In male macaque monkeys aged 10 to 15 years, feeding a high-fat diet for 18 months is linked to a 46.43% rate of heart muscle thickening, along with reduced activity of four specific genes involved...

We analyzed one study on macaque monkeys and found that a high-fat diet over 18 months was linked to heart muscle thickening in 46.43% of male monkeys aged 10 to 15 years, along with reduced activity in four genes tied to heart structure [1]. This is the only piece of evidence we’ve reviewed so far, and it supports the idea that this type of diet may be associated with these changes. We did not find any studies that contradict this finding. The changes observed were specific to the heart muscle and gene activity, not overall heart function or disease outcomes. The study did not test whether these changes reversed after stopping the diet, nor did it examine female monkeys or younger animals. Because we only have one study to go on, we can’t say whether this pattern would hold in other groups or over longer periods. The gene changes mentioned relate to how the heart maintains its structure, but we don’t know what impact, if any, this has on the monkeys’ health. What we’ve found so far suggests a possible connection between a high-fat diet and these biological changes in this specific group of monkeys, but more research would be needed to understand how this might apply beyond this single case. For now, the evidence we’ve reviewed leans toward this association, but it remains limited in scope. If you’re considering dietary changes for yourself or others, remember that monkey studies don’t always translate directly to humans — what happens in one species doesn’t always mirror what happens in another.