Soy Isoflavones and Lung Cancer Treatment
Two new laboratory studies show that – in mice – isoflavones extracted from soybeans increase the effect of radiation to destroy lung tumors, while reducing radiation damage in healthy cells. The studies, supported by AICR, build on previous animal studies by the same team of researchers showing similar effects for prostate tumors.
Both studies used a supplement composed primarily of genistein and daidzein, two isoflavone compounds found in soy that have phytoestrogen properties. In one study published last month, the mice consumed isoflavone supplements for three days before and four months after radiation. Supplementation with soy isoflavones protected mice against radiation-induced skin injury and hair loss.
In the second study mice with lung cancer consumed isoflavone supplements while undergoing radiation therapy. Compared to mice not given the supplement, the animals with combined isoflavone and radiation had slower tumor growth. And compared to the comparison group the animals that consumed the supplements showed less damage to the healthy surrounding lung tissue, including less inflammation and fibrosis, a scarring of the tissue around the air sacs.
Ongoing studies are investigating the mechanisms.
Hillman GG et al. J Thorac Oncol. Radioprotection of lung tissue by soy isoflavones. 2013 Nov;8(11):1356-64. doi: 10.1097/JTO.0b013e3182a4713e.
Hillman GG et al. Radiother Oncol. Differential effect of soy isoflavones in enhancing high intensity radiotherapy and protecting lung tissue in a pre-clinical model of lung carcinoma. 2013 Sep 7. pii: S0167-8140(13)00401-5. doi: 10.1016/j.radonc.2013.08.015. [Epub ahead of print]