To determine the level of adherence and to assess the association between higher adherence to the South African food based dietary guidelines (SAFBDG) and breast cancer risk.

Population-based, case–control study (the South African Breast Cancer study) matched on age and demographic settings. Validated questionnaires were used to collect dietary and epidemiological data. To assess adherence to the SAFBDG, a nine-point adherence score (out of eleven guidelines) was developed, using suggested adherence cut-points for scoring each recommendation (0 and 1). When the association between higher adherence to the SAFBDG and breast cancer risk was assessed, data-driven tertiles among controls were used as cut-points for scoring each recommendation (0, 0·5 and 1). OR and 95 % CI were estimated using multivariate logistic regression models.

Soweto, South Africa.

Black urban women, 396 breast cancer cases and 396 controls.

After adjusting for potential confounders, higher adherence (>5·0) to the SAFBDG v. lower adherence (<3·5) was statistically significantly inversely associated with breast cancer risk overall (OR = 0·56, 95 % CI 0·38, 0·85), among postmenopausal women (OR = 0·64, 95 % CI 0·40, 0·97) as well as for oestrogen-positive breast cancers (OR = 0·51, 95 % CI 0·32, 0·89). Only 32·3 % of cases and 39·1 % of controls adhered to at least half (a score >4·5) of the SAFBDG.

Higher adherence to the SAFBDG may reduce breast cancer risk in this population. The concerning low levels of adherence to the SAFBDG emphasise the need for education campaigns and to create healthy food environments in South Africa to increase adherence to the SAFBDG.

To compare the prevalence of modifiable risk factors for cancer and other chronic diseases between adult cancer survivors and persons with no history of cancer.

Cross-sectional.

Population-based sample residing in California and Hawaii.

A total of 177 003 men and women aged 45–75 years who participated in the Multiethnic Cohort Study (MEC). Logistic regression was used to examine adherence to recommendations regarding modifiable risk factors among cancer survivors (n 16 346) when compared with cohort members with no history of cancer (n 160 657).

Cancer survivors were less likely than cohort members with no history of cancer to meet recommendations specified in the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) 2007 report (OR = 0·97; 95 % CI 0·96, 0·99). No difference between groups was seen for adherence to dietary recommendations alone (OR = 0·99; 95 % CI 0·98, 1·01). Site-specific analyses showed that results for colorectal cancer were similar to those for all cancers combined, but survivors of breast (OR = 1·04; 95 % CI 1·02, 1·07) and prostate (OR = 1·04; 95 % CI 1·01, 1·07) cancer were more likely to meet dietary recommendations. Latino survivors were less likely to adhere to WCRF/AICR recommendations than Latino controls; however, differences across ethnic groups were not significant (Pinteraction = 0·64).

The modest differences found between adult cancer survivors and persons with no history of cancer suggest that a diagnosis of cancer in itself may not be associated with improvements in health behaviours related to cancer and other chronic diseases.