Breast cancer (BC) is the second most common cancer worldwide and the most commonly occurring malignancy in women. There is growing evidence that lifestyle factors, including diet, body weight and physical activity, may be associated with higher BC risk.
Study | Results | Reference | |||||||||||
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Fruits, vegetables | Meta-analysis (15 prospective studies) | RR = 0.89 (95% CI, 0.80–0.99, p = 0.67) fruits + vegetables; highest vs. lowest intake | RR = 0.92 (95% CI, 0.86–0.98, p = 0.36) fruits; highest vs. lowest intake | RR = 0.99 (95% CI, 0.92–1.06, p = 0.26) vegetables; highest vs. lowest intake |
[25] |
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Prospective study (75,929 women, 38–63 years, 24 years follow-up) | RR = 0.82 (95% CI, 0.71–0.96, p = 0.01), 2 servings/week of total berries | RR = 0.69 (95% CI, 0.50–0.95, p = 0.02), 1 serving/week of blueberries | RR = 0.59 (95% CI, 0.37–0.93, p = 0.02), 2 servings/week of peaches/nectarines |
[26] |
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Prospective study (31,000 women, 36–64 years, 11.25 years follow-up) | HR = 0.70 (95% CI, 0.57–0.86, p = 0.0001) leafy vegetables, highest vs. lowest quintile | HR = 0.75 (95% CI, 0.60–0.94, p = 0.01) fruiting vegetables, highest vs lowest quintile no association with fruit |
[27] |
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RR = 0.89 (95% CI, 0.79–0.99, | |||||||||||||
p | |||||||||||||
= 0.001), highest | |||||||||||||
vs. | |||||||||||||
lowest isoflavone intake (RR = 0.76, 95% CI: 0.65–0.86, | |||||||||||||
p | |||||||||||||
= 0.136 in Asian population; RR = 0.97, 95% CI: 0.87–1.06, | |||||||||||||
p | |||||||||||||
= 0.083 in Western population) | |||||||||||||
[ | 41] |
Study | Intervention | Results | Reference | |||||||||||||||||||||
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ω-3 PUFAs | Phase II clinical trial (n = 25 breast cancer patients, 31 months follow-up) | 1.8 g DHA/day anthracycline | Improvement of chemo-therapy outcome: median TTP = 6 months (95% CI, 2.8–8.7 months); median OS = 22 months (95% CI, 17–33 months) | No severe adverse side effects (grade 3 or 4 toxicity only for neutropenia and alopecia, 80%) |
[99] |
[64] |
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Pilot study (n = 38 postmenopausal breast cancer patients) | 4 g/day EPA + DHA for 3 months AI therapy | Inhibition of bone resorption in the fish oil responders vs. placebo (p < 0.05) |
[100] |
[65] |
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Controlled clinical trial (n = 249 postmenopausal breast cancer patients) | 3.3 g/day ω3 PUFA (560 mg EPA + DHA, 40:20 ratio) 24 weeks AI therapy | Reduction of arthralgia (4.36 vs. 5.70, p = 0.02) obese BC patients vs. placebo |
[101] |
[66] |
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Red meat | ||||||||||||||||||||||||
Controlled clinical trial (n = 20 breast cancer patients) | Meta-analysis (13 cohort, 3 case-control, 2 clinical trials) | RR = 1.06 (95%CI, 0.99–1.14) unprocessed red meat, highest vs. lowest intake | EPA (0.19 g/day) + DHA (1.04 g/day) paclitaxel | RR = 1.09 (95%CI, 1.03–1.16) processed red meat, highest vs. lowest intake | Reduction of paclitaxel-induced peripheral neuropathy incidence (OR = 0.3; 95% CI, 0.10–0.88, p[28] | |||||||||||||||||||
= 0.029), but not severity (0.95% CI = (−2.06–0.02), | p | = 0.054) EPA + DHA vs. placebo |
[102] |
[67] |
