Mushrooms may contain unusually high amounts of two antioxidants that some scientists suggest could help fight aging and boost health, according to a team of researchers at Penn State University in the US.
In a study, researchers found that mushrooms have high amounts of ergothioneine and glutathione, which are both important antioxidants, according to Robert Beelman, Professor Emeritus of Food Science and Director of the Penn State Center for Plant and Mushroom Products for Health. He adds that the researchers also found that the amounts the two compounds varied greatly between mushroom species.
“What we found is that, without a doubt, mushrooms are highest dietary source of these two antioxidants taken together, and that some types are really packed with both of them,” says Beelman.
Shielding against oxidative stress
Beelman says that when the body uses food to produce energy, it also causes oxidative stress because some free radicals are produced. Free radicals are oxygen atoms with unpaired electrons that cause damage to cells, proteins and even DNA as these highly reactive atoms travel through the body seeking to pair up with other electrons.
Replenishing antioxidants in the body may therefore help to protect against this oxidative stress.
“There’s a theory – the free radical theory of aging – that’s been around for a long time that says when we oxidize our food to produce energy there’s a number of free radicals that are produced that are side products of that action and many of these are quite toxic,” says Beelman.
“The body has mechanisms to control most of them, including ergothioneine and glutathione, but eventually enough accrue to cause damage, which has been associated with many of the diseases of aging, like cancer, coronary heart disease and Alzheimer’s,” Beelman continues.
According to the researchers, who report their findings in a recent issue of Food Chemistry, the amounts of ergothioneine and glutathione in mushrooms vary by species with the porcini species, a wild variety, containing the highest amount of the two compounds among the 13 species tested.
“We found that the porcini has the highest, by far, of any we tested,” says Beelman. “This species is really popular in Italy where searching for it has become a national pastime.”
The more common mushroom types, like the white button, had less of the antioxidants, but had higher amounts than most other foods, Beelman says.
The amount of ergothioneine and glutathione also appear to be correlated in mushrooms, according to the researchers. Mushrooms that are high in glutathione are also high in ergothioneine, for example.
Cooking mushrooms does not seem to significantly affect the compounds, Beelman says. “Ergothioneine are very heat stable,” he comments.
Beelman says that future research may look at any role that ergothioneine and glutathione have in decreasing the likelihood of neurodegenerative diseases, such as Parkinson’s disease and Alzheimer’s disease.
“It’s preliminary, but you can see that countries that have more ergothioneine in their diets, countries like France and Italy, also have lower incidences of neurodegenerative diseases, while people in countries like the United States, which has low amounts of ergothioneine in the diet, have a higher probability of diseases like Parkinson’s Disease and Alzheimer’s,” says Beelman.
“Now, whether that’s just a correlation or causative, we don’t know. But it’s something to look into, especially because the difference between the countries with low rates of neurodegenerative diseases is about 3 milligrams per day, which is about five button mushrooms each day,” Beelman concludes.