A Hidden Dietary Key to Living to 100 with a Healthy Brain?
Results from recent research points to an often-overlooked variable
By Austin Perlmutter, MD
In a 2024 systematic review, researchers started with an interesting question: if you look at 100+ year olds around the world, did they share any dietary attributes? Specifically, they included centenarians and near-centenarians (95 years old or over). They pooled all the relevant studies published to date on the topic from around the world and found the following: First, only 7% of centenarians and near-centenarians smoked, and 23% drank alcohol. When it came to diet, the makeup was revealing. These exceptional agers consumed roughly 60% of their calories from carbs, with about 19% protein and 29% fat. But the last may be the most interesting: 60% of people consumed a diverse diet.
In a separate study entitled “Healthy Lifestyle and the Likelihood of Becoming a Centenarian”, researchers followed 5222 people aged 80 or above, to see how lifestyle habits mapped onto people’s chances to make it to age 100. Their process was relatively simple: they built a composite score that included exercise, smoking and dietary diversity and looked at the correlations between people’s score and their chances of surviving to 100. The odds ratio for those with the highest score versus the lowest was 1.61, meaning that people who did not smoke, exercised regularly and had the highest dietary diversity had 61% higher odds of becoming centenarians.
The results of these two studies, while associative, indicate that dietary diversity may play a key role in making it to our later years. Notably, dietary diversity has been associated with several other positive outcomes. For example, in a 2025 study, scientists tracked over 100,000 people for an average of about 10.5 years and found that higher dietary diversity was linked to a lower risk for developing dementia. In a separate 2025 review, researchers concluded that “sustaining a diverse diet among older people may help maintain cognitive functioning.” And that dietary diversity could represent a promising opportunity to potentially prevent or slow worsening of cognitive decline in various brain disorders.
What is dietary diversity?
Dietary diversity is described as the diversity of foods or food groups eaten over a given period of time, and has been linked to better health. Over the last decades, the global diet has been massively altered by a trend towards monocultures—single crops raised at massive scale. While this has facilitated the ready availability of calories, it has come at the expense of diversity of dietary nutrients. Researchers report that of the 50,000 or so edible plant species only 250 are domesticated, of which 150 are cultivated at large scale. Yet the most striking statistic: roughly 70% of global calories come from just 15 crops, of which maize, rice, and wheat comprise about 50% alone. This leads to what has been called a “hidden hunger,” whereby despite caloric needs being met, we wind up without enough of key vitamins and minerals and plant phytonutrients linked to robust health and wellness.
What’s in a diverse diet that could lead to longevity and brain health?
In a 2026 review in the Journal of Translational Medicine entitled “Nutrition and longevity – diet in centenarians,” researchers looked specifically at which nutrients could target the key biological mechanisms behind longevity. By examining various diets (e.g., Mediterranean Okinawan, Nordic) associated with long-lived populations, they were able to tease out the potential for certain unifying factors. These include foods rich in micronutrients (vitamins and minerals) and polyphenols (nutrients used in plants as signaling molecules that are found in foods like fruits, vegetables, nuts, seeds, tea and spices).
Among the individual nutrient groups highlighted in this review paper are adequate levels of vitamins including B vitamins, vitamin C and vitamin E, and minerals including with zinc, magnesium and iron, in addition to omega-3 fats. This is particularly notable in the context of many modern processed foods being low in these types of nutrients. One great way to ensure you’re getting more of this range of nutrients is to consume a range of different minimally processed food.
Five considerations around increasing dietary diversity
While dietary diversity is likely a good bet for most people, there are several different perspectives on exactly how best to increase it. The following are some ideas, understanding that what works best for everyone may vary depending on their preferences, nutritional needs and underlying health states.
Shoot for 30 different plant foods each week: This could include fruits, vegetables, nuts, seeds, spices and herbs.
Try to “eat the rainbow:” This means trying to eat a range of colorful fruits, veggies and spices.
Experiment with new foods each week: many people get locked into a routine of eating the same foods each day, which can be practical for convenience, but consider trying at least one new vegetable legume or protein source per week.
Use herbs and spices: while often passed over for the more common seasonings, diverse herbs and spices are some of the most concentrated sources of polyphenols and other phytonutrients in our diet.
Shop local if possible: while it can be slightly more costly, choosing heirloom crops and farmer’s markets with local produce may increase nutrient diversity compared to processed or mass-produced versions of similar crops.
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This content is for informational and educational purposes only and does not constitute medical advice. Please consult with a qualified healthcare provider before making significant changes to your diet or lifestyle.
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