Flax Seeds Shrink Tumors

A Canadian study put flax seeds to the test for shrinking breast cancer tumors. Two groups of postmenopausal women were assigned to eat a muffin made with 25 grams of flax seed oil or a muffin without, every morning. The majority of women consuming flax seed muffins had a significant reduction in tumor size, similar to the effects of the drug tamoxifen.

An easy way to add flax to your diet is by sprinkling ground flax seeds on your cereal, salads, soups, and casseroles, or adding them to any baked goods. Be sure to refrigerate flax seeds and flax meal to insure freshness.

Haggans CJ, Hutchins AM, Olson BA, Thomas W, Martini MC, Slavin JL. Effect of flax seed consumption of urinary estrogen metabolites in postmenopausal women. Nutr Cancer 1999;33: 188-95.

Elevated IGF-I Levels Signal Breast and Prostate Cancer Risk

Just as high levels of cholesterol in the blood predict heart attacks, high levels of insulin-like growth factor, or IGF-I, are linked to cancer risk. Swedish researchers measured plasma samples in 149 men already diagnosed with the disease and for 298 men in a control group. The results showed cancer patients had significantly higher levels of IGF-I than healthy participants.

Similarly, a study reported in the International Journal of Cancer analyzed IGF-I levels in 172 premenopausal women and 115 postmenopausal women with breast cancer, compared to a control group free of the disease. In postmenopausal women, elevated IGF-I levels were not predictive of breast cancer risk; however, in premenopausal women they were. The finding suggests that high levels of IGF-I in women under 50 may signal future trouble. The good news is that IGF-I is exquisitely sensitive to diet. For example, vegans have lower IGF-I levels while daily use of two to three dairy servings boosts IGF-I levels by about 10 percent.

Stattin P, Bylund A, Rinaldi S, et al. Cancer risk: a prospective study. J Natl Cancer Inst 2000;92:1910-7.
Toniolo P, Bruning PF, Akhmedkhanov A, et al. Serum insulin-like growth factor-I and breast cancer. Int J Cancer 2000;88:828-32.

Pancreatic Cancer Linked to Obesity

Past studies have linked pancreatic cancer with cigarette smoking, diabetes, and family history of the disease. A new study, conducted by interviews with 526 pancreatic cancer patients, now adds obesity, high caloric intake, heavy alcohol consumption, and low intake of cruciferous vegetables (broccoli, cauliflower, cabbage, and Brussels sprouts) to the list of risk factors, suggesting important means of prevention.

Silverman DT. Risk factors for pancreatic cancer: a case-control study based on direct interviews. Teratog Carcinog Mutagen 2001;21:7-25.

Diet and Breast Cancer

A Journal of the American Medical Association report analyzed eight previously published studies, hoping to find clues to whether fruits and vegetables (and which ones in particular) cut breast cancer risk. Researchers examined food intake questionnaires of more than 350,000 women, noting consumption of various fruits, fruit juices, vegetables, and vegetable juices.

They found that women who consumed the highest amounts of fruits and vegetables were only 3 to 9 percent less likely to develop breast cancer—discouragingly low figures. However, a more thorough review of the study brings two important aspects to light: Researchers zeroed in on fruit and vegetable consumption, but not on the entire diet. Simply adding healthy foods to an otherwise poor diet, rather than getting rid of the troublemakers—meat, dairy products, and fried foods—may not offer the protection many had hoped. Secondly, foods that were eaten in childhood and young adulthood were not considered.

While scientists are hard at work searching for specific breast cancer-fighting compounds, the safest approach is to apply what we already know: Diets that are highest in a variety of plant foods and stay away from heavy oils, meat, and dairy products, help prevent a great many diseases. The earlier in life we start, the better.

Cancer experts add that several other lifestyle factors are undoubtedly linked to breast cancer. Women who drink more than one alcoholic beverage each day have about a 20 percent higher risk; a similar degree of risk applies to obese women. In both young and older women, exercising two to three hours per week can reduce risk by 30 percent, four or more hours by 50 percent.

Unfortunately, a survey by the Centers for Disease Control and Prevention recently found that just one in four U.S. adults is getting enough exercise for optimal health.

Smith-Warner SA, Spiegelman D, Yaun SS, et al. Intake of fruits and vegetables and risk of breast cancer: a pooled analysis of cohort studies. JAMA 2001;285:769-76.

Cancer Chemicals Reach Non-Smoking Housemates

Chemicals associated with lung cancer reach a five- to six-fold higher concentration in women who live with smokers than in those who live with nonsmokers. Researchers analyzed the urine of 23 nonsmoking women exposed to their husbands' cigarette smoke, finding elevated levels of compounds called NNAL and NNAL-Gluc, both metabolic products of NNK, a known carcinogen. The women showed higher levels of nicotine as well.

Previous studies have linked secondhand smoke and lung cancer. This study, appearing in the Journal of the National Cancer Institute, is the first to provide biochemical support of the observation.

Anderson KE, Carmella SG, Ye M, et al. Metabolites of a tobacco-specific lung carcinogen in nonsmoking women exposed to environmental tobacco smoke. J Natl Cancer Inst 2001;93:378-81.

Hormones May Harm Mammogram Accuracy

Hormone replacement drugs not only increase breast cancer risk. They may also make it harder to spot if it does occur. Hormones can cause breast tissue to become denser, making it more difficult to detect cancerous cells by mammography, according to a study published in the Journal of the American Medical Association. Researchers report that changes in breast density usually reverse if hormone therapy is discontinued, and that overweight women are more likely to be affected.

Rutter CM, Mandelson MT, Laya MB, Taplin S. Changes in breast density associated with initiation, discontinuation, and continuing use of hormone replacement therapy. JAMA 2001;285:171-6.