Historically, Seventh-day Adventists don’t drink coffee, tea, or cola drinks because of the caffeine. In the secular (and religious) community, there’s a wide spectrum of opinion about caffeine.

11 Reasons You Should Drink Coffee Every Day
http://www.huffingtonpost.com/2013/10/17/coffee-health-benefits_n_4102133.html

Caffeine can prevent memory loss in diabetes
http://www.informationaboutdiabetes.com/news/diabetes-research/caffeine-can-prevent-memory-loss-in-diabetes

How to Make Bulletproof Coffee
https://www.bulletproofexec.com/how-to-make-your-coffee-bulletproof-and-your-morning-too/

More Consensus on Coffee’s Benefits Than You Might Think
http://www.nytimes.com/2015/05/12/upshot/more-consensus-on-coffees-benefits-than-you-might-think.html?smid=fb-nytimes&smtyp=pay&smvar=mapkwp&kwp_0=16084&kwp_4=104299&kwp_1=142944&_r=0&abt=0002&abg=1

The Case for Drinking as Much Coffee as You Like
Every reason to justify it
http://www.theatlantic.com/health/archive/2012/11/the-case-for-drinking-as-much-coffee-as-you-like/265693/