Coffee has different effects on breast cancer for different women
Drinking coffee, especially unfiltered coffee (e.g., espresso), can raise cholesterol levels, including LDL (the harmful type of cholesterol). It also acts as a stimulant, increasing the production of cortisone and adrenaline. However, coffee drinking overall appears to be protective against heart disease. It also has been shown to reduce the risks of type 2 diabetes, Parkinson's disease, and gallstone development. Caffeine consumption has been associated with higher risks of osteoporosis, endometriosis, and fibrocystic breast disease. Fertility may be impaired for coffee drinkers. Childhood malignant central nervous system tumors have been found to be associated with maternal coffee drinking during pregnancy. Drinking coffee also has been shown to be correlated with a marginally increased risk of lung cancer in smokers. However, coffee is also associated with decreased risks of non–Hodgkin lymphoma, and liver, kidney and colorectal cancers. The coffee diterpenes kahweol and cafestol have been shown to offer some protection against mutagenic damage by heterocylic amines and aflatoxin B1 in laboratory rats and human consumption of these coffee components has been associated with lower rates of colon tumors. Caffeine, caffeic acid, the phytoestrogen trigonelline, various polyphenols, and volatile aroma and heterocyclic substances are also thought to contribute to the cancer-related effects of coffee consumption.Breast cancer-related effects of drinking coffee
Population studies generally have shown that coffee drinking has either a small positive or a small negative correlation with risk of breast cancer. Large prospective studies published in 2009 and 2008 found no statistically significant associations between coffee consumption and risk of breast cancer in the overall study populations. A Swedish study found that coffee consumption was associated with a reduction in the risk of breast cancer for lean women, whereas it appeared to have the opposite effect in heavy women. A Korean study found an association between coffee consumption and higher incidence of breast cancer.
The body's reaction to coffee can vary significantly for different women. One important 2008 study found that, for women with benign breast disease, statistically significant positive correlations existed between caffeine consumption and both estrogen receptor-negative, progesterone receptor-negative (ER-, PR-) breast cancer and breast tumors greater than 2 cm in size. The implication is that coffee drinking should be avoided by women with benign breast diseases such as fibrocystic breast disease.
Several studies have found that among women with BRCA1 or BRCA2 gene mutations, heavy consumption of coffee is associated with significantly reduced breast cancer risk. We would recommend coffee drinking (with caffeine) for BRCA1 and BRCA2 mutation carriers.
Studies have found that the effect of coffee consumption on breast cancer risk depends in part on a woman's CYP1A2 genotype. The CYP1A2 gene plays a crucial role in the metabolism of both estrogen and coffee. Like BRCA1 and BRCA2 mutations, a woman's CYP1A2 genotype can only be determined through genetic testing and this testing is not normally done. Regular heavy coffee consumption increases the expression of the CYP1A2 gene, which encodes a member of the cytochrome P450 family of enzymes. Coffee has been found to protect C-allele carriers against breast cancer by reducing breast volume. Coffee consumption has also been shown to slow the growth of ER-positive tumors in women with the CYP1A2*1F A/A genotype.
We conclude that women with benign breast disease should avoid coffee consumption, whereas women with BRCA1or BRAC2 mutations should consume it to reduce their respective risks of developing invasive breast cancer. Based on the available evidence, low to moderate coffee consumption appears to be safe for postmenopausal women who are estrogen receptor positive (ER+) breast cancer survivors. For a woman in none of these categories (i.e., no breast cancer diagnosis or ER- breast cancer survivor, no benign breast disease, not a BRCA1 or BRCA2 carrier), the potential risks of heavy coffee consumption appear to outweigh the potential benefits and it would appear prudent to limit coffee consumption.
