The study, lead by Xinfeng Liu, of the Nanjing University School of Medicine, looked at seven different studies -- four conducted in the U.S., two in Japan and one in Sweden -- that plotted and analyzed the health of 254,489 participants. The average length of the seven studies was 14 years.
Lui and his colleagues found that six of the seven studies found a correlation between higher protein intake and fewer strokes, although, only three of the six correlations were statistically significant.
As always seems to be the case with meta-analyses -- and especially studies concerning diet and nutrition -- the findings were heavily qualified.
"As with all meta-analyses, heterogeneity of studies always has a role," the authors wrote in their study, acknowledging that each study was conducted separately. Furthermore, none of the studies were designed specifically to parse out a relationship between protein intake and instances of stroke.
"Different geographic populations, poor or incomplete description of other diet components, and comorbidities should all be considered," they added.
The study was published this week in the journal Neurology.
In an accompanying editorial, another researcher further qualified the results.
"The grain study population was small, and ... this could have been a factor for the inconsistent result," said Arturo Tamayo, of the University of Manitoba. "Therefore, labeling animal protein completely as beneficial is not helpful until more data are available."
In other words, until more definitive results are available, an uptake in animal protein is probably not the best preventative measure for avoiding strokes.