June 26, 2006
Coffee Could Help Keep Diabetes AwayTopics: Health Issues
In April we learned from researchers in Japan that people who drink lots of green tea or coffee every day could lower their risk of diabetes by 33 percent, a result they linked to caffeine content. Drinking three or more cups of caffeinated coffee per day was associated with a 42 percent lower risk of diabetes. The prospective cohort study followed 17,413 persons in 25 different communities across Japan for five years, after adjusting for risk factors such as age, sex and body mass index..
Now we learn that Mark A. Pereira, a researcher at the University of Minnesota, has published findings from an 11-year study, that suggests drinking lots of coffee cuts women's risk of developing diabetes, however in Pereira's study, diabetes risk was reduced most in participants who preferred decaffeinated coffee. it appears that caffeine has nothing to do with the reduction in diabetes. Pereira suggests that its the antioxidants in coffee that is protecting against diabetes, not the caffeine.
...In the study, Pereira's team gathered data on nearly 29,000 older women who answered questions about risk factors for diabetes such as age, body mass index, physical activity and smoking. They also reported on their consumption of various foods and beverages, including regular and decaffeinated coffee.Confused, you've got reason to be, especially since both caffeinated and decaffeinated coffee appear to provide similar amounts of antioxidants. Unless we compare the researchers' materials and methods, and asked more questions, we don't know for sure where the basis lies for the different conclusions. What we do know is that the Japanese study was adjusted for risk factors such as age, sex and body mass index, and in the University of Minnesota study all of the samples were women .
... Adjusting for those risk factors, the researchers found that women who drank more than six cups a day of any type of coffee were 22 percent less likely to develop type 2 diabetes, the kind that occurs in adult life, compared to those who avoided coffee.
... But diabetes risk dropped even more -- by 33 percent -- for those who drank more than six cups a day of decaf, the study authors found.
... "When you get up to four or five or more cups per day, you might have very powerful antioxidant activity," he said. "That might be important for protecting the pancreas' beta cells from oxidant damage," he said.
... Beta cells produce insulin. Adult, or type 2, diabetes, occurs as the body slowly loses its ability to produce insulin.
For a take home message, if you're a man - I'd stick to regular coffee, if you don't find caffeine to be too much of a problem. If you're a woman, perhaps it may not matter.
The antioxidant activity of roasted coffee residues has been previously evaluated by researchers. Extraction with four solvents (water, methanol, ethanol, and n-hexane) showed that water extracts of roasted coffee residues (WERCR) produced higher yields and gave better protection for lipid peroxidation. WERCR showed a remarkable protective effect on oxidative damage of protein. In addition, WERCR showed scavenging of free radicals as well as the reducing ability and to bind ferrous ions, indicating that WERCR acts as both primary and secondary antioxidants. HPLC (high performance liquid chromatography) analyses showed that phenolic acids (chlorogenic acid and caffeic acid) and nonphenolic compounds [caffeine, trigonelline, nicotinic acid, and 5-(hydroxymethyl)furfuraldehyde] remained in roasted coffee residues. These compounds showed a protective effect on a liposome model system. The concentrations of flavonoids and polyphenolic compounds in roasted coffee residues were 8,400 and 20,400 ppm, respectively. In addition, the Maillard reaction products (MRPs) remaining in roasted coffee residues were believed to show antioxidant activity. These data indicate that roasted coffee residues have excellent potential for use as a natural antioxidant source because the antioxidant compounds remained in roasted coffee residues.
The two most common commercial methods of decaffeinating coffee are:
1. Swiss Water Process - involves using hot water and steam to remove the caffeine. Water is used to absorb much of the beans' caffeine, oils and flavors. This water is then passed through charcoal filters to remove the caffeine. The beans are then put back into the water solution to re-absorb the oils and flavors, before being dried and sent to be roasted. Although this non-chemical process may be better for us, much of the coffee flavor that is lost to the water cannot be returned to the bean.
2. European Chemical Process - involves soaking the beans in water and then using a chemical (methylene chloride) "wash" that absorbs the caffeine from the bean. The chemcals are then rinsed from the beans before they are dried and sent to be roasted. Most coffee drinkers prefer the more natural Swiss water method to this chemical method - even though there are virtually no chemicals left in the coffee by the time the beans are roasted. The main advantage of this method is that the coffee retains more flavor than in the water process.
Posted by Richard at June 26, 2006 8:34 PM
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- Coffee Could Help Keep Diabetes Away - Jun 26, 2006