Knocking back five cups of coffee per day may lead to weight gain and increase the risk of diabetes, researchers have warned.

　　While previous studies have shown coffee in moderation could help weight loss and actually reduce the risk of type 2 diabetes, these recent findings suggest that too much coffee could prevent weight loss.

　　Australian researchers found that over- consumption of certain polyphenols found in coffee called chlorogenic acid (CGA) could prevent fat loss and lead to insulin resistance.

　　The study, which was published in the Journal of Agricultural and Food Chemistry, tested CGA's effects on obese mice, which were given different doses of the compound.

　　The mice that were given doses equivalent to five or six cups of coffee per day showed retention of fat within cells.

　　The obese mice also showed more glucose intolerance, a pre-diabetic condition, and increased resistance to insulin regulation.

　　'Studies have shown that coffee consumption lowers the risk of developing type 2 diabetes,' said study co-author Professor Kevin Croft, of the University of Western Australia

　　'This also included research on decaffeinated coffee, which suggested that the health benefits are from a compound in coffee apart from caffeine.

　　'With this in mind, we studied the effects of polyphenols, or more specifically CGAs, which are very rich in coffee but also found in tea and some fruits including plums.

　　'The CGAs were previously known for their health benefits, increasing insulin sensitivity and reducing blood pressure and body fat accumulation,' he said.

　　'However, this study proved the opposite in dosages equivalent to five or six cups of coffee per day,' said study co-author Vance Matthews, of the Western Australian Institute for Medical Research.

　　'Everybody knows about the effects of caffeine, but when we're considering our lifestyle choices it's important to remember that compounds such as CGA can have an effect on our health if they're not consumed in moderation.'

　　He added that it was still fine for people to drink moderate amounts of coffee.

　　'It seems that the health effects are dose-dependent. A moderate intake of coffee, up to three to four cups a day still seems to decrease the risk of developing diseases such as cardiovascular disease and type 2 diabetes,' he said.

　　The researchers also found that CGA doesn't prevent weight gain in obese laboratory mice fed a high-fat diet when used at higher doses.

　　'People might be wasting their money if they're buying expensive products like green coffee bean dietary supplements which are currently considered to be amazing weight loss products,' Professor Croft said.

　　A recent study published in the European Journal of Neurology found that coffee drinkers can cut their risks of dementia by 60 per cent, while lowering risk of Parkinson's by up to 60 per cent.

　　澳大利亚的研究人员发现，每天喝咖啡超过5杯会导致肥胖，还会增加患糖尿病的风险。

　　研究发现，咖啡中含有的一种叫做绿原酸的物质能够阻止脂肪流失，并抑制胰岛素分泌。通过给老鼠摄入绿原酸，研究人员发现，那些摄入相当于5杯或以上咖啡所含剂量绿原酸的老鼠出现了脂肪累积的迹象，同时出现了葡萄糖耐受不良以及胰岛素抵抗等不良反应，这些都是糖尿病的早期症状。

　　尽管如此，研究人员表示，只要不要过量摄入绿原酸，适量喝咖啡还是有益于人体健康的。

　　“适量饮用咖啡，比如一天3到4杯，可以降低患2型糖尿病的风险。”一位研究人员说。(中国网)