What to Eat to Age in Good Health?

Overview

• Healthy aging can be defined as reaching at least the age of 70 without major chronic diseases and without impairment in cognitive function, physical function, or mental health.
• The long-term follow-up of individuals in their 50s has shown that a diet rich in plant-based foods (fruits, vegetables, whole grains, legumes, nuts) and low in animal-based and industrially processed products is strongly associated with a higher likelihood of healthy aging, both physically and mentally.

Life expectancy has increased considerably over the past century, to the point where a child born today in a wealthy society like ours can, on average, expect to live to age 85. However, these additional years are not necessarily spent in good health: for most people, the last 10 to 15 years of life are often marked by the onset of multiple chronic diseases (such as cardiovascular disease, diabetes, cancer, and dementia), which significantly reduce quality of life and diminish the true benefits of a longer lifespan. According to many experts (see here, here, and here, for example), the primary goal should not be merely to extend lifespan, but rather to improve the healthspan—the number of years lived in good health.

A Silent Development
Although chronic diseases usually manifest in old age, they do not appear suddenly. In reality, being diagnosed with a cardiometabolic disease, cancer, or dementia at age 60, 70, or 80 is often the result of a long process that began decades earlier. This means that the “foundation” of these diseases is often laid in midlife—especially in the 40s and 50s (or even earlier)—and that these conditions progress slowly and silently, without noticeable symptoms, toward more advanced stages. Preventing or at least slowing this gradual development is therefore essential to increasing the chances of aging in good health.

The Role of Lifestyle
This is where lifestyle comes in. It has long been known that exposure to toxic substances (tobacco, excessive alcohol), metabolic imbalances (poor diet, obesity, inactivity), and psychological stress (chronic stress, depression) can lead to oxidative stress, chronic inflammation, and insulin resistance—all of which promote chronic disease and reduce quality of life. On the other hand, studies show that a generally healthy lifestyle (no smoking, regular physical activity, plant-rich diet, normal body weight, moderate alcohol consumption) is associated with a 12- to 14-year increase in life expectancy—most of those additional years being lived in good health, free from chronic disease. There is therefore clearly a wide window of time in which it is possible to actively intervene to slow the development of diseases that compromise healthy life expectancy.

Diet as a Cornerstone of Healthy Aging
Among all lifestyle factors, diet likely plays a central role. Poor diet is the leading global risk factor for premature deathfrom non-communicable diseases, responsible for at least 11 million deaths per year—more than tobacco (8 million). Conversely, observational and interventional studies consistently show that a high-quality diet reduces the risk of cardiometabolic diseases and early death.
Overall, research indicates that low intake of plant-based foods (fruits, vegetables, nuts, legumes, whole grains), combined with excessive intake of sodium, red and processed meats, and ultra-processed industrial foods, is most strongly associated with a higher risk of chronic disease and early death. Therefore, increasing consumption of plant-based foods while reducing intake of animal and ultra-processed foods likely represents the most effective strategy to prevent chronic diseases and increase the chances of aging in good health.

Optimal Diets
A large-scale study involving 105,015 healthcare professionals in their 50s, followed for up to 30 years, illustrates the long-term impact of diet on healthy aging.
In the study (led by Dr. Anne-Julie Tessier, now a researcher at the EPIC Centre), participants were considered to have aged in good health if they lived to at least age 70 without any of 11 major chronic diseases (including cancer, diabetes, heart attack, coronary artery disease, heart failure, stroke, kidney failure, COPD, multiple sclerosis, ALS), and without impairment in cognitive, physical, or mental health.
Although a significant number of participants reached some of these benchmarks, fewer than 10% met all the criteria for healthy aging (see Table 1). Among those who lived to at least 70, however, 25% succeeded—and can be considered to have aged in good health.

