In April, researchers at Tufts University posed a nutrition riddle. They compared people who took vitamin pills with people who got the same nutrients the old-fashioned way, by eating food.
Tracking intake of vitamins A and K, magnesium, and zinc, the scientists found that people were less likely to die of heart attacks and other diseases when these nutrients occurred in their diets. As the Tufts researcher Fang Fang Zhang said at the time, “There are beneficial associations with nutrients from foods that aren’t seen with supplements.”
Many vitamin supplements are synthesized to be exact replicas of the compounds you’d get from eating an apple or an orange. The chemistry should have the same effects on the body. Unless, of course, something was missing from the equation.
In a similar puzzle, recent studies have illuminated harms associated with highly processed foods—even though many of these foods are packed with added vitamins. White pastas and breakfast cereals, for example, may contain an entire day’s worth of some vitamins (synthesized and added, sometimes by law). As long as we’re getting the nutrients, why should it matter whether food is “processed”? Is processing simply bad?
One explanation for the benefits of eating minimally processed foods is probably fiber, which processing often strips away. Fiber slows the absorption of sugars, so they don’t hit our blood as quickly and cause insulin to spike (as with eating an apple versus drinking apple juice). Fiber also feeds our microbes. People with low-fiber diets have less diverse gut microbes—the trillions of microorganisms that populate our bowels and are vital to our digestion, metabolic health, and the functioning of our immune systems. The best known indicator of a healthy biome is diversity.