SCIENTIFIC REDUCTIONISM 281 by increased intakes of fruits and vegetables, or reduced by exercise (either during the teenage years or during adulthood), dietary fiber, monounsaturated fats or polyunsaturated fats Also, the mineral selenium, long considered to be protective of certain cancers, has no effect on breast cancer In other words, we might as well conclude that diet is completely unrelated to breast cancer I can understand the frustration of Professor Meir Stampfer, one of the leading researchers in this group, when he was quoted as saying, "This has been our greatest failure and disappointment-that we have not learned more about what people can to lower their risk."6 He was making his comment in response to an opinion that "the Single biggest challenge for the future [is] sorting out the mess of contradictory findings and lack of information on breast cancer."6 I applaud Professor Stampfer for his candor, but it's unfortunate that so much money has been spent to learn so little Perhaps the most rewarding finding, ironically, was the demonstration that tinkering with one nutrient at a time, while maintaining the same overall dietary patterns, does not lead to better health or to better health information Yet Harvard researchers have been steadily cranking out their findings, despite these challenges From their slew of studies, here are some findings that I would consider as very troubling contradictions when comparing disease risks for men versus women: • Men who consume alcohol three or four times a week have a lower heart attack risk 31 • Men with Type diabetes who consume a moderate amount of alcohol have a lower risk of coronary heart disease.32 And yet • Alcohol consumption increases breast cancer incidence by 41% for women consuming 30-60 glday of alcohol compared to nondrinking women 33 Apparently alcohol is good for heart disease and bad for breast cancer The husband can have a drink with dinner but should never share it with his wife Is this a difference between men and women, or is this a difference in response between heart disease and cancer? Do you feel more informed or more confused? Then there are those wonderful omega-3 fatty acids Some types of fish contain relatively large amounts of these fats and have been getting 282 THE CHINA STUDY their share of positive press these days If you've heard anything about omega-3 fatty acids, it's that you need more of them to be healthy Again, more Harvard findings : • " contrary to the predominant hypothesis, we found an increased risk of breast cancer associated with omega-3 fat from fish" (This increased risk was statistically significant and was associated with an increase of only 0.1% of the total dietary energy.)l0 • "our findings suggest that eating fish once per month or more can reduce the risk of ischemic stroke in men"34 • "data suggest that consumption of fish at least once per week may reduce the risk of sudden cardiac death in men [but not reduce the] risk of total myocardial infarction, non-sudden cardiac death or total cardiovascular mortality"35 (In other words, fish may prevent some aspects of heart disease but ultimately has no effect on mortality from heart disease, or even heart attack risk.) Is this yet another question of deciding which disease you fear the least? Or is this another man versus woman difference? Here's an even older story: We have been warned for a long time to cut down on our cholesterol intake, and it was largely for this reason that consumption of eggs was brought into question One egg has a whopping 200 mg or more of cholesterol,36 which takes up a large proportion of our 300 mg recommended daily limit So, what the Harvard studies tell us on this timeworn issue? consumption of up to one egg per day is unlikely to have substantial overall impact on the risk of CHD or stroke among healthy men and women3? But, for breast cancer, Our findings [representing eight prospective studies] suggest a possible modest increase in [breast cancer] risk with egg consumption breast cancer risk was found to increase by 22% with every 100-g per day increment of egg consumption [about eggsJ26 [There was a 67% increase in risk for the Nurses' Health 5tudy.J26 But earlier, the Harvard researchers took a slightly different position: among healthy men and women, moderate egg consumption can be part of a nutritious and balanced diet38 SCIENTIFIC REDUCTIONISM 283 Most recently, the Nurses' Health Study is cited as having come up with an even more powerful endorsement for eggs A recent news item stated: Eating eggs during adolescence could protect women against breast cancer 39 The article goes on to quote a Harvard researcher as saying: Women who had, during adolescence, a higher consumption of eggs had a lower risk of breast cancer 39 Most people who read this news article will likely say that eggs are back in favor-even when they don't know how many eggs per day are okay or whether there are exceptions to this generalization Eggs will only seem to be more healthful when the henhouse industry adds their words of wisdom But wait a minute-evidence says egg consumption for teenage girls is okay, maybe even good, but evidence also says more egg consumption overall increases breast cancer risk By the way, here's something else to think about Multiple studies have rather conSistently shown that egg consumption can increase colon cancer risk, more so for women than for men.w What are we to believe? One minute alcohol intake can reduce our disease risks, the next minute it can increase them One minute fish consumption can help to reduce our disease risks, the next minute it can hurt One minute eggs are bad, the next minute they can be healthy It seems to me that what is missing here is the larger context What you have without that context is just a lot of confusion , r UNRAVELING DIET AND CANCER In addition to stating that diet and exercise are unrelated to breast cancer, the Harvard researchers have been