A team of scientists who followed more than 2 400 people for 15 years may have uncovered the secret to healthy ageing, reports The Independent – and it doesn’t come in the form of a pill.
Imagine two people in their 70s. Both are active, live independently and enjoy life. But over the next 15 years, one develops two or three chronic illnesses – heart disease, diabetes, depression – while the other remains relatively healthy. What made the difference?
According to the study by the Ageing Research Centre at the Karolinska Institutet, Sweden, diet may be a key part of the answer.
The group found that of the 2 400 people they followed, those who consistently ate a healthy diet developed chronic diseases more slowly, in contrast to those whose diets were considered more inflammatory; that is, diets high in processed meats, refined grains and sugary drinks, which are known to promote low-grade chronic inflammation in the body.
This is important because having several health conditions at the same time is one of the biggest problems faced by older people. It increases the risk of disability, hospitalisation and early death. It also places a huge burden on healthcare systems.
But while it has been long known that diet can help prevent individual diseases, this study, published in Nature Ageing, also shows that it may influence the overall pace of biological ageing.
The team looked at four well-known dietary patterns. Three of them – the Mind diet (designed to protect brain health), the Alternative Healthy Eating Index (based on foods linked to lower disease risk) and the Mediterranean diet – were associated with slower disease accumulation.
The fourth, a diet high in inflammatory foods, was linked to faster accumulation.
The strongest associations were seen for cardiovascular and psychiatric conditions. So, people who ate better were less likely to develop diseases including heart failure, stroke, depression or dementia.
The study did not, however, find a clear link between diet and musculoskeletal diseases such as arthritis or osteoporosis.
Some of the benefits of healthy eating were more pronounced in women and in the oldest participants: those aged 78 and above. This suggests that it is never too late to make changes. Even in very old age, diet matters.
Why does food have such a strong potential? One reason may be inflammation. As people age, many develop low-grade chronic inflammation – sometimes called “inflammaging” – which is linked to a wide range of diseases.
Diets high in vegetables, fruits, whole grains, and healthy fats tend to reduce inflammation. Diets rich in highly processed foods and sugar do the opposite.
Another reason is that healthy diets support the body’s resilience. They provide essential nutrients that help maintain immune function, muscle mass and cognitive health. Over time, this can make a big difference in how people age.
This was one of the longest and most comprehensive studies of its kind, with the researchers using repeated dietary assessments and tracking more than 60 chronic health conditions. They also tested their findings using different analytical methods to make sure they held up.
Of course, diet is just one piece of the puzzle, they said. Physical activity, social connections and access to healthcare all play important roles in healthy ageing. But improving diet quality is a relatively simple and accessible way to help older adults live longer, healthier lives.
So what should older adults eat? The message is clear: plenty of vegetables, fruits, legumes, nuts and whole grains. And healthy fats like rapeseed oil and fish. They said red and processed meats, sugary drinks and solid fats should be avoided.
These are the building blocks of the diets they studied – and they have been associated with slower ageing, better brain health and fewer chronic diseases in this and other research.
Ageing is inevitable. But people can shape how it unfolds. The findings suggest that even small changes in diet can make a meaningful difference in how people experience later life, regardless of their age.
Study details
Dietary patterns and accelerated multimorbidity in older adults
David Abbad-Gomez, Adrián Carballo-Casla, Giorgi Beridze, Esther Lopez-Garcia, Fernando Rodríguez-Artalejo, Maria Sala, Mercè Comas, Davide Liborio Vetrano, Amaia Calderón-Larrañaga.
Published in Nature Ageing on 28 July 2025
Abstract
Diet could influence disease development and shape multimorbidity trajectories. Here we examined how four dietary patterns relate to 15-year multimorbidity accumulation in 2,473 community-dwelling older adults from the Swedish SNAC-K cohort. Multimorbidity was operationalized as the total number of chronic conditions and grouped into three organ systems. Higher adherence to the Mediterranean-DASH Diet Intervention for Neurodegenerative Delay, the Alternative Healthy Eating Index and the Alternative Mediterranean Diet was inversely associated with the annual rate of total chronic disease accumulation (β coefficient (95% confidence interval) per 1-s.d. increment: −0.049 (−0.065 to −0.032), −0.051 (−0.068 to −0.035) and −0.031 (−0.048 to −0.014), respectively), whereas higher adherence to the Empirical Dietary Inflammatory Index was associated with a faster rate of accumulation (0.053 (0.035–0.071)). Similar associations were observed for cardiovascular and neuropsychiatric diseases but not for musculoskeletal diseases. Some associations varied by sex and age. Our findings support diet quality as a modifiable risk factor for multimorbidity progression in older adults, with possible implications for dietary guidelines, public health strategies and clinical practice.
See more from MedicalBrief archives:
The Longevity Diet: How nutrition affects ageing and healthy lifespan – US analysis
Mediterranean diet promotes healthy cellular ageing in women