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The Science Fiction of Nutritional Genomics

EDITOR’S NOTE: Dr. Gorski is currently in Chicago attending the American College of Surgeons Clinical Congress. As a result, he has not prepared a post for this week (although he doesn’t feel too guilty about missing this week, given that he did write two rather hefty posts last week, one on the cancer quackery known as the German New Medicine and the other on a rather dubious monkey study being promoted by the anti-vaccine movement). Fortunately, we have Ben Kavoussi to fill in with a post on some of the more exaggerated claims of advocates of nutritional interventions for various diseases and conditions. Enjoy!

A centipede was happy quite,
Until a frog in fun
Said, “Pray, which leg comes after which?”
This raised her mind to such a pitch,
She lay distracted in the ditch
Considering how to run.

Anonymous

Just like complementary and alternative medicine (CAM), nutritionism — meaning the unexamined assumption that food is only a conveyor of the substances it contains 1,2 — has evolved independently of science and medicine since the 1970s, and has caused so much wondering and confusion about food and diet that many Americans have become unable to eat properly. Today, there isn’t a popular magazine that doesn’t have a “health and nutrition” section that — often with the backing of very little science — promises many health benefits of a nutrient or warns against the harms of another; and then provides a list of foods that contain it. The same publication might time and again write the exact opposite, further adding to the already-prevalent nutritional confusion. Nutritionism is thus an ideology sourced by popular beliefs, academic reveries, and the food and dietary supplements industry, where food is simply seen as a mean to achieve a specific health goal. In its latest form, however, coupled with genomics and biomedical informatics, and called “nutrigenomics” or “nutritional genomics,” nutritionism takes academic reveries to such an extent that it could be accurately described as “science fiction.” The Center of Excellence for Nutritional Genomics at UC Davis writes indeed (in bold) on its website that:

“The promise of nutritional genomics is personalized medicine and health based upon an understanding of our nutritional needs, nutritional and health status, and our genotype. Nutrigenomics will also have impacts on society — from medicine to agricultural and dietary practices to social and public policies — and its applications are likely to exceed that of even the human genome project. Chronic diseases (and some types of cancer) may be preventable, or at least delayed, by balanced, sensible diets. Knowledge gained from comparing diet/gene interactions in different populations may provide information needed to address the larger problem of global malnutrition and disease.”


Nutritional genomics is one of the “omics” that have come out of the human genome project — meaning the mapping of the 3 billion base pairs that make up the 20,000-25,000 genes in the human genome — and claims that it can develop means to optimize nutrition by exploring “personalized” or “genome-based” nutrition, in which foods are optimized for each individual’s unique genetic makeup. This goal is presumably achieved by correlating gene expression or single-nucleotide polymorphisms in health and disease with the consumption of a food or a combination of foods. The website of the UC Davis Center also states that its goal is to “devise genome-based nutritional interventions to prevent, delay, and treat diseases such asthma, obesity, Type 2 diabetes, cardiovascular disease, and prostate cancer.” The Center also adds (again in bold) that its goal is also to “reduce and ultimately eliminate racial and ethnic health disparities resulting from environment and gene interactions, particularly those involving dietary, economic, and cultural factors.”

The fundamental clinical medicine and public health assumptions that underlie this narrative are (1) the supposition that our lack of understanding of the precise mechanisms of environment/gene interactions is at the origin of our failure to prevent or to delay these diseases; and (2) that the futuristic cognitive tools of nutrigenomics can convert the large, complex, high-dimensional and nonlinear data on the complex interactions between the genetic makeup of a susceptible population and multiple environmental variables into useful knowledge. Identifying the positive and negative connections between the common constituents of their diet with genetic determinants of health and disease, will presumably uncover the insufficient intake or overconsumption of certain nutrients, and a population’s inability to absorb, metabolize or excrete them. To encounter that, nutritional genomics claims to be able to recommend specific, “personalized” and “genome-based” nutritional adjustments. According to the Center of Excellence’s Director, Raymond Rodriguez, nutritional genomics has been identified “as an emerging research focus of critical importance to global health and a vital link between agriculture, food and human health.”

