Dietary intake and breast cancer risk in black South African women: the South African Breast Cancer study.

Inarie Jacobs,Tertia Van Zyl,Sabina Rinaldi,Christine Taljaard-Krugell,Ria Laubscher,Cristian Ricci,Hester Vorster,Herbert Cubasch,Isabelle Romieu,Maureen Joffe,Shane A Norris

doi:10.1017/s0007114518003744

Abstract

Incidence rates of breast cancer (BC) are increasing in South Africa. The aim of this study was to investigate the association between dietary intake and BC risk in black South African women. The study population included 396 BC cases and 396 population-based controls matched on age and residence, participating in the South African Breast Cancer study. Diet was assessed using a validated quantified FFQ from which twelve energy-adjusted food groups were formed and analysed. OR were estimated using conditional logistic regressions, adjusted for confounding factors, comparing highest v. lowest median intake. Fresh fruit consumption showed an inverse association with BC risk (OR=0·3, 95 % CI 0·12, 0·80) in premenopausal women, whilst red and organ meat consumption showed an overall inverse association with BC risk (OR=0·6, 95 % CI 0·49, 0·94 and OR=0·6, 95 % CI 0·47, 0·91). Savoury food consumption (sauces, soups and snacks) were positively associated with BC risk in postmenopausal women (OR=2·1, 95 % CI 1·15, 4·07). Oestrogen receptor-positive stratification showed an inverse association with BC risk and consumption of nuts and seeds (OR=0·2, 95 % CI 0·58, 0·86). Based on these results, it is recommended that black South African women follow a diet with more fruit and vegetables together with a decreased consumption of less energy-dense, micronutrient-poor foods such as savoury foods. More research is necessary to investigate the association between BC risk and red and organ meat consumption. Affordable and practical methods regarding these recommendations should be implemented within health intervention strategies.

Highlights

Breast cancer (BC) is currently the most general cancer diagnosed in women and the second leading cause of cancer mortality globally[1]
This study aimed to investigate the association between dietary intake and BC risk in black South African women
We found an inverse association with BC risk and consumption of fresh fruit in premenopausal women, whilst subgroups of animal protein showed inverse associations with BC risk

Summary

Introduction

Breast cancer (BC) is currently the most general cancer diagnosed in women and the second leading cause of cancer mortality globally[1]. The link, between dietary intake and BC risk within black South African women has not been given sufficient attention. Research investigating this specific association is lacking in South Africa. Despite the promotion of a less energy-dense and more nutrient-rich diet, a more Westernised diet is ever increasingly being followed by black South African women[14]. Monotonous diets are often a result of food insecurity and poverty that contributes to increased consumption of low-cost, energy-dense foods[14]. Overconsumption of high energy-dense foods and low physical activity levels together with increasing obesity rates in the black female population of South Africa[14,15] is worrisome risk factors for BC and raises concerns for health prevention strategies. The aim of this study was to determine the association between dietary intake and BC risk in a population-based study of black South African women within the SABC case– control study

Objectives

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Results

Conclusion