A trans-Atlantic dispute has opened up between two camps of researchers pursuing a gene that could lead to drugs that enhance longevity. British scientists say the longevity gene is “nearing the end of its life,” but the Americans whose work is under attack say the approach remains as promising as ever.

The dispute concerns genes that make sirtuins, proteins involved in controlling cells’ metabolism. Because of their metabolic role, the sirtuins may mediate the 40-percent-longer life enjoyed by laboratory rats and mice put on a very low-calorie diet. People cannot keep to such a low-fat diet, but drugs that activate sirtuin, such as resveratrol-mimicking drugs, would in principle be a painless way for humans to add years of lean and healthy life. But several aspects of the sirtuin story have come under scientific challenge.