A recent study conducted by scientists at the Scripps Research Institute in California has found smoking marijuana may stave off Alzheimer's disease. The experts say the active ingredient in the substance could prevent the disease by retaining the level of a neurotransmitter that is essential in the operation of the brain.

Delta-9-tetrahydrocannabinol, or THC, preserves the neurotransmitter acetylcholine better than current drugs which are administered to patients in hospitals. THC blocks clumps of protein blamed for damaging cognition and memory among patients of Alzheimer's.

The team, which reported its findings in the journal Molecular Pharmaceutics, said their discovery could help drug makers produce more efficient drugs to treat Alzheimer's. The disease is the major cause of dementia among elderly people.

The effects of Alzheimer's include memory loss, impaired decision-making, and diminished language and movement skills. The real cause of the disease remains unknown, but doctors say it is hereditary.

An estimated 4.5 million Americans have Alzheimer's disease. The number of Americans with Alzheimer's has more than doubled since 1980 and will continue to grow. By 2050 the number of individuals with Alzheimer's could range from 11.3 million to 16 million.