Older adults with stronger adherence to a Mediterranean diet had higher blood levels of two mitochondrial-derived microproteins—Humanin and SHMOOSE—in a small cross-sectional study, alongside lower levels of oxidative-stress markers.
Researchers led by Roberto Vicinanza at the USC Leonard Davis School of Gerontology analyzed blood samples from older adults and reported that closer adherence to a Mediterranean diet was associated with higher circulating levels of two mitochondrial microproteins, Humanin and SHMOOSE.
The peer-reviewed study—a cross-sectional analysis of 49 patients with non-valvular atrial fibrillation treated at Sapienza University of Rome—found that participants with higher Mediterranean diet adherence scores had higher measured levels of both microproteins. The researchers also reported lower levels of oxidative-stress markers, including soluble Nox2-derived peptide and 8-iso-prostaglandin F2α.
Dietary components within the Mediterranean pattern showed different relationships with the two microproteins. Higher olive oil consumption was associated with higher levels of both microproteins, while fish and legumes were additionally linked with higher Humanin levels. Lower intake of refined bread—a proxy for lower refined carbohydrate intake—was associated with higher SHMOOSE.
"These microproteins may act as molecular messengers that translate what we eat into how our cells function and age," Vicinanza said in comments accompanying the research.
Pinchas Cohen, the study’s senior author and dean of the USC Leonard Davis School, said the findings suggest a potential pathway through which the Mediterranean diet could influence cardiovascular biology, while emphasizing that more research is needed.
The study, published by Frontiers in Nutrition on March 10, 2026, was observational and cannot establish that changing diet directly raises these microprotein levels or reduces disease risk. The authors said future work is needed to test causality and clarify mechanisms.
