Oxford University scientists, who tracked almost 50,000 people for about 18 years, believe that lack of vitamins in vegetarians may cause a higher risk of stroke than those that consume meat. They found that vegetarians and vegans had a 20 per cent higher risk of stroke than meat eaters. This news has spread like wildfire on “reputable” news channels such as the BBC and Daily Telegraph.
So, should vegans worry?
Let’s analyze this study and see if it merits caution. The very first thing I have to say about this is that the study is confusing cause with association. Association (or correlation) means that two different things just coincide. My math teacher in high school, Mr. Parashar, used to say, “People with big feet have more IQ”. Does this mean big feet cause higher IQ? Maybe it is simply because people with bigger feet are older. Let’s take another stupid example of the number of times the actor Nicolas Cage appeared in movies and compare it to the number of people that drowned in a swimming pool. Here is the graph of these two events–
If you compare the two over years, you will see that almost every time Mr. Cage appears in a movie, there are more deaths in a swimming pool! Does this mean that he is causing the deaths? Of course not. Well, this study is doing exactly that. OK.So, now back to this so-called study–
- The study claims that since meat eaters get a substance known as choline from meat and vegetarians and vegans get none, this is the root cause of the additional risk. They however assume two things:
- Lack of choline means and automatic increased risk of stroke – not true.
- Second, they assume that only choline can reduce this risk – again not true. Studies (referenced below) have found that vitamin B12 supplements are just as effective in reducing the risk of strokes.
- The researchers started following subjects when the vegans and vegetarians were not advised on B12 supplementation.
- The increased risk of stroke may have nothing to do with people’s diets but may just be due to the differences in the lives of people who do not eat meat versus those that do.
- The added risk of 20% translated to about 3 people out of all the vegetarians and vegans in the study. Compare that to the risk of getting heart disease and diabetes by eating dairy and meat.
- Finally, and this is the most important point – they lumped all vegetarians and vegans together! As we all know, the dietary intake of vegans is very different than vegetarians that quite often rely on dairy.
So the next time someone tells you that being vegan will increase your risk of stroke, keep the above notes handy. Oh! One more thing – do make sure you keep taking vitamin B12. 🙂
Nutrition is far more important in stroke risk than most physicians suppose. Healthy lifestyle choices reduce the risk of stroke by ~80%, and of the factors that increase the risk of stroke, the worst is diet. Metabolic B12 deficiency is common and usually missed. It has serious neurological consequences, including an increase in the risk of stroke.