To illustrate the nutritionism in these assumptions, and the “sciencefictional” nature of the promised solutions to the current epidemic of obesity, Type 2 diabetes and cardiovascular disease in the US, let us first consider the last time nutritionists undertook such grandiose public health and clinical ambitions. I am referring to the fat-free diet craze of the late 1980s, which Gary Taubes and Michael Pollan independently deconstruct as politically-motivated nutritionism. As Taubes writes in The Soft Science of Dietary Fat:

Since the early 1970s, for instance, Americans’ average fat intake has dropped from over 40% of total calories to 34%; average serum cholesterol levels have dropped as well. But no compelling evidence suggests that these decreases have improved health. Although heart disease death rates have dropped–and public health officials insist low-fat diets are partly responsible–the incidence of heart disease does not seem to be declining, as would be expected if lower fat diets made a difference. Meanwhile, obesity in America, which remained constant from the early 1960s through 1980, has surged upward since then–from 14% of the population to over 22%. Diabetes has increased apace. Both obesity and diabetes increase heart disease risk, which could explain why heart disease incidence is not decreasing. That this obesity epidemic occurred just as the government began bombarding Americans with the low-fat message suggests the possibility, however distant, that low-fat diets might have unintended consequences–among them, weight gain.3

To that Michael Pollan, the author of The Omnivore’s Dilemma, adds in a New York Times article called Unhappy Meals:

Last winter came the news that a low-fat diet, long believed to protect against breast cancer, may do no such thing — this from the monumental, federally financed Women’s Health Initiative, which has also found no link between a low-fat diet and rates of coronary disease. The year before we learned that dietary fiber might not, as we had been confidently told, help prevent colon cancer.2

In other words, it appears that nutrition-based clinical medicine and public health in the last decades not only have been unable to prevent, delay, and treat diseases, but have actually contributed to the current rise of metabolic syndrome, obesity, Type 2 diabetes, cardiovascular disease, and a host of other conditions arising from glucose intolerance and metabolic syndrome. According to Gary Taubes, the rampaging epidemic of obesity in America is partially due to the disastrous ambitions of Senator George McGovern’s Select Committee on Nutrition and Human Needs that changed the nutritional and public health policy in this country in the late 1970s. McGovern’s Committee had a mandate to eradicate malnutrition and disease, but in the mid-1970s the original mandate was replaced by an overzealous fight against “overnutrition,” and the health concerns associated with the dietary excesses of Americans. The Committee held hearings in July 1976, at the end of which McGovern — who was heavily influence by the diet-guru Nathan Pritikin’s very low fat diet and exercise program — with the aid of a handful of his staff members created the basis for the disastrous fat-fear-mongering of the next three decades.

In the wake of the panel’s recommendations, to which a 1982 National Academy report added the association of dietary fat with cancer,4 Americans did change their diets; and their average fat intake dropped significantly. But instead of fruits, vegetables and legumes, the average person replaced the missing fat with refined carbohydrates and high-fructose corn syrup, ostensibly as a way to avoid the evils of fat. Gary Taubes adds that the food industry which had little incentive in advertising non-proprietary items such as vegetables has been a major contributor to this public health blunder, for it spends the great bulk of the $30-billion-plus spent yearly on food advertising on selling carbohydrates in the guise of fast food, sodas, snacks, and candy bars. Michael Pollan writes that paradoxically Americans got really fat on this new low-fat, high-carbohydrates diet.

Now that two of the top leading causes of death in the US, meaning heart disease (1st) and diabetes (6th),5 are predominantly arising from decades of nutritional confusion and fear-mongering, nutritional genomics, armed with Artificial Intelligence, data mining and pattern-recognition technology is poised to “sniff” through the 3 billion-byte-long code of the human genome, and uncover genetic patterns that would explain why and how the low-fat and high-carbohydrates diet recommendations of George McGovern’s Select Committee are causing glucose intolerance, obesity, Type 2 diabetes, and cardiovascular disease in susceptible individuals and populations! But all we need for this purpose is some common sense, a little knowledge of American public health history, and the initiative to look through the grocery bills, the refrigerators, the restaurant menus or the trash cans of susceptible individuals and populations, and we can easily find out how super-sized refined carbohydrates and high-fructose corn syrup have made their way to their diet. For this, there is no need to analyze their genome with the aid of computational biology and pattern recognition technology, unless we have a taste for science fiction and Digital Age divination — none of which merits to promise medicine and health!

