Nutrition and Longevity: What to Eat, How Much, and What to Avoid For a Long and Healthy Life

Ever since the dawn of time, humans have attempted to extend their lifespan and achieve the elusive state of immortality. However, what we really want are not just longer lifespans, but also longer healthspans — the number of years lived without developing chronic diseases that impact our quality of life. As no one wants to live to be 100 years old and beyond with dozens of debilitating health concerns, longevity researchers are looking for ways to not only extend life but also to extend health into our later years — and one of the simplest ways to do so involves what we eat today. 

A look at longevity around the globe

Although many ascribe their future lifespans to be genetic-based and inevitable, only 20% of longevity is attributed to hereditary factors. This leaves 80% up to the foods we eat, the lifestyles we live, and how we interact with our environment. A handful of regions around the world have figured out how to use this 80% to their advantage. Known as the Blue Zones, these areas — ranging from the Seventh Day Adventists in Southern California to the Okinawans in Japan — have high populations of healthy centenarians (people who live to be 100 or more). With the Blue Zones having ten times the number of centenarians as the United States does, we have a lot to learn from these regions’ dietary and lifestyle habits. 

Primarily plant-forward and pescatarian 

Many of the Blue Zones’ inhabitants place a dietary focus on eating lots of plants, including fruits, vegetables, beans, legumes, and nuts. While this doesn’t mean that entirely eliminating meat is necessary, research has found that adding more plant-based foods into your diet can bring significant boosts to longevity. 

An added benefit of increasing your consumption of plants is the effect on your gut microbes. Also known as the microbiome, this collection of bacteria in our intestines — both good and bad — has been found in recent years to have much more of an effect on health than previously thought. Now linked to everything from autoimmune disorders to Alzheimer’s disease, having a healthy makeup of gut bacteria has been found in animal studies to enhance both healthspan and lifespan. 

Making this switch doesn’t have to be too drastic — a recent study found that replacing just 3% of animal proteins with plant-based proteins, like beans or nuts, reduced the risk of premature death by 5%. And, it may not be just the type of protein we eat, but also the amount — one study reported that restricting protein consumption by two-thirds led to a 30% increase in lifespan and a reduction in frailty in male mice. 

However, this doesn’t mean that all meat is bad for you. Many researchers agree that small amounts of high-quality animal products that weren’t raised in factory farms, like grass-fed beef or pasture-raised chicken and eggs, can be healthy additions to a longevity-focused diet. Additionally, regular consumption of omega-3-rich fatty fish, like salmon and mackerel, is consistently linked to improved health outcomes, especially in reducing the risk of the leading cause of death in our country: heart disease.

From the right fats to the sweet stuff

Two other foods that are associated with heart disease — this time, with an increased risk — are inflammatory oils and added sugar. It’s pretty well-known that sugar is not beneficial for health, with one study finding that people who consumed more than 20% of their calories from added sugar experienced a 30% increased risk of mortality. Plus, the highly processed soybean, canola, corn, and other vegetable oils raise the risk of heart disease and mortality because they are high in pro-inflammatory omega-6 fats, rather than anti-inflammatory omega-3’s. 

The healthiest oil for boosting longevity is the antioxidant-rich extra-virgin olive oil, with avocado oil and coconut oil also being beneficial options. As for the sweet stuff, it’s recommended to keep added sugar intake to below six and nine teaspoons per day for women and men, respectively. However, when it comes to added sugar and longevity, the lower, the better.

Antioxidants, from A to Z

From alpha-carotene to zeaxanthin, these plant-based compounds called polyphenols act as antioxidants and fight oxidative stress in the body — the accumulation of inflammatory and reactive molecules that damage cells and DNA. A buildup of these harmful compounds significantly accelerates the aging process — both internally, in our innermost organs, and externally (think: sun damage and wrinkles on your skin). So, eating a diet rich in these plant-based antioxidants can reduce this oxidative damage and lead to extended life- and healthspans. 

Some of the antioxidant-rich foods and beverages to start adding to your shelves include berries, leafy green vegetables, herbs and spices, extra-virgin olive oil, dark chocolate, artichokes, beans, beets, green tea, coffee, and red wine.

Restricting calories to revamp health

One of the earliest research-backed methods found to increase longevity in animals is caloric restriction. Dating back decades, restricting caloric intake — but not under-consuming nutrients — has been found to extend lifespan by 30 to 50% across species, ranging from yeast to primates. The mechanisms behind caloric restriction’s longevity-boosting effects are multifactorial. First, limiting food intake resembles a state of scarcity— an evolutionary state that animals commonly experience in nature — which reduces the activity of pathways related to nutrient signaling and sensing, like TOR (target of rapamycin). The mammalian version of TOR (mTOR) is considered a significant and negative regulator of lifespan. 

When you fast or restrict calories, your body will activate a pathway that then inhibits mTOR. This inhibition of mTOR increases autophagy — our body’s “recycling” program that eliminates dysfunctional cells — and mitochondrial function, our cells’ energy powerhouses. While, at times, mTOR activation is beneficial, as it can enhance muscle growth and boost energy, generally, low mTOR levels are associated with increased longevity and better health outcomes. 

In addition to inhibiting mTOR with caloric restriction, some of the antioxidants mentioned above can also limit this pathway, including resveratrol in red wine, curcumin in turmeric, epigallocatechin-3-gallate (EGCG) in green tea, and quercetin found in many fruits and vegetables. These compounds can also be considered activators of sirtuins, a family of proteins involved in cellular metabolism and linked to longevity. 

Several other mechanisms play a role in how restricting calories boosts longevity, including improving blood-sugar metabolism and sensitivity to insulin (the hormone that shuttles sugar from the blood into cells), and lengthening telomeres — the protective endcaps on our chromosomes. These endcaps are considered a biological marker of aging; research with mice found that a 40% caloric reduction resulted in a significantly slower rate of telomere shortening with age.

In contrast to the various forms of fasting (like intermittent fasting or time-restricted eating), caloric restriction doesn’t involve only eating at certain times of the day. Rather, this form of eating entails consistently reducing daily caloric intake, typically by 10 to 30%. One well-known study of rhesus monkeys — one of the closest relatives to humans — found that restricting their calories by 30% for 20 years significantly extended lifespan and delayed the onset of age-related diseases, as the monkeys fed non-restrictive diets had a 3-fold increased risk of death during the study. 

Although the specific number of calories to consume each day varies widely from person to person, based on age, sex, height, weight, health status, and activity level, restricting calories by 10 to 30% of average intake may lead to extended lifespans. With the national guidelines for adult males generally recommending 2,500 calories per day, this would translate to reducing daily caloric intake by 250-750 calories. However, not enough research with humans has been done yet to determine the long-term effects of caloric restriction. 

Looking forward: Making the whole world a Blue Zone

With the available research on nutrition and longevity increasing day by day, it’s likely that we’ll soon know the optimal diet for extending lifespan in humans. For now, there’s plenty you can eat — or avoid — to boost your chances of becoming a healthy centenarian. These habits include limiting sugar and animal protein in favor of plants and seafood, eating as many antioxidant-rich polyphenols as you can, and reducing your daily calorie consumption while maintaining adequate nutrient intake. As these dietary recommendations are low-cost (or can even save you money in the case of caloric restriction), using nutrition may be easily accessible to boost longevity for all. Who knows — we may all be living in a Blue Zone one day.

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