Adherence to the Nordic Nutrition Recommendations as a measure of a healthy diet and upper respiratory tract infection

Objective: The Nordic countries have published joint dietary recommendations, the Nordic Nutrition Recommendations (NNR), since 1980. We evaluated adherence to the NNR as a measure of a healthy diet and its potential association with self-reported upper respiratory tract infection (URTI). Design: A prospective, population-based study with a follow-up period of 4 months. Dietary intake was assessed using a semi-quantitative FFQ with ninety-six items, along with other lifestyle factors, at baseline. URTI was assessed every three weeks. A Poisson regression model was used to control for age, sex and other confounding factors. Setting: A middle-sized county in northern Sweden. Subjects: Swedish men and women (n 1509) aged 20-60 years. Results: The NNR include recommendations on macronutrient proportions, physical activity and intake of micronutrients, sodium, fibre and alcohol. We found that overall adherence to the NNR was moderately good. In addition, we found that high adherence to the NNR (>5.5 adherence points) was not associated with a lower risk of URTI (incidence rate ratio (IRR) 0.89, 95% CI 0.73, 1.08) compared with low adherence (<4.5 adherence points). When investigating individual components of the NNR, only high physical activity was associated with lower URTI risk (IRR=0.82, 95% CI 0.69, 0.97) whereas none of the dietary components were associated with risk of URTI. Conclusions: Overall adherence to the NNR was moderately good. Overall adherence to the NNR was not associated with URTI risk in our study. However, when investigating individual components of the NNR, we found that high physical activity was associated with lower URTI risk.