Nut Consumption Is Associated with Decreased Health Risk Factors for Cardiovascular Disease and Metabolic Syndrome in US Adults: NHANES 1999-2004

Background: Few recent epidemiologic studies have assessed the effect that nut consumption (including tree nuts and peanuts) has on health risks, including metabolic syndrome (MetS). Objective: This study compared the health risk for cardiovascular disease, type 2 diabetes, and MetS of nut consumers with that of nonconsumers. Design: Adults 19+ years (n = 13,292) participating in the 1999-2004 National Health and Nutrition Examination Survey were used. Intake from 24-hour recalls was used to determine intake. Nut/tree nut consumers consumed >= 1/4 ounce per day. Covariate-adjusted means, standard errors, and prevalence rates were determined for the nut consumption groups. Results: The prevalence of nut consumers was 18.6% +/- 0.7% and 21.0% +/- 0.9% in those 19-50 years and 51 years and older, respectively. Nut consumption was associated with a decreased body mass index (27.7 kg/m(2) +/- 0.2 vs 28.1 +/- 0.1 kg/m(2), p < 0.05), waist circumference (95.6 +/- 0.4 cm vs 96.4 +/- 0.3 cm, p < 0.05), and systolic blood pressure (121.9 +/- 0.4 mmHg vs 123.20 +/- 0.3 mmHg, p < 0.01) compared with nonconsumers. Tree nut consumers also had a lower weight (78.8 +/- 0.7 kg vs 80.7 +/- 0.3 kg, p < 0.05). Nut consumers had a lower percentage of two risk factors for MetS: hypertension (31.5% +/- 1.0% vs 34.2% +/- 0.8%, p < 0.05) and low high density lipoprotein-cholesterol (HDL-C) (29.6% +/- 1.0% vs 34.8% +/- 0.8%, p < 0.01). Tree nut consumers had a lower prevalence of four risk factors for MetS: abdominal obesity (43.6% +/- 1.6% vs 49.5% +/- 0.8%, p < 0.05), hypertension (31.4% +/- 1.2% vs 33.9% +/- 0.8%, p < 0.05), low HDL-C (27.9% +/- 1.7% vs 34.5% +/- 0.8%, p < 0.01), high fasting glucose (11.4% +/- 1.4% vs 15.0% +/- 0.7%, p < 0.05), and a lower prevalence of MetS (21.2% +/- 2.1% vs 26.6% +/- 0.7%, p < 0.05). Conclusion: Nut/tree nut consumption was associated with a decreased prevalence of selected risk factors for cardiovascular disease, type 2 diabetes, and MetS.