RX For Readers: The health benefits of caffeine

Is coffee good for you?

Coffee beans 521 (photo credit: MCT)
Coffee beans 521
(photo credit: MCT)
I am a longtime former immigrant from the US, but I never got around to liking coffee – except occasional treats of coffee ice cream or cake. I prefer drinking tea, like the British. But I have heard recently that there are health benefits from drinking coffee regularly. What benefits are there, what is the mechanism and have these claims been proven scientifically? If so, should I start drinking coffee even though the taste doesn’t really appeal to me? – R.S., Netanya
Judy Siegel-Itzkovich replies: A recent issue of the Hebrew-language Israeli Journal of Family Practice relates at length to this issue. Dr. Sharon Maor, a clinical and sports dietitian at the Wingate Institute for Physical Education near Netanya and at Clalit Health Services, notes that coffee is an amalgamation of some 1,000 components, including carbohydrates, fats, vitamins (vitamin B3 and vitamin E), minerals (magnesium and potassium), alkaloids such as caffeine, organic compounds and nutritional fibers. It is one of the foods richest in antioxidants, which fight oxygenfree radicals that cause aging and the decline of cells in the body.
Many scientific studies, Maor writes, have investigated the connection between drinking coffee and health, and there is increasing evidence of a positive connection between various types of coffee and the prevention or lowered risk for diseases. But there are methodological problems in coffee research, such as the varying amount of caffeine according to the type of coffee, the way coffee is prepared, the size of the cup or glass reported in studies, how long the coffee beans have been roasted and various processes that influence the amount of nutrients in coffee. Nevertheless, research does testify to health benefits.
Long-term controlled studies have shown that caffeine disrupts glucose tolerance and reduces sensitivity to insulin during the period of the experiments. But large long-term epidemiological studies from various countries have proven that drinking coffee is linked to a lower risk of insulin resistance and type-2 diabetes, Maor writes. The proposed mechanisms are the suppression of the absorption of glucose and of the glucose 6 phosphatase system responsible for the production of glucose by the polyphenols in the coffee, as well as an increase in the level of magnesium in the blood, weight loss and metabolism caused by the caffeine.
Organic compounds called diterpenes raise the level of blood cholesterol, but apparently phenols (another type of organic chemical compound called carbolic acid) in coffee neutralize this influence and even raise the level of high-density lipoprotein (HDL or “good cholesterol”).
This means that the lower the amount of diterpenes in the coffee (as in filter and instant coffees), the higher the amount of the phenols. But the effect on cholesterol levels is very positive.
A number of studies have shown that drinking coffee raises the level of homocysteine in the blood. Homocysteine is a natural amino acid that, when at elevated levels, increases the risk of heart attacks, strokes, blood clot formation and possibly Alzheimer’s disease.
Short-term hypertension studies lasting one to 12 weeks showed that caffeine raises blood pressure significantly. However, long-term epidemiological research shows that there is no rise in blood pressure when drinking three cups a day or less. Some have even found a protective effect against increased hypertension, especially in women. Apparently, people’s bodies get used to the caffeine over the long term and minerals, vitamins, polyphenols and fibers in coffee neutralize the caffeine effect.
Caffeine may also slightly reduce weight because caffeine raises the metabolism rate, while polyphenols minimize the accumulation of abdominal fat and fat in the liver. Decaffeinated coffee also reduces dental cavities and gum diseases.
There is an inverse relationship between coffee drinking and Parkinson’s and Alzheimer’s diseases and dementia, the author writes. The effect was more powerful in men than in women not receiving hormone replacement therapy during menopause. Caffeine is believed to have a protective effect against toxicity of damaged brain cells. Statistical analysis shows coffee drinking reduces the risk of suicide as it improves psychomotor function, increases vitality and alertness, reduces fatigue and improves wellbeing. It can also minimize the risk for colorectal cancers and other malignant growths, liver cirrhosis, fibrosis and tumors.
In any case, consult your personal physician before deciding to drink considerable amounts of coffee.
As for limitations on coffee consumption, more than three cups (300 milligrams of caffeine) daily are generally not recommended.
Women who are pregnant or or have difficulty getting pregnant should limit themselves to three cups. It’s almost impossible to get caffeine poisoning, as this would mean drinking 50 cups or more a day, Maor writes.
Coffee drinking does not affect breast-feeding babies. Children should not get more than 2.5 milligrams of caffeine per kilo of body weight per day, and the elderly should not consume an unlimited amount. Caffeine could interact with medications and may reduce body mass in very thin people.
Maor concludes the article by saying that consumption of up to three cups a day by adults is safe – whether it is caffeinated or decaffeinated – and offers health advantages as well as the ability to reduce the risks for certain diseases.
Rx for Readers welcomes queries from readers about medical problems. Experts will answer those we find most interesting. Write Rx for Readers, The Jerusalem Post, POB 81, Jerusalem 91000, fax your question to Judy Siegel-Itzkovich at (02) 538- 9527, or e-mail it to [email protected], giving your initials, age and place of residence.