I'm fascinated with the age-old practice of bloodletting as a cure for various ailments. Thanks to the Straight Dope, I know bleeding (or giving blood) won't help me lose a significant amount of weight. But what about hypertension? Given the multitude of side effects for high blood pressure pills, there's a need for alternatives. It stands to reason that reducing the amount of blood you have is the easiest way to lower blood pressure. Would it work, and more important, is it advisable? -- Antonio Giamberardino, Ottawa
No, it's not advisable. It's idiotic. We need to get clear on that at the start. I say this because your idea is plausible enough to become the next colonic irrigation, and one wants to nip these things in the bud.
Bloodletting has a long and sorry history. The Egyptians, Romans, and medieval and Renaissance Europeans used it to treat all manner of ailments based on crackpot theories about imbalances in the bodily humors. Doctors undoubtedly killed more people via bloodletting than they cured. One possible victim was George Washington, who died after physicians treating him for a respiratory infection drained five to seven pints.
Sometimes bloodletting worked, sort of. It was used to treat dropsy, an old name for fluid retention or edema, one of the central elements in congestive heart failure. Among other things, edema can make it difficult to breathe, and until the introduction of diuretics and vasodilators, bloodletting was one of the few ways to deal with it -- the practice didn't die out until the 20th century.
Now to your question. You reduce tire pressure by letting out air, so why wouldn't the same idea work for blood? It's not that easy. The causes of hypertension, which affects one American in four, are poorly understood. Two significant factors are blood volume and narrowing of the blood vessels, but the relationship isn't simple. One study found patients with borderline hypertension had higher central blood volume than normal, but that just means more of their blood was concentrated in their body core -- total blood volume was about the same. The amount of blood in any case isn't the real problem. A more basic concern is salt. The more you've got floating around, the more fluid needed in your blood to keep the salt level stable and thus the higher your blood pressure. That's why hypertensives are put on low-salt diets.
If you donate blood, will your blood pressure drop? Temporarily, yes. One study found rapidly draining 15 percent of blood volume could lead to an equally steep decline in blood pressure. The pressure soon begins rising again as the blood vessels constrict, but after 90 minutes you could still be as much as 11 percent down. Long term, though, shedding blood won't make much difference. A comparison of 655 blood donors with 3,200 nondonors showed average blood pressure between the two groups was almost the same.
Still, bloodletting has its uses. I've seen a report of a surgeon who temporarily drew down a patient's blood to reduce bleeding while removing a vascular brain tumor. Phlebotomy, a classier-sounding term than bloodletting, can be used to treat chronic mountain sickness, caused by excessive hemoglobin buildup at high altitudes. As I've mentioned before, polycythemia, a disease where your body produces too many red blood cells, is often treated by removing blood, as are the enzyme disorder porphyria and hemochromatosis, a hereditary disease where your body absorbs too much iron. But for most people the surest benefit is still the warm fuzzy feeling you get after donating a pint at the blood bank, along with the free cookies and juice.
Is it true Brit Kane Kramer invented the iPod in 1979 but no one wanted it? The rumor goes it could only hold a couple of minutes of songs and the patents lapsed in 1988. There's a Facebook group which states: "Steve Jobs needs to right this wrong by buying Kane Kramer a Ferrari." Humor aside, is there any truth in this? -- Joe, UK
Kramer came up with a gimmick that sure looked like an iPod, I'll give him that -- specifically, an iPod Nano, complete with display screen and button array looking much like a thumbwheel. (Google "kane kramer" to see pictures; the resemblance is remarkable.) Nonetheless, while one wants to give the man credit, it's one thing to dream up a concept, something else to develop it into a practical product. Though most of the basic technology needed for the iPod had been invented by 1979, none of it was small, cheap, or powerful enough to make a solid-state music player commercially feasible. I paid roughly $100 for 128 kilobytes of computer memory in the mid-1980s; at that rate the 5 gigabytes in the first iPod would have cost $4 million. If Kramer was wronged, so was Dick Tracy creator Chester Gould, who introduced the proto-cell phone known as a two-way wrist radio in 1946.
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