Aging domains	Number of participants	Percentage of all participants (n=105,015)	Percentage of participants who survived to 70 years old (n=39,769)
Survived to 70 years old	39,769	37.9%
Intact cognitive health	35,555	33.9%
Intact physical health	29,543	28.1%
Intact mental health	27,842	26.5%
Free of chronic diseases	23,908	22.8%
Overall healthy aging	9,771	9.3%	25%

Table 1. Achievement of various healthy aging criteria among study participants in their 50s (average age = 53) (n = 105,015). Note that among individuals who reached age 70, about one quarter can be considered healthy older adults. Source: Tessier et al. (2025).

The analysis of participants’ eating habits throughout the study (from their 50s into older age) identified eight major dietary patterns that were associated with a greater likelihood of meeting the different criteria for healthy aging (Table 2).
To simplify, we chose to focus on five main types of diets that share several common features—particularly a strong emphasis on plant-based foods and a low or zero intake of animal products and added sugars (such as soft drinks).

Although each diet has its own particularities, they all share the common characteristic of emphasizing high intake of plant-based foods and reduced consumption of red meat, processed meats, and sugary drinks.

When comparing healthy aging outcomes between quintile 5 (the 20% with the highest adherence) and quintile 1 (the 20% with the lowest adherence) for each of these diets, a significant increase in the likelihood of meeting all healthy aging criteria was observed in all cases (Figure 1).

These results indicate that a diet rich in plant-based foods (fruits, vegetables, whole grains, nuts, and legumes) and low in meats, processed meats, and foods with added sugars is the combination most likely to promote healthy aging—both physically and mentally.

Notably, the positive effect was especially pronounced among individuals whose diets scored highest on the Alternate Healthy Eating Index (AHEI), which emphasizes higher intakes of polyunsaturated fats (≥10% of total calories) and long-chain omega-3 fatty acids (250 mg/day, or about two servings of fish per week). These participants had an 83% higher chance of aging in good health, and more than double the odds of reaching age 70 in good physical and mental condition (Figure 1).

Specific Foods
The contribution of plant-based foods and unsaturated fats to healthy aging becomes even clearer when looking at the individual impact of foods or food groups on various aging-related parameters (Figure 2). Overall, all foods positively associated with healthy aging were plant-based (shown in green in the figure), with the notable exception of yogurt and low-fat dairy products.

In contrast, the foods consumed more frequently by individuals who did not meet one or more criteria for healthy aging were mostly from animal sources (e.g. various meats) or ultra-processed products (e.g. processed meats, trans fats, sodium, sugary drinks, refined flours, and fast-food items like fries or pizza).Finally, regarding alcoholic beverages, wine was positively associated with healthy aging, while other types of alcohol—particularly spirits—were associated with negative outcomes. This is consistent with other studies showing that moderate wine drinkers have a much lower risk of premature death compared to those who consume other types of alcohol (see our article on the topic)

Ultra-Processed Foods Accelerate Aging

The sharp decrease in healthy aging likelihood among individuals who regularly consume animal-based and ultra-processed foods is concerning, especially since these two food groups dominate the diets of Canadians—two thirds of daily protein comes from animal sources, and about half of daily calories come from ultra-processed industrial foods.

This situation is especially problematic for ultra-processed foods, which are essentially industrial creations, made from multiple ingredients that do not exist in nature and containing a wide variety of additives meant to enhance appearance, taste, texture, and shelf life.

Numerous studies have documented the negative health effects of ultra-processed foods on chronic disease risk and premature mortality (see our article on this topic). It is therefore unsurprising that a similar negative effect is seen on healthy aging (Figure 3).

Compared to those who consume little of these products (Q1), people who eat the most ultra-processed foods (Q5) show a marked reduction in their likelihood of meeting the healthy aging criteria measured in the study. This negative effect is especially striking when compared with the notable increase in healthy aging chances among people who follow plant-rich, minimally processed diets such as the AHEI (Figure 3).

In summary, these results strongly suggest that adopting healthy dietary habits in midlife—especially a high intake of plant-based foods and a low intake of animal-based and ultra-processed foods—significantly increases the chances of reaching older age in good health, without major physical or mental limitations. When combined with no smoking, regular physical activity, and effective stress management (including quality sleep and strong social networks), this type of diet likely represents the best-known strategy for promoting long-term healthy aging.