Resveratrol could impair the formation of new brain cells, according to research published in The Journal of Biological Chemistry.

The compound is found in red wine, along with foods such as grapes, berries, pistachios and peanuts. Previous studies have found resveratrol could have a protective effect on age-related disorders such as neurodegenerative diseases, inflammation, diabetes, and cardiovascular disease.

In their study, Korean researchers injected healthy young adult mice with resveratrol daily for 14 days. The researchers also investigated the effect of resveratrol on mice brain cells that had been incubated in plastic culture dishes.

The Korean researchers found that resveratrol inhibited the growth of new brain cells in the hippocampus, an area of the brain associated with memory and learning. In a maze test, mice treated with resveratrol took longer to learn than mice that had not received any resveratrol.

The study appears to contradict previous research that found resveratrol improves cognitive function in mice. Though, differences in the dose and age of the mice could explain the different results. The previous research, published in 2011, tested older mice with a lower dose of resveratrol for a shorter period of time.

“However, in the hope of delaying aging and neurodegeneration, people have shown increasing interest in beneficial effects of resveratrol and are taking resveratrol routinely without regulation,” the researchers wrote in their study. “In fact, commercially available tablets contain up to 500 mg of resveratrol, which could result in the exposure of [brain cells] to concentrations similar to those used in the present study.”

Annual sales of resveratrol supplements have risen to $30 million in the United States.