There's a new reason to load up on plant-based foods and eat fewer highly processed foods. Research has long shown that a diet like that is linked to a lower risk of hypertension, stroke and diabetes, but a new study in Nature Medicine shows it’s good for healthy aging too.
“What makes this study stand out is it’s among the first to take a comprehensive look of how adapting an overall healthy eating pattern influences your health as you age, rather than how one specific dietary pattern factors into your longevity or risk of developing certain diseases,” says Frank B. Hu, M.D., Ph.D., professor and chair of the department of nutrition at the Harvard T.H. Chan School of Public Health, and one of the study’s co-authors.
What might be most interesting to the average person, though, is this study showed a healthful diet can help you live longer, even if you’re not physically at your best. “This is a very important finding because it means that regardless of your body weight, your smoking status and how much you exercise, a healthy diet can have independent benefits for healthy aging,” says Dr. Hu.
What the study found
To assess how eating patterns influence healthy aging, the Harvard team looked at the diets and health outcomes of more than 105,000 men and women, ages 39 to 69, over the course of 30 years. Every four years, the subjects filled out questionnaires about their adherence to any one of eight healthy dietary patterns including a plant-based diet, the DASH (Dietary Approaches to Stop Hypertension) and the MIND diet (a combo of the Mediterranean and DASH diets). The questionnaires also asked the participants about their exercise, sleep and smoking habits, along with questions to assess their cognitive function and mental health.
The data showed that 9.3% of the people in the study aged healthfully by the time they reached the age of 70. The researchers defined aging healthfully as someone as being free of any major chronic disease and having kept their physical, mental and cognitive health intact at 70 years old. After examining the data, they found the better adherence to a balanced and nutritious diet while in midlife, the greater the odds a person will stay disease free and maintain their overall physical, mental and cognitive abilities when they're older.
In particular, those who followed the Alternative Healthy Eating Index (AHEI) diet — one high in plant-based foods, whole grains and some healthy proteins — had an 86% greater chance of being healthy at age 70, and a more than two times greater odds of achieving healthy aging at 75, compared to people who ate less of these foods. Meanwhile, people who followed the Planetary Health Diet Index (PHDI), which emphasizes eating a plant-based diet and limiting animal-based foods, also fared especially well. Not surprisingly, diets high in ultra-processed foods and sugary beverages were linked to decreased chances of healthy aging.
What foods are in the AHEI and PHDI eating plans?
The AHEI diet emphasizes a high intake of fruits, vegetables, whole grains, nuts, legumes and unsaturated fats; a moderate consumption of healthy animal-based proteins such as lean skinless chicken, turkey, fish high in omega-3 fatty acids (salmon, sea bass, trout); and a low intake of red and processed meat like bacon or pre-packaged cold cuts.
“We’re not talking about an extreme, rigid diet here,” says Dr. Hu, who explains the AHEI eating pattern also follows the Healthy Eating Plate guidelines. “On your plate, you should have one-quarter of some type of whole grain food (quinoa, oats, brown rice), one-quarter of a healthy protein (fish, poultry, beans) and one-half taken up by fruits and vegetables.” Coffee, tea and water are okay to drink, but you should skip sugary drinks, limit dairy products to one to two servings daily, stick to no more than one serving of juice a day.
“Ideally, you'd follow this type of model at every meal, but it doesn't always have to be a 'plate' format,” says Ginger Hultin, D.C.N., R.D.N., C.S.O., a Seattle-based registered dietitian nutritionist, owner of Ginger Hultin Nutrition and author of Anti-Inflammatory Diet Meal Prep. “For example, for breakfast, if you had a whole grain tortilla, add some eggs or tofu for protein and mushrooms, spinach and bell peppers, that would be pretty close! Add a side of a tangerine, some grapes or half of a banana, and you've got the plate model.”
When it comes to the PHDI diet, there’s not a whole lot of difference from the AHEI eating pattern. It follows the same guidelines as the AHEI, but is less inclusive of animal-based products, especially red meat. Instead, the PHDI is more centered on eating whole plant-based foods that come from the earth, which is good for you and for the planet.
Why are these eating plans so good for aging?
“Both of these diets have similarities which are they're based on fresh, whole foods that are high in fiber and phytonutrients (natural, beneficial compounds found in plant-based foods), and are low in saturated fat and added sugar,” says Hultin. “When that happens, you often get better blood pressure, cholesterol levels, lower systemic/chronic inflammation levels and blood sugar control.”
Of course, keeping your blood pressure, cholesterol and glucose levels in check, and steering clear of any foods associated with inflammation such as ultra-processed ones, is going to give you a leg up later on. For instance, increased inflammation in the body can put you at risk for a myriad of chronic diseases, including rheumatoid arthritis, Parkinson’s disease, Crohn’s disease and even depression, all of which can negatively impact your overall well-being as you age.
“I think this study underscores the importance of eating a healthy diet, particularly one containing a lot of plant-based foods, can have long-term benefits,” says Dr. Hu. “It’s not just for living longer, but for enjoying a better quality of life.”
The bottom line
Following certain eating patterns could extend the number of years that you live disease-free and with good cognition, but you don't have to strictly follow one diet to reap the benefits. “You can mix and match and include the types of nutritious foods you like,” says Dr. Hu. “There’s no one-size-fits-all diet when it comes to successful longevity.” For instance, if an all plant-based diet feels too restrictive, and you enjoy a moderate amount of healthy animal-based proteins, go for it. Just keep in mind that although the study found a healthy diet seems to trump other factors, it doesn’t mean you should throw other healthy habits like exercise out the window, Dr. Hu adds.
