Nuts vs Atrial Fibrillation

Nuts are a rich source of protein and a number of vitamins and minerals. Nut consumption has been inversely associated with cardiovascular death, coronary heart disease, and stroke, byproducts of antioxidant and anti-inflammatory effects, as well as with beneficial effects on endothelial function. Most recently, a large Swedish registry study attempted to determine the relationship between nut consumption and incident atrial fibrillation (AF).

The study, published in Heart in April 2018, include 61,364 Swedish adults who had completed food questionnaires and had 17 years of prospective follow-up. In a multivariate adjusted model, there was an inverse association with nut consumption and AF with the greatest benefit coming from nut consumption 3 times a week or more (HR 0.83, 95% CI 0.68-0.99) or from 1-2 times a week (HR 0.93, 95% CI 0.68-0.99). Eating nuts less often (eg, 1-3 times a month) also appeared to be beneficial but the statistical significance was attenuated (HR 0.97, 95% CI 0.93-1.02). These results suggest an inverse, linear, dose-response relationship between nuts and incident AF. Interestingly, those who consumed the most nuts also had the highest consumption of vegetables.

The authors posit several plausible mechanisms for these findings. First, they invoke lower body weight, which is associated with nut consumption, as an explanation. They also discuss the beneficial effects on endothelial function, systemic inflammation, and LDL-C as additional mechanisms.

An obvious strength of this study is the large number of patients and the extended follow-up. Limitations include a limited demographic population (Swedish adults only), risk of additional unmeasured confounders, or changes in nutritional behaviors over time. Regardless, this study reminds us (and our patients) that food and nutrition continue to remain an important and highly modifiable risk factor for the development of incident AF in a global aging adult population.

Source: Larsson SC, Drca N, Björck M, et al. Nut consumption and incidence of seven cardiovascular diseases. Heart. Published Online First: 16 April 2018. doi: 10.1136/heartjnl-2017-312819