Eating for Longevity: Lessons From the World's Oldest People

Diet is one of the most fundamental pillars of health. Our bodies are built, maintained, and repaired from the food we consume. It is also the leading behavioural risk factor for noncommunicable diseases and a major contributor to global mortality burden [1].

Yet few topics are as contested as nutrition. Carnivore versus plant-based, keto versus Mediterranean, low-fat versus low-carb. More than a hundred named diets compete for attention.

Part of this confusion is methodological. Much of nutrition science relies on observational research, where separating causation from correlation remains difficult. But when the lens shifts to exceptional longevity, a clearer pattern begins to emerge.

Across centenarian populations, randomised trials, mechanistic studies, meta-analyses, and even lived experience, similar nutritional principles appear again and again.

Longevity nutrition begins with the individual

There is no universal diet that works for everyone. Genetic variations shape how we metabolise fats, carbohydrates, lactose, caffeine, and countless other foods. Ancestry, metabolic health, lifestyle, and the unique nuances of our biology all influence nutritional needs.

Still, while nutrition must be personalised, the foundations of a longevity-supportive diet tend to point in the same direction. Long-term adherence to Mediterranean, Nordic, Okinawan, DASH, and high-quality plant-forward diets is associated with healthy ageing, lower mortality, and multiple health benefits.

The Mediterranean-style diet has the most evidence as a dietary model for longevity across studies. It reduces all-cause mortality risk by 23%, cardiovascular mortality by 27%, and non-fatal cardiovascular events by 23% [2, 3].

The centenarian diet

Not all centenarians eat purely Mediterranean. In general, roughly 95% of their meals come from plants: fruits, vegetables, whole grains, unsaturated fats, nuts, legumes, and low-fat dairy products. Meat is seen as a side dish, and the absence of ultra-processed foods, sugary drinks, trans fats, and red or processed meat is a common denominator. Most preferred a low-salt diet [4]. The ingredients differ between geography, location, and seasonality.

Centenarian diets are overwhelmingly plant-forward, rooted in scarcity, not excess.

Centenarians eat at least a half cup of cooked legumes daily. This is the consummate food. Legumes are the primary protein sources that promote a healthy microbiome without the pro-ageing mechanisms triggered by high intake of red meat consumption [5]. Affordable, endlessly adaptable, and more nutrient-dense per gram than almost anything else you could put on your plate.

The addition of wild greens (horta), foraged greens that are packed with potent polyphenols, antioxidants, and nutrients that activate cellular defence mechanisms, is part of a daily ritual.

Fibre: the highest-return intervention

Free Guide: Slow Aging Guide

6 Easy Practices to Start Now

(Even if you’re short on time or motivation)

Send guide

By subscribing you will also be signed up for the New Zapiens newsletter

25,000+ Downloads • 100% Free

For most of human evolutionary history, fibre wasn't a dietary supplement. It was unavoidable. Plants are the most abundant, accessible food source on earth, and our digestive systems evolved alongside them.

The gut microbiome we inherited is, in large part, a fibre-processing ecosystem. Our ancestors likely consumed 100+ grams of fibre daily from whole plants, yet our modern averages hover around 10 to 15 grams, and official recommendations (26 to 38g) are better but remain modest.

The payoff is dramatic. Higher fibre intake is linked to a 23% reduction in all-cause mortality, 26% lower cardiovascular mortality, and 22% lower cancer mortality [6]. That relationship is roughly linear: every additional 10 grams per day correlates with about a 10% drop in mortality risk [7].

Fibre also boosts production of GLP-1, the same satiety hormone targeted by popular weight-loss drugs.

The gut lesson from the oldest centenarian

María Branyas Morera, the world's oldest living person, died at 117. Her gut microbiome resembled that of a much younger person, with high diversity and abundant Bifidobacterium, the type of bacteria that typically decline with age but are consistently found elevated in centenarians and supercentenarians [8].

María enjoyed yogurt up to four times a day as part of a lifelong Mediterranean-style diet. While her genetics undoubtedly played a major role, her case adds to mounting evidence that a diverse gut microbiome is one of the strongest biological markers of healthy longevity.

Fermented foods have a universal benefit: they increase microbiome diversity, raise anti-inflammatory proteins, and are associated with better health outcomes. Kefir, kombucha, and fermented vegetables such as kimchi and sauerkraut, among others, contain probiotics, bacteria that can settle in the gut and confer health benefits that outperform probiotic supplements [9, 10].

Probiotics need fuel, or prebiotics. These are the dietary fibres we can't digest but that our microbes thrive on, found in high-fibre-concentration foods such as leeks, asparagus, bananas, oats, and legumes.

Healthy fats and teas

Diets that are high in unsaturated fats, found in olive oil, nuts, seeds, and avocados, have been linked with lower mortality. Fatty fish like salmon, tuna, anchovies, and sardines are rich in omega-3 fatty acids, which are associated with better brain health and a longer life [1]. Diets rich in saturated fats, which are found in red and processed meats, seem to have the opposite effect.

Extra virgin olive oil is consumed in large quantities, not just as a cooking fat but as a centrepiece. This comes as no surprise, since olive oil is packed with multiple beneficial antioxidants and healthy fats. In one study, people who consumed a little more than half a tablespoon daily had a 19% lower risk of death from any cause over a 28-year period [11].

For hydration, centenarians rely on herbal teas and water, with some drinking the occasional local wine that has a high concentration of polyphenols.

