The reduced risk of stroke was from only a modest 20 grams of protein per day. From Science Daily:
People with diets higher in protein, especially from fish, may be less likely to have a stroke than those with diets lower in protein, according to a meta-analysis. The meta-analysis looked at all of the available research on the relationship between protein in the diet and the risk of stroke. Seven studies with a total of 254,489 participants who were followed for an average of 14 years were included in the analysis.
"The amount of protein that led to the reduced risk was moderate -- equal to 20 grams per day," said study author Xinfeng Liu, MD, PhD, of Nanjing University School of Medicine in Nanjing, China.
Overall, the participants with the highest amount of protein in their diets were 20 percent less likely to develop a stroke than those with the lowest amount of protein in their diets. The results accounted for other factors that could affect the risk of stroke, such as smoking and high cholesterol. For every additional 20 grams per day of protein that people ate, their risk of stroke decreased by 26 percent.
Liu noted that the analysis does not support increased consumption of red meat, which has been associated with increased stroke risk. Two of the studies were conducted in Japan, where people eat less red meat than westerners do and more fish, which has been associated with decreased risk of stroke.
The reduced risk of stroke was stronger for animal protein than vegetable protein. Protein has the effect of lowering blood pressure, which may play a role in reducing stroke risk, Liu said.