While several massive studies have shown that the people who drink the most coffee live longer and have a reduced risk of diseases like Alzheimer's and diabetes, not many folks out there really understand how this all works.

The thing about coffee is that it actually contains hundreds of different compounds, some of which have important health benefits. This is transferred via the brewing process, in which the substances in the coffee beans mix with the hot water to become part of the drink.

Some of these substances are well known, including caffeine, but there are hundreds of other compounds in there as well, many of which science has yet to identify. Most of these compounds are antioxidants that protect our bodies from oxidation. This involves free radicals that damage molecules in the body, and is believed to be one of the mechanisms behind ageing and common diseases like cancer and heart disease.

One groundbreaking study (the largest of its kind) was published in the New England Journal of Medicine in 2012. The study confirms that the more coffee people drank, the lower their risk of death was. The sweet spot seems to be at 4-5 cups per day, so drinking 6 or more cups per day will probably just going to make you end up visiting the loo more often.