 Stroke remains one of the most devastating of all neurological diseases, killing about 5 million people a year worldwide and is the leading cause of permanent disability in the United States. But the good news is that about 80% of stroke risk may be due to basic lifestyle factors, primarily improving your diet, stopping smoking, and getting regular exercise. The best way to stop smoking, evidently, is to have a heart attack. If you die, you automatically stop smoking, unless you're incinerated, I guess. And if you live, repeated strong advice from your doctor may persuade up to two-thirds to quit. Never smoke again in any form as long as you live. Yes, it's very addictive. Yes, it's very difficult. It doesn't matter. It has to be done. If you're walking along the lakeshore and one of your grandchildren is drowning, it's not a matter of willpower. It just has to be done. It's like a healthy diet. Some things just have to be done. Getting up at night to feed a baby can be difficult, too, but it's not a matter of willpower. Some things in life just have to be done. For stroke prevention, that means a more plant-based diet, like a traditional Mediterranean diet centered around whole grains, fruits, vegetables, lentils, beans, and nuts. A vegetarian or vegan diet may also work, but must be accompanied by a regular, reliable source of vitamin B12, meaning B12-fortified foods or supplements. Unfortunately, recommending taking B12 supplements may meet opposition among vegetarians, because misconceptions regarding this nutrient are prevalent. Many individuals still hold on to the old myth that deficiency of this vitamin is rare and only occurs in a small proportion of vegans. Future studies with vegetarians should focus on identifying ways of convincing vegetarians to routinely take vitamin B12 supplements in order to prevent a deficiency. The research is clear on that. Now we just need research on how we can convince vegetarians to actually take their B12 to prevent a deficiency. What is it about plant-based diets? Previously I talked about the role of fiber, potentially about a 1% drop in risk for every one gram of fiber per day, or maybe even a 1% more 12% drop associated with every extra 10 grams a day. In fact, fiber from like whole grains associated with not only lower chance of dying from heart attack and stroke, but also cancer and diabetes, and respiratory diseases and lower risk of dying even from infections or other causes. In other words, lower risk of dying prematurely from all causes put together. Why? Perhaps because of the anti-inflammatory effects of fiber, which could explain how it could help across the board. Or maybe they're eating fewer pro-inflammatory foods. Those who eat more whole plant foods, where fiber is found, may be eating less processed than animal foods. In fact, the study immediately preceding this one, this meta-analysis of fiber, was a meta-analysis on meat. They looked at red meat and processed meat, found about a 10% increase in risk of stroke associated with each 3.5 ounce daily portion. So that's like about the size of a deck of playing cards, or about 10% increase risk for every half-deck of processed meat. Perhaps it's because of the heme iron, the blood, muscle, iron, and meat, perhaps because of its pro-oxidative properties, whereas no association was found between non-heme iron and stroke the type of iron that predominates in plants. Or perhaps it's because of some of the toxic pollutants like PCBs that can build up in animal fats. We've known that living next to a toxic waste dump might increase stroke risk, but only recently have we realized that dietary exposure, even at so-called safe levels, may increase stroke risk, as much as 8 or 9 times the odds of stroke for those with the highest levels of these pollutants in their bloodstream.