Regular Oily Fish Eaters Show Healthier Tiny Blood Vessels, Study Finds

This study looked at whether eating oily fish regularly is linked to the health of very small blood vessels, called capillaries, in older adults. Researchers used a specialized imaging technique on the fingernail fold (nailfold capillaroscopy) to examine capillary shape and density in 306 community-dwelling older adults.

Dietary habits were tracked over five years to capture long-term patterns of oily fish consumption, and participants were grouped by how much oily fish they typically ate. After adjusting for age, lifestyle, and cardiovascular risk factors, people who ate more oily fish had fewer twisted (tortuous) capillaries, fewer abnormally widened (dilated) capillaries, and a greater overall density of capillaries compared to those who ate less.

These associations held up even after accounting for other health and lifestyle factors, suggesting a meaningful link between habitual oily fish intake and the structural health of small blood vessels. Because this was a pilot, cross-sectional study, it cannot prove that eating fish caused these differences, and the researchers plan follow-up studies to explore this further.