Nutritionism about prostate cancer has a connection to the dietary supplement industry that deserves to be mentioned here. A diet rich on animal fats and poor in grains, fruits and vegetables has been blamed for not providing enough of the presumably needed lycopenes, selenium, vitamins C and E, green tea, sulforaphane (found in broccoli, cabbage and cauliflower) and soy, and thus supplements, as David Heber, the Founding Director of UCLA Center for Human Nutrition, and coincidentally the Chairman of Herbalife’s Nutrition Advisory Board claims, could be used to prevent the occurrence of prostate cancer.6 According to a 2004 Forbes article, Heber joined the Board at roughly the same time the multilevel marketer of supplements and weight-loss products made a $3 million donation to establish the Mark Hughes Cellular & Molecular Nutrition Laboratory at the Center for Human Nutrition, leading to the criticism of Heber’s nutrition-based preventive claims as unfounded and pro-supplements, for obvious reasons.7 As for the value of any type of nutritional intervention to prevent, delay, and treat prostate cancer, Bill Nelson, a pioneer in the study of diet as preventive medicine at Johns Hopkins Brady Urological Institute tells us:

I’d have almost no reservations about advising someone to make sure his selenium levels are not too low, says Nelson. Beyond that, eat plenty of fruits and vegetables, and less red meat. And beyond that, take every story about a new dietary “wonder drug” with — pardon the food imagery — the proverbial grain of salt.8

The nutritional management of asthma is even less in need of avant-garde nutritionism. Merck Manual briefly mentions that “diets low in vitamins C and E and in ω–3 fatty acids have been linked to asthma, as has obesity,” and nothing beyond that.9 But if the deficiency of these nutrients and obesity are truly linked do asthma, then all we need is to “eat food, not too much, mostly plants,” as Michael Pollan recommends, and get them local, organic, seasonal and diverse, as others have suggested. And if you think that the link between obesity and asthma is a new discovery; and that the knowledge of how dietary chemicals alter gene expression or structure is required to address the problem, then read Galen of Pergamum’s (ca. 130-ca. 200) humbling treatise on the Thinning Diet:

The thinning diet is indicated for the majority of chronic diseases, which can, indeed, frequently be treated by such means alone, and without recourse to drugs. It is therefore important to form a clear idea of this diet; for wherever a result can be achieved purely by regimen, it is preferable to refrain from pharmaceutical prescriptions. Even with complaints of the kidneys and joints (provided the patient is not yet presenting joints full of ‘stones’), I have known many cases where the thinning diet lead either to complete remission or at least to a lessening of the pain. I have also known quite a few sufferers from chronic breathing difficulties derive such benefits from it that they returned completely to normal, or else suffered very few attacks over a long period.10

REFERENCES:

  1. Scrinis G. Functional foods or functionally marketed foods? A critique of, and alternatives to, the category of ‘functional foods’. Public Health Nutr. 2008
  2. Pollan M. Unhappy Meals, The New York Times, January 28, 2007
  3. Taubes G The Soft Science of Dietary Fat. Science. 30 March 2001. Vol. 291. no. 5513, pp. 2536 – 2545.
  4. Campbell TC, Campbell TM. The China Study: The Most Comprehensive Study of Nutrition Ever Conducted and the Startling Implications for Diet, Weight Loss and Long-Term Health. Benbella Books; 1 edition. 2004.
  5. Heron MP, Hoyert DL, Murphy SL, Xu JQ, Kochanek KD, Tejada-Vera B. Deaths: Final data for 2006. National vital statistics reports; vol 57 no 14. Hyattsville, MD: National Center for Health Statistics. 2009.
  6. Yip I, Heber D, Aronson W. Nutrition and prostate cancer. Urol Clin N America 1999;26:403-11.
  7. Pomerantz D. Supplemental Income. Forbes. November 04, 2004
  8. Nelson B. Prostate Cancer and Diet. Prostate Cancer Update. Volume V, Winter 2000.
  9. Beers MH, Porter RS, Jones TV. The Merck Manual. Merck. 18th Editions. 2006.
  10. Galen C, Singer PN. Selected Works, Oxford University Press. 1997.

Posted in: Herbs & Supplements, Nutrition

Leave a Comment (16) ↓

16 thoughts on “The Science Fiction of Nutritional Genomics

  1. Dr Benway says:

    DSHEA, the gift that keeps on giving.

    How to stop this crazy train filled with semi-plausible conjectures tarted up to look like understanding?

