Authors: T. Colin Campbell
Omega-3s appear to protect our bodies from inflammation; that is, they are anti-inflammatory, and thus being helpful in reducing rheumatoid arthritis and cardiovascular disease. Several small studies found that omega-3 fats improved clinical biomarkers of diabetes like glucose tolerance,
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blood triglycerides,
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and levels of high-density lipoprotein (HDLs, or the “good” part of one’s total blood cholesterol),
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which suggests that omega-3 fats may protect against diabetes.
Omega-3 fatty acids are one of the current darlings of the mainstream nutritional health world. To ensure we get enough of them, the media urges us to eat lots of fish, specifically fatty species like anchovies, herring, salmon, sardines, and tuna. (They don’t often mention that one form of omega-3, ALA, which is found in certain nuts and seeds, can be converted in the body into the other forms, making fish consumption unnecessary.) And of course, we are also urged to take omega-3 supplements.
Supplement makers sell omega-3 to us mostly in the form of fish oil capsules. They focus on claims of “purity” for their products, contrasting them against the fatty fish we eat that contain dangerously high levels of mercury, PCBs, and other contaminants. The WebMD website goes so far as to warn pregnant women and children away from many species of wild and all species of farm-raised fish. So omega-3 supplementation would appear to be the smarter way to get what we need of this essential nutrient. In reality, however, this has proven not to be the case.
When the findings for a huge group of eighty-nine studies (this is a lot of studies!) were summarized, it was concluded that “omega-3 fats
do not
have a clear effect on total mortality, combined cardiovascular events or cancer”
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(Emphasis mine). In a very large study of nearly 200,000 individuals over fifteen years,
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increasing consumption of omega-3 fats (combined intakes mostly from fish but some from supplements) was actually associated with increased risk of Type 2 diabetes: the higher the omega-3 intake, the more likely the subject was to develop diabetes. In total, the study included almost 10,000 Type 2 diabetes cases, and as the omega-3 intake increased, the number of diabetes cases trended upward, so it’s highly unlikely that this association is due to random chance.
Do higher intakes of omega-3 fats really increase Type 2 diabetes? What about those earlier, smaller studies that suggested omega-3s might prevent diabetes? How can we explain this discrepancy? When you look at
these studies carefully, there is no discrepancy. The earlier, smaller studies were short term and looked only at biomarkers associated with diabetes. That’s not the same as findings on the final occurrence of disease. Shortterm findings are only isolated blips in a very complex sea of events. Yet supplement makers rely on these reductionist rushes to judgment, rather than waiting for meaningful long-term study results, to convince us that their products are effective.
A now-classic example showing this shortsighted rush to judgment based on short-term effects is the story of beta-carotene, the vitamin A precursor found in plants that our bodies convert into “real” vitamin A. Beta-carotene occurs naturally in green leafy plants and brightly colored red, orange, and yellow vegetables such as chili peppers, carrots, and pumpkins. In the 1970s, beta-carotene was discovered to be a powerful antioxidant
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that could block the activities of free radicals thought to promote cancer growth. Also, beta-carotene-rich foods (i.e., vegetables and fruits) were associated with decreased lung cancer.
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Together, these observations provided suggestive evidence that beta-carotene might protect against lung cancer, and perhaps other cancers as well.
About ten years later, however, a human study among smokers in Finland showed that beta-carotene supplements given for 6.5 years increased lung cancer deaths by 46 percent,
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a very large and statistically significant effect. In addition, cardiovascular deaths were increased 26 percent for those taking the supplements.
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This adverse effect was so prominent that the study had to be terminated early. That’s right: beta-carotene supplementation increased death rates so dramatically that the trial was ended early to prevent further deaths.
Interestingly, in this same study, baseline beta-carotene consumption from food was associated with lower lung cancer risk. This difference was stark. Food beta-carotene was associated with less lung cancer, but supplement beta-carotene was associated with more lung cancer. This finding was confirmed in other big studies as well.
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Since that time, a consensus has emerged showing that beta-carotene supplementation does not decrease cancer or cardiovascular disease.
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We now have a ton of studies showing all manner of mechanisms by which beta-carotene, vitamin E, and other antioxidant vitamins
ought
to prevent diseases like heart disease and cancer, but, when tested alone (e.g., in pills), they don’t. Even though researchers are beginning to accept these specific findings, and are no longer recommending supplemental beta-carotene, vitamin E, or omega-3, they still tenaciously cling to the same old beliefs, claiming that, despite disappointments, we should continue to put our faith in preventing disease through isolated chemicals. What incredible stubbornness!
In the face of increasingly robust and consistent findings showing that isolated nutritional supplements are bad news, the supplement industry and its hired researchers are responding by digging their reductionist hole ever deeper. Some want to escalate the search for new antioxidant chemicals in plants, in the hopes that they have more pluses and fewer minuses than the current bunch.
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Others suggest that a more customized selection of clinical biomarkers might help unearth new health benefits for the same antioxidants we’re studying currently. That is, since the antioxidant effects that we’re looking at now seem disconnected from meaningful health outcomes, we should instead look for different intermediate effects that do predict things we care about, like less disease and longer life. But the reason we use biomarkers as proxies for actual health—because it’s cheaper and quicker to measure biochemistry than to follow study participants for years to see what happens to them—is exactly why biomarker studies are not appropriate for determining the true effects of a supplement on human health.
