Scientists have added another strike against high-fat diets. A recent animal study in the Journal of Infectious Diseases suggests that a diet high in saturated fat and cholesterol may accelerate HIV disease progression.

The study followed macaques with simian immunodeficiency virus (SIV), an infection model often used to test theories about HIV. Keith G. Mansfield, DVM, of the New England Primate Research Center, and his colleagues compared two groups of SIV-infected monkeys—eight where fed a diet high in saturated fat and cholesterol and 52 others were fed a normal diet. After six months, the macaques fed the high-fat diet had significantly higher levels of an immune messenger protein called interleukin-18, a predictor of faster disease progression.

Studies in humans will have to be conducted to determine whether the same holds true with HIV. However, most doctors already urge people to eat a heart-healthy diet that is low in saturated fat. This study may add one more reason to do so.