Introduction:
Agaritine is a mycotoxin found in the white button mushroom Agaricus bisporus and many other species of mushrooms found all over the world. Agaritine appears to have both health benefits for breast cancer, but also has been shown to promote mutation of DNA. There is also active testing of the substance as an HIV antiviral drug. Different types of mushrooms have been found to have a variable amount of agaritine contained in them, but cooking the mushrooms reduces the agaritine content.
Agaritine and breast cancer:
Agaritine has been shown to be beneficial for the association of the mushroom toxin with reduced risk of breast cancer. Agaritine may have a protective benefit against breast cancer. Mushroom consumption and risk of breast cancer were analyzed in 358 breast cancer patients and 360 cancer-free individuals. Comparing premenopausal women who ate the most mushrooms against the women who ate the least mushrooms, mushroom eaters had a 65% reduced risk of developing breast cancer. When the data was broken down by estrogen receptor status, the effect was stronger (70% risk reduction in women with estrogen receptor (ER)+/progesterone receptor (PR)+ than those with ER-/PR- tumors). (1)
Case control study on mushroom consumption and breast cancer:
A case control study of 362 Korean women aged 30-65 years reported an association between mushroom consumption and decreased risk of breast cancer. Comparing the women who ate the most mushrooms against the women who ate the least mushrooms, mushroom eaters had 48% reduced risk of developing breast cancer. When the data was broken down by menopausal status, the effect was far more dramatic. The post- menopausal mushroom eating subjects had an 84% decreased risk of breast cancer. (2)
Mushrooms and risk of breast cancer:
A study from China found that women could reduce their risk of breast cancer by consuming a small amount of mushrooms. When the women in the study included green tea, their breast cancer risk decreased even more. Intake of fresh mushrooms (greater than or equal to 10 grams per day) and dried mushrooms (greater than or equal to 4 grams per day) decreased risk by 64% and 47%, respectively. When consumption of green tea was added (more than 1g of tea-leaves per day), the protective effect was 89% reduced risk in women who consumed the most green tea plus fresh mushrooms and 72% reduced risk in women who consumed the most green tea plus dried mushrooms. (3)
Agaritine may be a harmful mycotoxin:
Agaritine studies using mushrooms and mushroom extracts have not provided convincing evidence of the harmful effects of agaritine or mushroom consumption in humans. Part of the reason may be the fact that most consumption is in the form of cooked mushrooms. The agaritine content is reduced in mushrooms by 50% after boiling for just 5 minutes and further reduced by 90% after boiling for 2 hours (as in sauce making). (4)
Agaritine toxicity:
Shephard SE et al researched toxicity of agaritine in transgenic mice. For 15 weeks, female mice were given one of 3 diets: fresh mushrooms 3 days/week followed by normal lab chow for 4 days/week (averaged daily agaritine dose 30mg/kg), 80 mg/kg daily freeze-dried mushrooms mixed at 25% agaritine, or 120 mg/kg daily of mushroom extract containing 30% agaritine. The findings in this study consisted of a significantly higher rate of gene mutations within the tissues of the organs in mice, especially the kidney and proximalstomach. The findings supported agaritine to be a mild carcinogen. The study results were translated to human consumption of Swiss mushrooms. An intake of about 4 grams of these mushrooms per day would be expected to contribute to a lifetime cumulative cancer risk in humans of about 2 cases per 100,000 lives. (5)
Assessment and Plan: Agaritine
Agaritine may have a protective benefit against breast cancer in observational studies (1-3), but there is currently not enough evidence to support intake of raw or cooked mushrooms, or supplements containing agaritine for prevention of breast cancer. Cooked domestic white button mushrooms as part of dietary intake appear to be safe but avoid if allergic. Estrogen and/or progesterone receptor positive breast cancer tumors or patients who may be at increased risk of this type of cancer may possibly benefit from white button mushroom intake, but more research is required (1). Unfortunately, agaritine consumed with the intake of raw mushrooms only, (not cooked) has a small amount of evidence that a small increase in the risk of cancer exists by causing gene mutations (5), but more research needs to be done on this as well. Agaritine content is reduced in mushrooms by 50% after boiling for just 5 minutes and further reduced by 90% after boiling for 2 hours (as in sauce making) (4).
References :
1.Shin A, Kim J, Lim SY, Kim G, Sung MK, Lee ES, Ro J. Dietary mushroom intake and the risk of breast cancer based on hormone receptor status. Nutr Cancer. 2010;62(4):476-83. http://www.ncbi.nlm.nih.gov/pubmed/20432168
2.Hong SA, Kim K, Nam SJ, et al. A case-control study on the dietary intake of mushrooms and breast cancer risk among Korean women. Int J Cancer 2008;122:919-923. http://www.ncbi.nlm.nih.gov/pubmed/17943725
3.Zhang M, Huang J, Xie X, et al: Dietary intakes of mushrooms and green tea combine to reduce the risk of breast cancer in Chinese women. Int J Cancer 2009 Mar 15;124(6):1404-1408. http://www.ncbi.nlm.nih.gov/pubmed/19048616
4.Roupas P, Keogh J, et al. Mushrooms and agaritine: A mini-review. J Funct Foods 2(2):8 (2010), http://www.sciencedirect.com/science/article/pii/S1756464610000241
5.Shephard SE, Gunz D, Schlatter C: Genotoxicity of agaritine in the lacI transgenic mouse mutation assay: evaluation of the health risk of mushroom consumption. Food Chem Toxicol 1995, 33: 257-264. http://www.ncbi.nlm.nih.gov/pubmed/7737599