  2. Harriet Hall says:

    Stephen Barrett and I wrote a Quackwatch article about dubious genomic testing back in the early days, targeting companies that were using the test results to sell useless supplements.

    http://www.quackwatch.org/01QuackeryRelatedTopics/Tests/genomics.html

    Genomic testing has great promise for the future, but it is being prematurely marketed with false promises.

  3. Dr Benway says:

    Just like the platelet injection thing Val wrote about and the recent stuff I’ve been reading from the fish-oil-for-everything crowd. There may be some preliminary interesting data from an animal study or correlations noted in a population survey, but nothing sufficient to warrant treatment recommendations.

    Doctors generally aren’t willing to do anything about peers overstating the evidence for novel therapies. “The five-dollar word is ‘pusillanimous.’”

    I think we need our basic science colleagues to help us stop the pseudoscience invasion of medicine.

  4. Calli Arcale says:

    Gary Taubes adds that the food industry which had little incentive in advertising non-proprietary items such as vegetables has been a major contributor to this public health blunder

    I don’t think the proprietariness of ingredients is quite as big an incentive as you might think. Isn’t this the same basic claim used by alties to argue that Big Pharma isn’t interested in herbal drugs — because they’re not “patentable”? But as we all know, the argument is bogus. Big Pharma will happily promote any drug that they can sell, and arising in nature is not actually a major impediment to patent. (It’s certainly not an impediment to trademarking or other forms of intellectual property protection.)

    The real reason why food manufacturers went for corn syrup wasn’t because it was more patentable than vegetables. (One major clue: it’s actually not any more patentable.) They went for it because it’s *cheap*. This is especially true in the junk food market. People who buy junk food are specifically looking for something cheap; add lots of veggies and it’ll be healthy, but also more expensive. How many people would buy a $5 candy bar? But if you see two seemingly similar bars in a vending machine, where both cost $0.75 but one has a “low-fat!” sticker on it, which one is more likely to sell?

    So just as with the drug industry, patenting is often a red herring in the food industry. It does have an affect (mostly in patenting processes and/or machines, such as the patented machinery that Hershey uses to make their Kisses), and they will exploit whatever they can to defend their intellectual property. But mostly it’s about maximizing profit, and substituting ingredients to improve marketability is often a prudent move as long as it doesn’t drive costs up.

  5. nitpicking says:

    HFCS is cheaper than cane sugar in this country for legal reasons, not technological or intrinsic. We have a huge tariff on cane sugar, which is justified as being anti-Castro. Then we subsidize maize (as Pollan has documented) drastically.

    There is (as Brian Dunning podcasted about) no evidence that HFCS is any more dangerous to eat than sucrose. This does NOT mean that I support eating tons of either one! Just don’t demonize one combination of fructose and sucrose over another.

    I said this on another forum, and someone actually found an article claiming that Colony Collapse Disorder (the syndrome threatening honeybee stocks in North America) was caused by feeding bees HFCS: http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/jf9014526?cookieSet=1

    Oddly, the authors don’t mention that
    a)honey has even more fructose in it than HFCS, and
    b)Sucrose ALSO produces hydroxymethylfuran when heated.

  6. nitpicking says:

    I mean, one combination of fructose and glucose, not “sucrose”. I wish this blog let me edit my comments.

  7. rbnigh says:

    Great post and interesting, informative comments.
    Actually there is some evidence that fructose, and possibly especially HFCS, induces insulin resistence and encourages obesity more than sucrose or other sugars

    Also the Campbell study didn’t exactly link “dietary fat with cancer”, though some have interpreted it thus. Campbell linked various degenerative diseases with transition to a ‘Western diet’, This involved a considerable increase in consumption of (factory fed) animal protein. Campbell suspected that the fat was the relevant factor but admitted that it was impossible to distinguish the effect of animal protein and animal fat. Consumption of animal products was closely correlated with blood cholestrol levels, which was the variable in his study most closely correlated with a number of degenerative diseases.

    Conclusion, follow Pollan’s advice.

  8. daijiyobu says:

    Per: “‘sciencefictional’ nature [loving that!...and] exaggerated claims of advocates of nutritional interventions for various diseases and conditions”,

    this caused my lateral-thinking brain to notice that my ‘naturopathy diagnostic bullshit’ meter was going bonkers within it!

