Eating Our Way to a Better Old Age

With health span, the years we spend in good health, offering personal and societal payoffs like greater independence, productivity, and lower healthcare costs, understanding the role of diet is more than a lifestyle issue. However, before diving into the study’s buzzworthy findings, it’s worth unpacking how the researchers defined healthy aging, who made it into the study, and how dietary data were collected, key methodological choices that shape what we can (and can’t) take from the results. 

Methodology

The study looked at people who were part of two large, long-term research projects—the Nurses’ Health Study and the Health Professionals Follow-Up Study, tracking health habits over decades. Both groups completed detailed questionnaires about their lifestyle and medical history every two years. Researchers focused on participants who had completed dietary questionnaires in 1986 and were old enough to potentially reach age 70 during the study period. They excluded anyone who already had one of eleven serious chronic illnesses based on prevalence in our population or severe debility. [1]  Through these choices, their sample contained more women and health professionals than represented an aging population in the US. 

To age “healthily,” a participant had to reach age 70 without being diagnosed with any of those eleven chronic illnesses and remaining mentally sharp, physically capable, and emotionally well. The presence of a chronic disease was self-reported and then verified by medical records. No effort was made to detect chronic illness without self-reporting, introducing potential under-reporting.

The researchers used each study's detailed food questionnaires, where participants reported every 4 years how often they ate each of 130 items over the past year. The reliability of these types of data collection for food is a well-known limitation of any real-world observational study. Based on that information, researchers generated eight different dietary pattern scores, each reflecting a specific eating style, like the Mediterranean or DASH diet. [2] These scores helped them see how different eating habits might relate to healthy aging. 

A bit of word choice is involved in describing the “adherence” to a given diet. Adherence refers to how closely someone follows a recommended plan or set of guidelines, and we have no evidence that the participants adhered to one set of dietary guidance for over 30 years. There is evidence from other longitudinal studies that dietary quality does improve with age, although socioeconomic factors may mitigate that effect. In any event, the researchers report characterizations of dietary patterns unmoored from specific participants over time, introducing uncertainty when applying their findings to individuals. 

However, study design isn’t just about questionnaires and data points; it’s about who gets included and their lives beyond the dinner plate. That’s where socioeconomic status enters the picture.

Beyond the Plate: Who Gets to Eat Well?

It’s tempting to think of diet as a matter of personal choice—eat more broccoli, age more gracefully. But healthy eating doesn’t happen in a vacuum. The study’s participants were predominantly nurses and health professionals, a more educated and health-literate population than the general public. These people are already better positioned to make “good choices.”

And even within that relatively privileged group, the data show a clear trend. Those with higher socioeconomic status (SES) were more likely to adhere to healthy dietary patterns, be physically active, take multivitamins, have lower BMIs, and report fewer mental health issues like depression. In other words, the folks eating their kale also had more time, money, and social stability to shop for, prepare, and benefit from it.

With those structural realities in mind, let’s look at what the study found—and how dietary patterns appeared to shape the path to age 70 and beyond.

Results 

Across these decades-long studies, out of 105,000 participants, roughly two-thirds women, 38% made it to 70 years, 23% avoided 11 chronic diseases, and around one-third kept their cognitive and physical abilities. Slightly over a quarter maintained good mental health. 9.3% achieved healthy aging – age 70 with no chronic illnesses. 

The eight healthful diets were all linked with better chances of being in that top 9.3%, the healthy agers. They concluded that the AHEI (Alternative Healthy Eating Index) diet conferred the greatest benefit. Looking at the absolute‐risk estimates from lowest (Q1) to highest (Q5) adherence, DASH shows the largest rise in the proportion of participants achieving healthy aging—indicating it has the greatest absolute impact among the listed diets. By contrast, the MIND diet, a combination of the Mediterranean and Dash diets, had the smallest difference between  Q1 and Q5. Joining MIND was EDIP (Empirical Dietary Inflammatory Pattern), not a diet as much as a score of biomarkers promoting inflammation. 

As you should expect, the graph shows that 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 were not.

Healthy eating patterns help preserve cognitive and physical function and mental health. As we have come to expect, higher intakes of fruits, vegetables, whole grains, nuts, legumes, and low-fat dairy consistently improved the odds of aging well, whereas more trans fats, sodium, red, and processed meats lowered those odds. In general, these diets were more protective for women, people who smoked, those with higher BMIs, or those less active. Eating a lot of ultra-processed foods (UPFs) cut the odds of aging healthily by about one-third.

“Our findings provide evidence to support that adherence to healthy dietary patterns represents a potential strategy for healthy aging … Greater long-term adherence to a healthy diet during mid-life was associated with greater odds of healthy aging and of its individual domains in US adults. Among the eight dietary patterns examined in this study, a diet that was developed to predict chronic disease risk as measured by the AHEI may confer the highest benefit for healthy aging in both men and women.”

While the data paints an encouraging picture of diet and health span, a closer look reveals some inconvenient truths—and the limitations of food as a standalone solution.

The Nutritional Narrative—And What It Leaves Out

The single most significant driver in the development of chronic illness is aging, which, despite the wishes of the tech-bros, is not preventable. That golden group, those who reached age 70 without chronic illness, shrunk by 45% by age 75. The study's strength came from consideration of dietary patterns rather than single ingredients – recognizing that our diet is more than its constituent parts. Its weakness lies in the inability to disentangle the interactions of diet with all the moving parts of our lives.

What the researchers included in their tables but did not discuss was that even those least adherent to a dietary pattern made it to 70 without chronic illness. For example, in the AHEI dietary grouping, essentially non-adherence with the diet accounted for 5.6% of the healthy 70s, and best adherence, 13.7%. While diet patterns play a role, a healthy lifestyle is more than just our diet. 

Lost in the tables and given little attention in the narrative was that a healthful life requires knowledge and economic and sociological space to purchase nutritious foods, exercise, and manage our weight. If you look at the socioeconomic scoring, the disparity between those least and most adherent was, with one exception, generally two-fold, 200%.   

Diet remains a modifiable lever to a longer health span, but the degree of that effect remains unclear. The takeaway isn’t that kale will save you or that a burger dooms you—it’s that diet matters, but it’s only one ingredient in a much larger recipe. Healthful aging depends on access to knowledge, time, resources, and a system that supports good choices. Rearranging MyPlate or tightening the rules on SNAP won’t fix a broken food system —especially when too many Americans may be trying to cook a healthy life with a half-stocked pantry and a faulty stove.

[1] The 11 major chronic diseases included “cancer (except for non-melanoma skin cancers), diabetes, myocardial infarction, coronary artery disease, congestive heart failure, stroke, kidney failure, chronic obstructive pulmonary disease, Parkinson disease, multiple sclerosis and amyotrophic lateral sclerosis.” 

[2] The eight “healthy dietary patterns” included “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 ultra-processed food (UPF) consumption.” A UPF diet was based on the NOVA classification

Source: Optimal dietary patterns for healthy aging Nature Medicine DOI: 10.1038/s41591-025-03570-5