Foods, macronutrients and breast cancer risk in postmenopausal women: a large UK cohort

Abstract

Background The role of diet in breast cancer aetiology is unclear; recent studies have suggested associations may differ by estrogen receptor status. Methods Baseline diet was assessed in 2000–04 using a validated questionnaire in 691 571 postmenopausal UK women without previous cancer, who had not changed their diet recently. They were followed by record linkage to national cancer and death databases. Cox regression yielded adjusted relative risks for breast cancer for 10 food items and eight macronutrients, subdivided mostly into five categories of baseline intake. Trends in risk across the baseline categories were calculated, assigning re-measured intakes to allow for measurement error and changes in intake over time; P-values allowed for multiple testing. Results Women aged 59.9 (standard deviation (SD 4.9)) years at baseline were followed for 12 (SD 3) years; 29 005 were diagnosed with invasive breast cancer. Alcohol intake had the strongest association with breast cancer incidence: relative risk (RR) 1.08 [99% confidence interval (CI) 1.05–1.11] per 10 g/day higher intake, P = 5.8 × 10−14. There were inverse associations with fruit: RR 0.94 (99% CI 0.92–0.97) per 100 g/day higher intake, P = 1.1 × 10−6, and dietary fibre: RR 0.91 (99% CI 0.87–0.96) per 5 g/day increase, P = 1.1 × 10−4. Fruit and fibre intakes were correlated (ρ = 0.62) and were greater among women who were not overweight, so residual confounding cannot be excluded. There was no heterogeneity for any association by estrogen receptor status. Conclusions By far the strongest association was between alcohol intake and an increased risk of breast cancer. Of the other 17 intakes examined, higher intakes of fruit and fibre were associated with lower risks of breast cancer, but it is unclear whether or not these associations are causal.

Body mass index, diet, physical inactivity, and the incidence of dementia in 1 million UK women

“…After 15 years of follow-up, 89% were still alive and still being followed up with no hospital record that had mentioned dementia, and (apart from being older) their characteristics at year 15 were similar to those of the entire cohort at baseline. No major secular changes in BMI, diet, or physical activity occurred in this population, 7,13,15 and confounding by other possible risk factors appeared to have little effect on the findings.…”

“…During that period, 30,957 women had ≥1 hospital admissions with dementia mentioned, of which only the first is analyzed. During the first 5 years of follow-up, 478 women had their first hospital admission with mention of dementia; during follow-up years 5 to 9, a further 2,410 did so; during follow-up years 10 to 14, a further 9,374 did so; and during follow-up years 15+ (mainly years [15][16][17][18][19], a further 18,695 did so, at a mean age of 77 (SD 4) years. At year 15 after study entry, 89% of all participants were still alive with no hospital record mentioning dementia and were still being followed up for details of any subsequent hospital admissions or deaths (table).…”

“…At year 15 after study entry, 89% of all participants were still alive with no hospital record mentioning dementia and were still being followed up for details of any subsequent hospital admissions or deaths (table). Apart from having become older, their average characteristics were not materially different from those of the entire population at baseline, and all analyses of dementia detection rates during follow-up years 15+ (mainly years [15][16][17][18][19] are based only on these survivors with no record of dementia before follow-up year 15 (data available from Dryad, table 2, doi.org/10.5061/dryad.3s755j8).…”

“…The dementia detection RRs among women who had been obese at study entry compared to women who had been of desirable BMI (20-24.9 kg/m 2 ) are shown separately in figure 1 for follow-up years <5, 5 to 9, 10 to 14, and 15+ (mostly years [15][16][17][18][19], mean year 17.3 for the cases). During the first 5 years of follow-up, the dementia detection RR for obese vs desirable was only about two-thirds (RR 0.65, 95% CI 0.49-0.85, p < 0.0001).…”

“…There was good short-term repeatability for most dietary questions, 14 and intakes did not change appreciably over time in the cohort as a whole. 15 All participants were registered with the NHS. With the use of each individual's unique NHS number and date of birth, study participants were linked electronically to routinely collected NHS data on hospital admissions (as day cases or as inpatients), deaths, and emigrations by NHS Digital in England (in which up to 20 diagnoses are coded for every hospital admission) 16 and by the NHS Central Register and Information Services Division in Scotland (in which up to 6 diagnoses are coded for every hospital admission).…”