Researchers have compared eight dietary patterns to determine which are associated with the most years of life without chronic disease. A researcher behind the study says that a healthy diet minimising ultraprocessed food is generally associated with a long life free of chronic disease.
How does diet affect a person’s chances of living disease-free well into old age and being both physically and cognitively healthy?
Researchers have examined this in a new study comparing eight diets and their association with the likelihood of being healthy at 70 years of age.
Overall, the research shows that many diets are associated with a long, healthy life and that a common feature is that ultraprocessed foods increase the risk of disease, whereas eating fruit, vegetables and nuts is associated with health.
“Diet is often considered in the context of disease, such as whether a specific diet is associated with a lower risk of developing diabetes. We turned this around and instead examined how dietary patterns affect the likelihood of growing old without getting sick,” explains a researcher behind the study, Marta Guasch-Ferré, Associate Professor, Section of Epidemiology, Department of Public Health, University of Copenhagen, Denmark.
The research has been published in Nature Medicine.
Investigated eight dietary patterns and ultraprocessed food
The researchers aimed to determine how eight dietary patterns affect the probability of not having chronic disease, such as cardiovascular disease, metabolic disorders or cancer at the age of 70 years, and affect the probability of being physically able to climb stairs or function well cognitively.
The dietary patterns studied were the Alternative Healthy Eating Index (AHEI), Alternative Mediterranean Index (aMED), the Dietary Approaches to Stop Hypertension (DASH), the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), the healthful plant-based diet (hPDI), the Planetary Health Diet Index (PHDI), the empirically inflammatory dietary pattern (EDIP), the empirical dietary index for hyperinsulinemia (EDIH) and ultraprocessed food (UPF).
The various dietary patterns were developed with the aim of lowering blood pressure (DASH), counteracting cognitive decline (MIND), eating healthily in relation to the Earth’s resources (PHDI) and reducing inflammation (EDIP).
“These diets also consider people’s different dietary needs. For example, some people can tolerate being vegetarian, whereas others cannot. However, all the diets except ultraprocessed food are considered healthy,” says Marta Guasch-Ferré.
More than 100,000 people studied
The researchers examined the relationship between diet and health in data from two large population studies in the United States with 105,515 people followed over 30 years.
Every four years, the participants answered questionnaires, including questions on diet and health.
The researchers thus categorised the participants based on their dietary patterns and how healthily they aged.
Women comprised 66% of the participants, who averaged 53 years when the study started in 1986.
The researchers defined healthy ageing as being free of chronic disease until the age of 70 years.
“We did not instruct people what to eat. They eat whatever they want, and we categorised their diet based on this,” explains Marta Guasch-Ferré.
One diet doubles the likelihood of healthy ageing
The results revealed that 9,771 participants experienced healthy ageing at the age of 70 years, meaning free of chronic disease and functioning well cognitively and physically.
All the investigated diets except ultraprocessed food were associated with an increased likelihood of healthy ageing compared with not following one of these diets.
For example, the Alternative Healthy Eating Index was associated with an 86% increased likelihood of healthy ageing. This diet also had the strongest association with functioning well physically and cognitively at 70 years.
The likelihood of healthy ageing at 75 years was doubled for those who followed the Alternative Healthy Eating Index dietary pattern.
Those who had eaten the healthful plant-based diet experienced the lowest increased likelihood of healthy ageing – 45% – although this was still healthier than the diets not investigated.
The greater the participants adhered to a healthy diet over three decades, the greater the probability of healthy ageing.
Foods that promote healthy ageing
The eight healthy diets investigated include substantial fruit, vegetables, whole grains, unsaturated fat, nuts, legumes and low-fat dairy products, which is probably why they all increase the likelihood of healthy ageing.
Conversely, a high intake of trans-fat, salt, sweetened beverages and red and processed meat was associated with a higher likelihood of chronic disease at 70 years.
“The results are not surprising, but they show that eating foods proven to be healthy increases the likelihood of healthy ageing. Another message is that there are many ways to combine foods to create a dietary pattern that matches each person’s needs. For example, for many years the Mediterranean diet has been considered healthy, but trying to eat a Mediterranean diet may not be appropriate in Denmark. Combining healthy foods in another diet may make more sense to obtain health benefits,” says Marta Guasch-Ferré.
Living more healthily
Marta Guasch-Ferré says that the researchers are sending a message with the study that may resonate with more people.
The focus is not what to eat to avoid cancer or cardiovascular disease but how to eat to be healthy and fit and be able to function well both cognitively and physically into old age.
“The aim is to discover and disseminate knowledge about how to live longer and how to live better,” concludes Marta Guasch-Ferré.
