.
3.When it comes specifically to the links between nutrition and disease, we know even less, again because of how complex the relationships are and how many different factors are involved. Add to this the tremendous variability in individual response to various dietary components and you have a level of complexity that is not describedwell using 30-second MTV-like sound bytes.
4.Critics complaints that the diet group did not lower their fat content enough to make a real difference may or may not be true (that, of course would take another $415 million to know for sure). Other researchers pointed out however, that, perhaps the lesson to be learned is that people are not willing to make more drastic changes. Interestingly some research suggests that going to the degree of very low fat diet that was prescribed might actually be helpful for only some people and actually harmful for others. (research done by Dr. Ronald Krauss, American Heart Association head of nutrition back in the late nineties)
So, after all is said and done, whether you believe the results of this study or not, what are we left with in terms of recommendations for what to eat to support our health? Perhaps it might be good to acknowledge that, along with the understanding of the difficulty of trying to single out individual contributing factors to complex, multifactorial diseases, the study of nutrition as a major cause of, or protection from, disease is in its infancy. As with other types of human research, too often intuition and observation get substituted for good science with potentially hazardous consequences.
Over the years, nutrition recommendations in the United Stateshave changed dramatically from a focus on the minimal nutrition required for good health to an ever more prescriptive focus on disease and obesity prevention. The problem is, of course, that the specific recommendations related to “healthy eating” have not been static, tending to change with the prevailing scientific and cultural winds. The result is a population that is anxious about food and confused about what they should and shouldn’t be eating for their health.
With all the rapidly expanding research supporting the powerful impact that our emotions have on our health, existing in an ongoing state of apprehension and confusion over everything we eat is not likely to be health promoting. Perhaps a return to the basics is the answer. This would involve eating a wide variety of foods and paying more attention to our hunger and fullness and less attention (not to mention money) to others telling us what we should be eating. Over and above that it might also be helpful to heed the words of Dr. Robert Ornstein and Dr. David Sobel in their landmark book Healthy Pleasures when they say:
“The important point is that worrying too much about anything – be it calories, salt, cancer, or cholesterol – is bad for you, and that living optimistically, with pleasure, zest, and commitment, is good. Medical terrorism shouldn’t attack life’s pleasures.”