Protein: quality and timing over quantity

Centenarian diets rely mostly on plant proteins like beans, lentils, whole grains, nuts, and seeds.

Large cohort studies have found that replacing just 3% of calories from animal protein with plant protein lowered all-cause mortality by 5%, while replacing 3% of energy from processed red meat, unprocessed red meat, and eggs with plant protein lowered mortality risk by 34%, 12%, and 19%, respectively [12, 13].

Increasing red meat intake by just half a serving per day over eight years was associated with a 10% higher mortality risk [14]. Replacing one daily serving of red meat with legumes, nuts, fish, poultry, low-fat dairy, or whole grains was linked to a 7% to 19% lower mortality risk [15].

Protein needs also shift with age. Lower protein intake during midlife (ages 50 to 65) may support longevity through reduced IGF-1 and insulin signalling, while after age 65, the literature suggests a moderate intake of 1.0 to 1.2 g/kg, or 1.2 to 1.5 g/kg in illness, helps preserve muscle mass and reduce frailty [16, 17].

Why polyphenols matter for longevity

Polyphenol-rich foods sit at the heart of why the world's longest-lived populations age so well. Their diets centre on plants dense in these compounds. Polyphenols influence all twelve hallmarks of ageing. They support mitochondrial function, telomere stability, autophagy, and a healthy inflammatory response.

Foods with high concentrations of polyphenols, such as olive oil, blueberries, nuts, green tea, and spices, also deliver secondary metabolites that help the human gut to thrive.

The pattern beneath the plate

Across many centenarian cultures, eating follows a pattern of moderation.

In Okinawa, this is captured in hara hachi bu: stopping when one is about 80% full rather than eating to complete satiety. This kind of caloric restraint has been associated with improved metabolic health, reduced oxidative stress, and pathways linked to longevity.

Their food is also deeply tied to place and season. It is local, minimally processed, and often consumed soon after harvest, when nutrient density and polyphenol content are at their highest.

Meals are slow, communal, and embedded in the social fabric of daily life. What is remarkable is not that these populations discovered some hidden formula, but that they preserved a way of eating that modern societies have largely abandoned.

The lesson is not to imitate a centenarian's exact grocery list. It is to build a relationship with food, and with the rituals surrounding it, that could sustain you for a hundred years.

How to eat like a centenarian: practical steps

Make plants the foundation. Eating 30+ different plants a week is linked to a more diverse gut microbiome, improved digestion, lower cancer risk, reduced inflammation, heart disease, and overall mortality.

Eat legumes and pulses every day. These are the most consistently consumed foods across centenarian populations worldwide. Rich in fibre, resistant starch, and plant protein, they support microbial diversity, metabolic health, and glycaemic stability.

Choose nutrient-dense vegetables. Prioritise leafy greens, cruciferous vegetables, sprouts, and wild or local greens like dandelion or horta. Skip pale lettuce such as iceberg, which is mostly water with low nutrient value. Darker, looser leaves absorb more sunlight and deliver far higher levels of vitamins A and K, iron, and antioxidants.

Snack on nuts. An intake of 28g/day of nuts compared with not eating nuts was associated with a 21% reduction of cardiovascular disease and 22% reduction in all-cause mortality [18].

Choose the darker, less refined option. Rye bread over white bread, black lentils over lighter varieties, whole-grain rice over polished white rice. Darker and less processed foods tend to retain more fibre, minerals, and phytochemicals.

Include fermented foods every day. Foods like yogurt, kefir, kimchi, sauerkraut, miso, and kombucha provide microbial diversity and bioactive metabolites that probiotic supplements rarely replicate [9].

Make extra virgin olive oil a foundation. Among all dietary fats, olive oil stands out for its strong association with reduced cardiovascular risk and longevity.

Minimise ultra-processed food. Reduce refined sugars, refined flours, industrial additives, artificial colourants, emulsifiers, and highly engineered food products. The closer food remains to its natural form, the stronger its nutritional integrity.

Reduce red and processed meat. High intake is consistently associated with increased mortality, cardiovascular disease, and cancer risk. Across the world's longest-lived populations, meat is eaten sparingly and often reserved for special occasions.

Diversify your seeds. Flax, chia, hemp, pumpkin, sesame, and sunflower seeds are concentrated sources of omega-3s, minerals, lignans, and antioxidants. Small daily amounts can meaningfully improve nutrient density.

Drink for longevity. Green tea provides catechins such as EGCG, linked to improved cellular resilience and metabolic health. Coffee, in moderation, is also associated with reduced all-cause mortality, though individual response depends on genetics and tolerance. Avoid soda, including diet soda.

Emphasise variety, seasonality, and social eating. Eat a diverse range of whole foods, preferably fresh and local when possible. Share meals with others.

Use supplements with precision. Supplementation works best as a targeted intervention, guided by clinical assessment or biomarkers. Its role is to correct deficiencies or support specific physiological needs, not to replace a nutrient-dense diet.

A note on what we can and can't claim

A word of caution belongs here. Nearly all of this evidence is associational. Observational studies can reveal powerful and consistent patterns, but they cannot prove that any single food causes a longer life.

The people who eat this way also tend to move more, sleep better, live within tight communities, and carry genes selected over generations, and longevity almost certainly emerges from the interaction of all of these, not from diet alone.

The dietary patterns of the world's longest-lived people are best understood not as a prescription, but as a remarkably consistent signal pointing in the same direction. That signal is worth following, even as science continues to refine exactly how and why it works.