Humans have consumed caffeine since the Stone Age. No longer do we chew the seeds, bark or leaves of certain plants to ease fatigue, stimulate awareness, elevate mood or become generally twitchy.

Instead, we order such strange-sounding brews as Decaf Komodo Dragon Blend® or Brazil Ipanema Bourbon(TM) or an "Iced Decaf Triple Grande Vanilla Non-fat with Whipped Latte" in such bizarre sizes as Venti and Grande. Then there's always the "Large Swamp-Thick Black Sludge Toilet Buster" fallback (preferred here at IMT and theoretically trademarked by this blogger).

Today coffee is the most widely consumed beverage in the world after water. It is the most widely consumed antioxidant in the United States. According to the National Coffee Association, about 68 percent of Americans last year said they were hooked on coffee. CoffeeScience.org claims that nearly eight in 10 Americans drink coffee — around 400 million cups every day — importing 2.7 million lbs. of beans each year for it.

That's clearly a lot of consumption of one beverage.

There are plenty of health benefits brewing (sorry) in this beloved beverage. Some 19,000 studies in recent decades have been done examining coffee's impact on health. And for the most part, the results are pleasing to those of us downing the beverage like it were, well, coffee.

After analyzing data on 125,000 people for as long as 18 years, a Harvard researcher has calculated that downing one to three cups of caffeinated coffee daily can reduce type-2 diabetes risk by single digits compared with not partaking in our favorite a.m. drink. But having six cups or more each day slashed men's risk by 54 percent and women's by 30 percent over java avoiders. The Harvard researcher's findings are similar to those in a less-publicized Dutch study.

At least six studies indicate that people who drink coffee on a regular basis are up to 80 percent less likely to develop Parkinson's disease, with three showing "the more they drink, the lower the risk," according to WebMD:

Other research shows that compared to not drinking coffee, at least two cups daily can translate to a 25 percent reduced risk of colon cancer, an 80 percent drop in liver cirrhosis risk, and nearly half the risk of gallstones … There's also some evidence that coffee may help manage asthma and even control attacks when medication is unavailable, stop a headache, boost mood, and even prevent cavities.

Yet despite a number of studies over the years having indicated positive medical impacts, coffee remains maligned and misunderstood about as much as it is undoubtedly beloved.

Is the beverage on which so many of us depend to make it through the day a health tonic? Or is it simply a Styrofoam cup of black (no sugar) death?

Is coffee friend or foe?

Based on studies of the science behind caffeine and, specifically, coffee, let's have the good and the bad face-off:

Pros

• Long-term coffee drinking may lower the risk of developing type-2 or adult onset diabetes.

• Consistent coffee drinking may protect against Parkinson's disease, though the protective effects are largely lost in women taking hormone replacement therapies.

• Coffee consumption seems to protect and fight against the development of Alzheimer's disease; human studies have found that Alzheimer's patients drank significantly less coffee than un-afflicted people in the 20 years prior to diagnosis; a recent mouse study showed that caffeine equivalent to five cups of coffee per day reduced the buildup of destructive beta-amyloid plaques in the brain.

• Coffee can protect against liver cirrhosis. One study of more than 100,000 Americans found that people who drank four or more cups per day cut their risk of cirrhosis by 80 percent.

• Coffee is an age-old asthma medication; caffeine is related to theophylline, a compound that helps relax and expand asthmatic lungs. In a 2001 meta-analysis, a United Kingdom team of doctors concluded that coffee was a weak — but nonetheless helpful — asthma treatment that could last up to four hours.

• Coffee lowers the risk of developing kidney stones, because it makes you urinate more calcium rather than letting it pile up in your kidneys.

• Canadian researchers recently found the risk of gout was 40 percent lower for men who drank four to five cups a day compared with non-coffee drinkers.

• Caffeine increases alertness and mental performance by blocking adenosine, one of the biomolecules responsible for creating that feeling of drowsiness.

Cons

• There's simply not enough of it, as far as we can tell. OK, really…

• It takes at least 30 minutes for the body to absorb caffeine, so there is no instant-alertness effect.

• Caffeine is addictive and, of course, comes with regular drug addiction problems, such as withdrawal symptoms. (Coffee headache, anyone?)

• Coffee contains two cholesterol-raising compounds cafestol and kahweol, though these can be nearly eliminated by using filters (and some evidence suggests they may even be anti-cancer agents themselves).

• Imbibing coffee can exacerbate heartburn.

• Caffeine can increase the risk of heart attack, especially among those people who carry the "slow" gene variant for the enzyme that metabolizes caffeine.

• For some, coffee is like Exlax.

• A coffee beverage can cost more than $5 at certain successful franchises alluded to in this post's first paragraph.

It appears to be a toss-up. (But we know the truth.) Now how about those health benefits of Irish coffee?

Check back in with IMT next week, when our issue — "The Daily Grind" — will address issues in our everyday working environment (including jerks in the office).

Resources

National Coffee Association

Coffee Science Source (National Coffee Association)

Coffee @ National Geographic

WebMD

Inkling Magazine