A cup of coffee a day keeps the doctor away
A cup of coffee a day keeps the doctor away
Every morning Lesli Boldt starts her day with a serious cup of coffee -- a two-shot espresso with hot water. “I have one coffee a day and I want it to be a good one,” says Lesli, 35, a manager of marketing and communications for the Vancouver Public Library.
Not only does Lesli's coffee taste good, but new research suggests that it may also be good for her. Recent studies have found that drinking coffee can actually be a healthy habit, enhancing athletic performance, increasing mental alertness and protecting against serious diseases such as Alzheimer's, Parkinson's and even liver and colon cancers. “Coffee consumption fits into a very healthy diet and, if anything, may have a beneficial effect,” Dr. Eileen Madden, a toxicologist and food-safety expert, told a symposium on coffee and health last fall at the New York Academy of Sciences.
That's surprising news for most Canadians who love coffee but treat it as something of a guilty pleasure. Canadians have mixed feelings about the beverage they love to drink, says Massimo Marcone, a food scientist and adjunct professor at the University of Guelph in Ontario who has studied coffee production and consumption all over the world. “People have a preconceived idea about coffee -- they think it's bad for you,” he says.
And no wonder. Almost every day media reports tell us that consuming coffee may be associated with serious health problems, such as osteoporosis, elevated cholesterol, high blood pressure, heart disease, infertility, fibrocystic breast disease (FBD), breast cancer and even miscarriage. But, say the experts, many of those findings were based on poorly designed research and were not supported by further studies.
The benefits of coffee
If you love coffee, here's some of the latest good news.
• A study of 90,000 Japanese by the National Cancer Center in Tokyo found that people who drank one to four cups of coffee daily had half the liver cancer risk of those who never drank coffee. Researchers aren't sure why, but they speculate that antioxidants may play a role.
• A study by researchers at the Harvard School of Public Health that followed more than 125,000 men and women for more than a decade found that regular coffee drinkers had a significantly lower risk of developing type 2 (or late-onset) diabetes. Studies in Sweden and Finland also concluded that coffee consumption offers protection from type 2 diabetes. Again, researchers aren't sure why.
• A half-dozen recent international studies showed a positive relationship between drinking caffeinated beverages -- including coffee -- and lower rates of Parkinson's disease and Alzheimer's disease.
• Other research links coffee consumption with reduced risk of cirrhosis of the liver, colon cancer and asthma.
• A cup or two of coffee can improve endurance in activities such as running, cycling and swimming, according to other research. Coffee has a strong ergogenic effect, meaning it helps people work harder and longer, explains Lawrence Spriet, an exercise physiologist at the University of Guelph who has researched the effects of caffeine on athletic performance for more than a decade. "Even small amounts of caffeine can be quite powerful,” he says.
Page 1 of 3 – on page 2: find out how much caffeine is in your fave drink!
It's still too early for blanket endorsements, but this kind of evidence has many scientists cautiously optimistic about the health-enhancing powers of coffee. "There is some solid scientific data that show there are some health benefits to moderate coffee consumption," says Marcone.
That's good news, especially for the 81 per cent of Canadians who drink coffee occasionally and the more than 63 per cent (18 years of age and over) who drink it every day. The average Canadian consumes about 2.6 cups of coffee a day.
Caffeine is the key
Although there are about 2,000 substances in a cup of coffee, its main active ingredient is caffeine, a naturally occurring alkaloid. Tea leaves, cola nuts and cocoa beans also contain caffeine, but coffee beans have far more. An eight-ounce cup of brewed coffee has about 135 milligrams of caffeine compared with 36 to 46 milligrams for the same amount of cola and 43 milligrams for the same amount of average-blend tea (instant coffee contains 76 to 106 milligrams of caffeine).
Caffeine acts as a stimulant, promoting the release of adrenaline in the body and suppressing a natural relaxant in the brain called adenosine. The result? Less fatigue, elevated mood, increased alertness and more energy. Not surprisingly, people who need to drive long distances, focus on a project, work a night shift or fight off jet lag drink caffeinated drinks to stay alert. The stimulating effects of caffeine may also result in enhanced athletic performance.
The benefits are a blessing to coffee lovers, but there's a price to pay. Because caffeine is a mild stimulant to the central nervous and cardiovascular systems, it can temporarily raise your blood pressure and, in larger doses, cause sleeplessness, anxiety and nervousness. “Caffeine jazzes up your body and creates a stress reaction,” explains Dr. David Posen, a stress-management consultant in Oakville, Ont.
Caffeine is habit-forming, too, and although not technically addictive, it can cause some mild withdrawal symptoms such as headaches, fatigue or drowsiness if you stop cold turkey.
Page 2 of 3 – on the next page: find out why drinking coffee in moderation is the best!
Moderation is best
So what's the bottom line? Overall, coffee consumed in moderation is safe. After reviewing numerous studies on the effects of caffeine on human health, researchers at Health Canada recently concluded that for the average adult, a moderate intake of caffeine (400 to 450 milligrams per day, or the equivalent of three to four 8-ounce cups of brewed coffee) “is not associated with any adverse effects.”
Marcone agrees, saying, “As long as you stay within the guidelines, you're safe, and I'm confident of that based on the best science.”
Rosie Schwartz, an author and dietitian in Toronto, also concurs with this assessment. “Moderation is the best approach,” she says.
You're the best judge of your coffee capacity, but remember that your response to caffeine may change over time. “The key,” says Schwartz, “is to figure out how it's affecting you. Listen to what your body is telling you.”
If you're feeling stressed, jittery or are having trouble sleeping, Posen recommends that you gradually reduce your coffee intake as an experiment. And he suggests that you don't drink coffee after lunchtime.
Similarly, if you're planning to get pregnant or are already pregnant or breastfeeding, you should consider moderating your intake of caffeine. Health Canada recommends a maximum of 300 milligrams per day (about two to three 8-ounce cups) of brewed coffee. Although there are no definitive studies showing adverse effects, Schwartz advises pregnant women to drink even less than the two to three cups recommended by Health Canada. “It's best to err on the side of caution,” she says.
If you love coffee and want to drink several cups a day, Schwartz has some great advice: use good quality coffee, but try a blend of half-caffeinated and half-decaffeinated. And if too much coffee irritates your stomach, giving you indigestion or heartburn, try a low-acid coffee, says Schwartz.
“Coffee, in moderation, is one of life's great pleasures,” says Marcone. “You should not feel guilty when you're drinking it. When you have a cup of coffee, enjoy it.”
The caffeine content of your favourite drink
The caffeine content of coffee varies depending on how the beans are roasted, the amount of coffee used per cup and how it is brewed. For soft drinks, the caffeine content is consistent.
Espresso coffee (1.5 to 2 oz)
45 to 100 mg of caffeine
Red Bull energy drink (8.2 oz)
80 mg of caffeine
Brewed coffee (8 oz)
80 to 135 mg of caffeine
Cola beverages (12 oz)
43 to 55 mg of caffeine
Warning: Some prescription and over-the-counter medicines contain significant amounts of caffeine. Be sure to check the label or talk with your pharmacist or other primary care provider before taking them.
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