Like vitamin C, mushrooms have been spoken about in holistic circles as being a wonderful cancer prevention and cure.
Whether or not this is true, they are said to possess properties that are immensely good for the immune system.
This may have started as early as the year 2000, when Cancer Research UK and the University of Strathclyde published a review of Japanese studies into people taking an extract of a certain type of mushroom, which they say seemed to reduce the side effects of chemotherapy and radiation.
But Cancer Research UK is quite keen to point out that there is no hard evidence to back this up.
On their website, they say: "Some studies seemed to show that these mushrooms could stimulate the immune system to fight disease. There is some evidence from a Japanese study that people who eat a particular type of mushroom all their lives have a lower risk of getting cancer.
"In some people mushrooms did seem to affect their cancer. But we have to be very cautious about the results because most of these early trials were not randomised or controlled. So, there was no proper comparison made between patients having the mushrooms and similar patients not being treated with mushrooms or drugs developed from mushrooms."
However, The Guardian has picked up the baton, writing a feature about how mushrooms may play a key role in cancer prevention. Even more interestingly, about Shiitake mushrooms (glorious, meaty things).
"Not only is it a delicious ingredient," writes Matthew Jenkin, "but it is also famed for its compound lentinan. Several papers have found the polysaccharide could help increase the survival rate of cancer patients, including research carried out by a team of scientists at Harbin University, China, in 2008, which found that lentinan was "beneficial in terms of increasing mean survival duration, tumour necrosis and reducing the recurrence rate"."
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Green tea is rich in the polyphenol EGCG (epigallocatechin-3-gallate), which has been shown to slow the spread of breast cancer cells, according to breastcancer.org.
Cruciferous vegetables, but broccoli in particular, make for anti-cancer powerhouses thanks in part to a compound called sulforaphane that actually helps the body fight the spread of tumors. Recent research revealed the underlying reason: sulforaphane may inhibit an enzyme, called an HDAC, that works to suppress the body's tumor fighting ability, as we've previously reported. And sprouts are even more potent: three-day old broccoli sprouts have 20 to 50 times the sulforaphanes as mature broccoli, according to Johns Hopkins research. For more about the cancer fighting properties of all cruciferous vegetables, check HuffPost blogger Dr. Joel Fuhrman's analysis of cabbage, brussels sprouts, bok choy and more.
Garlic is considered a cancer-fighting food for several forms of the disease, according to the National Cancer Institute. One French study found that women who regularly ate garlic had a significantly reduced risk of breast cancer. Garlic's mild cousin, onions also had a protective effect, according to the study.
Pomegranates are known for their anti-cancer properties, thanks to a richness in anti-inflammatory antioxidants, polyphenols. But they may offer a specific benefit against breast cancer: research shows that a phytochemical found in abundance in pomegranates, called ellagitannins, interfere in the production of aromatase, an enzyme that, as HuffPost blogger Dr. Nalini Chilkov explained, "increases hormone production in breast tissue." That's important because breast cancer is hormone-dependent, meaning that it feeds off of hormones like estrogen to grow and spread. "Hormone dependent cancers such as breast cancer are commonly treated with aromatase inhibitors, which block this enzyme," wrote Chilkov.
Although preliminary, research in mice has found that including walnuts in a healthful diet throughout the entire lifespan reduced the risk of developing breast cancer by half.
Curcumin, the compound in turmeric, may play a role in blocking the expression of a molecule called RANKL, which is found in the most deadly and aggressive breast cancer tumor cells.
Berries have several powerful antioxidants, primarily anthocyanins and ellagic acid, which have been shown in cell culture studies to reduce free radical damage to healthy cells, according to the American Institute for Cancer Research. In separate research, they were shown to slow the growth and shorten the lifespan of breast cancer (as well as mouth, colon and prostate cancer) cells.
Most research regarding flax's anti-cancer properties has been done in mice or in-vitro cell cultures, but what it shows could be profound: in one study, according to the American Cancer Society, the lignans found in flax slowed the movement and "stickiness" of breast cancer cells, causing it to spread more slowly in a cell culture simulation.
Tomatoes are rich in the antioxidant lycopene, which is thought to slow breast cancer cell growth.
On the subject of Shiitake mushrooms, Cancer Research UK says that clinical research is being conducted to explore the possible health benefits. "Lentinan is a beta glucan. This is a type of complex sugar compound. Beta glucan is believed to stimulate the immune system and trigger certain cells and proteins in the body to attack cancer cells. In laboratory studies, it seems to slow the growth of cancer in some cell cultures.
In mice, lentinan has been shown to stop the growth of bowel cancer cells. In laboratory tests, the protein part of lentinan (lentin) can stop the growth of some fungal cells. It can also stop leukaemic cells dividing."
Another mushroom, which you can't buy widely in the UK except as an extract, is Reishi, also known as ganoderma.
Jenkins writes: "It has been used in Chinese medicine for 2,000 years and numerous studies have investigated its much-vaunted anti-cancer and immune-boosting properties. In a paper published last year in the US's Proceedings of the National Academy of Sciences (PNAS) journal, a team of scientists linked its use to cancer-cell death."
Another mushroom that Cancer Research UK mentions is the agaricus sylvaticus mushroom. A Brazilian study gave patients these as part of their diet after bowel cancer surgery and found that "patients who had the mushrooms had a better quality of life compared to patients who did not have the mushrooms."
This included: more ability to do physical exercise, better sleep and appetite and fewer aches and pains.
Sadly for UK mushrooms, there seem to be few benefits - when it comes to cancer, anyway.
(H/T: The Guardian)