Scurvy is a nasty disease. It causes collagen, the protein substance found in the fibers of connective tissue, bone, and cartilage, to form improperly, meaning wounds don't heal, gums bleed, and severe pain occurs.

If untreated, it leads to death.

But in 1747, James Lind, a Scottish naval surgeon, fed lemons and limes to sailors with scurvy, and soon the symptoms stopped. After a few years of stopping scurvy this way, Lind wrote a paper about it. The British Royal Navy was impressed and adopted the practice yet others kept searching for better treatments.

Their motivation, you see, sprang from the fact Lind couldn't explain exactly why his treatment worked, which led others to doubt it.

By the time Robert Falcon Scott made his first expedition to the Antarctic in 1902, good hygiene, regular exercise, and the avoidance of tainted food not consuming citrus fruits were seen as the keys to avoiding scurvy.

So Scott didn't pack lemons and limes, and surprise, surprise an outbreak of it forced him to abort the mission.

Scurvy would also plague Scott's second attempt, which ended in Scott and his crew freezing to death in 1912, the same year two Norwegian researchers were finally able to isolate the specific element in citrus fruits that caused Lind's treatment to work.

Vitamin C.

The moral to the story: While science should always strive to know why, medicine should never look a gift horse in the mouth.

Not in 1747 or 1912 or even now.

That's why if you have a history of Alzheimer's disease in your family or you just want to guard against the disease, you may want to start drinking four or five cups of drip coffee a day. The latest research proves that the practice unquestionably counteracts the disease.

Without being able to explain why.

The research released in an online issue of the Journal of Alzheimer's Disease in late June was done with lab mice by a team of researchers at the University of South Florida. Some of the lab mice used were genetically engineered to be prone to Alzheimer's; some of them were typical lab mice.

All mice that were given the equivalent of four to five cups of drip coffee a day had "greatly and significantly" increased the levels of three proteins in their blood that are known to stop the production of another protein believed to be the cause of Alzheimer's disease.

From this finding and the fact that there's such a similarity between mice and humans in these matters the research team believes "moderate coffee consumption can appreciably reduce your risk of [Alzheimer's] or delay its onset."

Yet they believe this without really being able to explain why.

What they do know is that decaffeinated drip coffee or caffeine alone did not increase the three aforementioned proteins in the bloodstream. Only real drip coffee produced that result.

Therefore, the researchers surmise that the caffeine in the coffee is being "synergized" by an unknown element in coffee to elevate these protein levels.

And they do know that their previous studies with coffee and mice have found drinking moderate amounts reduces the levels of beta-amyloid protein, the protein pegged as a product or a cause of Alzheimer's.

Additionally, when the researchers focused on one of the three aforementioned proteins, granulocyte-colony stimulating factor, or GCSF, they found further proof that consuming coffee in moderate helps brain function. In fact, the Alzheimer's-susceptible lab mice that underwent a long period of coffee consumption improved their working-memory performance when it should've been getting worse.

That occurred because GCSF does three important things. It brings stem cells to the brain to neutralize the beta-amyloid protein, the one linked to Alzheimer's disease; it creates new connections between brain cells, always a good thing; and it increases the rate of brain cell production, another obvious positive for brain optimal function.

The next task for the University of South Florida researchers is to see if they can isolate the "unknown ingredient" to determine if that could be used in conjunction with caffeine outside of coffee possibly in pill form to protect against Alzheimer's.

But if you worry about the disease or you believe in learning from history, you shouldn't wait for the pill form to hit the market. After all, it took scientists 165 years from the time Lind made his discovery to learn that that unknown ingredient was vitamin C.