Health impact assessment of salt reduction in bread in Portugal: a pilot study

Hypertension is a risk factor for cardiovascular diseases, which can be caused by excessive salt intake. In Portugal, one of the main foods to contribute to ingestion of salt is bread. Thus, a voluntary Protocol was signed between stakeholders with the aim to reduce salt content in bread by 2021. Herein, a retrospective HIA was carried out to assess the impact in blood pressure (BP) after this agreement. In order to find average values of salt intake and BP in Portuguese population, national surveys were used. Also, estimates of BP reduction and its size effects were calculated based upon meta-analysis data. It is expected that salt intake will be reduced mostly in individuals with low educational level, men, aged between 65-74 years old and residents in South region of Portugal. Results in hypertensive patients indicate that a higher effect on BP will occur in the same profile of individuals, except age (between 55 and 64 years old). However, the estimated effect is very low for all groups, suggesting that the Protocol will contribute to modest health gains. Complementary measures supported by HIA studies need to be adopted to actively promote salt intake reduction and effectively prevent hypertension.