Lifestyle

In our modern, germ-free world, you can reliably find vitamin B12 only in dietary supplements, animal products, and fortified foods. Vegans and vegetarians should take a preparation with at least 50 micrograms of cyanocobalamin (that is, the most stable form) daily, or at least 2000 micrograms once weekly, and so should everyone between 50 and 65, regardless of how they eat (because as we age, we lose the ability to absorb vitamin B12 from food). After that, the recommended amounts change.

Beyond 65, a single daily dose of 50 micrograms—or even 100 micrograms—may no longer be enough. Researchers have tried to determine the appropriate dose for this life stage, and it appears most people need at least 650 to 1030 micrograms a day; therefore, I recommend that everyone 65 and older take a daily dose of 1000 micrograms of cyanocobalamin, ideally as a chewable tablet, sublingually, or in liquid form. It helps absorption if the B12 mixes with saliva because our salivary glands secrete a B12-binding protein that helps transport the vitamin safely through the digestive tract. If we chew a vitamin B12 tablet, our levels can rise ten times more than if we had swallowed the same amount of B12.

Vitamin B12 deficiency is a serious matter and can cause a wide range of disorders in the blood, the intestines, the brain, and the nervous system. With ever-increasing demands for cleanliness in our food supply, it is especially important that we secure a regular and reliable vitamin B12 source, and dietary supplements are probably the easiest, safest, and cheapest.

What about vitamin K2?

For a deeper dive, see see.nf/vitamink, but in summary, the suspected benefits for bones, the heart, and the brain have not been confirmed (also because some of the large studies had worked with fabricated data, which has since been admitted). Even if such a benefit should still emerge, we can get all the vitamin K we need from the vitamin K1 in greens, because we don’t need the vitamin K2 in certain animal products and fermented foods. And even if findings about a truly unique benefit of K2 were suddenly to appear, it would still be the case that our microbiome makes K2 from the K1 in vegetables, and we then absorb that into our body. But what about the very specific form of K2 that only mammals make? We are mammals! Therefore, even with problems in the microbiome, our own cells can make vitamin K2 from K1, just as is the case in other animals.

Among all dietary components associated with all-cause mortality, the best available evidence supports leafy greens and salads, whose intake helps us maximize our time on Earth. Therefore, it’s not surprising that lower circulating levels of vitamin K1 in the blood—the marker for inadequate intake of leafy greens—are associated with premature death. Eat. Your. Greens.

Lifestyle

In the 13th century, the famous scholar Roger Bacon recommended good nutrition, adequate rest, exercise, a moderate lifestyle, good hygiene, and—oh, how lovely!—“the breath of a virgin” for a longer life. As for the first few tips, though, he was right!

“Diet” comes from the Ancient Greek diaita, meaning “way of life,” and thus doesn’t refer only to nutrition. In 1903, Thomas Edison predicted that the doctor of the future would give patients “no medicine but will instruct them in the care of the human frame with proper diet and in the cause and prevention of disease.” 101 years later, the American College of Lifestyle Medicine (ACLM) was founded, and I’m proud to be a founding member.

We physicians still prescribe medications when needed, but we’re aware that often the way we live is the underlying cause of what afflicts us, and therefore what we eat matters. Food and cigarettes are the main reasons for disability and death. More broadly, a research summit recently described lifestyle medicine as “a predominantly whole food and plant-based diet, regular physical activity, restorative sleep, stress management, avoidance of risky substances, positive social connection, and emotional wellbeing as the primary therapeutic modalities for the treatment, reversal, and prevention of chronic disease.”

On the basis of 74 studies with millions of participants, those with the healthiest lifestyle had less than half the risk of death as those who, in their reports, had to admit to all sorts of unhealthy habits. On average, these studies spanned more than a decade. We all know fascinating stories of cigar-chewing, gin-guzzling 100-year-olds, but the truth about lifestyle and longevity is more prosaic. If you simply follow four simple rules for a healthy lifestyle, it helps prevent some of our deadliest diseases: don’t smoke, don’t be obese, get a half hour of exercise a day, and eat healthier, which means: less meat and more fruit, vegetables, and grains.

These four factors alone account for 78 percent of our risk of developing chronic disease. If you make a fresh start and manage to follow all four rules, you may thereby eliminate more than 90 percent of diabetes risk and more than 80 percent of heart attack risk, cut your stroke risk in half, and reduce your overall cancer risk by more than a third. Some cancers—for example, colorectal cancer, the second deadliest cancer—would have been preventable in 71 percent of cases through a few minimal changes in diet and lifestyle. Imagine what that means in numbers. Right now, each year one million US citizens have their first heart attack or stroke, one million develop diabetes, and one million get cancer. It’s time to stop blaming genes for everything and to focus on the roughly 80 percent of risk we can directly influence.

What does that mean for mortality? Similar healthy habits predicted a fourfold difference in all-cause mortality, and their effect was estimated to correspond to 14 chronological years of life. In other words: Those who took care of themselves died overall as late as if they were 14 years younger. Imagine you could turn the clock back 14 years—not with a drug or a time machine, but simply by eating and living more healthfully.

And if you’ve already chosen chemistry and are treating your high blood pressure and cholesterol levels with medications? Switching to the essential healthy habits works just as well on mortality whether you take preventive medications or not. Moreover, it’s never too late to turn back the clock. Even if you follow the basics starting in midlife—eat at least five servings of fruits and vegetables daily, walk for about 20 minutes, maintain a healthy weight, don’t smoke—that translates into a considerable reduction in the risk of death, and immediately. We’re talking about about a 40 percent lower risk of death over the next four years. The researchers concluded: “Making the necessary changes and living healthily is very worthwhile, and even in middle age”—in this case 45 to 64 years—“it is not too late to do something.”