Imagine that a juicy new diet controversy has piqued your curiosity. People on one side of the debate are claiming that a certain category of food or type of nutrient is bad, while people on the other side are claiming the opposite. You want to know who’s right. Where can you go for an unbiased answer? The best place to look is PubMed, a U.S. Library of Medicine-funded online database that contains more than 23 million citations for biomedical literature. This is where nutrition scientists themselves go when they need a question answered.
For the sake of illustration, let’s suppose that the particular diet controversy that has captured your interest is the one surrounding grains. One on side of this debate are low-carb and Paleo diet advocates claiming that all grains are unhealthy. On the other side are vegetarians, “clean eaters,” and others claiming that whole grains are healthy. Who’s right? A quick visit to PubMed will answer this question in a jiffy.
Start by typing “whole grain” (or “whole grains”) in the search box. As you punch the keys, an auto-complete function will generate a dropdown menu with suggestions for specific searches that contain your key words. Examples are “whole grain cardiovascular,” “whole grain diabetes,” and “whole grain inflammation.” Choose a search string from among these options, then browse through the list of studies that are called up until you find one that interests you. Click on the title and you will be taken to a one-paragraph abstract that summarizes the study. Now look at some of the related studies whose titles appear on the right of your screen. When you’re satisfied that you’ve come up to speed on the current scientific understanding of the effect of whole grain consumption on cardiovascular disease risk (or whatever), back up and choose another whole grain-related search string.
If you actually do this, you will quickly discover that whole grains are in fact exceedingly beneficial to human health. For starters, they promote a healthy body weight. A 2011 study conducted by researchers at the Harvard School of Public Health and published in the New England Journal of Medicine found that adults who increased their consumption of whole grains gained 11 percent less weight over a 20-year period compared to the average person.
Whole grains are also good for cardiovascular health. A 2003 study published in the Journal of the American Medical Association found that elderly men and women who consumed lots of whole grains had a 21 percent lower incidence of cardiovascular disease.
The effect of whole grains on type 2 diabetes is even more striking. In 2002, researchers at Simmons College published the results of an experiment in which they tracked whole grain consumption and diabetes risk in a population of nearly 43,000 men for 12 years. Those who ate the most whole grains were found to be almost 50 percent less likely to develop type 2 diabetes compared to those who ate the least whole grains.
The beneficial effects of whole grains on the risk for chronic diseases such as cardiovascular disease and type 2 diabetes appears to be mediated in part by the food’s effect on systemic inflammation, which is an underlying factor in many chronic diseases. Numerous studies have shown that consumption of whole grains reduces systemic inflammation. For example, a 2008 study published in the American Journal of Clinical Nutrition found that 12 weeks of substituting refined grains with whole grains reduced levels of C-reactive protein, a major marker of systemic inflammation, by 38 percent in a group of overweight adults.
There is so much good news about whole grains in the PubMed database that, after looking through it, you might be left wondering why whole grains are condemned as unhealthy by the low-carb and Paleo crowds. The reason is that the creators of the low-carb and Paleo diets made up their minds about whole grains without reference to the published research. In the case of the low-carb philosophy, the notion that carbohydrate is bad serves as a first principle. Since whole grains are rich in carbohydrate, they must be unhealthy, regardless of what the research says. In the case of the Paleo diet, the first principle is that humans living today should not eat foods that were not eaten by our ancestors a million years ago. Since cultivated grains were not eaten a million years ago, they must be unhealthy, regardless of what the research says.
The fact that science overwhelmingly supports the healthfulness of whole grains presents a problem for low-carb and Paleo diet proponents with respect to their efforts to win new converts. How do these diet cults convince people to stop eating whole grains when science says they keep us from getting fat and developing chronic diseases? With trickery, that’s how! There are two tricks in particular that the low-carb and Paleo diet cults use to create the illusion that science does not support the healthfulness of whole grains.
The first trick is a special form of nitpicking that entails focusing on microscopic mechanisms instead of big-picture final outcomes. The anti-grain faction delights in pointing out that many grains contain a tiny compound called phytic acid that is known to limit the absorption of some vitamins and minerals. It sounds bad, but reduced absorption of some vitamins and minerals is not itself a disease. It is merely an intermediate effect of digestion that could conceivably be linked to long-term health consequences. But we’ve already seen that the long-term health outcomes associated with eating lots of whole grains are all positive. What’s more, big eaters of whole grains are actually less likely than others to be deficient in essential vitamins and minerals. So phytic acid is a problem without a consequence—which means it’s not really a problem.
