Objective: To test whether high dietary intakes of fat, protein, and milk are associated with the development of non-Hodgkin lymphoma in older women.
Design: Prospective cohort study with a 7-year follow-up period.
Setting: General community.
Participants: Sample of 35 156 Iowa women aged 55 to 69 years with no prior history of cancer who returned the 1986 baseline questionnaire.
Main outcome measure: Non-Hodgkin lymphoma (104 incident cases).
Main results: After controlling for age, marital status, residence, total energy intake, and transfusion history, the relative risks (RRs) for the highest tertile of intake compared with the lowest were 2.00 (95% confidence interval [CI], 1.21-3.30; P for trend = .01) for animal fat, 1.69 (95% CI, 1.07-2.67; P for trend = .02) for saturated fat, and 1.90 (95% CI, 1.18-3.04; P for trend = .01) for monounsaturated fat, and there was no association with vegetable fat or polyunsaturated fat. Greater intake of animal protein (RR = 1.52; 95% CI, 0.94-2.44; P for trend = .08), but not vegetable protein, was associated with elevated risk, and this was mainly explained by greater consumption of red meat (RR = 1.98; 95% CI, 1.13-3.47; P for trend = .02) and hamburger in particular (RR = 2.35; 95% CI, 1.23-4.48; P for trend = .02). Milk and dairy product consumption were not associated with elevated risk. There was also a decreased risk of non-Hodgkin lymphoma with greater consumption of fruits (RR = 0.64; 95% CI, 0.40-1.05; P for trend = .07).
Conclusions: A high-meat diet and a high intake of fat from animal sources is associated with an increased risk of non-Hodgkin lymphoma in older women.