british and american tobacco makes $47 billion offer for U.S. rival Reynolds Is British American Tobacco (BTI)

Fruits rich in vitamin C, like oranges, guavas, mangoes, pineapples, papayas and bananas also help in converting tryptophan into serotonin

Other factors like alcohol use, obesity, and acid reflux also contribute but smoking remains the most significant preventable cause

Bulletin of the World Health Organization: the International Journal of Public Health 2004

Now its in a top medical journal, Washington Post How I used public radio to recruit 20,000 participants for a peer-reviewed study on walking breaks, STAT What science knows about grief, New Yorker Ophthalmology venture grabs investors attention, raises $330 million, STAT