Caffeine consumption has been associated with lower risks for multiple diseases, including type II diabetes, heart disease, and stroke, but the mechanism underlying these protective effects has been unclear.
The study, published in the journal PLOS Biology, a protein called p27, known mainly as an inhibitor of the cell cycle, was present in mitochondria in the major cell types of the heart. In these cells, mitochondrial p27 promoted migration of endothelial cells, protected heart muscle cells from cell death, and triggered the conversion of fibroblasts into cells containing contractile fibers -- all crucial for repair of heart muscle after myocardial infarction.
Researchers, including those from IUF-Leibniz Research Institute for Environmental Medicine in Germany, found that caffeine induced the movement of p27 into mitochondria, setting off this beneficial chain of events, and did so at a concentration that is reached in humans by drinking four cups of coffee.
Caffeine was protective against heart damage in pre-diabetic, obese mice, and in aged mice. Researchers said that in humans, the protective effect was reached at a concentration equivalent to consumption of four cups of coffee, suggesting the effect may be physiologically relevant "Our results indicate a new mode of action for caffeine, one that promotes protection and repair of heart muscle through the action of mitochondrial p27," said Judith Haendeler, from Heinrich-Heine-University in Germany.
"These results should lead to better strategies for protecting heart muscle from damage, including consideration of coffee consumption or caffeine as an additional dietary factor in the elderly population," said Haendeler. "Furthermore, enhancing mitochondrial p27 could serve as a potential therapeutic strategy not only in cardiovascular diseases but also in improving healthspan," she said.