Introduction
For decades, epidemiologists have debated the limitations of traditional causal models of diseases that focus on the linear and sequential views of causality. The recent shift towards understanding the interplay between social, environmental, and biological factors in shaping health over a lifetime marks a significant evolution in public health approaches. Aging is not a random process; it is influenced by numerous factors, with genetic inheritance playing a minor role compared with broader characteristics and environmental interactions. Factors such as sex, ethnicity, occupation, education, and wealth, combined with lifestyle choices, significantly affect the aging process.
Ecological approaches to health issues have become central to disease prevention and health promotion. Factors influencing aging start interacting from childhood and contribute to the diversity observed in older age. Negative influences such as a sedentary lifestyle, poor diet, smoking, and stress can accelerate aging, whereas positive behaviors such as exercise, proper nutrition, quality sleep, and stress avoidance can decelerate it.
The Impact of Diet on Aging
Diet is one of the most modifiable factors that affect the aging process. Malnutrition is prevalent among older adults, affecting up to 46% of community-dwelling and institutionalized individuals. Conversely, obesity also negatively affects aging by increasing the risk of chronic diseases and reducing vaccine efficacy due to obesity-associated chronic low-grade inflammation and micronutrient deficiency. Good nutrition is crucial for healthy aging and is a key target for interventions aimed at decelerating the aging process.
Inflammation and Aging
Inflammation is a natural immune response to injury, which promotes repair and recovery. However, chronic low-grade inflammation, known as inflammaging, can lead to long-term damage across multiple systems and increase the risk of diseases, such as diabetes and coronary heart disease. The Western diet, characterized by high consumption of fats, sugars, processed foods, and additives, is a powerful trigger of inflammation. In contrast, diets rich in fruits, vegetables, and whole grains are associated with lower levels of inflammatory markers.
The Mediterranean Diet: A Lifelong Ally
The Mediterranean diet (MD) is more than just a dietary pattern; it encompasses values such as social dining and sustainability. It emphasizes the high consumption of fruits, vegetables, whole grains, legumes, nuts, and olive oil, with moderate consumption of fish, lean meat, and dairy and limited intake of red meat, sweets, and saturated fats. Recognized by UNESCO as an Intangible Cultural Heritage of Humanity, the MD is linked to numerous health benefits, including a reduced risk of cardiovascular disease, cancer, diabetes, and cognitive impairment.
Nutritional Components and Immune Function
Key components of MD, such as vitamins and polyunsaturated fatty acids (PUFAs), play crucial roles in immune function and inflammation management. Vitamins, such as E, A, and D, support immune cell function, maintain mucosal barriers, and promote bone health. Zinc and selenium are essential trace elements that regulate the immune response and oxidative stress. Omega-3 PUFAs found in fish and vegetable oils have anti-inflammatory properties and promote immune resolution.
The Role of Gut Microbiota
Gut microbiota, influenced by diet, plays a central role in immune function and overall health. MD, which is rich in fiber and plant-based foods, promotes diverse and healthy gut microbiota. This diversity is crucial for maintaining gut barrier integrity and preventing the leakage of harmful substances into circulation, which can lead to inflammation and chronic diseases.
Polyphenols: Plant-Based Powerhouses
Polyphenols, which are abundant in fruits, vegetables, herbs, and spices, are metabolized by gut microbiota into bioactive compounds with various health benefits. They support the growth of beneficial bacteria and inhibit harmful species, thereby contributing to immune homeostasis and reducing the risk of chronic diseases.
Conclusion
The Mediterranean diet positively affects immune health through multiple mechanisms. It helps maintain a healthy body weight, controls cardiovascular risk factors, directly influences immune cell populations, and promotes healthy gut microbiota. The Mediterranean diet is a powerful tool to promote healthy aging by fostering a balanced immune response and minimizing chronic inflammation. In the context of “food as medicine,” the Mediterranean diet truly emerges as the best prescription for longevity and well-being.
Read the paper at: Ecarnot, F., Maggi, S. The impact of the Mediterranean diet on immune function in older adults. Aging Clin Exp Res 36, 117 (2024). https://doi.org/10.1007/s40520-024-02753-3