Green Tea and its Effects on Breast Cancer Metastasis and Recurrence

Abstract/summary: 472 women were studied who had invasive breast carcinoma. 117 had stage I, 273 stage II, and 82 stage III and all had undergone a partial or total mastectomy. This epidemiological survey was carried on for 9 years from 1984 to 1993. The questionnaire included intake of green tea, coffee, black tea, various food groups such as soy and seaweed and fish and vegetable, cigarettes, alcohol as well as breast tumor characteristics, tumor markers, adjunct treatments, medical history and various physical parameters.

The researchers determined that in stage I and II breast cancer, increased consumption of green tea was associated with less metastasized axillary lymph nodes in premenopausal women and an increased progesterone and estrogen status in postmenopausal women. No such associations were seen in stage III breast cancer patients. The consumption of green tea among the 349 women without a recurrence of breast cancer was significantly higher than among the 123 women with a breast cancer recurrence. In stage I and II patients, there was a 16.7% recurrence rate for those consuming 5 cups or more of green tea (average 8 cups) per day. For those who consumed 4 or less cups per day (average of 2), there was a 24.3% recurrence rate. Disease-free survival was also significantly improved in stage I and stage II breast cancer patients with a greater consumption of green tea. Of all the predictors, green tea was the most statistically significant predictor for a decreased rate of recurrence in the stage I and II patients. No improvement in prognosis was seen in stage III patients.

Commentary: The estimated risk of developing breast cancer in one's lifetime for Western women is at least one in nine and dropping. In Japan, it is estimated to be 1 in 40. This paper points to the discrepancy being due to green tea although there is also a significant body of data to suggest that the difference in rates of breast cancer is due to soybean product consumption as well as fish consumption.

Green tea (Camellia sinensis) contains several polyphenols including epigallocatechin gallate (EGCG). EGCG enhances glutathione peroxidase and catalase as well as being a potent free-radical scavenger. It has also been shown to inhibit the growth of several breast cancer cell lines in vitro, inhibit urokinase that is involved in tumor invasion and metastasis and induces apoptosis. The suggestion is that EGCG found in green tea has multiple anticancer properties.

A possible bias influencing this survey study is that perhaps those individuals who drink so much green tea are also those who are more health conscious. It is also my experience that getting a Western woman to drink an average of 8 cups of anything per day besides coffee or soft drinks is very difficult. However, once these results are shared with new breast cancer patients, advising something as benign and potentially significant as merely drinking tea, may inspire greater compliance. One option might be to use green tea extract in tablet form. It is estimated that one cup of green tea contains 30 to 40 mg of EGCG.

In the spirit of common sense, it would seem that your average non-breast cancer patient and women at higher risk for breast cancer, should extrapolate this data to the point of drinking green tea as a preventive measure.

Green tea has not been associated with any significant side effects or toxicity. Due to the caffeine, it may produce a stimulant effect, although for some reason the caffeine in green tea does not often produce the symptoms of anxiety and irritability and insomnia that other sources of caffeine may induce.

Nakachi K, Suemasu K, Suga K, et al. Influence of drinking green tea on breast cancer malignancy among Japanese patients. Japan J Cancer Res 1998;89:254-261.

Ginger for Nausea and Vomiting in Pregnancy

Seventy pregnant women at or before 17 weeks' gestation were randomized in a double-blind design to receive either ginger 1 gm per day (250 mg four times daily) or placebo for 4 days. The women graded the severity of their nausea and recorded the number of vomiting episodes in the previous 24 hours before treatment, and again during 4 consecutive days while taking the ginger or placebo. The median change in nausea scores in the ginger group was significantly greater (P=0.14) than that in the placebo group. All 32 women in the ginger group and 33 of 35 women in the placebo group had one or more vomiting episodes during the 24 hours before treatment. After 4 days of treatment, the proportion of women who had vomiting in the ginger group (12 of 32) was significantly less than that in the placebo group (23 of 35). Patients also reported their subjective response to treatment. 28 of 32 (87.5%) ginger-treated women reported that their symptoms improved, compared with only 10 of 35 (28.6%) in the placebo group.

Commentary: Only one previous randomized cross-over trial of ginger for hyperemesis gravidarum (severe nausea and vomiting) has been published in the English literature. In that study, 70.4% women preferred the ginger treatment compared with 14.8% of women receiving placebo. There was also a significant reduction in the number of vomiting episodes in the ginger group. It's a testimonial to the desire of women to utilize safe effective natural substances that ginger has gained as much popularity as it has with only one previous clinical trial on pregnant women with nausea and vomiting. Side effects were minimal in this study with five women experiencing headaches in the placebo group and six in the ginger group. One ginger patient had abdominal discomfort, one heartburn and one had diarrhea for one day. There were three spontaneous abortions in the placebo group and one in the ginger group. There were no differences in term delivery and no infant congenital abnormalities.

Vutyavanich T, Kraisarin T, Ruangsri R. Ginger for nausea and vomiting in pregnancy: randomized, double-masked, placebo-controlled trial. Obstetrics and Gynecology 2001;97(4):577-582.

Walking and the Prevention of Hip Fractures after Menopause

In this analysis to determine the effect of just walking on risk of hip fractures, researchers studied the relation between hip fracture and walking and leisure-time activities in 61,200 postmenopausal women from the Nurses Health Study. (ages 40 to 77; 98% were Caucasian). Study participants did not have histories of osteoporosis, cancer, or cardiovascular disease upon entry. The intent was to more clearly understand the intensity of exercise activity required to increase bone mineral density and reduce hip fractures.

During a follow-up of 12 years, 415 hip fractures were reported. After an analysis that controlled for age, BMI, hormone therapy use, smoking and diet, it was determined that the risk for hip fracture declined by 6% for every increase of 3 metabolic equivalent (MET) hours per week (equivalent to 1 hour of waling at average pace). Women with at least 24 MET-hours per week had a 55% reduction in risk compared with women with less than 3 MET-hours per week. Women who were heavier in body weight were at lower risk for hip fracture and their risk reduced further by increasing exercise. For the women who walked as their only activity, 4 hours per week had a 41% lower risk for hip fracture than those who walked less than 1 hour per week.

Commentary: We have known for some time that exercise will increase muscle mass, improve muscle strength, improve balance, increase bone mineral density, and reduce falls that can cause a hip fracture but it has not always been clear as to what intensity of activity is required to achieve these benefits. Observational studies have short comings, but the message for postmenopausal women is still strong: Walking as few as 4 hours per week reduces hip-fracture risk and more exercise yields further reductions in risk. For clinicians, we should use this information to further encourage our patients to engage in regular exercise, even though it may be as simple as walking. It's easy, without expense, accessible, convenient, and does not require complex skills. For those postmenopausal women with health problems that limit their ability to walk, we must continue to be creative in searching for a regular physical activity that they can perform.

Feskanich D, et al. Walking and leisure-time activity and risk of hip fracture in postmenopausal women. JAMA 2002; Nov 13; 288:2300-2306.

Estriol and Pelvic Floor Muscle Exercise for Stress Incontinence

Sixty-six postmenopausal women with stress incontinence (SI) were randomized to a group treated with estriol 1 mg per day and pelvic floor muscle exercise (PFME) and a group treated with PFME alone. Patients were evaluated every 3 months and efficacy of treatment was evaluated in patients who had been treated for two years.