A cup of joe does more good than harm

If you enjoy reading your morning paper while sipping a cup (or two) of coffee, it seems there's no reason to stop. Mounting evidence suggests that, for most people, drinking coffee does more good than harm.

It wasn't long ago when coffee was linked to heart disease, osteoporosis, infertility and pancreatic cancer. Now research suggests that if you drink enough of it, you'll lower the risk of developing Type 2 diabetes, heart disease, asthma, gallstones, Parkinson's disease, liver cancer and possibly colon cancer. And you'll feel more alert and work out harder at the gym.

That's positive news for coffee-loving Canadians who prefer the beverage over tea, milk, juice, soft drinks and beer. According to the Coffee Association of Canada, nearly two-thirds of Canadians drink an average of 2.33 cups of coffee every day.

The most promising evidence for coffee's health benefits come from studies on diabetes. In a report that combined data from nine large studies, people who drank four to six cups of coffee a day were 28 per cent less likely to develop Type 2 diabetes compared with those who drank two cups or fewer. Drinking more than six cups each day reduced the risk by 35 per cent.Despite earlier concerns that coffee might be bad for your heart, studies haven't found a connection. In fact, one study conducted among 41,836 healthy women, aged 55 to 69, found that drinking one to six cups of coffee a day - caffeinated and decaffeinated - reduced the risk of dying from heart disease. A daily intake of four to six cups was found to be most protective.

Several studies have connected habitual coffee consumption with protection from Parkinson's disease. In two studies, Harvard researchers found that men who consumed the most caffeine reduced their risk for Parkinson's disease by 48 per cent. Among women, those who drank one to three cups of coffee a day had a 50-per-cent reduction in risk.

Coffee also seems to protect the liver from the effects of alcohol and toxins. A recent analysis of findings from nine studies on more than 240,000 people with and without a history of cirrhosis concluded that the risk of liver cancer was cut by 43 per cent for each two cups of coffee a day.

In terms of performance, studies suggest that two cups of coffee can improve endurance performance in activities such as running, cycling and cross-country skiing. Coffee also stimulates the brain and enhances mental alertness, particularly if you spread your intake out over the course of the day.

Researchers suspect that some of coffee's benefits are linked to its antioxidants, some of which become more potent during roasting. Antioxidants in coffee - both caffeinated and decaffeinated - are thought to dampen inflammation in the body and improve how it uses insulin, the hormone that lowers blood sugar. Coffee also contains magnesium, a mineral linked to blood sugar regulation.

Caffeine is also thought to play a role. The caffeine in coffee helps treat asthma symptoms, enhances physical performance and boosts mental alertness. Coffee's protective effects against gallstones and Parkinson's disease are also attributed to caffeine.

But regular coffee isn't for everyone. Studies suggest that excess caffeine can boost blood pressure and heart rate, a concern for people with high blood pressure and heart disease. In postmenopausal women who don't get enough calcium, consuming 450 milligrams of caffeine a day - about three eight-ounce cups of coffee - has been linked with having a lower bone density. (Caffeine increases the amount of calcium your kidneys excrete in the urine.) And some studies suggest that high intakes of caffeine during pregnancy can increase the risk of miscarriage.

Caffeine is a stimulant drug that's mildly addictive. If you're a habitual coffee drinker and you miss your daily dose, you can experience indigestion, muscle soreness, headache, irritability and even slight depression.

Caffeine sensitivity - the amount it takes to elicit an effect - varies by person. In general, the smaller the person, the less caffeine it takes to produce side effects. But regardless of body size, the more caffeine you consume, the less sensitive you become to its effects. In other words, it takes more caffeine to feel its jolt.

A standard cup (eight ounces) of coffee is often assumed to provide 100 milligrams of caffeine, but tests conducted in 2004 for The Globe and Mail and CTV News showed that caffeine content of coffee ranged from 78 to 165 milligrams a cup, depending on the coffee house. (Most coffee shops don't offer eight-ounce cups of coffee. The smallest serving is usually 10 or 12 ounces.)

Based on a review of the evidence, Health Canada contends that healthy adults are not at risk for adverse effects from caffeine, provided you limit your daily intake to 450 milligrams. During pregnancy, women are advised to consume no more than 300 milligrams a day but some experts suggest a stricter limit of 200 milligrams. Having high blood pressure, insomnia and osteoporosis are other sensible reasons to limit your caffeine intake.

Yet for most people, coffee in moderation is harmless, and there's no reason to cut back. It seems that coffee's perks extend beyond kick-starting your day.

Leslie Beck, a Toronto-based dietitian at the Medcan Clinic, is on CTV's Canada AM every Wednesday. Visit her website at lesliebeck.com.

lesliebeck.com

HOW MUCH CAFFEINE

Healthy adults are advised to consume no more than 450 milligrams a day and pregnant women no more than 300 milligrams. Children, aged 12 and under, should consume no more than 2.5 milligrams of caffeine for each kilogram body weight a day.
Coffee, brewed, 8 ounces 100 mg
Coffee, instant, 8 ounces 66 mg
Coffee, decaffeinated, 8 ounces 3 mg
Espresso, 2 ounces 54 mg
Starbucks coffee, venti, 20 ounces 415 mg
Second Cup coffee, large, 20 ounces 391 mg
Timothy's, large, 18 ounces 245 mg
Tim Hortons, large, 20 ounces 270 mg
Tea, black, 8 ounces 43 mg
Tea, green, 8 ounces 30 mg
Cola, 1 can, 355 ml 37 mg
Diet Cola, 1 can, 355 ml 50 mg
Red Bull energy drink, 250 ml 80 mg
Dark chocolate, 1 ounce 20 mg

Source:www.theglobeandmail.com