Mushrooms are a source of many important vitamins and minerals including B vitamins, iron, potassium and selenium.
Recent research has also discovered that they are a prime natural source of the powerful antioxidant L-Ergothioneine. Led by Professor Robert Beelman, researchers at Pennsylvania State University found that just a handful of white button mushrooms have about 12 times more of the antioxidant than wheat germ and four times more than chicken liver which were previously thought to be the best sources. L-Ergothioneine scavenges free radicals and protects the body’s DNA from damage. As a result of this research, the university advocated that white mushrooms be elevated to 'superfood' status.
Mushrooms are in fact one of the highest antioxidant vegetables in the world, in the same league as the red pepper and spinach. Research led by Joy Dubost, also at Pennsylvania State University, found that cultivated mushrooms contain another group of antioxidants called polyphenols which play a role in protecting the body’s DNA against free radicals.
The white button mushroom is often considered to be the poor relation to its more exotic cousins. But new research from The French Institute of Agricultural Research which compared the antioxidant activity of button mushrooms and the exotic maitake and matsutake mushrooms, found that the white button mushroom has as much, and in some cases more antioxidant properties than more exotic varieties. (Published in the SCI's Journal of the Science of Food and Agriculture, October 2007)
Meanwhile, research published by Hanyang University in South Korea found eating mushrooms may lower the risk of breast cancer. The research was based on more than 700 women, half of whom had the disease. The group who ate mushrooms everyday were estimated to have an 80 per cent reduced risk of cancer. It was thought the fungi interfered with the action of aromatase, an enzyme that helps the body make oestrogen. White button mushrooms had the strongest effect.
A similar study on mice by researchers at the City of Hope, California (published December 2006) found that when the rodents were fed mushroom extract they had a 58 per cent reduction in breast cancer growth. White flat mushrooms had the strongest effect, with shiitake, white button, Portabello and chestnut mushrooms also having significant inhibitory effects on aromatase, even when cooked.
New research findings, which were splashed across Australian, American and UK press in early 2009, revealed that eating a small portion of mushrooms every day could slash the risk of breast cancer by nearly two thirds.
The Daily Express reported that experts at the University of Western Australia in Perth had analysed the eating habits of more than 2,000 women in China, half of whom had suffered breast cancer. They claimed that those who ate at least 10g – around a third of an ounce – of fresh mushrooms every day were 64 per cent less likely to develop a tumour. And concluded that a “higher intake of mushrooms decreased cancer risk in both pre- and post-menopausal Chinese women.” The researchers also claimed that when combined with drinking green tea regularly, the risk is cut by 90 per cent.
Breast cancer is now the most common cancer in the UK and while there is no one particular food that will protect you from cancer, experts agree that eating a healthy balanced diet is one of the most effective ways of minimising the risk.
A further study from the John Hopkins Bloomberg School of Public Health in Baltimore, America has shown that the humble white button mushroom may have a role to play in the fight against obesity. The study suggests that swapping beef for button mushrooms in just under 10 meals could lead to a reduction in body fat of 1lb. If one such substitution was made every week, this would amount to saving of nearly 20,000 calories in a year, or more than 5 lbs in body fat. What was particularly important about the research was that it also looked at palatability (meal appeal), appetite, satiation (after-meal fullness) and satiety (general fullness) and volunteers gave similar scores across the two different meal categories.
The Glycaemic Index (GI) of mushrooms is so low it can’t even be measured. In fact, to get a GI measurement in mushrooms you would need to eat 1.2kg in less than 10 minutes! Mushrooms are also a useful source of protein for vegetarians.
An 80g serving, around 14 baby button mushrooms, four large closed cup mushrooms or one large flat mushroom counts towards the 5-A-DAY target.