You’ve already heard that fruits, vegetables, nuts and beans are good for you. But apparently you can also add bread, pasta and mashed potatoes — along with some baked goods and even pizza — to that list.
So says a new medical study led by researchers at Tufts University that is due to be published this week in the American Journal of Clinical Nutrition. The study is based on an analysis of 48,000 women over 32 years.
Those whose diets included a lot of plant-based proteins were 46% more likely to stay healthy in their later years than those who didn’t, the researchers found. That meant they were more likely to avoid such conditions as heart disease, cancer and diabetes, as well as declines in cognitive and mental health.
The same was not true of those who ate a lot of animal-based proteins, such as meat, fish and cheese.
The major sources of plant-based protein named in the study included bread, vegetables, fruits, mashed potatoes, nuts, beans, peanut butter, pasta and even pizza, cereal, and baked items.
“Consuming protein in midlife was linked to promoting good health in older adulthood,” Andres Ardisson Korat, the lead author of the study and a researcher at the Jean Mayer USDA Human Nutrition Research Center on Aging, said in a statement. “We also found that the source of protein matters. Getting the majority of your protein from plant sources at midlife, plus a small amount of animal protein, seems to be conducive to good health and good survival to older ages.”
But … pizza? Baked goods? When reached by phone, Ardisson Korat said that the findings should not be misinterpreted. Bread, pizza and baked goods appear on the list because they are major parts of the U.S. diet and because they contain gluten, a plant-based protein. “It doesn’t mean that everything on [the list] is healthy, but [those items] ended up aggregated in the group of plant-based proteins,” he said.
In other words, it’s not so much that eating lots of pizza is necessarily good for you, but that if you do have pizza, as so many of us do, the plant-based proteins it contains are good for you.
The research was based on the Nurses’ Health Study, a long-running observational study of female healthcare professionals. Researchers studied a cohort of women from 1984 to 2016. Subjects ranged in age from 38 to 59 at the start of the study and were between 70 and 91, if they were still alive, at the end.
Researchers looked at those who stayed healthy and those who didn’t, and then compared their diets. Participants in the study had completed surveys every four years detailing their food consumption.
The study has some clear limitations: It is observational and is based on self-reported nutrition data. And the overwhelming majority of the study’s subjects were white women, raising questions about whether the findings can be applied to people of other ethnic backgrounds or to men.
The findings are also relative. You may be better off eating bread and even pizza than, say, bacon double cheeseburgers — but that doesn’t mean you are better off eating bread and pizza than you are eating beans, salads and fruit.
It also doesn’t mean you are better off eating more of these foods than you would be simply eating less overall. Other studies have found that calorie restriction — not eating too much — is probably good for you, including one from the National Institutes of Health and one from Columbia University.
Science, naturally, is a continuing process of inquiry and testing. Another study recently argued that vegans, vegetarians and pescatarians fared much better with COVID than did omnivores, but this has already received a sharp rebuttal.
But the latest findings are happy news for those of us who like thin-crust pizzas with a whole-grain base, small amounts of cheese and lots of fresh ingredients. They aren’t as good for those who crave a giant deep-dish pizza covered processed meats. Common sense, as usual, remains useful. While a slice of pizza may be better for you than a cheeseburger, a healthy salad is probably better still.