Low-fat diet and skin cancer risk: the women's health initiative randomized controlled dietary modification trial.

Abstract

BACKGROUND:

Large cohort studies have reported no relationship between dietary fat and nonmelanoma skin cancer (NMSC), although a low-fat diet intervention reduced NMSC risk in a small clinical trial. In animal studies, skin tumor development has been reduced by low-fat diet. We evaluated the effect of a low-fat dietary pattern on NMSC and melanoma in the Women's Health Initiative Dietary Modification trial.

METHODS:

Postmenopausal women aged 50 to 79 years (n = 48,835) were randomly assigned to the low-fat dietary pattern intervention (n = 19,541) or comparison group (n = 29,294). The intervention goals included decreasing fat intake to 20% or less of calories, increasing vegetable and fruit intake, and increasing grain intake. Self-reported incident NMSC (n = 4,907) and physician-adjudicated incident melanoma (n = 279) were ascertained every 6 months.

RESULTS:

Over 8.1 years of follow-up, the low-fat diet intervention did not affect overall incidence of NMSC [HR 0.98; 95% confidence interval (CI), 0.92-1.04] or melanoma (HR, 1.04; 95% CI, 0.82-1.32). In subgroup analyses of melanoma risk, baseline fat intake interacted significantly with group assignment (Pinteraction = 0.006). Among women with higher baseline fat intake, the dietary intervention significantly increased risk (HR, 1.48; 95% CI, 1.06-2.07), whereas, among women with lower baseline fat intake, the intervention tended to reduce melanoma risk (HR, 0.72; 95% CI, 0.50-1.02).

CONCLUSIONS:

In this large randomized trial, a low-fat dietary pattern did not affect overall incidence of NMSC or melanoma.

IMPACT:

A low-fat diet does not reduce incidence of NMSC, but an interaction between baseline fat intake and dietary intervention on melanoma risk warrants further investigation.

• Authors: Christina S Gamba, Marcia L Stefanick, James M Shikany, Joseph Larson, Eleni Linos, Stacy T Sims, James Marshall, Linda Van Horn, Nathalie Zeitouni, Jean Y Tang
• Journal: Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology (Cancer Epidemiol Biomarkers Prev) Vol. 22 Issue 9 Pg. 1509-19 (Sep 2013) ISSN: 1538-7755 [Electronic] United States
• PMID: 23697610 (Publication Type: Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Dietary Fats

Topics

• Aged
• Cohort Studies
• Diet, Fat-Restricted (statistics & numerical data)
• Dietary Fats (administration & dosage)
• Feeding Behavior
• Female
• Humans
• Incidence
• Middle Aged
• Postmenopause (metabolism)
• Risk Factors
• Skin Neoplasms (epidemiology)
• Treatment Outcome