Developing breast cancer (BC) is a frightening prospect for many women as it is the most common cause of cancer death, and the most common cancer in women worldwide (one million women are diagnosed with BC annually).
One in eight women and one in four women develop breast cancer in the US and the UK respectively, and Egypt follows closely behind the UK’s prevalence rate. BC is primarily a disease of lifestyle and diet as only 15 percent of BC is associated with genetic and familial factors. Migratory studies show that people migrating to another country develop BC at the same prevalence as that of the population of the country to which they migrate (e.g. one in forty women develop breast cancer in Asia, but when they migrate to the U.S, their rate increases to that of American women) suggesting that dietary factors play a large role, and this is supported by numerous epidemiological studies.
A recent epidemiological study published in the International Journal of Epidemiology by the University of Leeds in the UK has shown that eating more fiber, particularly cereal fiber markedly reduces the risk of .developing breast cancer among pre-menopausal women.
The study researched the diet of over thirty five thousand women for the past seven years, and found that among the pre menopausal women, those who consumed the greatest amount of fiber had a fifty percent reduction in breast cancer risk. The same results were not found in the post menopausal woman group, suggesting that fiber protective effects occur earlier on in life. The women that did develop cancer were found to derive a greater percentage of energy from protein, and have lower intakes of fiber and vitamin C compared to cancer-free women. Fiber’s protective effects against bowel cancer have been well documented, but this is the first study to find such a convincing link between fiber and BC.
In the study, women who consumed 30g of fiber a day halved their risk of developing BC compared to women who consumed less than 20g per day. In order to consume 30g of fiber, you should have a high fiber cereal for breakfast, switch to whole meal bread, and eat five portions of fruit and vegetables. Fiber containing foods abound and include; whole grain breads and whole wheat pasta; breakfast cereals, whole grains such as barley, corn, brown rice; dried fruits such as apricots and dates; fruits such as berries, oranges and apples, kiwi, mango and pears; vegetables such as broccoli, spinach, dark green leafy vegetables, peas, dried peas; beans such as kidney, black-eyed peas, chick-peas and lentils; and nuts and seeds, such as almonds flaxseed and soy nuts..
But how do fiber foods protect against BC? Fiber foods are rich in vitamins, zinc and other micronutrients which have protective antioxidant and anti-carcinogenic (anti cancer) properties. Fiber also regulates hormones in the body that are involved in BC such as insulin, high levels of which are implicated in breast cancer, and estrogen. The more a woman is exposed to estrogen throughout her life (early onset of menses, late menopause, less or delayed childbearing) the more likely she will develop breast cancer.
Soy products have been heralded to protect against BC, and this is because they act as phyto estrogens that bind to estrogen receptor sites in our cells, including breast cells, blocking these receptors from being bound by estrogen, and interfering with the cancer-promoting effects of estrogen on breast tissue. Women who consume soy have lower levels of BC than those who don’t. Phyto estrogens are also found in flax seeds, nuts and seeds, which are also rich in omega 3 fatty acids, another BC protective agent.
Other dietary factors thought to protect against BC include cruciferous vegetables, components of which help to breakdown estrogens, Calcium D glucarante which prevents the re-absorption of excreted estrogens, and green tea, which has been shown to be protective against estrogen related cancers.
Alcohol and being overweight are directly proportional to increasing your risk for development of BC, as is smoking (and passive smoking!). Saturated animal fats are also thought to pose some risk for BC, particularly grilled and well cooked meats, which become more carcinogenic the more they are cooked. Other environmental factors linked to BC included exposure to pesticides, radiation, synthetic compounds that mimic estrogen, and lack of exposure to sunlight.
As it is not known at which point in life diet impacts on a woman’s susceptibility to BC, it would be prudent to maintain a healthy diet throughout our lives and from the beginning of our children’s lives. The power of food in preventing disease is becoming ever more apparent and it’s time we used it accordingly and taught our children to do the same. Instilling fiber rich foods in our children’s diet may protect them later on, not just from BC, but from many other cancers and diseases.
Dr. May El Meleigy holds a Ph.D in Immunology from the London School of Hygiene and Tropical Medicine, as well as an MSc. (Toxicology/pathology) and a B.Sc in pharmacology) from London University. El Meleigy is a freelance medical/health writer and is currently producing Health Education programs for Egyptian TV.