Selected studies
Consumption of filtered and boiled coffee and the risk of incident cancer: a prospective cohort study Cancer Causes and Control, May 2010The present Swedish study was designed to examine the associations between drinking boiled or filtered coffee and risk of cancer. There are potentially relevant chemical differences between filtered and boiled coffee. Scandinavian boiled coffee is similar chemically to French press and Turkish or Greek coffee. Percolators are typically used in the home to make boiled coffee. Boiled coffee contains up to 80 times more coffee-specific fatty acids than the filtered version. These fatty acids have been reported to inhibit the growth of cancer in animal experiments. The study included women in the Västerbotten Intervention Project, which comprises 64,603 participants (including 3,034 breast cancer cases), with up to 15 years of follow up. Multivariate Cox regression was used to estimate hazard ratios (HRs). No associations were found between coffee consumption and overall cancer rates (for all cancer sites combined), or for prostate or colorectal cancer. However, boiled coffee was associated with increased risk of respiratory tract cancer in men (HR = 1.81, 95% confidence interval (CI) = 1.06-3.08, p trend = 0.084), but not women, and significantly increased risk of pancreatic cancer (HR = 2.51, 95% CI = 1.15-5.50, p trend = 0.006). Total coffee consumption (boiled plus filtered) was associated with reduced risk of renal cell cancer (HR = 0.30, CI = 0.11-0.79, p trend = 0.009). Drinking boiled coffee at least four times per day was found to be associated with reduced risk of breast cancer (HR = 0.52, 95% CI = 0.30-0.88, p trend = 0.247) compared to consuming it less than once per day. However, when stratified by menopausal status, total coffee consumption (boiled plus filtered) was found to be associated with increased risk of premenopausal breast cancer (HR = 1.69, 95% CI = .96-2.98, p trend = 0.015) and reduced risk of postmenopausal breast cancer (HR = 0.60, 95% CI = 0.39 - 0.93, p trend = 0.006). Filtered coffee consumption was associated with a similar increase in risk of premenopausal breast cancer (HR = 1.76, 95% CI = 1.04-3.00, p trend = 0.045) and reduction in risk of postmenopausal breast cancer (HR = 0.52, 95% CI = 0.30-0.88, p trend = 0.045). The authors conclude that brewing method may be relevant in investigations of coffee consumption and cancer risk, but this must be confirmed in future studies.
Coffee and black tea consumption and risk of breast cancer by estrogen and progesterone receptor status in a Swedish cohort Cancer Causes and Control, December 2009
The present prospective study was designed to investigate the associations of caffeinated coffee and black tea consumption with risk of breast cancer overall and by hormone receptor status. The study included 61,433 women in the Swedish Mammography Cohort who were cancer free during the baseline enrollment period of 1987 to 1990. Coffee and tea intake was determined using a food-frequency questionnaire administered both at baseline and in 1997. Swedish cancer registers were accessed to obtain information concerning the incidence and nature of newly diagnosed invasive breast cancers in the study cohort. During an average follow-up period of 17.4 years (through year-end 2007), 2,952 incident cases of invasive breast cancer were found. Coffee consumption was found not to be associated with overall risk of breast cancer (multivariate relative risk (RR) for at least four cups per day compared to less than one cup per day = 1.02; 95% confidence interval (CI) = 0.87 - 1.20). Nor was any association found between coffee consumption and breast cancer subtype defined by estrogen receptor (ER) and progesterone receptor (PR) status. On the other hand, black tea intake was found to be significantly positively associated with risk of breast cancer overall and ER+/PR+ tumors in particular. The multivariate RRs comparing at least two cups of black tea per day with no consumption were 1.22 (95% CI = 1.05 - 1.42) for breast cancer overall and 1.36 (95% CI = 1.09 - 1.69) for ER+/PR+ breast cancer. The authors conclude that the study findings do not support a role of coffee consumption in the development of breast cancer. However, the results suggest that black tea may be positively associated with risk of ER+/PR+ breast cancer.
Coffee and tea intake and risk of breast cancer Breast Cancer Research and Treatment, October 2009
The current prospective study was designed to investigate the associations between coffee and tea consumption and the risk of breast cancer. The associations were assessed among women in the EPIC-NL cohort in the Netherlands, which has 27,323 participants. A validated food frequency questionnaire was used to estimate exposure to coffee and tea. Direct linkage with the Netherlands Cancer Registry was utilized to obtain cancer diagnosis-related data. During a 9.6-year follow-up period, 681 invasive primary breast cancers were diagnosed. Before adjustment for breast cancer risk factors and lifestyle, coffee intake was found to increase the risk of breast cancer by more than double as compared to non-coffee drinkers (HR = 2.25, 95% CI = 1.30-3.90). However, this association did not hold after multivariate adjustment, which resulted in HR = 1.17, 95% CI = 0.65-2.12. In fact, after adjustment for breast cancer risk factors and lifestyle, no associations were found between intake of coffee or tea and risk of breast cancer across all levels of intake. The results also were also not affected by body mass index. The authors conclude that coffee and tea consumption does not seem to be related to the risk of breast cancer in women.
