Animal Study: Soy Before Puberty Reduces Breast Cancer Recurrence

How soy plays a role in breast cancer risk and recurrence is one of the most common questions we get asked. A large body of human research suggests eating tofu, soy milk and other soy foods in moderation safe. Now an animal study that may help explain what is seen in human research, shows that eating soy foods when young boosts the immune response against tumors, reducing cancer recurrence.soy_tofu_dreamstime_13994134

The study is being presented at the American Association for Cancer Research (AACR) annual meeting, and is not yet published.

Soy contains compounds called isoflavones that mimic the effect of estrogen. This raised concerns that it would stimulate breast tumors fueled by estrogen and may interfere with anti-estrogen treatment, such as tamoxifen. Early animal studies did find a link between isoflavones increasing risk of breast cancer. According to the news release, one reason may be that this early animal research used animals that do not have certain immune cells called cytotoxic T cells. These are among the cells that act against breast tumors. Continue reading


Study: Carotenoids Lower Risk of Breast Cancer, Recurrence

Having plenty of tomatoes, carrots and other foods high in carotenoids may reduce the risk of breast cancer, especially the most deadly types, suggests a new study that spanned 20 years. The study, published in The American Journal of Clinical Nutrition, adds to a growing body of research on carotenoids, diet and breast cancer risk.17539703_s

Carotenoids are a large group of phytochemicals that you can spot in many red, orange and yellow fruits and vegetables. Beta-carotene and lycopene, found in carrots and tomatoes to name a few foods, are a couple of the more well-known carotenoids. They’re also in dark green vegetables, such as kale and spinach.

Previous studies on carotenoids and breast cancer have been mixed. This study builds on research by the same group suggesting that carotenoids affect different types of breast tumors. We wrote about that here.

As in their previous study, the researchers used blood levels of carotenoids to measure intake. Back in 1989-90, they collected blood samples from almost 33,000 women who were part of the Nurses Health Study. Ten years later they collected another sample, with slightly less than half of the women participating again. All the women were regularly answering questionnaires about their health, weight, diet and other factors. Continue reading