Associations of intakes of total protein, protein from dairy sources, and dietary calcium with risks of colorectal, breast, and prostate cancer: a prospective analysis in UK Biobank.

BACKGROUND: Evidence concerning intakes of protein or sources of dairy protein and risks of colorectal, breast, and prostate cancers is inconclusive. METHODS: Using a subsample of UK Biobank participants who completed ≥2 (maximum of 5) 24-h dietary assessments, we estimated intakes of total protein, protein from total dairy products, milk, and cheese, and dietary calcium in 114,217 participants. Hazard ratios (HRs) and 95% confidence intervals (CI) were estimated using multivariable-adjusted Cox regression. RESULTS: After a median of 9.4 years of follow-up, 1193 colorectal, 2024 female breast, and 2422 prostate cancer cases were identified. There were inverse associations of total dairy protein, protein from milk, and dietary calcium intakes with colorectal cancer incidence (HRQ4 vs Q1:0.80, 95% CI: 0.67-0.94; 0.79, 0.67-0.94; 0.71, 0.58-0.86, respectively). We also observed positive associations of milk protein and dietary calcium with prostate cancer risk (HRQ4 vs Q1:1.12, 1.00-1.26 and 1.16, 1.01-1.33, respectively). No significant associations were observed between intake of dairy protein and breast cancer risk. When insulin-like growth factor-I concentrations measured at recruitment were added to the multivariable-adjusted models, associations remained largely unchanged. Analyses were also similar when looking at total grams of dairy products, milk, and cheese. CONCLUSION: Further research is needed to understand the mechanisms underlying the relationships of dairy products with cancer risk and the potential roles of dietary protein and calcium.

Adiposity and risk of prostate cancer death: a prospective analysis in UK Biobank and meta-analysis of published studies.

BACKGROUND: The association of adiposity with prostate cancer specific mortality remains unclear. We examined how adiposity relates to fatal prostate cancer and described the cross-sectional associations of commonly used adiposity measurements with adiposity estimated by imaging in UK Biobank. We also conducted a dose-response meta-analysis to integrate the new data with existing prospective evidence. METHODS: 218,237 men from UK Biobank who were free from cancer at baseline were included. Body mass index (BMI), total body fat percentage (using bioimpedance), waist circumference (WC) and waist-to-hip ratio (WHR) were collected at recruitment. Risk of dying from prostate cancer (primary cause) by the different adiposity measurements was estimated using multivariable-adjusted Cox proportional hazards models. Results from this and other prospective cohort studies were combined in a dose-response meta-analysis. RESULTS: In UK Biobank, 661 men died from prostate cancer over a mean follow-up of 11.6 years. In the subsample of participants with magnetic resonance imaging and dual-energy X-ray absorptiometry, BMI, body fat percentage and WC were strongly associated with imaging estimates of total and central adiposity (e.g. visceral fat, trunk fat). The hazard ratios (HR) for prostate cancer death were 1.07 (95% confidence interval = 0.97-1.17) per 5 kg/m2 higher BMI, 1.00 (0.94-1.08) per 5% increase in total body fat percentage, 1.06 (0.99-1.14) per 10 cm increase in WC and 1.07 (1.01-1.14) per 0.05 increase in WHR. Our meta-analyses of prospective studies included 19,633 prostate cancer deaths for BMI, 670 for body fat percentage, 3181 for WC and 1639 for WHR, and the combined HRs for dying from prostate cancer for the increments above were 1.10 (1.07-1.12), 1.03 (0.96-1.11), 1.07 (1.03-1.11), and 1.06 (1.01-1.10), respectively. CONCLUSION: Overall, we found that men with higher total and central adiposity had similarly higher risks of prostate cancer death, which may be biologically driven and/or due to differences in detection. In either case, these findings support the benefit for men of maintaining a healthy body weight.

Risk of cancer in regular and low meat-eaters, fish-eaters, and vegetarians: a prospective analysis of UK Biobank participants.

