Tea and coffee reduce the risk of insulin-resistant diabetes that many develop in middle age and later.
Drinking more coffee (regular or decaffeinated) or tea appears to lower the risk of developing type 2 diabetes, according to an analysis of previous studies reported in the December 14/28 issue of Archives of Internal Medicine, JAMA (1).
By the year 2025, approximately 380 million individuals worldwide will be affected by type 2 diabetes (1).
Despite considerable research attention, the role of specific dietary and lifestyle factors remains uncertain, although obesity and physical inactivity have consistently been reported to raise the risk of diabetes mellitus. A previously published meta-analysis suggested drinking more coffee may be linked with a reduced risk, but the amount of available information has more than doubled since.
Decaffeinated coffee appears to cut risks the most while tea cuts risks the least. This makes caffeine unlikely to be the protective agent.
When the authors combined and analyzed the data, they found that each additional cup of coffee consumed in a day was associated with a 7 percent reduction in the excess risk of diabetes.
Individuals who drank three to four cups per day had an approximately 25 percent lower risk than those who drank between zero and two cups per day.
In addition, in the studies that assessed decaffeinated coffee consumption, those who drank more than three to four cups per day had about a one-third lower risk of diabetes than those who drank none. Those who drank more than three to four cups of tea had a one-fifth lower risk than those who drank no tea.
Magnesium and some antioxidants might offer protection.
Other compounds in coffee and tea including magnesium, antioxidants known as lignans or chlorogenic acids may be involved, the authors note.
Okay, so is magnesium a plausible protective agent? First off, let us look at how much magnesium is in a cup of coffee. A real cup is 8 ounces though people frequently drink less than 8 ounces at a time. But let us assume 3 8 ounce cups or 24 ounces per day. That's at least in the ballpark since some people drink 4 smaller servings. Well, each ounce of coffee contains 24 mg of magnesium and 34.5 mg of potassium. It also provides 1.6 mg of niacin. 24 ounces times 24 mg equals 576 mg of magnesium - a quite substantial amount.
Over the age of 30 the recommended daily dose of magnesium for males is 420 mg and for females 320 mg. So a 4 cup coffee drinker is going to get more than the recommended daily dose of magnesium.
But tea only contains .3 mg of magnesium per ounce. So tea's protective effect must not be due to magnesium. Tea's lack of magnesium does not mean that the magnesium in coffee isn't helping however. A number of studies have found that magnesium lowers type 2 diabetes risk and risk of metabolic syndrome.
If you want to get more magnesium without drinking coffee then nuts, green leafy vegetables, beans, and whole grains will help.
|Share |||Randall Parker, 2009 December 19 08:04 PM Aging Diet Metabolism|