Xref: utzoo sci.med:15138 sci.bio:2738 Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!rutgers!mcdchg!ddsw1!starkid From: starkid@ddsw1.MCS.COM (Lance Sanders) Newsgroups: sci.med,sci.bio Subject: Re: Caffeine Questions Message-ID: <1990Feb22.182148.10802@ddsw1.MCS.COM> Date: 22 Feb 90 18:21:48 GMT Reply-To: starkid@ddsw1.MCS.COM (Lance Sanders) Organization: ddsw1.MCS.COM Contributor, Mundelein, IL Lines: 104 On 20 Feb 90 03:46:34 GMT, ss6349@leah.Albany.Edu (Steven H. Schimmrich), in message <2569@leah.Albany.Edu> writes: > Can anyone give me any references > as to the effects of caffeine? A report presented several years ago at an annual meeting in St. Louis of the Federation of American Societies of Experimental Biology found that caffeine consumption can double the amount of calcium a person loses through urination. Calcium loss was seen in all but two of 135 volunteers who were tested. Biochemist James T. MacGregor, Ph.D., at the U. of California, Berkeley, has found that even slight folic-acid deficiencies (folic acid is one of the B vitamins found in spinach and other leafy greens) can be genetically damaging for coffee drinkers who consume five to six caffeinated cups a day. The combination nearly doubles the normal amount of chromosome damage. [ Note: include tea and colas ] Caffeine should especially be avoided by pregnant women and people prone to panic attacks. Caffeine stays in a smoker's bloodstream only half as long as in a non-smoker's. When a smoker quits, metabolism slows down within about three days, and three cups of coffee will produce about twice the caffeine blood level as before. [ Drs. Neal Benowitz, Sharon Hall; U. of California Medical School at San Francisco ] Caffeine may make it more difficult for some women to get pregnant. A team of researchers from the National Institute of Environmental Health Services in Research Triangle park, N.C., surveyed 104 healthy women in their late 20's and early 30's who had unsuccessfully tried to become pregnant for three months. About 97 of the 104 women drank caffeinated beverages: brewed and instant coffee, tea and soft drinks. 54 drank more than one cup of coffee or its equivalent per day, and 50 drank less. Caffeine may depress the fertility of only "a susceptible subgroup of women". Studies at the U. of Texas and Emory University found that caffeine can increase pressure in the eye, which can aggravate problems related to glaucoma (a disease in which fluid buildup increases pressure in the eye). The high pressure can damage the optic nerve, resulting in serious vision loss. 50 people were divided into three groups: (1) young healthy adults who drank 16 ounces (two cups) of caffeinated coffee. (2) young adults who got for cups. (3) all older adults with glaucoma who drank two cups. Results? Significant increase in eye pressure among the healthy adults who drank two cups. The pressure increased in those who drank four cups and the glaucoma aptients who had only two cups. Verdict? Anyone with glaucoma should limit themselves to drinking no more than two cups of caffeinated coffee per day. Any individual with family histories of glaucoma should do likewise. Researchers at the Erasmus U. Medical School in Rotterdam, the Netherlands, found that boiled coffee, in which ground coffee is placed directly in water, significantly increases cholesterol levels, but filtered coffee does not. 107 young adults with normal blood cholesterol levels were divided into three groups. For three weeks, all received filtered coffee. Then they were randomly divided into three groups: one which drank four to six cups a day of boiled coffee, one, the same amount of filtered coffee, and the third, no coffee. The boiled coffee group showed a 10 percent increase in total blood cholesterol. Those drinking filtered coffee or no coffee at all showed no increase. The difference is being attributed to the fact that filters trap most of the fats in coffee. The Netherlands study came a week after one by Stanford U. (Dr. Robert Superko, lead researcher) which showed that decaffeinated coffee raises the level of low-density lipoprotein (LDL, or "bad" lipoprotein). Of 180 healthy middle-age men who drank three to six cups of black coffee a day for two months, cholesterol levels remained the same among caffeinated and non-coffee drinkers, while LDL levels rose an average of 7 percent for decaffeinated drinkers. A 7 percent LDL rise translates to approx. a 12 percent rise in heart attack risk. Used specifically as opposed to chronically, caffeine can be beneficial. In limited amounts, caffeine in most people acts as a mood elevator and boosts physical and mental performance, though Nancy Clark, a sports nutritionist from Brookline, Mass., says that recent studies indicate a physically fit, carbohydrate-loaded competitor derives no performance lift from caffeine. A one to two cup per day limit of caffeinated coffee appears to be a safe, upper limit. Moderate consumption is defined as about 200 milligrams per day (about two cups of coffee). Colas contain 30 to 70 mg., tea about 15 to 30 mg., and cocoa 5 to 20 mg. per cup. ---------------------------- Lance Sanders starkid@ddsw1.MCS.COM "Never does nature say one thing FidoNet: 1:115/743.0 and wisdom another." GEnie: L.Sanders6 ---Juvenal Voice: (312)667-5958