BACKGROUND: Following a vegetarian diet has become increasingly popular and some evidence suggests that being vegetarian may be associated with a lower risk of cancer overall. However, for specific cancer sites, the evidence is limited. Our aim was to assess the associations of vegetarian and non-vegetarian diets with risks of all cancer, colorectal cancer, postmenopausal breast cancer, and prostate cancer and to explore the role of potential mediators between these associations. METHODS: We conducted a prospective analysis of 472,377 UK Biobank participants who were free from cancer at recruitment. Participants were categorised into regular meat-eaters (n = 247,571), low meat-eaters (n = 205,385), fish-eaters (n = 10,696), and vegetarians (n = 8685) based on dietary questions completed at recruitment. Multivariable-adjusted Cox regressions were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for all cancer incidence and separate cancer sites across diet groups. RESULTS: After an average follow-up of 11.4 years, 54,961 incident cancers were identified, including 5882 colorectal, 7537 postmenopausal breast, and 9501 prostate cancers. Compared with regular meat-eaters, being a low meat-eater, fish-eater, or vegetarian were all associated with a lower risk of all cancer (HR: 0.98, 95% CI: 0.96-1.00; 0.90, 0.84-0.96; 0.86, 0.80-0.93, respectively). Being a low meat-eater was associated with a lower risk of colorectal cancer in comparison to regular meat-eaters (0.91, 0.86-0.96); however, there was heterogeneity in this association by sex (p = 0.007), with an inverse association across diet groups in men, but not in women. Vegetarian postmenopausal women had a lower risk of breast cancer (0.82, 0.68-0.99), which was attenuated and non-significant after adjusting for body mass index (BMI; 0.87, 0.72-1.05); in mediation analyses, BMI was found to possibly mediate the observed association. In men, being a fish-eater or a vegetarian was associated with a lower risk of prostate cancer (0.80, 0.65-0.99 and 0.69, 0.54-0.89, respectively). CONCLUSION: The lower risk of colorectal cancer in low meat-eaters is consistent with previous evidence suggesting an adverse impact of meat intake. The lower risk of postmenopausal breast cancer in vegetarian women may be explained by their lower BMI. It is not clear whether the other differences observed for all cancers and for prostate cancer reflect any causal relationships or are due to other factors such as residual confounding or differences in cancer detection.

Dietary patterns and age at natural menopause: Evidence from the UK Women's Cohort Study.

OBJECTIVES: To investigate prospective associations between dietary patterns and age of natural menopause. STUDY DESIGN AND MAIN OUTCOME MEASURES: Menopausal status was reported at two time points 4  years apart in the UK Women's Cohort Study (UKWCS). Diet of participants was measured using a 217-item food frequency questionnaire at baseline. Principal component analysis (PCA) and reduced rank regression (RRR) were used to derive dietary patterns for 13,916 women. Cox proportional hazards regressions were used to estimate hazard ratios (HR) and 95 % confidence intervals (CIs) for each pattern in relation to age at natural menopause, adjusting for potential confounders. RESULTS: Five patterns were identified from the PCA, labelled as: 'vegetables and legumes', 'animal proteins', 'fruits', 'fats and sweets' and 'low-fat products'. Three patterns were derived from RRR: 'sweets, pastries and puddings', 'low-fat dairy and meat', and 'red meat and processed meat'. Women who scored 1 standard deviation higher on the 'animal proteins' pattern were 6% more likely to experience a later natural menopause over the study (HR = 0.94, 95 % CI: 0.90-0.97) compared with those who scored lower. The 'red meat and processed meat' pattern similary predicted a 7% higher risk for a later menopause during the study (HR = 0.93, 95 % CI: 0.87-1.00) per 1 standard deviation. CONCLUSIONS: Women whose diets are highly loaded with animal proteins, as well as red and processed meats, are more likely to have a later natural menopause.

Soy intake and vasomotor menopausal symptoms among midlife women: a pooled analysis of five studies from the InterLACE consortium.

