A new study suggests that there may be a simple way to help reduce the risk of liver cancer and extend lifespan: consume mushrooms, soy, whole grains, aged cheese, and other foods rich in spermidine.
Researchers found that mice fed an oral supplement of spermidine were less likely to develop liver fibrosis and hepatocellular carcinoma (HCC) - the most common form of liver cancer - compared with rodents that did not receive the supplement.
Furthermore, the research team - from Texas A&M University in College Station - found that spermidine increased the lifespan of mice by as much as 25 percent.
Study co-author Leyuan Liu, Ph.D., of the Institute of Biosciences & Technology at Texas A&M, and colleagues recently reported their findings in the journal Cancer Research.
Spermidine is a polyamine - a compound that has at least two amino groups - that was originally isolated from sperm, hence its name. Spermidine is also naturally found in a variety of food products, including aged cheese, mushrooms, legumes, soy, whole grains, and corn.
Previous research has suggested that dietary spermidine may have health benefits. One study published in Nature Medicine last year, for example, associated oral supplementation of spermidine with better heart health and longevity in mice, while a more recent study linked the compound to reduced blood pressure.
For this latest study, Liu and colleagues investigated whether spermidine might have anti-cancer properties.
Spermidine supplementation led to 'dramatic increase' in lifespan
To reach their findings, the researchers gave an oral spermidine supplement to mice that were predisposed to develop HCC or liver fibrosis - that is, a buildup of scar tissue in the liver that can lead to liver cancer.
Not only were the mice less likely to develop HCC or liver fibrosis than rodents that were not given the spermidine supplement, but they were also found to live much longer.
"It's a dramatic increase in lifespan of animal models, as much as 25 percent," says Liu. "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 authors note that the 25 percent increase in lifespan was only seen in mice that had lifelong spermidine supplementation; rodents that were given the supplement later in life experienced a 10 percent increase in longevity.
'A novel strategy to prolong lifespan'
In this study, the researchers found that the benefits of spermidine diminished in the absence of a protein called MAP1S, which is known to trigger autophagy. As such, the team speculates that the cancer-protective effects of the compound are down to its enhancement of MAP1S-related autophagy.
Further studies are needed to determine the safety and efficacy of spermidine supplementation in humans, but the team believes that it could offer significant health benefits.
"Just think: if we added spermidine to every bottle of beer, it might balance out the alcohol and help protect the liver," says Liu.
"It's still early, but perhaps one day this approach will provide a novel strategy to prolong lifespans, prevent or reverse liver fibrosis, and prevent, delay, or cure hepatocellular carcinoma in humans."
Leyuan Liu, Ph.D.