In a recent case-control study published in Public Health 2017, the relationship between a vegetarian diet and breast cancer was evaluated in 469 Asian women of the same age (233 patients with breast cancer and 236 controls). From the analysis of the questionnaires on the vegetarian diets used and 27 frequently consumed food products belonging to the categories: meat, sausages, fruit / vegetables / soy, dessert / sugar and fermented foods, a correlation emerged between high consumption of meat and sausages and the risk of breast cancer. In contrast, the vegetarian diet, the high consumption of isoflavones and high levels of albumin are inversely related to the risk of breast cancer. The authors emphasize the highest daily dose of isoflavones compared to non-vegetarians (25.9 ± 25.6 mg vs 18.1 ± 15.6 mg).

Chang, Yao-Jen, et al. “Is vegetarian diet associated with a lower risk of breast cancer in Taiwanese women?.” BMC public health17.1 (2017): 800.