Here's one from the damned if you do, damned if you don't file. While doctors have said switching to a plant-based diet can help ward off coronary heart disease, a new study says it could up your risk of a stroke. Writing in the British Medical Journal, researchers at Oxford University found that vegetarians and vegans had a 20 percent higher risk of a hemorrhagic stroke than meat-eaters. A hemorrhagic stroke occurs when an artery causes bleeding in or around the brain. The cause, they believe, could be linked to herbivores having lower levels of circulating cholesterol and key vitamins like B12.