Caffeine consumption and the risk of breast cancer in a large prospective cohort of women Archives of Internal Medicine, October 2008
In this prospective study, the association between caffeine consumption and breast cancer risk in 38,432 women 45 years or older and enrolled in a completed cancer prevention trial was studied. The women were cancer free at baseline (1992-1995), when detailed dietary information was collected from them. There were 1,188 invasive breast cancer cases during a mean follow-up period of ten years. Consumption of caffeine, caffeinated beverages and caffeinated foods was found not to be significantly associated with overall risk of breast cancer. Multivariate relative risks (RRs) of breast cancer were found to be 1.02 (95% confidence interval [CI]: 0.84-1.22) for caffeine (top vs. bottom quintile), 1.08 (CI: 0.89-1.30) for coffee (greater or equal to four cups daily vs. almost never), and 1.03 (CI: 0.85-1.25) for tea (greater than or equal to two 2 cups daily vs. almost never). However, for women with benign breast disease, a borderline significant positive association with breast cancer risk was found for the highest quintile of caffeine consumption (RR = 1.32; CI: 0.99-1.76). In addition, for the highest coffee consumption (greater than or equal to four cups per day), tests for interaction were marginally significant (1.35; CI: 1.01-1.80). Caffeine consumption was also found to be significantly positively associated with the risk of estrogen and progesterone receptor negative (ER-,PR-) breast cancer (1.68; CI: 1.01-2.81) and with breast tumors larger than two cm (1.79; 1.18-2.72). While the data showed no overall association between caffeine consumption and breast cancer risk, they indicate the possibility of increased risk in women with benign breast disease for tumors that are estrogen and progesterone receptor negative or larger than 2 cm.
Coffee, tea, caffeine and risk of breast cancer: a 22-year follow-up International Journal of Cancer, May 2008
The relationship between coffee, tea and caffeine consumption and the risk of breast cancer remains unsettled. In the current prospective study, data from 85,987 female participants in the Nurses' Health Study was used to evaluate whether high intake of coffee and caffeine is associated with increased risk of breast cancer. Levels of intake of coffee, tea and caffeine were assessed in 1980, 1984, 1986, 1990, 1994, and 1998 and the follow-up period extended through 2002. There were 5,272 new cases of breast cancer. The following multivariate relative risks (RRs) of breast cancer were found for caffeinated coffee consumption: 1.0 for fewer than one cup per month (reference category), 1.01 (95% confidence interval: 0.92-1.12) for one cup per month to 4.9 per week, 0.92 (0.84-1.01) for 5 cups per week to 1.9 cups per day, 0.93 (0.85-1.02) for 2 to 3.9 cups per day, 0.92 (0.82-1.03) for greater than or equal to 4 cups per day (p for trend = 0.14). None of these relationships were statistically significant. Intakes of tea, decaffeinated coffee, and caffeine also were not found to be significantly correlated with risk of breast cancer. However, a significant inverse relationship between caffeine intake and breast cancer was found among postmenopausal women; for the highest quintile of intake compared to the lowest quintile RR = 0.88 (95% CI = 0.79-0.97, p for trend = 0.03). The authors conclude that the study uncovered no substantial association between coffee and tea consumption and the risk of breast cancer in the overall cohort. However, a weak inverse association between caffeine-containing beverages and the risk of postmenopausal breast cancer was found.