Cohort study (262,195 women, 7 years follow-up) Meta-analysis | |||||||||||||||||||
Green tea | HR = 1.21 (95% CI, 1.08–1.35, p = 0.001), >9 g/day processed red meat | Prospective cohort study (n = 1160 breast cancer patients, 8 years follow-up) | RR = 1.09 (95% CI 1.03–1.15, p = 0.662), >9 g/day processed red meat in post-menopausal women | RR = 0.99 (95% CI 0.88–1.10, p = 0.570), >9 g/day processed red meat in pre-menopausal women |
[29] |
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Regular consumption of green tea | Inverse association between regular green tea consumption (≥3 cups/day) and BC recurrence for stage I/II patients (HR = 0.69; 95% CI, 0.47–1.00, p < 0.05) |
[103] |
[68] |
Dietary Fat | ||||||||||||||||||||
Prospective cohort study (n = 472 breast cancer patients, 7 years follow-up) | Randomized controlled trial (48,835 post-menopausal women, 8.1 years follow-up) | HR = 0.91 (95% CI, 0.83–1.01, NS) intervention group vs. control group | Regular consumption of green tea | Inverse association between regular green tea consumption (≥5 cups/day) and BC recurrence for stage I/II patients (RR = 0.564; 95% CI, 0.350–0.911, p < 0.05) |
[30] |
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[ | ] |
[69] |
Meta-analysis (cohort + case-control studies) | |||||||||||||||||||||
Prospective cohort study (n = 5042, 9.1 years follow-up) | RR = 1.091 (95% CI, 1.001–1.184) cohort PUFA | RR = 1.042 (95%CI, 1.013–1.073) case-control total fat | RR = 1.22 (95% CI, 1.08–1.38) case-control PUFA | Regular consumption of green tea |
[31] |
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Reduced risk of total mortality (HR = 0.57; 95% CI: 0.34–0.93) and recurrence (HR = 0.54; 95% CI: 0.31–0.96) for the first 60-month post-diagnosis period |
[105] |
[70] |
Systematic review (18 studies) | 45–78% increased risk of death with increased intake of | ||||||||||||||||||||
Vitamin C | trans fats | Controlled clinical trial (n[32] | ||||||||||||||||||||||
= 54 post-menopausal breast cancer patients) | Vitamin C (500 mg) and E (400 mg) +tamoxifen (10 mg twice a day) for 90 days | Decrease of total cholesterol, TG, VLDL (p < 0.001) and LDL (p < 0.01) vs. tamoxifen alone | Increase of HDL ( p < 0.01) vs. tamoxifen alone |
[106] |
[71] |
EPIC study (337,327 women, 11.5 years follow-up) | HR = 1.20 (95% CI, 1.0–1.45, p = 0.05), highest vs. lowest quintile of total fat intake (ER+PR+ BC) | HR = 1.2 (95% CI, 1.09–1.52, p = 0.009), highest vs. lowest quintile of saturated fat intake (ER+PR+ BC) | HR = 1.29 (95% CI, 1.01–1.64, p = 0.04), highest vs. lowest quintile of saturated fat intake (HER2− BC) |
[33] |
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Controlled clinical trial (n = 40 breast cancer patients) | Vitamin C (500 mg) and E (400 mg) + 5-fluorouracil (500 mg/m2) + doxorubicin (50 mg/m2) + cyclophosphamide (500 mg/m2) (every 3 weeks for six cycles) | Increase of SOD, CAT, GST, GPx, GSH (p < 0.01) vs. chemotherapy alone | Decrease of MDA, DNA damage ( p < 0.01) vs. chemotherapy alone |
[107] |
[72] |
Meta-analysis (6 cohort studies + 3 case-control studies) | ||||||||||||||||||
Vitamin E | RR = 1.29 (95% CI, 1.06–1.56), highest vs. lowest cholesterol intake | Prospective cohort study (n = 7 breast cancer patients, 30 days follow-up) |
[34] |
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Vitamin E (400 mg) + tamoxifen (20 mg daily) for 30 days | Vitamin E supplement interferes with the therapeutic effects of tamoxifen (increase expression of biomarkers of estrogen-stimulation (ER, PR, p-ERK in breast biopsies) |
