For many years, scientists have known that the Mediterranean diet is one of the healthiest eating patterns in the world. People who follow it tend to have lower rates of heart disease, type 2 diabetes, memory loss, and early death.
A new study now suggests that this famous diet may help people age more slowly by influencing tiny proteins made inside the body’s cells.
The research was led by Dr. Roberto Vicinanza at the USC Leonard Davis School of Gerontology and was published in the journal Nature Communications.
The study gives scientists a possible new explanation for why the Mediterranean diet appears to protect health.
The Mediterranean diet is based on foods traditionally eaten in countries bordering the Mediterranean Sea. It includes plenty of vegetables, fruits, beans, olive oil, fish, nuts, and whole grains while limiting sugary foods, refined carbohydrates, and heavily processed products.
Researchers have long wondered exactly how this eating pattern protects the body. While vitamins, healthy fats, and fiber are known to play important roles, the new study focused on mitochondria, tiny structures inside cells that produce energy.
Scientists now know that mitochondria also send chemical signals that influence inflammation, metabolism, and aging.
The team studied blood samples from older adults with different levels of adherence to the Mediterranean diet. People who followed the diet most closely had much higher levels of two mitochondrial microproteins called humanin and SHMOOSE. Earlier research has linked both proteins with healthier brains, healthier hearts, and protection against age-related diseases.
The researchers also found that these participants had lower levels of oxidative stress. Oxidative stress happens when harmful molecules build up faster than the body can remove them, damaging cells, proteins, and DNA. This process is believed to contribute to aging and many chronic diseases.
Certain foods appeared to have particularly strong effects. Olive oil, fish, and legumes were linked with higher levels of humanin, while olive oil and eating fewer refined carbohydrates were associated with more SHMOOSE. These findings suggest that different foods may support healthy aging in different ways.
Humanin and SHMOOSE are unusual because they are produced from the small amount of DNA found inside mitochondria rather than the cell nucleus. For many years scientists believed these regions had little purpose, but recent discoveries show they produce biologically active proteins that may help protect the body from disease.
The researchers also found that higher humanin levels were linked with lower activity of an enzyme called Nox2, which can increase harmful oxidative stress. This suggests the Mediterranean diet may protect the heart not only through healthy nutrients but also by activating natural protective systems inside cells.
The study was relatively small and observational, so it cannot prove that the Mediterranean diet directly caused these changes. Exercise, medicines, genetics, and other healthy habits may also have contributed. Larger clinical studies will be needed to confirm the findings.
Even so, the research opens an exciting new area of nutrition science known as precision nutrition. In the future, doctors may be able to measure these tiny proteins to see how well a person’s body is responding to a healthy diet and design more personalized nutrition plans.
Review and analysis: This study offers an important biological explanation for the long-recognized health benefits of the Mediterranean diet. Its main strength is the discovery of a possible molecular pathway linking food choices to healthy aging.
However, because it shows only an association, stronger clinical trials are still needed before these microproteins can be used as medical markers or treatment targets.
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Source: USC Leonard Davis School of Gerontology.
