Fish is associated with a decreased risk for stroke.
The primary protein driver was fish intake, while animal protein appeared to be associated with increased risk. So stroke risk may be reduced by replacing red meat with other protein sources such as fish.
Researchers searched PubMed and Embase for studies with a prospective design that investigated intake of protein — including total protein, animal protein, and vegetable protein — and included the outcome of stroke and stroke subtype.
The analysis included 7 studies with a total of 254,489 participants. The length of follow-up ranged from 10.4 to 18 years, with a median of 14 years. Four studies assessed the dietary protein intake by food-frequency questionnaires and 3 by 24-hour dietary recall.
The results suggest that protein from fish is a major contributor to stroke protection while red meat was associated with an increased risk. The association between protein intake and risk for stroke was stronger in women than men.
The protective effect of protein could be due to its lowering of blood pressure, triglycerides, total cholesterol, or non–high-density lipoprotein or through a substitution effect, where patients replace potentially harmful foods with high-protein ones.
The research team acknowledged that other factors may account for the observed association. For example, dietary protein tends to be associated with nutrients, such as potassium, magnesium, and dietary fiber, that may also prevent stroke.
The protective impact, they say, is due to the favorable effects of certain polyunsaturated fatty acids on blood pressure, lipid profiles, platelet activity, and endothelial function.
It is paramount to promote diets low in sodium and higher in potassium, magnesium and calcium.