This isn’t the only research that has shown neuroprotective effects from cannabis. Some research shows that the plant may help protect the brain after other traumatic events like concussions.
Gradually its use spread from China to India, and then to North Africa, and reached Europe as early as AD 500. Marijuana was listed in United States Pharmacopeia from 1850 till 1942. It was prescribed for different medical uses such as labor pain, nausea, and rheumatism.
Marijuana can help reduce these side effects, reducing pain, decreasing nausea, and stirring up the appetite. Also, there are other FDA approved cannabinoid drugs that use THC, for the same purposes. 
13. Reduce severe pain, and nausea from chemo, and stimulates appetite
Recent studies from Israel shows that smoking marijuana remarkably reduces pains and tremors and improves sleep for Parkinson’s disease patients. What was impressive about the research was the improvement of the fine motor skills among patients.
In 2010, University of Nottingham researchers have found that chemicals in marijuana, including THC, and cannabidiol, interact with cells in the body that play an important role in gut function, and immune system. 
A 2006 study in the European Journal of Gastroenterology and Hepatology discovered that 86% of patients using marijuana successfully finished their therapies, while only 29% of the non-smokers completed their treatments, maybe because marijuana helps to lessen the treatments’ side effects.
Jody Cory Bloom studied 30 multiple sclerosis patients with painful contractions in their muscles. These patients didn’t respond to other medications, but after smoking marijuana for few days, they reported that they were in less pain. The THC in the pot bonds the receptors in the nerves and and muscles to relieve pain.
The researchers, writing in the Journal of the American Medical Association, say that the big drags taken by weed smokers may actually ‘train’ lungs to be more efficient.
A 2012 study in Consciousness and Cognition found that marijuana made people more creative – at least in terms of how well they used language.
4) Weed can help athletes perform better
Smoking weed helps patients give up opiates such as heroin, a new study has found.
‘Even when not stoned, other aches and pains seem to dissipate, too.
Marijuana being smoked during a Prohibition-era themed New Year’s Eve party celebrating the start of retail pot sales, at a bar in Denver. (AP Photo/Brennan Linsley)
One chemical found in marijuana, called cannabidiol, prevents cancer from spreading, researchers at California Pacific Medical Center in San Francisco reported in 2007.
Intense anxiety, fear, distrust, or panic are common side effects.
The 2006 study, published in the journal Molecular Pharmaceutics, found that THC, the active chemical in marijuana, slows the formation of amyloid plaques by blocking the enzyme in the brain that makes them. These plaques are what kill brain cells and cause Alzheimers.
Patients with inflammatory bowel diseases like Crohn’s disease and ulcerative colitis could benefit from marijuana use, studies suggest.
University of Nottingham researchers found in 2010 that chemicals in marijuana, including THC and cannabidiol, interact with cells in the body that play an important role in gut function and immune responses. The study was published in the Journal of Pharmacology and Experimental Therapeutics.