BACKGROUND/OBJECTIVES: Phytoestrogen rich-foods such as soy may be associated with less frequent/severe vasomotor menopausal symptoms (VMS), although evidence is limited. We thus investigated the associations between the consumption of soy products and soy milk and the frequency/severity of VMS. SUBJECTS/METHODS: We pooled data from 19,351 middle-aged women from five observational studies in Australia, UK, USA, and Japan that contribute to the International Collaboration for a Life course Approach to reproductive health and Chronic disease Events (InterLACE). Information on soy consumption, VMS and covariates were collected by self-report. We included 11,006 women who had complete data on soy consumption, VMS and covariates at baseline for the cross-sectional analysis. For the prospective analysis, 4522 women who were free of VMS at baseline and had complete data on VMS at follow-up were considered. Multinomial logistic regression and binary logistic regression models were used. RESULTS: No statistically significant evidence of an association was found between soy products (relative risk ratio (RRR): 0.92, 95% CI: 0.76-1.11) or soy milk (RRR: 1.24, 95% CI: 0.93-1.65) and the likelihood of reporting frequent or severe VMS cross-sectionally. Prospective results indicated that frequent consumption of soy products (odds ratio (OR): 0.63, 95% CI: 0.45-0.89) but not soy milk (OR: 1.11, 95% CI: 0.85-1.45) was associated with lower likelihood of reporting subsequent VMS, after adjustment for socio-demographic and reproductive factors. CONCLUSIONS: These are the first ever findings from pooled observational data of association between consumption of soy products and VMS.

Diet, menopause and the risk of ovarian, endometrial and breast cancer.

Menopause, the permanent cessation of the menstrual cycle, marks the end of a woman's reproductive lifespan. In addition to changes in sex hormone levels associated with menopause, its timing is another predictor of future health outcomes such as duration of the presence of vasomotor symptoms (VMS) and the risk of hormone-related cancers. With ageing of the population, it is estimated that worldwide 1·2 billion women will be menopausal by the year 2030. Previously the effects of reproductive factors (e.g. parity, age at menarche, pregnancy) and socio-demographic factors on intermediate and long-term health outcomes of menopause have been widely documented. However, little is known about whether diet could have an impact on these. Therefore, we review current evidence on the associations of diet with menopause, presence of VMS and the risk of hormone-related cancers such as ovarian, endometrial and breast cancer. Dietary factors could influence the lifespan of the ovaries and sex-hormones levels, hence the timing of natural menopause. Few studies reported an association between diet, in particular soya consumption, and a reduced risk of VMS. Sustained oestrogen exposure has been associated with a higher risk of hormone-related cancers and thus high-fat and meat diets have been linked with an increased risk of these cancers. However, to better understand the mechanistic pathways involved and to make stronger conclusions for these relationships, further studies investigating the associations of dietary intakes and dietary patterns with menopause, presence of VMS and the risk of hormone-related cancers are required.

Diet and risk of breast, endometrial and ovarian cancer: UK Women's Cohort Study.

This study aimed to investigate the association between diet and the risk of breast, endometrial and ovarian cancer in the UK Women's Cohort Study. A total of 35 372 women aged 35-69 years were enrolled between 1995 and 1998 and completed a validated 217-item FFQ. The individual foods were collapsed into sixty-four main food groups and compared using Cox proportional models, adjusting for potential confounders. Hazard ratio (HR) estimates are presented per portion increase in food items. After approximately 18 years of follow-up, there were 1822, 294 and 285 cases of breast, endometrial and ovarian cancer, respectively. A high consumption of processed meat and total meat was associated with an increased risk of breast and endometrial cancer. High intake of tomatoes (HR 0·87, 99 % CI 0·75, 1·00) and dried fruits (HR 0·60, 99 % CI 0·37, 0·97) was associated with a reduced risk of breast and endometrial cancer, respectively. Mushroom intake was associated with a higher risk of ovarian cancer (HR 1·57, 99 % CI 1·09, 2·26). Subgroup analysis by pre- or postmenopausal cancer further demonstrated an association between processed meat intake and both postmenopausal breast cancer and endometrial cancer. Intake of dried fruits was associated with a reduced risk of postmenopausal endometrial cancer (HR 0·55, 99 % CI 0·31, 0·98). Our findings suggest that while some foods may trigger the risk of these cancers, some foods may also be protective; supporting the call for further randomised controlled trials of dietary interventions to reduce the risk of cancer among pre- and postmenopausal women.

