WE’VE BEEN TOLD SINCE WE WERE KIDS TO EAT OUR FRUITS AND VEGETABLES, which provide the essential vitamins and nutrients that support strong bodies and brains. New research suggests we should never stop spooning peas and carrots onto our plates. A diet rich in plant-based foods may help slow the biological aging process and promote healthy aging, according to research from Nicola McKeown, a nutrition research professor who studies dietary patterns and their impact on health, wellness, and longevity. In collaboration with her colleague and senior author Jiantao Ma at the Tufts Friedman School of Nutrition Science and Policy, McKeown examined data from participants in the Framingham Heart Study, the longest-running heart disease study in the country and a joint project of BU and the National Heart, Lung, and Blood Institute. McKeown and Ma coauthored a study published in The American Journal of Clinical Nutrition, finding that poorer diet quality was linked to age acceleration.
THE POWER OF GOOD FOOD
What they observed is that people who followed a DASH diet—which has more vegetables, fruits, nuts, legumes, whole grains, and low-fat dairy, and less sodium, red and processed meats, and sugary drinks—experienced slower age acceleration.
These results were not surprising to McKeown, who has spent two decades studying the impact of carbohydrate quality and foods, including whole grains and sugary drinks, on risk factors for heart disease and type 2 diabetes. “When people talk about pursuing low-carb diets, I automatically jump in and say, ‘But hold on, not all carbohydrates are created equally,’” says McKeown. “Whole grains are incredibly beneficial to health, but the same can’t be said for sweet, refined grain foods or sugar-sweetened drinks.”
McKeown’s previous research showed that a diet rich in whole grains led to smaller gains in waistlines and less belly fat, a particularly dangerous type of fat surrounding vital organs. Individuals who consumed three or more servings of whole grains daily also had lower increases in blood pressure and blood sugar levels compared to those who ate less than half a serving. Conversely, her research has found that these health benefits are not observed among those who eat more refined grains.
“I recommend people try to increase their intake of whole grains by replacing some refined grains with wholegrain alternatives, such as switching from sugary ready-to-eat breakfast cereals to oatmeal or switching from white rice to quinoa or brown rice,” McKeown says. “Over time, these small shifts may improve risk factors linked to heart disease.”
WHAT NOT TO EAT
For those looking for a specific diet to support healthy aging, good options are the Mediterranean and DASH diets as well as the MyPlate plan, which all emphasize plants and minimize highly processed foods laden with added sugars, salt, or saturated fats. “These diets are similar in that they contain more plant foods and less red and processed meats than the typical Western diet,” says McKeown.
The Western diet is clearly detrimental to our health, explains McKeown. This low-quality diet pattern is high in refined grains, processed food and meat, sugary beverages, candy, and sweet desserts, not to mention lacks healthful plant foods.
Unfortunately, added sugar—ubiquitous in our food supply—is a carbohydrate almost everyone is overeating. The Dietary Guidelines for Americans (DGA) recommends limiting added sugars to less than 10 percent of daily calories, but, on average, upwards of 15 percent of our daily caloric intake is derived from added sugar in the diet. Sugary beverages are among the biggest problems. McKeown found that people who drink more sugar-sweetened beverages are at greater risk of developing nonalcoholic fatty liver disease, prediabetes, dyslipidemia, and more of that unhealthy belly fat. There is overwhelming evidence linking the Western diet to the rising prevalence of obesity. According to the US Department of Health and Human Services, one in three adults in the US is overweight, and older adults with a higher body mass index are at greater risk for age-related conditions such as cognitive decline, osteoarthritis, macular degeneration, heart disease, and diabetes.
ADAPT AS YOU AGE
As we grow older, our calorie needs decline. This means that to maintain a healthy weight or lose weight, we should be consuming fewer calories as we age. Your diet doesn’t need to be restrictive, McKeown says. For example, Mediterranean and vegetarian diets are both healthy and in line with DGA, and aging adults may choose the one that better aligns with their preferences. After all, says McKeown, “a healthy diet can be personalized to align with what you enjoy to eat, so you don’t need to limit yourself.”