For the study, the researchers followed two groups of participants- one of 5,050 people and the other of 8,302 people, each with an average age of 50, for six years and nine years. Both groups were from Buddhist communities where vegetarianism is encouraged while smoking cigarettes and drinking alcohol is discouraged. Furthermore, around 30% of both groups were vegetarians (defined as people who eat neither meat or fish).
At the beginning of the study, each participant was given a medical exam and asked about their diet. In doing so, they found that vegetarians tended to eat more nuts, vegetables and soy products than non-vegetarians. While they also consumed less dairy, both groups consumed equal amounts of eggs and fruits.
At the end of each study, the researchers then matched initial overall health and diets to their incidence of having a stroke later on.
All in all, among the first group of people with 5,050 participants, the researchers counted 54 strokes. While vegetarians experienced three ischemic strokes (strokes wherein blood flow to part of the brain is blocked) per 1,424 people (at a rate of 0.21%), there were 28 strokes for every 3,626 non-vegetarians (0.77% of the cohort). Thus, the researchers concluded that vegetarians in this group had a 74% lower chance of having an ischemic stroke than those eating meat and fish.
In the second group consisting of 8,302 people, 121 strokes were recorded. Including both ischemic and hemorrhagic strokes (when blood from an artery bleeds into the brain), in the vegetarian group of around 2,719 people, there were 24 (0.88%), whereas in the non-vegetarian group of 5,583, there were 97 (1.73%). After adjusting for factors such as age, sex and other health conditions, the researchers found that vegatarians in this group had a 48% lower risk of overall stroke than those eating meat.
Author of the study, Chin-Lon Lin said, “Overall, our study found that a vegetarian diet was beneficial and reduced the risk of ischemic stroke even after adjusting for known risk factors like blood pressure, blood glucose levels and fats in the blood...This could mean that perhaps there is some other protective mechanism that may protecting those who eat a vegetarian diet from stroke."
Before these findings may be taken too conclusively however, it is important to consider their limitations. To begin, as the patients only provided information about their diets at the start of the study, it is unknown whether alterations throughout the study period may have influenced their risk of developing a stroke later. Also, as the participants did not smoke or drink, their results may be limited in their ability to reflect the general population.
Sources: Science Daily and Medical Xpress
