Mushrooms are full of antioxidants that may have anti-aging potential
Mushrooms may contain unusually high
amounts of two antioxidants that some scientists suggest could help fight aging
and bolster health, according to a team of Penn State researchers.
In a study, researchers found that
mushrooms have high amounts of the ergothioneine and glutathione, both
important antioxidants, said Robert Beelman, professor emeritus of food science
and director of the Penn State Center for Plant and Mushroom Products for
Health.
He added 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," said
Beelman.
Beelman said 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, then, may help 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," said 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."
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," said 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 said.
The amount of ergothioneine and
glutathione also appear to be correlated in mushrooms, the researchers said.
Mushrooms that are high in glutathione are also high in ergothioneine, for
example.
Cooking mushrooms does not seem to
significantly affect the compounds, Beelman said.
"Ergothioneine are very heat
stable," said Beelman.
Beelman said 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," said 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 worked with Michael D.
Kalaras, postdoctoral assistant in food sciences; John P. Richie, professor of
public health sciences and pharmacology; and Ana Calcagnotto, research
assistant in public health sciences.
