Chapter 49
Comparing Butts to Hamburgers
As with the calcium in dairy products, fish also contains healthy components, namely the long-chain omega-3 fatty acids EPA and DHA. For the heart, however, they are not the best. In the most comprehensive systematic investigation to date of the effects of omega-3 fatty acids on cardiovascular health, it turned out that increased consumption of fats from fish oil does virtually nothing. If anything, the plant omega-3 fats from flaxseed and walnuts help. The long-chain omega-3 fatty acids are important for brain health. Fortunately, there are also other calcium sources besides dairy products, and similarly there are toxin-free EPA and DHA sources (in algae).
What it comes down to: Even if you lump all animal foods together, ignore the influence of industry funding, and simply look at the evidence base, nine out of ten overviews show that the effect of a whole-food plant-based diet on diet-related diseases such as obesity, type 2 diabetes, mental health, bone health, cardiovascular disease, and cancer is at least not bad, whereas about eight tenths of the reviews rate animal foods as not good.
Comparing Butts to Hamburgers
How much “not good” are we talking about? Meat consumption is associated with an increased risk for more than 20 different diseases, but how strong is the link? To be able to compare different chronic risks, researchers developed the concept of a “microlife,” defined as 30 minutes of life expectancy. Someone in their mid-20s has, on average, about 57 years left to live. That’s roughly 20,000 days, half a million hours, or a million half-hours. A microlife is one of the one million half-hours that may still remain to us. If a 30-year-old man smokes two cigarettes or drinks a liter of beer, it costs him, on average, a microlife, just like every day on which he carries around five kilos of excess weight. See how easily you can compare risks that way? If you drink, for example, half a liter of beer, that reduces life expectancy by the same amount as one cigarette you smoke. If it would be unthinkable to you to respect your own health so little that you would even smoke two cigarettes a day, it should be just as unthinkable to drag around five kilos of excess weight.
Alternatively, life-extending behaviors can be compared. For example, it can add an average of four years to your lifespan if you eat at least five servings of fruits and vegetables every day. That helps twice as much as the estimated effect of daily exercise. But even 20 minutes of exercise can extend your life by an hour (two microlives). And for those who say they have no time for exercise: exercise brings you a threefold return. Invest 20 minutes of life, and you theoretically get 60 back. Beyond that, the yield drops off somewhat, but even with an hour of exercise a day, you still get back more time than you invest.
And what about meat? Each individual burger corresponds to the loss of a microlife. Is a burger worth 30 minutes of your life to you? In terms of lifespan, then, a burger is equivalent to two cigarettes. If you don’t want to light up a cigarette before and after eating, you might consider a bean burrito instead.
An egg salad sandwich would not be a particularly good choice either. In 2021, the largest prospective study ever on egg consumption and mortality was published, the NIH-AARP Diet and Health Study, funded by the National Institutes of Health (NIH) and the American Association of Retired Persons. As part of this study, more than half a million people were followed for an average of 16 years. Each half egg eaten per day was associated with a 7-percent increase in all-cause mortality, which, in terms of reducing lifespan, equates an egg with a burger.
Bacon Causes Cancer
Processed meat is even worse. Imagine two people who are the same in every respect, except that one eats about 50 grams of processed meat per day—about a large sausage, a hot dog, or a few strips of bacon—and the other does not. Just the daily consumption of this one serving of processed meat costs about two years of life.
The whole thing can also be expressed as loss per day. A sandwich with just two slices of deli meat like bologna or ham amounts to about an hour less life. Does your day never have enough hours either? It’s quite possible it will be one less, depending on what you pack in your lunchbox.
Processed meat—bacon, deli meats, hot dogs, and the like—causes cancer. In 2015, the world’s most prestigious cancer research institution classified processed meat as a Group 1 carcinogen, as a substance known to cause cancer. Critics complained that processed meat was placed in the same category of carcinogens as asbestos, tobacco, and mustard gas, but the classifications refer to the strength of the evidence that the substance in question causes cancer or not, not to how much cancer. The substances in this Group 1 are not all equally dangerous. Although both are in Group 1 of carcinogens, it is less concerning to eat a pastrami sandwich than one with plutonium.
And how dangerous is processed meat exactly? Each daily consumed 50-gram serving of processed meat increases colon cancer risk by 18 percent. So if you eat a sandwich with two small slices of bologna every day for lunch, you increase your colon cancer risk by 18 percent. Half a pound of pastrami on rye carries a more than 80-percent risk. How can this “18 percent increased cancer risk” be compared with other risky behaviors? When I gave my assessment before the 2020–2025 U. S. Dietary Guidelines Scientific Committee, I said: “We try not to smoke in the presence of our children. So why do we send them to school with a bologna sandwich?” That sounds exaggerated, but it isn’t. According to the head of the US health authority, living with a smoker increases one’s own lung cancer risk by 15 percent. Daily secondhand smoke increases lung cancer risk almost as much as daily consumption of a single serving of processed meat increases the risk of colon cancer.
Lung cancer is the leading deadly cancer, and right behind it is colon cancer. So if you don’t smoke, colon cancer could represent the greatest cancer threat. However, you can reduce this risk by about one fifth simply by cutting a serving of processed meat from your daily diet.
Back to Nature
The healthiest foods come from plants, so it is not surprising that healthy plant-based eating is associated with a lower risk of premature death in the general population and especially among older adults. The foundation of the diet recommended for healthy aging, a long life, and delaying age-related diseases is a whole-food plant-based diet. With it, for example, one could cut Alzheimer’s risk by more than half and save the health care system billions. Just one additional serving of fruits or vegetables per day could reduce spending on medical treatments in the US by five billion annually.
The benefits of a plant-based diet presumably arise from the two facts that you eat more substances with protective effects (such as fiber) and fewer pathogenic (disease-causing) substances such as saturated fatty acids. As part of the Baltimore Longitudinal Study of Aging, participants who were an average of about 60 years old at the beginning were followed for 18 years. During that time, the researchers observed an association between consuming more fruits and vegetables, and fewer saturated fatty acids, with a lower likelihood of cardiac death, but only the combination of more fruits and less saturated fat significantly lowered overall mortality risk. This way of eating corresponds to what our evolution has built into us.