Coffee Consumption and CYP1A2*1F Genotype Modify Age at Breast Cancer Diagnosis and Estrogen Receptor Status Cancer Epidemiology, Biomarkers & Prevention, April 2008
The current study was designed to test the hypothesis that relatively high coffee consumption (at least two cups per day), combined with the CYP1A2*1F A/A genotype, is associated with a later age at diagnosis and a greater likelihood of ER-negative (ER–) tumors among women with breast cancer. The CYP1A2 gene plays a crucial role in the metabolism of both estrogen and coffee. Women with the CYP1A2*1F A/A genotype and high coffee intake have a high ratio of 2-hydroxyestrone (2-OHE1) to 16-OHE1. 2-OHE1 is a weak estrogen and may block the estrogen receptor, whereas 16-OHE1 promotes cancer. A study group of 458 Swedish breast cancer patients aged 25 to 99 were genotyped for CYP1A2*1F. Information on lifestyle factors and the breast tumor characteristics was collected from preoperative questionnaires and pathology reports. For the 51.3% of the women with CYP1A2*1F A/A genotype, moderate to high coffee consumption was associated with a later age at breast cancer diagnosis compared to low coffee consumption (59.8 years of age vs. 52.6 years, P = 0.0004). The CYP1A2*1F A/A patients with moderate to high coffee intake were also more likely to have ER– tumors than similar patients with low coffee intake (14.7% versus 0%, P = 0.018). Coffee intake was not associated with age at diagnosis or ER status in patients with at least one C allele. Age at diagnosis was not related to ER status in patients with CYP1A2*1F A/A, but younger patients (i.e., younger than 50 years old) with at least one C allele were more likely to have ER– tumors compared to older patients (odds ratio, 4.2; 95% CI: 1.9-9.3; P = 0.0002). The authors conclude that coffee consumption may slow the growth of ER-positive tumors in patients with CYP1A2*1F A/A.
Comparisons of food intake between breast cancer patients and controls in Korean women Nutrition Research and Practice, September 2007
The current case-control study was designed to compare the diets of a group of Korean breast cancer patients with a healthy control group. The cases included 97 women with newly confirmed diagnoses of breast cancer at the inpatient or outpatient clinic of Yeouido St. Mary’s Hospital in Seoul, and excluded women with any history of liver diseases, diabetes mellitus, respiratory disorders and cardiovascular diseases. The 97-person control group also excluded women with known malignant, hormonal, gynecological or endocrine diseases. Intake of nutrients in 117 food items were estimated in the breast cancer patients and age-matched healthy controls using a quantitative food frequency questionnaire administered by a trained dietitian. The questionnaire also included general information (age, sex and marital status), age at menarche, and pregnancy history. It was found that the average caloric intake of the breast cancer patients and the healthy controls did not differ significantly. However, the breast cancer patients consumed significantly less fat and antioxidant nutrients such as vitamin A, retinol, beta-carotene, vitamin C and vitamin E than did the controls. Consumption of eggs (p<0.01), legumes (p<0.05), vegetables (p<0.05), seasonings (p<0.001), and oils and fats (p<0.01) was significantly lower in the breast cancer patients. However, the level of energy from fat is relatively low in Korean patients compared to their Western counterparts, and fat consumption may not be an independent risk factor at this level of intake. With respect to particular foods, in addition to eggs, the breast cancer patients consumed a significantly lower quantity of bean curd (tofu), onion, garlic, green pepper, sweet pepper, kale, cucumber, seasoned bean sprouts, sesame leaf, zucchini, radish, mushroom, crown daisy, red pepper paste, bean paste, spicy bean paste, orange juice, grape juice, and tomato juice than the controls. On the other hand, the breast cancer patients consumed significantly greater quantities of cooked rice, noodles, deep fried chicken, satsuma mandarin, Korean melon, kimchi and coffee than the controls. The authors conclude that since the breast cancer patients consumed less soy and vegetables, they had a lower intake than the controls of rich sources of antioxidant nutrients, phytosterols, fiber and non-nutritional components that may reduce the risk of cancer. In addition, the breast cancer patients in this study consumed lower quantities of red pepper paste, bean paste and spicy bean paste, causing their intake of pepper flavonols (which may have a protective effect on breast cancer risk) to be lower than that of the controls.
The CYP1A2 Genotype Modifies the Association Between Coffee Consumption and Breast Cancer Risk Among BRCA1 Mutation Carriers Cancer Epidemiology, Biomarkers & Prevention, May 2007
The consumption of coffee has been reported to be associated with a significant reduction in breast cancer risk for BRCA1 mutation carriers. Because the metabolism of caffeine is mediated primarily by CYP1A2, the study examined whether the CYP1A2 genotype is related to the association between coffee consumption and the risk of breast cancer. A common A to C polymorphism in the CYP1A2 gene has been found to be associated with decreased enzyme production and impaired caffeine metabolism. In the current study, coffee consumption habits were collected for 411 BRCA1 mutation carriers (170 cases and 241 controls) for which the CYP1A2 genotype also had been determined. The odds ratios (ORs) and 95% confidence intervals (CIs) for breast cancer associated with the CYP1A2 genotype and history of coffee consumption before age 35 were calculated, adjusting for potential confounding factors. The CYP1A2 genotype was not found to affect breast cancer risk directly. Among women who had at least one variant C allele (AC or CC), those who consumed coffee were shown to have a 64% reduction in breast cancer risk, compared with women who never drank coffee (OR = 0.36; CI: 0.18-0.73). A significant protective effect of coffee consumption was not observed among women with the CYP1A2 AA genotype (OR, 0.93; 95% CI, 0.49-1.77). Similar results were found when the calculated included only caffeinated coffee. The authors conclude that caffeine protects against breast cancer in women with a BRCA1 mutation.
