No one likes to be nagged, but that's often what health advice seems to do. There are all those don'ts (as in smoke, eat too much, gain weight). And the do's (exercise, eat fruit and vegetables) are predictable, even for people who don't mind them.
Lately, however, health researchers are reporting results that suggest maybe we can have our health and enjoy ourselves, too. Never has high living looked quite so healthful, although it's high living on a leash. The permission to indulge almost always comes with a reminder about doing everything in moderation.
Dozens of studies have shown that moderate alcohol consumption protects against heart disease and stroke. Drinking increases "good" HDL cholesterol, reduces factors in blood that make it more likely to clot, and may directly affect blood vessels, keeping the linings smooth and pliable and thus less vulnerable to atherosclerosis. European researchers reported interesting findings in 2008 that show a connection between alcohol intake and higher blood levels of omega-3 fats. Indeed, temperate tippling has been associated with everything from greater bone density to less risk for Alzheimer's disease and vascular dementia.
Moderation is flexibly defined, but the American Heart Association guidelines are often cited: for men, one to two drinks a day; for women, just one. A drink is defined as a 12-ounce beer, 4 ounces of wine, or 1.5 ounces of 80-proof liquor.
Women do need to worry about alcohol increasing breast cancer risk, although at moderate amounts (the drink-a-day level), the risk is small.
A steady stream of studies has won chocolate cardiovascular laurels by showing that it improves blood flow through arteries that supply the heart and the brain. Chocolate's winning ways continued in 2008. Harvard researchers found that two weeks of enhanced chocolate intake quickened blood flow through the middle cerebral artery.
Not every study has been a thumbs up. Moreover, the chocolate-as-healthful dream needs a couple of reality checks. The most likely explanation for chocolate's good effects is that cocoa beans contain substances called flavonols that stimulate production of nitric oxide, a chemical that relaxes blood vessels. In the studies cited above, researchers have used "flavonol-rich" chocolate. But typically, the processing of cocoa beans into chocolate removes flavonols.
Another caveat: the sugar and fat content of chocolate candy translates into calories. And some of the fat in many chocolate bars is the unhealthful saturated variety.
For the health conscious, a cup of coffee was once a somewhat perilous pleasure. Early studies showed a connection between coffee and heart attack. Some other studies cast the gloomy shadow of cancer risk.
But the cancer research was flawed or overturned by more definitive findings. Not all the evidence has been exculpatory, however. A Harvard study published in 2008 found hints of a connection between caffeine consumption and breast cancer risk in women with a history of benign breast disease and those whose tumors were estrogen- and progesterone-receptor negative.
Meanwhile, the coffee–cardiovascular disease research has done an about-face: now the gist is that coffee drinkers seem to be less likely to have heart attacks and strokes and develop diabetes than nondrinkers. The caffeine in coffee does constrict blood vessels and may increase your heart rate a little, but those are transitory effects. Coffee has other ingredients that seem to cancel out whatever negative effects chronic exposure to caffeine might have.
The good healthkeeping seal of approval for coffee comes with cautionary notes. Pregnant women are still advised to limit, if not avoid, caffeine intake. Another caution: unfiltered coffee — which includes coffee drinks made with espresso — may increase "bad" LDL levels because some harmful substances in the coffee don't get filtered out. There's nothing wrong with the occasional latte or cappuccino, but overdoing it may mean a return to the bad old days when coffee was cardiovascularly suspect.
We're resting easier (sometimes longer) these days because of the laurels that sleep is winning for its health benefits — or, more precisely, because of the evidence of all the bad things that can happen when we don't get enough of it. Several epidemiologic studies — the kind that involve following thousands of people over many years — have shown that "short sleepers" put on more pounds than people who sleep seven to eight hours a night, which is the amount that seems optimal for most adults. Other studies have linked skimping on sleep to the high-risk pool for heart attacks, diabetes, and early death. When healthy volunteers stay awake for long stretches, it wreaks hormonal havoc: levels of cortisol, a stress hormone, go up, and leptin and ghrelin, hormones that influence appetite, get thrown out of whack.
Of course, lack of sleep has a very direct effect on the brain, influencing memory, mood, and attention. We've all experienced grogginess after not getting enough sleep.
Can you sleep too much? Several of the epidemiologic studies of sleep show that long sleep (nine hours nightly or more) is associated with just as many health problems as short sleep, if not more. But it's probably more often the case that an underlying illness causes people to sleep more, not the other way around.
We could all use a little help from our friends, but just having them may also help us stay healthier. A slew of studies has shown an association between social networks and good health. Cognitive decline, high blood pressure, the risk of dying after a heart attack — they've all been linked to social isolation and loneliness. Tending to friendships, family, and community life is a good habit to cultivate for health and other reasons.
May 2009 update