While numerous studies have teased at potential benefits of resveratrol, a polyphenolic compound found in red wine and many plants, scientists are still trying to understand its impact on the human body. In a recent study out of University College London, author Dr. Henry Bayele has found an interesting explanation for its potential as an antiaging substance. Dr. Bayele’s team found that resveratrol can mimic the hormone estrogen in the human body to activate antiaging proteins called sirtuins, which may help prevent age-related health problems.
The study, published in Scientific Reports, explores dietary sirtuin-activating compounds (dSTACs), including resveratrol. Sirtuins have become a promising target for researchers interested in slowing the aging process. They are proteins produced by the body that appear to impact metabolism and protect against several conditions including obesity, type 2 diabetes, cancer and cardiovascular and neurodegenerative diseases. Learning what spurs the body to produce sirtuins has been a common goal of longevity-focused scientists over the past two decades.
The interest in sirtuins started in 1999, when it was reported that the proteins’ activation can extend yeast lifespans by as much as 70 percent. “The antiaging action of sirtuins appears to be conserved from yeast to mammals,” stated a 2017 study published in Biogerontology. “However, the complexity of their function increases with the complexity of the organism.”
In the lab, Dr. Bayele and his team treated human liver cells in vitro with different types of compounds and found that resveratrol activated sirtuin signals through estrogen receptors by mimicking the hormone. Although estrogen is commonly defined as a female hormone, men and women both produce it, and it can help protect against the same things sirtuins prevent, such as heart disease.
Results also showed that resveratrol mimics estrogen in low doses, but becomes antiestrogenic in higher concentrations, consequently suppressing sirtuin signals. “Excessive intake may in fact be counterproductive because, in high doses, the study found that resveratrol inhibited sirtuin activation of the estrogen receptors,” Dr. Bayele told Wine Spectator. “Therefore, the low doses of resveratrol found in a regular glass of red wine should be sufficient to activate the sirtuins. Simply put, for red wine or resveratrol to improve healthspan, less is more.”
So what’s a low dose? Dr. Bayele explains that a regular glass of table wine contains about 0.5 to 1 milligram of resveratrol. “Of note, these concentrations are similar to those at which resveratrol behaves like estrogen to induce maximal sirtuin signaling through the estrogen receptors,” he said.
Other dSTACs studied were better than resveratrol at activating sirtuins, such as isoliquiritigenin, which is found in licorice. According to Dr. Bayele, resveratrol has attracted the most attention due to its accessibility in red wine, combined with its demonstrable protection against metabolic, cardiovascular and neurodegenerative diseases. “It has been shown to increase lifespan in diverse organisms,” he writes in the study.
While the research shows promise, the findings have yet to face human trials or long-term studies, and must be better understood before potential treatments can be developed. Dr. Bayele also warns that dSTACs are poorly soluble, and it’s difficult to determine how much are absorbed in the cell culture. His main takeaway is that wine lovers must also incorporate a healthy diet to improve healthy aging and prevent the onset of metabolic and age-related diseases.
In the case of resveratrol, Dr. Bayele says that when humans consume it, only small amounts are rapidly absorbed, while a large proportion gets metabolized in the small intestine, which complicates the validity of the data. In short, it is still unclear how resveratrol intake would affect sirtuin signaling in vivo, but Dr. Bayele is confident that these dietary compounds are hidden treasures.
“While [resveratrol’s] role in aging/lifespan regulation remains controversial,” Dr. Bayele writes, “Its contribution to healthspan is not in doubt.”