Coffee consumption and breast cancer risk among BRCA1 and BRCA2 mutation carriers International Journal of Cancer, July 2005
The current case-control study assessed the association between coffee consumption and breast cancer risk in 1,690 women with BRCA1 or BRCA2 mutations. The study participants were recruited from 40 centers in four countries (Canada, Poland, the United States, and Israel). Included were 845 BRCA1/BRCA2 mutation carriers with breast cancer and a control group of 845 BRCA1/BRCA2 carriers without breast cancer. Cases were matched to controls based on age, parity, age upon first giving birth, alcohol consumption, use of oral contraceptives, and body mass index. A questionnaire was used to collect information on coffee drinking. Women with BRCA1 or BRCA2 mutations who consumed at least six cups of coffee per day were found to have a significantly lower risk of breast cancer than BRCA carriers who never drank coffee. After adjusting for potential confounding factors, it was found that the odds ratios for breast cancer in BRCA carriers who habitually drank one to three, four to five, and more than six cups of coffee per day were 0.9 (95% confidence interval (CI): 0.72-1.12), 0.75 (0.47-1.19), and 0.31 (0.13- 0.71), respectively, compared with BRCA carriers who did not drink coffee (P for trend = 0.02). These results held only for caffeinated coffee. The authors concluded that among women with BRCA gene mutations, coffee consumption is unlikely to be harmful and high levels of consumption may in fact be related to reduced breast cancer risk.
Consumption of coffee, but not black tea, is associated with decreased risk of premenopausal breast cancer Journal of Nutrition, January 2006
The current hospital-based, case-control study was designed to assess the role of coffee (including decaffeinated coffee) and black tea on the risk of breast cancer. Participants included 1,932 breast cancer cases and 1,895 hospital controls with noncancer conditions. All of the women completed a detailed questionnaire. For premenopausal women, coffee consumption was found to be associated with linear declines in the risk of breast cancer (P for trend = 0.03). Those who drank at least four cups per day experienced a 40% risk reduction (odds ratio = 0.62, 95% CI: 0.39-0.98). No clear relationships between consuming black tea or decaffeinated coffee and breast cancer risk were found among premenopausal women. However, drinking black tea was associated with a protective effect for those with lobular breast cancer. For postmenopausal women, no associations were found between consumption of coffee, tea, or decaffeinated coffee and breast cancer risk. Results did not differ for those with lobular breast cancer among the postmenopausal women. The authors conclude that coffee intake has a protective effect on premenopausal, but not postmenopausal breast cancer risk.
The relationship between diet and breast cancer in men Cancer Causes & Control, April 1999
The present case-control study was designed to examine the associations between food and beverage consumption and the development of breast cancer in men. The study, which was conducted between 1983 and 1986, included 200 male breast cancer cases, which were found using 10 population-based cancer registries. A total of 291 controls were selected by random-digit dialing (< age 65) and Medicare beneficiary lists (> or = age 65). The only trend found with increasing intakes of specific foods was an increase in breast cancer risk with consumption of citrus fruits. Similarly, no increase in risk with increasing amounts of specific fats, vitamins, or minerals, or with protein, fiber, carbohydrate, starches, nitrites, or alcohol consumed was found, except for an increase in risk associated with dietary vitamin C consumption. However, a decreasing trend in risk with dietary niacin and with coffee, and an increasing trend in risk with tea consumption were seen. No associations were found between risk of breast cancer and use of any dietary supplements, including vitamin C. The authors comment that the study findings are inconsistent with those from studies of breast cancer in women and probably do not represent causal relationships. Furthermore, they conclude that dietary factors are unlikely to be strong determinants of breast cancer in men.
