In 1997, the data hit me like a welcome cold water balloon on a hot Chicago day. I was researching all things that had big league health or RealAge effects and what a great surprise: Coffee and caffeine were healthy. They made you substantially younger, if about two years matters (it does). And it’s pretty easy to get two years younger by drinking something you love.

These data came from four studies that showed that people, no matter where they lived, had less mental dysfunction as they aged and less Parkinson’s the more coffee and caffeine they consumed. And it wasn’t a trivial difference: approximately a 40% reduction in significant memory loss, or memory loss postponed by 8 years, and a 40% reduction in Parkinson’s risk. This is if you consumed six (8 oz) standard cups of black coffee every day.

The benefit seemed to start at three cups or 250 mg of caffeine a day and build to a max benefit at 500 to 650 mg a day (the data on the high end of the effect were not clear, as few people were tested or followed who used more than 500 mg every day). That 6-cup-a-day habit would make the typical American of age 55 about 1.8 years younger.

But – there always are some buts – you’d have to give up cream and sugar with it, as milk or cream protein literally sucked all the benefit from it. What’s more, saturated fat and sugar made it an aging drink.

And more data did appear – that’s the great thing about this Wellness field – there are a lot of people trying to find out what slows your aging. Black coffee (note the emphasis on black) and caffeine were repeatedly associated with greater health. Black coffee decreases insulin resistance (important for avoiding and reducing complications in diabetes), decreases risk of some cancers like basal cell and liver, and the data on delaying mental decline and avoiding Parkinson’s got stronger than Arnold in his prime. But you’ll notice I didn’t mention energy drinks or caffeine in anything but water, straight tea, or black coffee. And for a reason.

Data also appeared that you needed a paper filter, no milk protein, no saturated fat and no added sugars for coffee to make you younger. The paper filter is needed to bind a compound that increases LDL cholesterol; the milk protein would bind whatever it is that makes you younger (and that’s not good); the saturated fat and simple added sugars age you so much that they overcome the benefits. And many of the so-called energy drinks and other things have stuff in ‘em that causes aging in animal studies. We as humans haven’t had energy drinks long enough to know what they’re likely to do to us.

Side note: Mayor Bloomberg is one smart dude – he wants to make it easy for you to stay young and hard for you to lose your mind – or get diabetes.

So what about you? If you like black coffee or straight tea, and it likes you back – which means you don’t experience side effects like migraine headaches, abnormal heart beats, gastric upset, or anxiety – go for it. More may be better.