To drink or not to drink? New studies tout the health benefits of coffee. For some, coffee is a nutritional enemy. For many others, it is an imperative part of their day. Either way, coffee is a popular drink considered a boost in the morning and an afternoon pick-me-up, thanks to its major ingredient, caffeine, a stimulant believed to make us more alert. About 80 per cent of the world's population consume it daily, which is why research continues on its health benefits and consequences. But seasoned coffee drinkers have often had enjoyment of their daily cup blighted by studies blaming caffeine for various diseases and health problems. Caffeine can be found in tea, some carbonated drinks and chocolates, and some prescription medicines, among other products. This has led to concern that caffeine intake (which is now higher with the influx of global coffee shop chains) is greater than we realise - and potentially harmful. In the past decade, studies have shown caffeine can negatively affect fluid balance, bone loss, leads to increased anxiety, sperm count reduction, miscarriage, increased cholesterol and stomach ulcers. Yet for every caffeine scare, there has been good news for coffee lovers in recent months - but only when coffee is drunk in moderation. One study showed those who had two to four cups a day had a 20 per cent lower risk of heart disease compared with those drinking less than two or more than four cups. Moderate coffee intake also slightly reduced the risk of death from heart disease. Dutch researchers from the University Medical Centre, Utrecht, studied 37,514 participants for 13 years for the occurrence of cardiovascular heart disease (CHD). They found that the 'results suggest a slight risk reduction for CHD mortality with moderate coffee consumption and strengthen the evidence on the lower risk of CHD with coffee and tea consumption'. Studies have also linked coffee - both caffeinated and decaf - with reduced risk of type II diabetes. Caffeine has also been linked to a reduction in Alzheimer's and prostate cancer. Last year, the University of South Florida found that when aged, mice bred to develop symptoms of Alzheimer's disease were given caffeine - the equivalent of five cups of coffee a day - and their memory impairment was reversed. Also late last year, Australian researchers who looked at 18 different studies, covering more than 450,000 people, found that those who drank three to four cups a day had a 25 per cent lower risk of developing diabetes than those who drank little or no tea or coffee. Yet pregnant women need to drink it in moderation. The British-based Food Standards Agency says that when pregnant, limit the intake of caffeine to less than four cups of coffee a day (less than 200mg a day). In July, the American College of Obstetrics and Gynecologists said moderate caffeine consumption 'did not appear to cause miscarriage or pre-term birth'. But it remained unclear whether high levels of caffeine consumption had any link to miscarriage. For everyone else, about 300mg per day is optimum for good health, or about three average sized cups of coffee. As with most things in life, too much of anything is never a good idea.