Eating Certain Foods In Adolescence Could Reduce Breast Cancer Risk
Posted November 20, 2006 12:00 pm.
This article is more than 5 years old.
If you ate a soy-rich diet as an adolescent, you could be at a reduced risk for breast cancer.
Soybeans and tofu contain isoflavones, one of the two main classes of phytoestrogens. Phytoestrogens are compounds produced naturally in plants. A study published Monday by Cancer Causes Control suggests that foods containing phytoestrogens, if consumed before adulthood, could play a role in reducing the threat of breast cancer later in life.
Phytoestrogens are found in many common foods – not just soy products. Another major source of isoflavones is chickpeas and legumes. The other main class of phytoestrogens is known as lignans – and lignans are found in flaxseeds, sesame seeds, grains and breads, nuts, beans, tea, coffee, and some fruits and vegetables.
The study involved 6,444 women from Ontario, 3,024 of which had recently been diagnosed with breast cancer, and asked them to provide information about their teenage eating habits. Scientists found that increased intake of foods containing the compounds in adolescence was associated with a reduced risk for breast cancer.
“These findings may provide important clues about the timing of dietary phytoestrogen intake and how this may relate to breast cancer prevention as adolescence is a time when breast tissue is rapidly developing and may be particularly sensitive to environmental factors,” said Dr. Michelle Cotterchio, a scientist with Cancer Care Ontario.
It’s the first study to examine the importance of lignan intake – which is particularly important in North American diets where soy food consumption has traditionally been quite low.
Cancer Care Ontario and other health organizations recommend people eat five to 10 servings of fruit and vegetables a day to help ward off cancer.
Here are the common risk factors for breast cancer, courtesy Mayo Clinic:
Age. Your chances of developing breast cancer increase as you get older. The disease rarely affects women younger than 25 years of age, whereas close to 80 percent of breast cancers occur in women older than age 50. At age 40, you have a one in 252 chance of developing breast cancer. By age 85, your chance is one in eight.
A personal history of breast cancer. If you’ve had breast cancer in one breast, you have an increased risk of developing cancer in the other breast.
Family history. If you have a mother, sister or daughter with breast or ovarian cancer or both, or even a male relative with breast cancer, you have a greater chance of also developing breast cancer. In general, the more relatives you have with breast cancer who were premenopausal at the time of diagnosis, the higher your own risk. If you have one close relative with the disease, your risk is doubled. If you have two or more relatives, your risk increases even more.
Genetic predisposition. Between 5 percent and 10 percent of breast cancers are inherited. Defects in one of several genes put you at greater risk of developing breast, ovarian and colon cancers. Usually these genes help prevent cancer by making proteins that keep cells from growing abnormally. But if they have a mutation, the genes aren’t as effective at protecting you from cancer.
Radiation exposure. If you received radiation treatments to your chest as a child or young adult, you’re more likely to develop breast cancer later in life. The younger you were when you received the treatments, the greater your risk.
Excess weight. The relationship between excess weight and breast cancer is complex. In general, weighing more than is healthy for your age and height increases your risk if you’ve gained the weight as an adult and especially after menopause. The risk is even greater if you have more body fat in the upper part of your body. Although women usually have more fat in their thighs and buttocks, they tend to gain weight in their abdomens starting in their 30s, which can increase their risks.
Exposure to estrogen. The longer you’re exposed to estrogen, the greater your breast cancer risk. In general, if you have a late menopause (after age 55) or you began menstruating before age 12, you have a slightly higher risk of developing breast cancer. The same is true for women who never had children, or whose first pregnancy occurred when they were age 35 or older.
Race. Caucasian women are more likely to develop breast cancer than black or Hispanic women are, but black women are more likely to die of the disease because their cancers are found at a more advanced stage. Although some studies show that black women may have more aggressive tumors, it’s also likely that the disparity is at least partially due to socioeconomic factors. Women of all races with incomes below the poverty level are more often diagnosed with late-stage breast cancer and more likely to die of the disease than are women with higher incomes. Low-income women often don’t receive the routine medical care that would allow breast cancer to be discovered earlier.
Hormone therapy. In July 2002, a study sponsored by the National Institutes of Health (NIH) was halted as researchers reported that hormone therapy, once considered standard treatment for menopausal symptoms, actually posed more health risks than benefits. Among these was a slightly higher risk of breast cancer for women taking the particular combination of hormone therapy – estrogen plus progestin – used in the study. In addition, combination hormone therapy can make malignant tumors harder to detect on mammograms, leading to cancers that are diagnosed at more advanced stages when they’re harder to treat. Because combination hormone therapy can result in serious side effects and health risks, work with your doctor to evaluate the options and decide what’s best for you.
Birth control pills. The hormone therapy studies have raised questions about the relationship between birth control pills and breast cancer. Unfortunately, there are no clear answers. A large study of women between the ages of 35 and 64 published in June 2002 in the “New England Journal of Medicine” concluded that current or former use of oral contraceptives didn’t increase the risk of breast cancer. For the latest information on the pill and breast cancer, talk to your doctor.
Smoking. A Mayo Clinic study published in April 2001 found that smoking significantly increases the risk of breast cancer in women with a family history of breast and ovarian cancers. And a 2005 study published in the “International Journal of Cancer” found that exposure to secondhand smoke also increases the risk of breast cancer in premenopausal women. Researchers think that higher estrogen levels combined with cancer-causing agents in tobacco spark the development of breast tumours.
Exposure to certain carcinogens. Polycyclic aromatic hydrocarbons are chemicals found mainly in cigarette smoke and charred red meat. Studies have shown that exposure to these chemicals can significantly increase your chances of developing breast cancer. Exposure to certain pesticides also may increase your risk, but more research needs to be done to establish a clear link.
Excessive use of alcohol. Women who consume more than one alcoholic drink a day have about a 20 percent greater risk of breast cancer than do women who don’t drink. The National Cancer Institute recommends limiting alcohol intake to no more than one drink daily.
Precancerous breast changes (atypical hyperplasia, carcinoma in situ). These changes are often discovered only after you have a breast biopsy for another reason, but they can double your risk of developing breast cancer. If you have carcinoma in situ, discuss treatment and monitoring options with your doctor.
Courtesy Mayo Clinic
