This Diet Leads to Healthy Aging

Diets rich in plant-based foods and moderate amounts of animal-based foods may enhance healthy aging, a new longitudinal cohort study revealed.

“I was surprised by the strength of the associations between healthy eating patterns in midlife and healthy aging, even after accounting for other key factors like physical activity, which also impact health,” lead author Anne-Julie Tessier, RD, PhD, of the University of Montreal, Montreal, Quebec, Canada, told Medscape Medical News.

“Interestingly, all the healthy diets we studied were linked not only to overall healthy aging but also to its individual domains, including cognitive, physical, and mental health,” she noted.

“A novel finding was the association between the planetary health diet and healthy aging,” she added. “This diet, which minimizes animal products and emphasizes fruits, vegetables, whole grains, and healthy fats, emerged as one of the leading dietary patterns associated with healthy aging. This is particularly interesting because it suggests that we can eat a diet that benefits both human health and environmental sustainability.”

The study was published online in Nature Medicine.

‘No One-Size-Fits-All Approach’

Researchers used longitudinal questionnaire data from 1986 to 2016 derived from the Nurses’ Health Study and the Health Professionals Follow-Up Study to examine the association of long-term adherence to eight dietary patterns and ultraprocessed food (UPF) consumption with healthy aging.

Researchers defined healthy aging as surviving to age 70 years without the presence of 11 major chronic diseases and with no impairment in cognitive function, physical function, or mental health.

The eight included diets were: The Alternative Healthy Eating Index (AHEI), Alternative Mediterranean Diet (aMED) index, Dietary Approaches to Stop Hypertension (DASH), Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), healthful plant-based diet (PDI), Planetary Health Diet Index (PHDI), the empirical inflammatory dietary pattern , and the empirical dietary index for hyperinsulinemia. 

The researchers examined overall associations in addition to associations in specific subgroups, stratified by sex, ancestry, socioeconomic status (SES), and lifestyle factors. Associations of individual foods and nutrients contributing to these dietary patterns were also examined.

After up to 30 years of follow-up, 9771 (9.3%) of 105,015 participants (mean age, 53 years; 66% women) achieved healthy aging. For each dietary pattern, higher adherence was associated with greater odds of healthy aging and its domains.

In the pooled cohorts, 37.9% reached the age of 70 years; 22.8% remained free of 11 chronic diseases; 33.9% maintained intact cognitive function; 28.1% maintained intact physical function; and 26.5% maintained intact mental health.

Compared with those in the lowest energy-adjusted dietary pattern score quintile, participants in the highest quintile were more likely to have a higher SES, take multivitamins, and have a higher level of physical activity and a slightly lower body mass index. They were also less likely to have a history of depression.

When the age threshold for healthy aging was shifted to 75 years, the AHEI diet showed the strongest association with healthy aging, with an odds ratio of 2.24.

In analyses of specific foods, higher intakes of fruits, vegetables, whole grains, unsaturated fats, nuts, legumes, and low-fat dairy products were linked to greater odds of healthy aging. In contrast, higher intakes of trans fats, sodium, sugary beverages, and red or processed meats (or both) showed inverse associations with healthy aging.

In addition, when comparing the highest with the lowest quintile, higher UPF consumption was associated with 32% lower odds of healthy aging, as well as lower odds of reaching the age of 70 years and maintaining intact cognitive function, physical function, and mental health, and living free of chronic diseases.

Each pattern emphasizes specific components, the authors noted. For instance, while the aMED diet focuses on olive oil, fish, and nuts, MIND further highlights the cognitive benefits of berries. The DASH diet prioritizes sodium restriction for blood pressure control, while the PHDI emphasizes healthy, low greenhouse gas emission foods, such as plant-sourced protein. The healthful PDI uniquely attributes positive scoring to healthy plant-based foods and negative scoring to animal-derived foods.

Higher adherence to all dietary patterns was associated with greater odds of healthy aging.

“There is no one-size-fits-all approach to diet for promoting healthy aging,” Tessier said. “It’s important for clinicians to recommend diets rich in nutrient-dense foods like vegetables, fruits, whole grains, and healthy fats while also taking into account patients’ personal preferences, cultural backgrounds, and individual needs. As we age, our protein needs increase. Including some healthy animal-based foods, such as fish or yogurt, or ensuring the substitution with high-quality plant proteins like legumes, can be beneficial for maintaining physical function and overall health.”

“The healthy diets we examined share common principles, such as being rich in vegetables, fruits, whole grains, and healthy fats,” she added. “My own diet most likely aligns with the Planetary Health Diet but also with the Mediterranean Diet, with fruits and vegetables making up most of my plate, whole grains, legumes, small amounts of healthy animal protein, and olive oil as a culinary fat.”

Best Diet Promotes Adherence

Peminda Cabandugama, MD, a specialist in endocrinology, diabetes and metabolism, and obesity medicine at Cleveland Clinic, Cleveland, commented on the study for Medscape Medical News. The large number of participants, duration of follow-up, and statistical significance of the findings “all lend eye-opening insights into how different diets can affect aging in different ways,” he said. “Strong work like this will hopefully lead to more studies that will lead to more tailored diets for different components that affect the quality of life as our population ages and lives longer.”

That said, he has concerns about the generalizability of the results, given that there were twice as many women as men in the study; much of the population had a higher SES; and the researchers analyzed self-report questionnaires, which tend to be subject to bias.

“It would be nice to see the breakdown of these studies in a more objective way — eg, looking at which diets would help to retain muscle, using objective measurements such as body composition, and how that impacts quality of life as we age,” he noted.

Nevertheless, “the overriding theme of this study, along with all the other large-scale literature that is out there, is that the best diet is the diet that works for that individual, as it promotes adherence,” he affirmed. “Adherence is the most important thing when it comes to any current diet, and this needs to be coupled with physical exercise to maintain the best possible quality of life as we age.”

The Nurses’ Health Study and the Health Professionals Follow-Up Study were supported by grants from the US National Institutes of Health. Tessier was supported by a Canadian Institutes of Health Research Postdoctoral Fellowship Award. Tessier and Cabandugama declared no competing interests.

Marilynn Larkin, MA, is an award-winning medical writer and editor whose work has appeared in numerous publications, including Medscape Medical News and its sister publication MDedge, The Lancet (where she was a contributing editor), and Reuters Health.