A low-fat, high-fiber diet can significantly reduce estrogen levels.5,6 Cancer researchers have taken great interest in this phenomenon because lowering the level of estrogen in the blood helps reduce the risk of breast cancer. Less estrogen means less stimulation for cancer cell growth.
If a woman eating a Western diet cuts her fat intake in half, her estrogen level will be about 17% lower. If the amount of fat is cut even more, the estrogen level will drop further. A lower hormone level will have less effect on the uterine cells.
In addition to lowering estrogen, a low-fat diet may also be beneficial because high-fiber vegetables, beans, fruits, and whole grains help the body to eliminate estrogens. Estrogen is normally pulled from the bloodstream by the liver, which sends it through a small tube, called the bile duct, into the intestinal tract. There, fiber soaks it up like a sponge and carries it out with other waste. The more fiber in the diet, the better the natural “estrogen disposal system” works.
Animal products and many processed foods do not contain fiber. When an individual’s diet consists predominantly of packaged foods, refined grains, meat, or dairy, daily fiber needs may not be met. The extra estrogens, which should bind to fiber in the digestive tract and leave the body, get absorbed back into the bloodstream. This hormone “recycling” increases the amount of estrogen in the blood.
However, the reabsorption of estrogens can be blocked with the fiber found in grains, vegetables, beans, and other plant foods. When researchers asked women in Japan what foods they ate most often and how they would rate their menstrual pain, they found that eating high amounts of fiber was significantly related to having less menstrual pain. By blocking the reabsorption of estrogen, fiber helps to reduce estrogen levels and subsequent menstrual cramps.
Not only do animal products lack fiber, but they also can contribute to worse menstrual pain. A study showed that higher intakes of red meat and processed meat may lead to endometriosis—a painful condition in which uterine cells extend to other organs in the body. The women who ate the most red meat (more than two servings a day) increased their risk of developing endometriosis by as much as 56%. In addition, dairy products may contribute to extra estrogen circulating in the blood since cows are usually pregnant while being milked and may pass along estrogen through their milk.
By avoiding animal products, processed foods, and added oils, estrogen production is reduced. And by replacing chicken, skim milk, and other nonfiber foods with grains, beans, and vegetables, estrogen elimination is increased.
In a research study published in Obstetrics & Gynecology, a low-fat, vegan diet significantly reduced pain and PMS for many women. The study included 33 women who followed either the low-fat vegan diet or their regular diet and then switched treatments. The diet change was designed to do two things. First, it eliminated all animal fats and nearly all vegetable oils. Second, its emphasis on plant-based foods increased the fiber in the diet. While these women followed the low-fat vegan diet, the intensity of their pain was significantly lower than during their regular diet. They also noticed less water retention and fewer mood swings. The effect of the diet was so powerful that some women refused to switch back to their regular diet, even though the study design required it.
