Prioritise plant protein, limit ultraprocessed foods, don’t forget the big picture: how to eat for a long and healthy life

If hit podcasts, bestselling books and influencer culture are any indication, millions of people are obsessed with longevity. But just as important as your lifespan is your health span, or the number of years you live in good health.
The length and quality of your life will be determined in part by your genetics, but how you live your life is important, too, including how much you exercise and sleep, whether you drink excessively or smoke – and how you eat, said Susan B Roberts, the senior associate dean for research at the Geisel School of Medicine at Dartmouth, Connecticut.
Eating for longevity isn’t an exact science, of course. It’s unrealistic, and possibly unethical, for researchers to ask people to faithfully follow various diets for decades and then see how their lives turn out, said Dr Frank Hu, a professor of nutrition and epidemiology at the Harvard TH Chan School of Public Health.
But researchers can look for associations between people’s dietary habits and their long-term health, he said.
Here are the best clues we have for how to eat for a long and healthy life.
Research suggests that those who consume more protein tend to live longer and stay stronger and healthier later in life than those who consume less.
But where you get your protein matters. Plant-based sources such as legumes, nuts and whole grains seem to be especially beneficial, whereas protein from red and processed meat has been linked with shorter lives, Dr Lars Fadnes, a professor of global public health at the University of Bergen in Norway.
Protein is key to maintaining strong muscles and bones, which can help older adults stay active and avoid falls and fractures.
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Denise K Houston, a professor of gerontology and geriatric medicine at Wake Forest University School of Medicine, and other experts have recommended that those 65 and older consume at least 0.45 to 0.54 grammes of protein per pound of body weight per day. For a 10-stone adult, this translates to about 68 to 81 grammes of protein.
To help your body better absorb and use protein, try to distribute it across meals throughout the day.
In addition to protein, be sure to get enough calcium and vitamin D to support your bone health as you age, Roberts said.
Dairy milk, as well as fortified plant milks, orange juices and cereals, can be good sources of both nutrients. You can also find calcium in yoghurt, cheese, tofu, beans and leafy green vegetables. Much of your vitamin D can come from exposure to sunlight, but foods including fish, mushrooms and eggs provide additional amounts.
It’s best to get calcium from foods if you can, Houston said. But if you’re falling short on either nutrient, talk to your doctor about whether supplements are right for you.
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Fruits, vegetables, whole grains and other plant foods, such as nuts and legumes, are rich in polyphenols – antioxidant and anti-inflammatory compounds that some research suggests can support healthy ageing.
Coffee, for example, is a big source of polyphenols. Drinking as much as three to five cups per day has been linked with reduced risks for type 2 diabetes, heart disease, some cancers, Parkinson’s disease, cognitive decline and earlier death, Hu said. Green tea may have similar benefits, he added, though the research is less robust.
Researchers have also linked other polyphenol-rich foods such as berries, dark leafy green vegetables, avocados and extra-virgin olive oil to health benefits, including a longer life and improved brain health.
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Diets that are high in unsaturated fats, found in olive oil and most other plant oils, nuts, seeds and avocados, have been linked with lower mortality, Hu and his colleagues have found. Alternatively, diets that are rich in saturated fats, which are found in red and processed meats, seem to have the opposite effect.
Fatty fish such as salmon, tuna, anchovies and sardines are rich in omega-3 fatty acids, which are associated with better brain health and a longer life, Houston said.
Ultraprocessed foods – which include many packaged products such as hot dogs, chicken nuggets, sodas and many baked goods – are increasingly linked with greater risks for health conditions including heart disease, type 2 diabetes, dementia and a shortened lifespan.
In one study published in 2023, researchers found that processed meats and sugar-sweetened beverages such as soda were strongly associated with earlier death – so those categories are important to limit for improved life expectancy, Fadnes said.
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Ultraprocessed foods are often high in “fast carbohydrates”, Hu said, which are quickly digested and can lead to blood sugar spikes. Over time, those spikes may increase the risk for type 2 diabetes and cardiovascular disease, he said. Many ultraprocessed foods are also often high in sodium, which can contribute to high blood pressure, Houston said.
More than any one food, it’s your overall diet that matters, Hu said. He has studied several different eating patterns – including the Mediterranean diet, plant-based diets and diets based on federal guidelines for healthy eating – and has found that all of them are associated with reduced risks of earlier death.
These diets prioritise a variety of unprocessed or minimally processed foods, including plenty of vegetables, whole grains, nuts and legumes, Hu said. Beyond that, he added, there’s a lot of flexibility in how to eat for healthy ageing. “One size does not fit all,” he added.
Hu, for example, has long followed what he calls a traditional Asian diet, regularly consuming tofu, seaweed and green tea. But because he recognises the benefits of the Mediterranean diet, he also uses extra-virgin olive oil. And he enjoys his coffee, too.
– This article originally appeared in The New York Times.