Where health is concerned, the ultimate big picture is longevity. If eating a given food type increases lifespan, the details of how it is digested and metabolized really don’t matter. A 2008 study from the Harvard School of Public Health found that a diet including large amounts of whole grains reduced the risk of death by 21 percent in a population of 72,000 women over a period of 18 years. In short, people who eat lots of whole grains live longer. Who the hell cares if the phytic acid in whole grains slightly reduces the amount of iron in the body if whole grains as a whole add years to a person’s life?
The trick of turning public attention away from final health outcomes (which matter) and toward intermediate digestive and metabolic mechanisms (which don’t), which low-carb and Paleo diet advocates use to disparage whole grains, is used by other diet cults to disparage other food types. No food type is immune to such scrutiny. If you look closely enough at nuts, fish, or even vegetables, you will find something microscopic inside that the body has a little trouble dealing with. Big deal! No food is perfect. The anti-grain faction wants to use one small imperfection in grains to distract you from their big-picture benefits and convince you that wheat, rice, and so forth are “killing you slowly” (as one “wellness” blogger put it). It’s amazing to me that anyone is fooled by this kind of chicanery, but at least you won’t be fooled by it ever again.
The second trick that certain diet cults use to create the appearance that science does not support the healthfulness of whole grains is to discredit the relevant research. Because this trick is so desperate and outlandish, members of the anti-grain faction typically resort to it only when the first one fails, but when backed into a corner they will not hesitate to insinuate or even claim outright that the hundreds of studies proving the healthfulness of whole grains represent a giant conspiracy funded by, and serving the interests of, the grain industry.
It is true that industry money has some influence on nutrition science. One of the studies I described above, the one concerning systemic inflammation, was paid for by General Mills. An anti-grain zealot will look at such corporate backing and reflexively assert that the results cannot be trusted. That’s a bit over the top. While industry dollars do sometimes determine which studies are conducted in the first place, and corporate influence may at times be used to ensure that unfavorable results are not published, nutrition scientists by and large do not risk their reputations and careers by going so far as to manipulate data to please breakfast cereal makers. To suspect this is to take cynicism to the brink of slander.
People become scientists because they love and respect truth. Some are corruptible, but most are not. The typical nutrition scientist is like David Katz, a professor at Yale University, who said in a recent article on theatlantic.com, “I don’t have a dog in the fight. I don’t care which diet is best. I care about the truth.”
Even if a rogue researcher were tempted to fudge data to make whole grains look better, it would be hard for him to get away with it. Science has many layers of checks and balances—including peer reviews, the requirement to disclose funding sources, and the practice of duplicating results independently in multiple labs—to minimize the impact of unethical scientists.
In any case, the majority of studies linking positive health outcomes with whole-grain consumption are not underwritten by the grain industry. For example, a recent study by Korean researchers that found favorable effects of whole grains on fasting glucose and triglyceride levels was funded by the National Research Foundation of Korea and the Ministry of Science, ICT & Future Planning. (Here’s where the most bug-eyed anti-grain crusaders try to argue that these organizations have an interest in boosting the Korean grain industry. The problem here is that there essentially is no Korean grain industry.)
Conspiracies do exist, but they can only get so big and last so long before they are exposed and brought down. For example, the cigarette industry maintained a conspiracy to hide scientific evidence that cigarettes create health risks. But this conspiracy was exposed by whistleblowers including Merrell Williams, Jr., who leaked documents proving that the cigarette makers acknowledged the risks internally. No whistleblower has come forward with evidence showing that the vast ocean of science supporting the healthfulness of whole grains is tainted by fraud. And none will ever come forward, because there is no conspiracy.
You can’t reason with people who want to believe what they believe, but if I were to try, I would make one last point. The soft drink and confectionary industries are huge and powerful and rich beyond imagining. They have poured a lot of money into efforts to counter scientific evidence that consuming lots of refined sugar is not healthy. Those efforts have failed miserably. If you go to PubMed and type in search phrases such as “high fructose corn syrup diabetes” or “soft drinks obesity” you will find all kinds of bad news about excess refined sugar consumption and not much good news.
If nutrition science were corruptible on a large scale, every college nutrition textbook would teach students that soda pop is healthy. But they don’t, so when science says that whole grains are healthy, you can trust it. What you cannot trust is any diet cult advocate who resorts to the conspiracy argument. The use of this tactic should instantly disqualify its user from further debate, the same way throwing up in a beer mile invalidates a competitor’s finishing time (unless he completes a penalty lap).
Like the first trick I discussed—that of distracting public attention from meaningful final health outcomes and turning it towards meaningless digestive and metabolic mechanisms—this second trick of sweepingly discrediting research that produces “inconvenient truths” is used by many diet cults, not just those that have a beef with grains (so to speak). Look for both of these tricks in your future dealings with diet cult advocates of all varieties, and don’t fall for them!