Spermidine—a compound found in foods like aged cheese, mushrooms, soy products, legumes, corn and whole grains—seems to prevent (at least in animal models) liver fibrosis and hepatocellular carcinoma, which is the most common type of liver cancer.

Researchers gave animal models an oral supplement of spermidine and found that they lived longer and were less likely than untreated individuals to have liver fibrosis and cancerous liver tumors, even when predisposed for those conditions.

“It’s a dramatic increase in lifespan of animal models, as much as 25%,” says Leyuan Liu, assistant professor at the Texas A&M Institute of Biosciences and Technology’s Center for Translational Cancer Research, College Station, Texas. “In human terms, that would mean that instead of living to about 81 years old, the average American could live to be over 100.”

The trouble is that people would need to begin ingesting spermidine from the time they begin eating solid food to get this kind of significant improvement in their lifespans; those animal models treated later only saw a 10% increase in longevity. Still, it may be the most sustainable option scientists have found yet.

“Only three interventions—severely cutting the number of calories consumed, restricting the amount of methionine (a type of amino acid found in meat and other proteins) in the diet and using the drug rapamycin—have been shown to truly prolong the lifespans of vertebrates, but eating less and not eating meat will not be welcomed by general population, while rapamycin has shown to suppress the human immune system,” Liu says. “Therefore, spermidine may be a better approach. Spermidine is a product naturally found in food, so we hope it would have minimal side effects. The next steps would be human clinical trials to determine safety and efficacy.”