People who eat meat and fish have a greater chance of living to at least 100

According to a large Chinese study of older adults, people who eat meat and fish have a greater chance of living to the age of 100. This surprised the researchers, who had previously assumed that a plant-based diet protects against chronic disease and premature death. They also found that older adults need considerably more protein to maintain muscle mass, as age-related muscle loss can lead to sarcopenia, reduced quality of life, and early death. One important thing to consider, is that meat contains specific amino acids needed for building muscle tissue. Meat, fish, and eggs also contain vitamin B12, iron, iodine, selenium, zinc, and omega-3 fatty acids, which are difficult or impossible to obtain in sufficient amounts from a strictly plant-based diet. For older adults and many others, the optimal approach is therefore a varied diet based on high-quality animal and plant foods.

The new Chinese study included 5,000 participants aged 80 years or older who were recruited from a large population-based study called the Chinese Longitudinal Healthy Longevity Survey. Over a period of 20 years, the study revealed that participants who avoided meat had a lower likelihood of reaching the age of 100 years or older compared with those who ate meat. The researchers also found that underweight individuals who avoided meat had a shorter life expectancy. Participants who avoided meat but consumed other animal products such as fish, shellfish, eggs, and dairy products also had a greater chance of living to at least 100.
The findings surprised the researchers, as plant-based diets have for decades been regarded as healthier due to their association with a lower risk of cardiovascular disease, type 2 diabetes, and overweight. This has largely been attributed to the higher content of fiber, vitamin C, and other antioxidants in plant-based diets. However, health, stable blood sugar, and weight regulation are influenced by many other factors, and most dietary studies have been conducted in younger populations.

The body’s needs change as we age

The researchers behind the study subsequently emphasized that people aged 80 years and older have different nutritional needs than younger individuals. With age, a number of physiological changes occur in metabolism and hormonal systems. Appetite often decreases, the absorption of certain nutrients is impaired, and metabolic processes slow down. Muscle mass declines, and bone density decreases. All of these changes increase the risk of malnutrition and frailty. For this reason, older adults also require more protein to maintain muscle mass.
There can also be an increased need for certain vitamins and minerals to support bone health, immune function, the nervous system, and protection against oxidative stress.

Animal products contain specific amino acids needed for muscle maintenance

Because meat, organ meats, fish, shellfish, eggs, and dairy products contain all essential amino acids, these animal sources provide complete proteins. Among these amino acids is leucine, which plays an important role in muscle protein synthesis. This is particularly important in preventing age-related muscle loss, including sarcopenia, which is associated with reduced quality of life and a higher risk of fractures, as muscles normally act as shock absorbers. Sarcopenia also increases the risk of nursing home placement and premature death.
Health authorities generally recommend a daily protein intake of 0.8 grams per kilogram of body weight. However, older adults need significantly more (approximately 1.0–1.2 grams of protein per kilogram of body weight) to maintain muscle mass. It can be very difficult to obtain this amount of protein from a plant-based diet, which also lacks sufficient amounts of the essential amino acid leucine.

Animal foods provide important vitamins, minerals, and omega-3 fatty acids

Vitamin B12 is found exclusively in animal foods. It plays an important role in energy production, nervous system function, cognitive performance, and immune function. A deficiency of vitamin B12 can therefore lead to fatigue, reduced sense of taste, digestive problems, poor memory, mental sluggishness, and dementia. These are conditions and disorders that many older adults experience, and vitamin B12 deficiency is often diagnosed too late.
Iron, iodine, zinc, and selenium are also more easily obtained or absorbed from animal sources. Deficiencies in these minerals, which are common among older adults, can negatively affect thyroid function, immune function, circulation, and a wide range of metabolic processes.
In addition, fatty fish contains the active omega-3 forms EPA and DHA, which are important for cardiovascular health, cognitive function, and mood. EPA and DHA also help regulate inflammation, and so-called “inflammaging” (age-related inflammation) is considered a common underlying factor in most age-related diseases.
Fatty fish, eggs, and liver also contain vitamin D, which is important for bone health, muscle function, immune defense, circulation, brain health, and mood. However, it can be difficult to obtain sufficient vitamin D from the diet alone, which is why higher supplemental intakes are recommended - especially true for older adults and throughout the year.
Finally, animal foods contribute to stable blood sugar levels and a greater sense of satiety, reducing the temptation to consume empty calories.

A varied diet provides the widest range of essential nutrients

As outlined above, a varied diet provides the greatest diversity of nutrients. Plant-based foods primarily provide fiber, vitamin C, vitamin E, magnesium, and other beneficial plant compounds. Animal foods, including fatty fish, provide vitamin B12, iron, iodine, zinc, selenium, and the active omega-3 fatty acids EPA and DHA, all of which are nutrients that are difficult or impossible to obtain in adequate amounts from a plant-based diet alone.

References:

Chloe Casey. Are meat eaters really more likely to live to 100 than non-meat eaters, as a recent study suggest? The Conversation. 2026

Attilio Giacosa et al. The Nutritional and Food Science Technology. Frontiers in Nutrition. 2024
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