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Monday, August 27, 2007

Caffeine -- Myths and Facts

People throughout Asia have enjoyed foods and beverages containing caffeine for thousands of years. Whether green, black or oolong, tea has been savoured in Asia for almost 5,000 years. Coffee, a relative newcomer discovered some 1,000 years ago, continues to bring people together in the coffee houses and cybercafes springing up across the region. Over the last hundred years, cola drinks, ready-to-drink tea and coffee beverages and a new crop of "energy drinks" have steadily gained in popularity.

All these beverages have a common ingredient - caffeine. Although products containing caffeine have been enjoyed all over the world for centuries, there are still many misperceptions about this common food component. Food Facts Asia looks at some of the more common myths regarding caffeine.

MYTH: Caffeine's effects are addictive.

FACT: People often say they are "addicted" to caffeine in much the same way they say they are "addicted" to shopping, working or television. The term "addiction" actually refers to a strong dependence on a drug characterised by severe withdrawal symptoms, tolerance to a given dose and the loss of control or the need to consume more and more of the substance at any cost. Addicts tend to exhibit anti-social behaviour or even commit crimes to perpetuate the abuse. Consumers of caffeine-containing beverages do not fall into this category. The Diagnostic and Statistical Manual for Mental Disorders (1994), a document that characterises various addictions, does not list caffeine as a substance that causes addiction. According to the World Health Organization, "There is no evidence whatsoever that caffeine use has even remotely comparable physical and social consequences which are associated with serious drugs of abuse."

MYTH: Pregnant women should avoid caffeine.

FACT: Just as with nearly everything else they do, pregnant women can take caffeine in moderation. Many women find they experience taste changes during pregnancy and cannot drink tea or coffee. For those who continue to enjoy their tea and coffee, most physicians and researchers agree that moderate amounts of coffee daily will have no adverse effects on the outcome of the pregnancy or the infant's health.

MYTH: Caffeine is a risk factor for osteoporosis.

FACT: The established risk factors for osteoporosis are insufficient dietary calcium and vitamin D, high protein diets, smoking, the onset of menopause, low oestrogen levels, low body weight and a lack of physical activity. Several well-controlled studies have concluded that consuming moderate amounts of caffeine does not increase the risk of developing osteoporosis. A 1994 National Institute of Health Consensus Statement on optimal bone health does not list caffeine amongst the risk factors which modify calcium balance and influence bone mass. A study by Penn State Medical School found that lifetime consumption of caffeine (up to 800 mg daily or the equivalent of 6-7 cups of coffee a day) had no effect on bone density in 188 post-menopausal women.

Nevertheless, caffeine does cause a small amount of calcium to be lost in the urine รข€“ about the amount in one to two tablespoons of milk per cup of tea or coffee. For this reason, nutritionists recommend that women take their coffee with added milk, drink one extra glass of milk daily or take a calcium supplement if they are heavy coffee drinkers (over 5 cups of coffee daily).

MYTH: Caffeine increases the risk of heart disease.

FACT: Despite previous controversy on the subject, scientists now agree that regular caffeine use has little or no effect on blood pressure, cholesterol levels or risk of heart disease.

Studies show that while first-time caffeine use can cause a slight increase in blood pressure (similar to that experienced when walking up stairs), the changes are minimal and disappear with regular use.

It has also been found that only boiled, unfiltered coffee, such as that taken in some Scandinavian countries, elevates cholesterol. It seems the oils in the coffee that are not filtered out are responsible for this effect, not the coffee or caffeine. Consumption of caffeine-containing beverages does not typically affect cholesterol levels.

MYTH: Caffeine causes cancer.

FACT: Substantial scientific evidence demonstrates that caffeine is not a risk factor for cancer. A number of human epidemiological studies have examined the risk of developing cancer at different locations in the body. Two studies of large numbers of people in Norway and Hawaii found no relationship between regular coffee consumption and cancer risk. Two projects conducted on caffeine - one in Japan and the other in Germany - demonstrated no link between caffeine consumption and the incidence of tumours in test animals. This confirms the position of the American Cancer Society, that states, "Available information does not suggest a recommendation against the moderate use of coffee. There is no indication that caffeine, a natural component of both coffee and tea, is a risk factor in human cancer."

MYTH: Caffeine adversely affects the health of children.

FACT: Children generally consume much less caffeine than adults do, since soft drinks and tea are their primary sources of caffeine. Children generally have the same ability to process caffeine as adults. Studies have shown that foods and drinks containing caffeine, when taken in moderate amounts, have no detectable effects on activity levels or attention spans in children.

MYTH: Caffeine has no health benefits.

FACT: Recent research has found some surprising health benefits associated with caffeine consumption. Many caffeine-containing beverages, most notably tea and more recently coffee, have been found to contain antioxidants. Antioxidants may have health benefits in terms of heart health and cancer prevention.

Caffeine is well recognised as increasing both alertness levels and attention spans. A cup of coffee or tea is often recommended to counter sleepiness, especially for those driving long distances and many people resort to an afternoon "cuppa" to get back on top of their workload.

Recent reports suggest that caffeine may be useful in treating allergic reactions due to its ability to reduce the concentration of histamines, the typical body response to an allergy-causing substance. More research is needed in this area before conclusions can be drawn. Caffeine has long been known to help many people suffering from asthma.

There is also evidence to suggest that caffeine may reduce the risk of kidney stones.


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