Oats (Avena sativa) are a good source of soluble dietary fiber (especially β-glucan), and also contain meaningful amounts of iron, manganese, thiamin (vitamin B1), and zinc. Oats are also a dietary source of melatonin and the lignan enterolactone. Avenanthramides, polyphenols found in oats, have been shown to exhibit anti-inflammatory and anti-itch activity in the skin. Consumption of oats or β-glucan has been shown to reduce cholesterol, improve colon health, offset the increased risk of upper respiratory tract infection caused by stressful exercise, and reduce high blood pressure in obese subjects. High consumption of whole grains has been associated with lower risk of colon cancer.
Whole grain consumption has also been shown to be associated with greater insulin sensitivity and lower body mass index in adolescents, especially among the heaviest. A diet containing 10% oat lipids has been shown to reduce the incidence and size of carcinogen-induced liver tumors in laboratory rats.
Breast cancer-related effects of eating oats
Diets rich in soluble fiber and whole grains have been found to be protective against breast cancer in some studies and not associated with breast cancer risk in others. Oats are a source of melatonin, which has been shown to be associated with lower risk of breast cancer. A 2008 study suggested that bowel motility was inversely related to breast cancer risk because it increases estrogen excretion. Consumption of oats increases bowel motility. A 2018 study reported that Finnish women with high oatmeal consumption had a lower risk of breast cancer.
Oat groats are whole oats that have been hulled (to remove their inedible hulls). Steel-cut oats are groats that have been cut into two or three pieces. Rolled oats are made by steaming oat groats and then rolling them into flakes. All three are good choices.
Below are links to recent studies concerning this food. For a more complete list of studies, please click on oats.