Nut consumption and incidence of hypertension: The SUN prospective cohort

Background and aims: The consumption of tree nuts could reduce the risk of hypertension, but scarce research has been done to evaluate this potential association. We assessed the association between nut consumption and the incidence of hypertension among 9919 Spanish university graduates followed-up biennially for a median of 4.3 years. Methods and results: Food habits were assessed with a validated 136-item food-frequency questionnaire. Nut consumption was classified into four categories: rarely/never, 1-3/month, 1/week, and 2+/week. A participant was classified as an incident case of hypertension when, being free of hypertension at baseline, he/she subsequently reported a physician-made diagnosis of hypertension in at least one of the follow-up questionnaires. The incidence of hypertension was 12.4 per 1000 person-years. We found no association between nut consumption and incidence of hypertension after adjusting for sex, age and other dietary and non-dietary potential confounders (hazard ratio [HR] for those in the highest vs. lowest nut consumption category = 0.77 [IC 95%: 0.46-1.30] p = 0.795). Results were not modified when we stratified them analyses according to sex or to body mass index. Conclusion: Our data do not provide evidence for an inverse association between nut consumption and incident hypertension in our cohort. Further results from cohorts and trials with a higher baseline risk of hypertension should be obtained to test this relationship. (C) 2009 Elsevier B.V. All rights reserved.