[108] |
[73] |
Dairy products | Pooled analysis (8 prospective cohort studies) (351,041 women, 15 years follow-up) | NS |
[35] |
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Meta-analysis (18 prospective cohort studies, n = 1,063,471) | RR = 0.91 (95% CI, 0.80–1.02, p = 0.003), milk consumption | RR = 0.85 (95% CI, 0.76–0.95, p = 0.01), highest vs. lowest total dairy food |
[36] |
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Meta-analysis (22 cohort + 5 case-control studies) | RR = 0.90 (95% CI, 0.83–0.98, p = 0.111), highest vs. lowest dairy products | RR = 0.91 (95% CI, 0.83–0.99, p = 0.991), yogurt consumption | RR = 0.85 (95% CI, 0.75–0.96, p = 0.121), low-fat dairy consumption |
[37] |
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Vitamin D | Prospective cohort study (n = 232 post-menopausal breast cancer patients, 1-year follow-up) | Calcium (1 g) + vitamin D3 (800 IU/d and additional 16,000 IU, every 2 weeks) + AI therapy for 1 year | Reduction of AI-associated lumbar spine bone loss: 1.70% (95% CI, 0.4–3.0%; p = 0.005) (women with 25(OH)D serum levels ≥40 ng/ml vs. women with serum levels <30 ng/ml) |
[109] |
[74] |
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Prospective cohort study (n = 60 post-menopausal breast cancer patients, 16 weeks follow-up) | 50,000 IU/week + AI therapy for 12 weeks | Decrease of disability from joint pain (52 vs. 19%; p = 0.026); reduction of fatigue (BFI scores 1.4 vs. 2.9; NS); reduction of menopausal symptoms (MENQOL scores 2.2 vs. 3.2, p = 0.035) (women with 25OHD levels > 66 ng/ml vs. women with levels < 66 ng/ml) |
[110] |
[75] |
Carbohydrate, Glycaemic Index | Meta-analysis (19 prospective studies) | RR = 1.04 (95% CI, 1.00–1.07, p = 0.19), 10 units/d for glycemic index | RR = 1.01 (95% CI, 0.98–1.04, p = 0.07), 50 units/d for glycemic load | RR = 1.00 (95% CI, 0.96–1.05, p = 0.01), 50 g/d for carbohydrate intake |
[38] |
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Soy products, isoflavones | Meta-analysis (14 case-control + 7 cohort studies) | RR = 0.75 (95% CI, 0.59–0.95, p = 0.023), soyfood intake | RR = 0.81 (95% CI, 0.67–0.99), isoflavone intake |
[39] |
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Meta-analysis (1 cohort + 7 case-control studies) | OR = 0.71 (95% CI, 0.60–0.85, p = 0.023), highest vs. lowest soy intake in Asians | OR = 0.88 (95% CI, 0.78–0.98, p = 0.60), moderate vs. lowest soy intake in Asians | OR = 1.04 (95% CI, 0.97–1.11, p = 0.42), highest vs. lowest soy isoflavone intake in Western populations |
[40] |
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Meta-analysis (18 prospective studies) |
AI: aromatase inhibitor; BC: breast cancer; BFI: big five inventory; CAT: catalase; DHA: docosahexaenoic acid; EPA: eicosapentaenoic acid; ER: estrogen receptor; GPx: glutathione peroxidase; GSH: reduced glutathione; GST: glutathione transferase; HDL: high density lipoprotein; HR: hazard ratio; LDL: low density lipoprotein; MDA: malondialdehyde; MENQOL: menopause-specific quality of life; NS: not significant; OS: overall survival; p-ERK: phosphorylated extracellular signal–regulated kinase; PR: progesterone receptor; PUFA: poly unsaturated fatty acids; RR: relative risk; SOD: superoxide dismutase; TG: triglycerides; TTP: time to progression; VLDL: very low density lipoprotein; 25OHD: 25-hydroxycholecalciferol.