As insulin resistance is often characterized as the most critical factor contributing to the development of type 2 diabetes, the findings “provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said.

The research group also confirmed that increased levels of an enzyme called SIRT1, which earlier studies had linked to longevity, DNA repair, and insulin secretion, improve insulin sensitivity in mice. Resveratrol is known to activate the SIRT1 enzyme.

The results suggest that “red wine might have some benefits for insulin sensitivity, but it needs to be confirmed by further investigation,” said Qiwei Zhai of the Chinese Academy of Sciences. Given the potential complications of drinking alcohol, “an even better option may be to find other natural foods enriched with resveratrol or foods supplemented with resveratrol,” he added, noting that the chemical is also an active ingredient in other plants, including one called Polygonum cuspidatum used in traditional Chinese and Japanese medicine.

Earlier studies had reported a connection between SIRT1 and the processes of glucose metabolism and insulin secretion. However, whether SIRT1 was directly involved in insulin sensitivity remained largely unknown, the researchers said.

The findings suggest that those who drink red wine for the health-promoting benefits of resveratrol might “think about drinking less,” Zhai said. Previously, he noted, the effects of resveratrol seen in mice had implied that humans might need to drink about 120 liters of red wine each day to get enough resveratrol to enjoy the same benefit. “According to our findings, people might need to drink about three liters of red wine each day to get sufficient resveratrol–about 15 mg–for its biological effects.”

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