Dietary Influence on Longevity

Longevity is defined as living a longer, healthier life, and longevity research seeks to improve these two aspects – length of life or lifespan, and health of life, or healthspan. Optimal diet is a hotly debated topic, and there is no definitive best diet for every individual’s longevity. However, there are some broad themes that run through all healthy diets because of how they impact the aging process, disease risk and symptom burden.

Increasing inflammation, reduced immunity, metabolic dysfunction and sarcopenia (loss of muscle mass and function) are major components of aging. These factors influence common causes of reduced quality of life and mortality, such as heart disease, stroke, cancer, diabetes, dementia and Alzheimer’s, all of which may be prevented, or mitigated by lifestyle changes.

Important dietary factors for healthspan and lifespan


Antioxidant-rich phytochemicals are bioactive substances found in plants that scavenge free radicals, thereby reducing oxidative stress to cells and exert anti-cancer, anti-inflammatory, anti-microbial, anti-parasitic, anti-viral, anti-hyperglycemic effects and more. A few examples include limenols, carotenoids, glucosinolates, anthocyanins, and phenols. Each plant color provides a unique array of phytochemicals so diet variety is ideal. Two diets characteristically known to be high in phytochemicals when well-balanced are vegetarian and Mediterranean diets. A 2018 study found both diets improved body weight, body fat, and cholesterol markers – major factors for cardiovascular disease risk.

Food Sources: colorful vegetables, fruits, legumes, nuts & seeds


Fiber is the part of carbohydrates that is undigested by the human body and is present in a wide variety of plants. Soluble fiber dissolves into water, is fermentable and becomes gel-like in liquid. Insoluble fiber does not dissolve in water and stays mostly intact throughout the digestive system. Both are crucial for long-term health as they promote regular bowel function, toxin removal, improved metabolic health and fuel for the colon’s microbiota. High fiber intake has been shown to prevent disease by improving risk factors as well as reduce symptoms and markers of active disease.

Food Sources: vegetables, fruits, legumes, nuts & seeds, whole grains


Since sarcopenia and fragility are a concern in the elderly due to their association with falls, hip fractures and rapid decline, studies have been done to determine preventative and treatment measures. One study found that administration of leucine, an amino acid rich in animal foods, improved sarcopenia and respiratory muscle function. The International Protein Board also recommends protein intake of 1.4 - 1.75g protein/kg body weight for healthy aging, far above the minimum RDA of 0.8g/kg.

Food Sources: meat, poultry, fish, eggs, dairy, legumes, some nuts

FERMENTED FOODS (link to probiotic/prebiotic article)

Fermented foods are foods that have been fermented by bacteria or fungi, contain healthy microbes or probiotics, and yield a more easily-digestible food. These healthy microbes have extensive health benefits including immune modulation, inflammation regulation and gut health – all important components of longevity. A 2021 study found those eating a high fermented food diet had decreased inflammatory markers and improved microbiota diversity, therefore regular, if not daily, consumption of fermented foods is optimal for most people.

Food Sources: Unsweetened yogurt, kefir, sauerkraut, kimchi, kombucha, fermented vegetables


Omega-3 fatty acids, EPA and DHA, are anti-inflammatory fats that have been linked with improved cardiovascular and cognitive function, reduced inflammation and other health improvements. One study found that administration of a combination of probiotics and omega-3 improved metabolic health and inflammation in those with non-alcoholic fatty liver disease (NAFLD). Another study found omega-3s improved markers of inflammation, autoimmunity and cardiovascular risk.

Food Sources: Omega-3-rich foods include salmon, sardines, anchovies, trout, barrimundi, and pastured eggs. Plant sources such as walnuts and flaxseed also contain omega-3's but in ALA - an inferior form of omega-3s.


All successful diets that result in improved health, whether that be metabolic function or body composition or both, primarily include whole foods and avoid/minimize processed foods. Processed foods are often deprived of micronutrients, fiber, and phytochemicals, but are high in added sugars, synthetic ingredients and calories. A Standard American Diet (SAD) - high in sugar, salt, fat, and processed foods while lower in fiber and fruits and vegetables – is associated with many chronic diseases such as obesity, diabetes, cardiovascular disease, cancer and inflammatory conditions.


Both excessive sugar (> 6 tsp/24g for women, and >9 tsp/36g for men, or >10% of calories), and excessive alcohol consumption (>1 drink/day for women, >2 drinks/day for men) increase the risk of cardiovascular disease, obesity, diabetes, metabolic syndrome, fatty liver disease, and/or cancer – all major reasons for reduced healthspan and lifespan – whereas low intake helps to mitigate risk factors. Alcohol negatively impacts sleep quality as well as contributes to behavioral health problems and injuries.

Bottom Line

No matter what particular dietary pattern you may think is best or may choose to follow, major dietary themes overlap in any healthful diet – whether Mediterranean, vegetarian, paleo, keto, etc. Start with the basics first – reduce sugar, alcohol, and processed foods, while emphasizing more phytochemicals, fiber, protein, omega-3's, and whole foods – and you may find yourself reaching your health goals without having to get too extreme or nuanced.

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