Cannabis may be an effective treatment for Alzheimer's disease, says Dr. Gary Wenk of Ohio State University. That's because Alzheimer's is linked to brain inflammation and cannabis has known anti-inflammatory properties.

Wenk's research has found that early detection of brain inflammation can determine whether someone will develop Alzheimer's disease nearly 40 years before it sets in. He says that while brain inflammation happens naturally as people age, it can also be induced by injury or trauma. So athletes and anyone else who has suffered a blow to the head might want to look into medical marijuana now to offset the lingering effects of their injuries later.

Even at very low dosages - as little as "a puff a day" - brain inflammation was noticeably reduced, Dr. Wenk found after experimenting on lab rats. Those results have inspired Wenk to tell his students, "that if their patients were in a car accident and had a severe head injury, the first thing they should tell their patient to do is start smoking marijuana heavily for the next few weeks because it would protect the brain."