Optimal Anti-Aging: How to Do It

The best foods

The Global Burden of Disease Study, funded by the Bill & Melinda Gates Foundation, brought together nearly 500 scientists from more than 300 institutions and 50 countries, and they examined almost 100 000 data sources. One of their findings is the realization that the typical American diet kills most Americans, more than smoking in second place. These days, in America, only an estimated half a million people die per year from the consequences of smoking—the diet kills far more.

When it comes to the aging process, healthspan, and life expectancy, diet is considered the most important modifiable factor. When studies find that “optimal nutrient density,” “healthy dietary patterns,” or “higher-quality diets” are associated with increased life expectancy, a lower risk for all chronic diseases, a higher quality of life, or successful aging, what do they mean by a healthy diet?

Food that scores high on each of the four most important dietary-quality rating scales is associated with a longer lifespan and a lower likelihood of developing heart disease or dying of cancer, and it always comes down to four core elements: more fruit, more vegetables, more whole grains, and more nuts and beans. This diet is based on plant ingredients. Dietary patterns, by contrast, in which primarily animal products are eaten and hardly any plants—that is, what we refer to as a Western or westernized diet—are associated with higher risks.

The Global Burden of Disease Study identified five major risk factors for a shortened life expectancy, four of which would easily be modifiable: Eating more vegetables could save about one and a half million lives worldwide each year. More nuts and seeds? Two million lives. More fruit? Almost two and a half million lives. Inadequate intake of whole grains could be responsible each year for the loss of three million lives. Perhaps the salvation for millions lies not in new medications or vaccines, but in more whole, healthy plant foods. (Vegetables pickled with salt and canned fruit with sugar do more harm than good.)

The worst foods

How do we make our decisions when it comes to life or death—for example, by deciding what we and our family should eat best? In this context I often use the phrase “best available evidence,” but what does that mean? The claims of individual studies are less important than the totality of the peer-reviewed body of knowledge.

Single studies often prompt headlines like this one in Forbes magazine: “Study finds no link between secondhand smoke and cancer.” To find out whether there truly is no link between secondhand smoke and lung cancer, we should instead look to a review or a meta-analysis that brings together multiple studies. The problem is that even these collected data sometimes contradict one another. For example, some reviews say that secondhand smoke causes lung cancer, while others not only claim the effects are insignificant and information of this kind could “promote irrational fears,” but even state that it is harmless if you yourself smoke four to five cigarettes a day. (You can imagine who funded the study.)

Why do reviews on the health effects of secondhand smoke arrive at different conclusions? It likely won’t surprise you that about 90 percent of reviews by researchers with ties to the tobacco industry portrayed secondhand smoke as harmless, whereas about 90 percent of independent reviews found it harmful. To be precise, authors close to the tobacco industry were 88 times more likely in their reviews to conclude that secondhand smoke was harmless. This was all part of a targeted corporate strategy aimed at discrediting science by—as the US Tobacco Institute’s own market research consultants put it—“developing and widely disseminating medical evidence that secondhand smoke does not harm the health of nonsmokers.”

In that case, can’t we just stick to the independent reviews? If only we could so easily tell which ones are truly independent! Industry-funded researchers know all sorts of tricks to avoid having to disclose conflicts of interest, which is why it is so difficult to trace the money back. But even if we don’t know exactly who funded what, the majority of reviews still conclude that secondhand smoke is harmful. So just as a single study doesn’t help as much as multiple studies, a single review doesn’t help as much as a compilation of reviews. A review of reviews may give you a better sense of where the best available evidence might lie. Since for secondhand smoke, 63 percent of reviews found it harmful to health, 37 percent said it was neutral, and not a single one claimed it was beneficial, it’s better not to inhale.

If only there were also a review of reviews for different foods! There is. At last we have an exhaustive review of meta-analyses and systematic reviews on the relationships between groups of foods and beverages and the most important diet-related chronic diseases. For the best overview, the researchers first divided the food groups into “plant-based” and “animal-based.” The overwhelming majority (94 percent) of reviews on whole plant foods show they are protective or at least neutral, whereas most studies on animal foods (77 percent) find harmful effects or, at best, no effects on health. (The percentages were rounded, which is why the total does not always add up to 100.)

The “plant-based” category was divided into five groups: fruit, vegetables, whole grains, legumes, and nuts and seeds, and all scored well, between 87 and 98 percent beneficial or at least neutral. In the five groups of animal foods, by contrast, very clear differences emerged. As you can see in the chart, animal foods would be classified almost entirely (98.7 percent) as neutral or harmful if you subtract dairy products and fish.

In the chapter “Beverages” I will discuss in detail the influence of dairy-industry funding and the effects of substitution. For example, people who drink milk consume fewer sodas, which are condemned even more harshly, so any benefit is relative and does not necessarily arise from what you consume but from what you avoid. That also explains the findings on fish. After all, the choice is usually between chicken and fish, not between chicken and chicken feed. Not a single review found even one positive effect of poultry consumption. Even the soda industry achieves 14 percent beneficial effects, but for poultry and eggs you could more aptly sum up the results with “Well, I’ll be damned!”—and that despite all the funding from the National Chicken Council and the American Egg Board. As with the reviews on secondhand smoke, such a whitewashed portrayal may be all you get for your money.