Dietary intake and age at natural menopause: results from the UK Women's Cohort Study.

BACKGROUND: Age at natural menopause is a matter of concern for women of reproductive age as both an early or late menopause may have implications for health outcomes. METHODS: Study participants were women aged 40-65 years who had experienced a natural menopause from the UK Women's Cohort Study between baseline and first follow-up. Natural menopause was defined as the permanent cessation of menstrual periods for at least 12 consecutive months. A food frequency questionnaire was used to estimate diet at baseline. Reproductive history of participants was also recorded. Regression modelling, adjusting for confounders, was used to assess associations between diet and age at natural menopause. RESULTS: During the 4-year follow-up period, 914 women experienced a natural menopause. A high intake of oily fish and fresh legumes were associated with delayed onset of natural menopause by 3.3 years per portion/day (99% CI 0.8 to 5.8) and 0.9 years per portion/day (99% CI 0.0 to 1.8), respectively. Refined pasta and rice was associated with earlier menopause (per portion/day: -1.5 years, 99% CI -2.8 to -0.2). A higher intake of vitamin B6 (per mg/day: 0.6 years, 99% CI 0.1 to 1.2) and zinc (per mg/day: 0.3 years, 99% CI -0.0 to 0.6) was also associated with later age at menopause. Stratification by age at baseline led to attenuated results. CONCLUSION: Our results suggest that some food groups (oily fish, fresh legumes, refined pasta and rice) and specific nutrients are individually predictive of age at natural menopause.

Healthy Diet and Nutrition Education Program among Women of Reproductive Age: A Necessity of Multilevel Strategies or Community Responsibility.

BACKGROUND: Reproductive years represent a major proportion of women?s life. This review focuses on recommended nutritional considerations, physical activity pattern as well as the effect of nutrition education (NE) on behavior modification and health outcomes of women of reproductive age using either single-level, multiple-level or community-level interventions. METHODS: For this narrative review, numerous searches were conducted on databases of PubMed, Science Direct and Google Scholar search engine using the keywords women, reproductive age, NE, interventions, community-based. RESULTS: Even though single intervention is effective, multiple intervention programmes in addition to behavior modification components are even more successful in terms of modified behaviors and health outcomes. Moreover, community based interventions using multilevel strategies are further useful for improved health outcomes and behavior modification. CONCLUSION: NE programmes have been effective in positive behavior modification measured in terms of eating pattern and health quality. Thus, it is recommended that health professionals use multiple intervention strategies at community level to ensure improved outcomes. Political support is also required to create culturally sensitive methods of delivering nutritional programmes. Finally, as policy is dependent on program cost, nutritional programmes need to combine methods of cost analysis to show cost effectiveness of supplying adequate nutrition for women throughout the lifecycle.

A Scientific Assessment of Sociodemographic Factors, Physical Activity Level, and Nutritional Knowledge as Determinants of Dietary Quality among Indo-Mauritian Women.

A healthy diet is of particular concern throughout the life of women to avoid many chronic illnesses especially during their 30s to 50s. There are published data on dietary quality and its determinants among women, but there is a lack of similar data regarding women in Mauritius. This study aimed to investigate the association between age and dietary quality in relation to sociodemographic factors, physical activity level (PAL) and nutritional knowledge (NK). A survey-based study was conducted in 2012 among Indo-Mauritian women including 117 young (21.35 ± 1.98), 160 reaching middle age (34.02 ± 5.09) and 50 middle-aged (37.85 ± 8.32). Validated questionnaires were used to elicit information on the determinants. A food frequency table consisting of 18 food items was used to assess dietary quality. Univariate and multivariate analyses were used to determine the association between various factors and dietary quality. The mean dietary score of middle-aged women (18.70 ± 2.67) was closer to recommended dietary guidelines compared to young women (17.22 ± 3.40), and women reaching middle age (17.55 ± 3.29). Educational level, PAL, NK, and age were main determinants of dietary quality among Indo-Mauritian women (P < 0.05). Younger women with low educational level, PAL, and NK are at risk of poor dietary quality.