The reaction of researchers to the news about the failure of vitamin E, beta-carotene, and other isolated antioxidants to create health disheartens me. Many researchers are now aware of these failed studies.
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They acknowledge the complex nature of antioxidant activity and the legitimacy of several reports showing that vitamin supplements may in some circumstances cause toxicity. But rather than consider giving up on this dead-end approach to health, in some cases these researchers present still more technical details they hope will justify additional and more complex supplement research. After all these years and all these studies, they still
fail to see the futility of continuing to go down this same very expensive and virtually useless path of searching for some new antioxidant analog that has the special ability to create health. Someday, perhaps, they’ll find that needle in the haystack—the reductionist supplement that outperforms its natural counterpart. But I wouldn’t count on it.
During the mid-1980s, when the nutrient supplement industry was initially emerging, I spent about three years giving substantial testimony, at the request of the National Academy of Sciences, to the U.S. Federal Trade Commission as to whether health claims favoring vitamin supplementation were justified by the then-existing evidence. I testified against the industry’s proposed health claims both because reliable evidence did not exist and because, from the biological perspective I held then, it did not make sense. The perspective I held then is the same one I’ve presented here in this book a quarter-century later: nutrients rarely if ever act alone, or at least not properly so. After a few hundred billion (mostly) taxpayer dollars spent doing the research, we are now finally getting evidence that may prove helpful in moving this mountain.
Please understand: I’m not saying that there is no benefit for some people for some supplement preparations, especially when the chemical composition of the supplement begins to approximate the composition of whole plants, as in some dried herbal compounds. These products may be helpful under some conditions for certain people. But for me, the burden of proof is on those who make such assertions, and by “burden of proof,” I mean objective research findings that pass the test of peer review. It is not appropriate to propose or even infer that these “natural supplements” are the best health option without also making clear that the routine consumption of whole, plant-based foods—from whence these products came—will produce far better health at a far cheaper price.
The danger of our increasing consumption of supplements is more than just the documented negative effects on our health. It’s that our love affair with the magic bullet of supplementation lets us believe we’re “off the hook” when it comes to eating right. Why eat your veggies when you can binge on hot dogs and ice cream and, if you get into trouble, make it all better with a pill?
Nutritional supplementation is proving to be the canary in the coal mine for the reductionist approach to health. While the pharmaceutical approach continues unabated, the supplement initiative, at least, appears to
have reached a research dead end. Only by applying reductionist research methods—attributing too much significance to biomarkers and individual chemicals and refusing to look at real health outcomes—can the supplement industry defend its project of factory-formed fragments of former food as the road to good health.
Reductionist Social Policy
Whatever we do to the earth, we do to ourselves.
—
CHIEF SEATTLE
S
o far in Part II, we’ve been looking at reductionism in terms of nutrition and food policy, and how reductionism’s effects impact individual health outcomes and quality of life through diet. But our reductionist approach to nutrition affects other areas of life, too. Social policy isn’t my area of expertise, but as a member of several high-profile food- and health-policy expert panels, I’ve certainly considered the likely impact of dietary recommendations on social and cultural practices. Thus, I’d be remiss not to at least touch on the way reductionism affects the way we look at social problems, and how the nutrition information that reductionism discourages us from seeing—the benefits of the plant-based diet over one high in animal products—also affects the world we live in.
When you connect the dots of some of our biggest social, economic, and environmental problems, you can clearly see nutrition looming large as a causal factor and potential solution. It turns out that eating—how we literally absorb nature, or an artificial substitute, into our bodies—holds
huge implications for how we treat the rest of nature and our fellow humans.
Every July 4th weekend, my adopted home town of Durham, North Carolina, hosts a wonderful crafts and music festival to raise money to preserve a local river. Bands come from all over the country to share their music in a beautiful state park. Vendors sell handmade jewelry, pottery, and clothing. Activists and environmentalists hold forth on solar energy, river cleanup projects, opposition to nuclear facilities, and various other causes. Every napkin, spoon, plate, and cup given out by food vendors is 100 percent biodegradable. In short, you couldn’t hope to find a more environmentally conscious gathering.
Except for one thing: most of the food that festivalgoers shovel into their bodies. Deep-fried funnel cakes slathered in synthetic syrup and confectioners’ sugar. Giant turkey drumsticks, hamburgers, chicken breasts, and corn dogs sourced from factory farms that pump hormones and antibiotics into their products. French fries submerged in fryers of genetically modified cooking oil. While we know that littering and polluting rivers and streams is bad, somehow we’ve accepted that polluting our own bodies is okay, as if what we eat has no impact on the rest of the environment.
I know many environmentalists whose commitment is manifest and commendable, but stops at their lips. It’s understandable; many of our favorite “foods” (or, more properly, food-like items) are highly addictive. And our relationship with food is far more emotionally fraught than, say, our relationship with incandescent light bulbs or plastic shopping bags. But even these far-seeing and far-thinking activists are wearing reductionist blinders if they cannot see that their personal food choices matter at least as much as—and I would argue considerably more than—recycling and using energy-efficient light bulbs.