Adopting diets to stave off diabetes in your 40s could be key to physical and mental fitness in your 70s, research suggests.
Eating plenty of vegetables, whole grains and lean meats in middle age was found to help keep chronic illnesses and cognitive decline at bay decades later.
The study involving more than 100,000 people spanning 30 years found those who followed one of eight healthy diet patterns were up to 84 per cent more likely to be functioning well at 70.
Harvard University experts said the links remained strong even when other lifestyle factors were factored in, emphasising that diet should be used to promote ageing well.
While previous studies have shown that healthy lifestyles can help to ward off chronic diseases, here researchers looked at the absence of disease alongside the ability to live independently with a good quality of life.
Eating plenty of vegetables, whole grains and lean meats in middle age was found to help keep chronic illnesses and cognitive decline at bay decades later
They analysed data from more than 106,000 people dating back to 1986, from diet questionnaires taken every four years.
Participants were at least 39 years old and free of chronic diseases at the start of the study.
The researchers compared rates of healthy aging among people in the highest and lowest 20 per cent for adherence to healthy dietary patterns.
By 2016, nearly half had died and only 9.2 per cent survived to age 70 or older, disease-free and good physical, cognitive and mental health.
Those who ate the most fruits, non-starchy vegetables, whole grains, unsaturated fats, nuts, legumes and low-fat dairy were 84 per cent more likely to age well compared to those who ate the least.
Meanwhile, a low-carbohydrate ‘hyperinsulinemia’ diet – named after the condition where the body has too much insulin and often recommended to type 2 diabetics – increased the chances by 78 per cent.
The planetary health diet – usually consisting of half a plate of fruits and vegetables and the other of whole grains, plant proteins such as beans, lentils, pulses, nuts and small amounts of meat and dairy -came next at 68 per cent.
Harvard University experts said the links remained strong even when other lifestyle factors were factored in, emphasising that diet should be used to promote ageing well
This was followed closely by the Mediterranean diet, which typically includes two or three servings of fish a week, while a predominantly plant-based diet carried a 43 per cent increased chance of ageing well.
Those who had higher intakes of trans fat, sodium, total meats, red and processed meats had the lowest chances of healthy ageing, according to the findings presented at the Nutrition conference in Chicago.
Dr Anne-Julie Tessier, lead author, said: ‘People who adhered to healthy dietary patterns in midlife, especially those rich in fruits, vegetables, whole grains and healthy fats, were significantly more likely to achieve healthy aging.
‘This suggests that what you eat in midlife can play a big role in how well you age.’