    Hey, as I remember, NDs/NMDs do this fictional stuff (see http://dnaandyourhealth.com/services.html ) [what woo don't they do?!].

    But, don’t worry, because at dnaandyourhealth.com we’re told:

    “[NDs] are the only primary care physicians trained both in biomedical and biochemical sciences with a thorough knowledge of natural therapeutics and preventive medicine [...and we're told, ultimately, to] remember: genes don’t lie!”

    So what this NMD does diagnostically must be….true? You must trust.

    What I’m really gaga over is the ‘bioimpedance analysis’ diagnostics she uses wherein:

    “a computer then gathers data on your body fat, toxins, nutritional status, hydration and cellular health” (see http://dnaandyourhealth.com/testimonials.html ).

    What’s most funny is that she links to http://en.wikipedia.org/wiki/Bioimpedance which states:

    “the reliability of bioimpedance for obtaining accurate data has been called into question.”

    Eh, trust the expert, who will ‘determine the diagnosis first, then read the genetic tea leaves / voltages for support’.

    -r.c.

  9. Ben Kavoussi says:

    Greetings from Balad, Iraq.

    1. Dr Benway, yes, indeed DSHEA has played a role in this. My next article is about DSHEA and herbs. I will submit it in 2 weeks.

    2. Thanks Harrit, I will read the post on dubious genomic testing.

    3. Calli Arcale, I agree with nitpicking’s argument on the artificial price of US-made corn syrup. Again, it is agro-politics, not science driving healthcare policies.

    4. rbnigh, thank you, I did not know about HFCS induced insulin resistance and caused obesity more than sucrose.

    5. daijiyobu, thanks I will read the links later today. Please keep posting, it is really interesting.

  10. Scott says:

    HFCS is cheaper than cane sugar in this country for legal reasons, not technological or intrinsic. We have a huge tariff on cane sugar, which is justified as being anti-Castro. Then we subsidize maize (as Pollan has documented) drastically.

    It truly is astounding how much policy is driven purely by buying votes in the Iowa caucuses. Corn-based ethanol is another case in point.

  11. Speaking of not being able to resist woo of any sort, let’s not forget that a “naturopathic doctor” peddled “nutritional genomics” even before it went by that name.

  12. nitpicking says:

    @rbnighon:

    Actually there is some evidence that fructose, and possibly especially HFCS, induces insulin resistence and encourages obesity more than sucrose or other sugars

    But HFCS has essentially the same glucose:fructose ratio as sucrose does. Since sucrose breaks down into monosaccharides in the gut almost instantly, how could HFCS have a different effect?

    I’m oversimplifying, there are several types of HFCS, but the point stands.

    Note that “natural” foods like apples and honey have an even higher proportion of fructose than an HFCS used in human foods.

  13. Ben Kavoussi says:

    “let’s not forget that a “naturopathic doctor” peddled “nutritional genomics,” even before it went by that name.

    Indeed. This matter deserves a whole article on its own. But in its current form, nutritional genomics has further attracted many proponents of CAM and dietary supplements, to include naturopathic doctors. I went to the Second Bruce Ames International Symposium in Nutritional Genomics held in 2007 at the UC Davis. Besides the “Four Horsemen of the Nutritional Apocalypse,” (Dean Ornish, Jeffrey Bland, Bruce Ames, and Ray Rodriguez), as I call them, and saw there many CAM providers looking for genetic justifications for interventions that are often supported by very little evidence.

  14. Ben Kavoussi says:

    I wanted to add to the comments made about glucose versus fructose. I should have addressed this issue in the article.
    It is not the nature of the sugar that really matters but its mere presence. If you look at the French, Japanese or Italian diets, the only place you find sugar and the sweet taste is in pastries and perhaps in the morning coffee. They do not make the food, the bread, the sauces and the salads sweet like we do here. This is why I say that refined carbohydrates and high-fructose corn syrup have made their way to our diet.

  15. skepsis says:

    @nitpicking it is not about minor differences in percentage glucose/fructose, but of total consumption. Total sugars is above 150 lbs/capita today. Compared with 100 about 1950 and and about 80 in 1900.

    Sources
    http://www.usda.gov/factbook/chapter2.htm
    Bente and Gerrior, 2002. Family economics and nutrition review 14:43-52.

    And BTW the American Heart Association is as much to blame for the sugar craze as the sugar industry.

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