chipping away at other popular notions regarding diet and cancer For example, the Harvard studies have not been able to detect any association between colorectal cancer and fiber or fruit and vegetable intake • 1, 42 Dietary fiber, of course, only comes from plant-based foods, thus these findings put a dent in the idea that fiber or fruits , vegetables and cereals prevent large bowel cancer Keep in mind that the Harvard studies are dealing with uniformly carnivorous populations, almost none of which are using a whole foods, plant-based diet that is naturally low in fat and high in fiber It is likely that the potential protective effect of 284 THE CHINA STUDY fiber or fruits and vegetables does not kick in against colorectal cancer until there is a complete dietary shift away from an animal-based diet Between the colon cancer and breast cancer findings, the Nurses' Health Study has done much to confuse, if not discredit, the idea that diet is related to cancer After these decades of work, Professor Walt Willett says: increasing fruits and vegetables overall appears to be less promising as a way to substantially reduce cancer risk the benefits [of these foods] appear greater for cardiovascular disease than for cancer4 This statement sounds a bit ominous Colon cancer, historically one of the first cancers said to be prevented by a plant-based diet,43-45 now is being said to be unrelated to diet? And low-fat diets don't prevent breast cancer? With results like these, it's only a matter of time before the hypothesis of a dietary connection to cancer starts falling apart In fact, I have already heard people within the scientific community beginning to say that diet may have no effect on cancer These are the reasons that I believe that the Nurses' Health Study has done considerable damage to the nutrition landscape It has virtually nullified many of the advances that have been made over the past fifty years without actually posing a scientifically reliable challenge to earlier findings regarding diet and cancer This problem of studying a population that uniformly consumes a high-risk diet and looking at the differences in consumption of one nutrient at a time is not unique to the Nurses' Health Study It is common to virtually all studies using Western subjects Furthermore, there is little or no value to pooling the results of many large studies for analysis in order to get a more reliable result if all the studies have the same flaw A pooling strategy is often used for identifying cause-and-effect associations that are more subtle and uncertain within single studies This is a reliable assumption when each study is properly done, but obviously it is not when all the studies are similarly flawed The combined results only give a more reliable picture of the flaw The Harvard researchers have done several of these multi-study pooled analyses One such pooled analysis concerned the question of whether meat and dairy foods had any effect on breast cancer.26 A previous 1993 pooling of nineteen studies46 had shown a modest, statistically significant 18% increase in breast cancer risk with increased meat intake SCIENTIFIC REDUCTIONISM 285 and 17% increase with increased milk intake 46 The Harvard researchers therefore summarized in 2002 a more recent group of studies, this time including eight large prospective studies where dietary information was thought to be more reliable and where a much larger group of women was included The researchers concluded: We found no significant association between intake of meat or dairy products and risk of breast cancer.26 Most people would say, "Well, that's it There is no convincing evidence that meat and dairy foods are associated with breast cancer risk." But let's take another look at this supposedly more sophisticated analysis All eight of these studies represented diets that had a high proportion of animal-based foods In effect, each study in this pool was subject to the same flaw from which the Nurses' Health Study suffered It makes no sense, and does no good, to combine them In spite of there being 351,041 women and 7,379 breast cancer cases in this mega-database, these results cannot detect the true effect of diets rich in meat and dairy on breast cancer risk This would be true even if there were a few million subjects in the study Like the Nurses' Health Study, these studies all involved typical Western diets highly skewed toward the consumption of animal-based foods, where people are tinkering with the intake of only one nutrient or one food at a time Every study failed to take into account a broader range of dietary choiceS-including those which demonstrated positive effects on breast cancer risk in the past IGNORING MY CRITIQUE Once, after reading a publication on animal protein and heart disease in the Nurses' Health Study,9 I published a critique47 summarizing some of the same points that I am making in this chapter, including the inability of the Nurses' Health Study to advance our understanding of the original international correlation studies They responded, and our exchange is as follows First, my comment: Within a dietary range [so rich in animal-based foods 1, it makes no sense to me that it is possible to reliably detect the so-called independent associations of the individual constituents of this group when it can be expected that they share the same disease outcomes ...282 THE CHINA STUDY their share of positive press these days If you've heard anything about omega-3 fatty acids, it's that you need more of them to be healthy Again, more... effect on cancer These are the reasons that I believe that the Nurses' Health Study has done considerable damage to the nutrition landscape It has virtually nullified many of the advances that... mega-database, these results cannot detect the true effect of diets rich in meat and dairy on breast cancer risk This would be true even if there were a few million subjects in the study Like the Nurses'