Mediterranean diet raises mitochondrial microproteins that may shield the aging heart and brain

The Mediterranean diet, rich in olive oil, fish, beans, lentils, fruits, and vegetables, has long been linked to lower risk of heart disease, type 2 diabetes, and cognitive decline. What has remained unclear is exactly how it delivers such wide-ranging benefits. A new study from the USC Leonard Davis School of Gerontology points to a possible mechanism involving tiny proteins made by mitochondria, the structures that generate most of a cell's energy.

Researchers led by Roberto Vicinanza examined blood samples from older adults who followed the Mediterranean diet to varying degrees. Those whose eating habits most closely matched the diet had significantly higher levels of two mitochondrial microproteins, humanin and SHMOOSE. They also had lower indicators of oxidative stress, in which reactive oxygen species overwhelm the body's defenses and can damage proteins, DNA, and other cell components over time.

Specific foods appeared to map onto specific microproteins. Higher intake of olive oil, fish, and legumes was associated with more humanin. Olive oil and lower consumption of refined carbohydrates, such as white bread, pastries, and sugary snacks, were associated with higher SHMOOSE. Both microproteins have previously been connected to protection against cardiovascular disease and neurodegeneration. Senior author Pinchas Cohen suggested they could serve as biomarkers of Mediterranean diet adherence with clinical significance, while Vicinanza described them as molecular messengers translating diet into cellular function and aging.

For health-optimizing readers, the work reinforces the value of prioritizing olive oil, fish, and legumes while cutting back on refined carbohydrates. It also highlights mitochondrial signaling as a promising frontier in nutrition and aging research, and hints that blood-based measures might one day gauge how well a diet is biologically working.

Several caveats apply. The findings are observational associations, so they cannot show that diet directly raises these proteins or that higher levels cause better outcomes. Diet was likely self-reported, sample details were not provided in the excerpt, and the article is a press summary. Interventional trials are needed to confirm causality and clinical usefulness.