Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality – a systematic review and dose-response meta-analysis of prospective studies

Background: Questions remain about the strength and shape of the dose-response relationship between fruit and vegetable intake and risk of cardiovascular disease, cancer and mortality, and the effects of specific types of fruit and vegetables. We conducted a systematic review and meta-analysis to clarify these associations. Methods: PubMed and Embase were searched up to 29 September 2016. Prospective studies of fruit and vegetable intake and cardiovascular disease, total cancer and all-cause mortality were included. Summary relative risks (RRs) were calculated using a random effects model, and the mortality burden globally was estimated; 95 studies (142 publications) were included. Results: For fruits and vegetables combined, the summary RR per 200 g/day was 0.92 [95% confidence interval (CI): 0.90–0.94, I2 = 0%, n = 15] for coronary heart disease, 0.84 (95% CI: 0.76–0.92, I2 = 73%, n = 10) for stroke, 0.92 (95% CI: 0.90–0.95, I2 = 31%, n = 13) for cardiovascular disease, 0.97 (95% CI: 0.95–0.99, I2 = 49%, n = 12) for total cancer and 0.90 (95% CI: 0.87–0.93, I2 = 83%, n = 15) for all-cause mortality. Similar associations were observed for fruits and vegetables separately. Reductions in risk were observed up to 800 g/day for all outcomes except cancer (600 g/day). Inverse associations were observed between the intake of apples and pears, citrus fruits, green leafy vegetables, cruciferous vegetables, and salads and cardiovascular disease and all-cause mortality, and between the intake of green-yellow vegetables and cruciferous vegetables and total cancer risk. An estimated 5.6 and 7.8 million premature deaths worldwide in 2013 may be attributable to a fruit and vegetable intake below 500 and 800 g/day, respectively, if the observed associations are causal. Conclusions: Fruit and vegetable intakes were associated with reduced risk of cardiovascular disease, cancer and all-cause mortality. These results support public health recommendations to increase fruit and vegetable intake for the prevention of cardiovascular disease, cancer, and premature mortality

Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies

Background: Dairy product and calcium intakes have been associated with increased prostate cancer risk, but whether specific dairy products or calcium sources are associated with risk is unclear. Objective: In the Continuous Update Project, we conducted a meta-analysis of prospective studies on intakes of dairy products and calcium and prostate cancer risk. Design: PubMed and several other databases were searched up to April 2013. Summary RRs were estimated by using a random-effects model. Results: Thirty-two studies were included. Intakes of total dairy products [summary RR: 1.07 (95% CI: 1.02, 1.12; n = 15) per 400 g/d], total milk [summary RR: 1.03 (95% CI: 1.00, 1.07; n = 14) per 200 g/d], low-fat milk [summary RR: 1.06 (95% CI: 1.01, 1.11; n = 6) per 200 g/d], cheese [summary RR: 1.09 (95% CI: 1.02, 1.18; n = 11) per 50 g/d], and dietary calcium [summary RR: 1.05 (95% CI: 1.02, 1.09; n = 15) per 400 mg/d] were associated with increased total prostate cancer risk. Total calcium and dairy calcium intakes, but not nondairy calcium or supplemental calcium intakes, were also positively associated with total prostate cancer risk. Supplemental calcium was associated with increased risk of fatal prostate cancer. Conclusions: High intakes of dairy products, milk, low-fat milk, cheese, and total, dietary, and dairy calcium, but not supplemental or nondairy calcium, may increase total prostate cancer risk. The diverging results for types of dairy products and sources of calcium suggest that other components of dairy rather than fat and calcium may increase prostate cancer risk. Any additional studies should report detailed results for subtypes of prostate cancer

Dietary compared with blood concentrations of carotenoids and breast cancer risk: a systematic review and meta-analysis of prospective studies.

BACKGROUND: Measurement errors in the dietary assessment of fruit and vegetable intake may attenuate associations with breast cancer risk and might explain the weak associations observed in epidemiologic studies. Carotenoid concentrations in blood are biomarkers of fruit and vegetable intake; however, no systematic assessment has compared dietary intake with blood concentrations of carotenoids and breast cancer risk. OBJECTIVE: We conducted a systematic review and meta-analysis of prospective studies of dietary intake and blood concentrations of carotenoids and breast cancer risk. DESIGN: We searched PubMed and several other databases for relevant studies up to 31 August 2011. Random-effects models were used to estimate summary estimates. RESULTS: Of the 6 dietary carotenoids assessed, only intake of β-carotene was significantly associated with a reduced breast cancer risk (summary RR: 0.95; 95% CI: 0.91, 0.99; I(2): 0%) per 5000 μg/d (n = 10). In contrast, the summary RR for blood concentrations of carotenoids was 0.78 (95% CI: 0.61, 0.99; I(2): 53%) per 100 μg total carotenoids/dL (n = 7), 0.74 (95% CI: 0.57, 0.97; I(2): 43%) per 50 μg β-carotene/dL (n = 13), 0.82 (95% CI: 0.73, 0.92, I(2): 3%) per 10 μg α-carotene/dL (n = 12), and 0.68 (95% CI: 0.52, 0.89; I(2): 0%) per 25 μg lutein/dL (n = 6). CONCLUSIONS: Blood concentrations of carotenoids are more strongly associated with reduced breast cancer risk than are carotenoids assessed by dietary questionnaires. Our results suggest that the use of certain biomarkers may clarify inconsistent and weak results between dietary intake and breast cancer risk

Dietary patterns and breast cancer risk among women in northern Tanzania: a case–control study

BACKGROUND: Breast cancer is the second most common cancer among women in the Kilimanjaro Region of Tanzania. It was tested within a case–control study in this region whether a specific dietary pattern impacts on the breast cancer risk. METHODS: A validated semi-quantitative Food Frequency Questionnaire was used to assess the dietary intake of 115 female breast cancer patients and 230 healthy age-matched women living in the same districts. A logistic regression was performed to estimate breast cancer risk. Dietary patterns were obtained using principal component analysis with Varimax rotation. RESULTS: The adjusted logistic regression estimated an increased risk for a “Fatty Diet”, characterized by a higher consumption of milk, vegetable oils and fats, butter, lard and red meat (OR = 1.42, 95 % CI 1.08–1.87; P = 0.01), and for a “Fruity Diet”, characterized by a higher consumption of fish, mango, papaya, avocado and watery fruits (OR = 1.61, 95 % CI 1.14–2.28; P = 0.01). Both diets showed an inverse association with the ratio between polyunsaturated and saturated fatty acids (P/S ratio). CONCLUSION: A diet characterized by a low P/S ratio seems to be more important for the development of breast cancer than total fat intake

Red and processed meat intake and risk of colorectal adenomas: a systematic review and meta-analysis of epidemiological studies.

Current evidence indicates that red and processed meat intake increases the risk of colorectal cancer; however, the association with colorectal adenomas is unclear