What worries you most? Decaying teeth, thinning bones, heart disease, stroke, diabetes, dementia, cancer, obesity? Whatever tops your list, you may be surprised to know that all of these health problems are linked to the beverages you drink — or don’t drink.
Last year, with the support of the Unilever Health Institute in the Netherlands (Unilever owns Lipton Tea), a panel of experts on nutrition and health published a “Beverage Guidance System” in hopes of getting people to stop drinking their calories when those calories contribute little or nothing to their health and may actually detract from it.
The panel, led by Barry M. Popkin, a nutrition professor at the University of North Carolina, was distressed by the burgeoning waistlines of Americans and the contribution that popular beverages make to weight problems. But the experts also reviewed 146 published reports to find the best evidence for the effects of various beverages on nearly all of the above health problems. I looked into a few others, and what follows is a summary of what we all found.
At the head of the list of preferred drinks is — you guessed it — water. No calories, no hazards, only benefits. But the panel expressed concern about bottled water fortified with nutrients, saying that consumers may think they don’t need to eat certain nutritious foods, which contain substances like fiber and phytochemicals lacking in these waters. (You can just imagine what the panel would have to say about vitamin-fortified sodas, which Coca-Cola and Pepsi plan to introduce in the coming months.)
Sweet Liquid Calories
About 21 percent of calories consumed by Americans over the age of 2 come from beverages, predominantly soft drinks and fruit drinks with added sugars, the panel said in its report. There has been a huge increase in sugar-sweetened drinks in recent decades, primarily at the expense of milk, which has clear nutritional benefits. The calories from these sugary drinks account for half the rise in caloric intake by Americans since the late 1970s.
Not only has the number of servings of these drinks risen, but serving size has ballooned, as well, with some retail outlets offering 32 ounces and free refills.
Add the current passion for smoothies and sweetened coffee drinks (there are 240 calories in a 16-ounce Starbucks Caffe Mocha without the whipped cream), and you can see why people are drinking themselves into XXXL sizes.
But calories from sweet drinks are not the only problem. The other matter cited by the panel, in its report in The American Journal of Clinical Nutrition, is that beverages have “weak satiety properties” — they do little or nothing to curb your appetite — and people do not compensate for the calories they drink by eating less.
Furthermore, some soft drinks contribute to other health problems. The American Academy of General Dentistry says that noncola carbonated beverages and canned (sweetened) iced tea harm tooth enamel, especially when consumed apart from meals. And a study of 2,500 adults in Framingham, Mass., linked cola consumption (regular and diet) to the thinning of hip bones in women.
If you must drink something sweet, the panel suggested a no-calorie beverage like diet soda prepared with an approved sweetener, though the experts recognized a lack of long-term safety data and the possibility that these drinks “condition” people to prefer sweetness.
Fruit juices are also a sweet alternative, although not nearly as good as whole fruits, which are better at satisfying hunger.
Coffee, Tea and Caffeine
Here the news is better. Several good studies have linked regular coffee consumption to a reduced risk of developing Type 2 diabetes, colorectal cancer and, in men and in women who have not taken postmenopausal hormones, Parkinson’s disease.
Most studies have not linked a high intake of either coffee or caffeine to heart disease, even though caffeinated coffee raises blood pressure somewhat and boiled unfiltered coffee (French-pressed and espresso) raises harmful LDL and total cholesterol levels.
Caffeine itself is not thought to be a problem for health or water balance in the body, up to 400 milligrams a day (the amount in about 30 ounces of brewed coffee). But pregnant women should limit their intake because more than 300 milligrams a day might increase the risk of miscarriage and low birth weight, the panel said.
Mice prone to an Alzheimer’s-like disease were protected by drinking water spiked with caffeine equivalent to what people get from five cups of coffee a day. And a study of more than 600 men suggested that drinking three cups of coffee a day protects against age-related memory and thinking deficits.
For tea, the evidence on health benefits is mixed and sometimes conflicting. Tea lowers cancer risk in experimental animals, but the effects in people are unknown. It may benefit bone density and help prevent kidney stones and tooth decay. And four or five cups of black tea daily helps arteries expand and thus may improve blood flow to the heart.
Alcohol is a classic case of “a little may be better than none but a lot is worse than a little.” Moderate consumption — one drink a day for women and two for men — has been linked in many large, long-term studies to lower mortality rates, especially from heart attacks and strokes, and may also lower the risk of Type 2 diabetes and gallstones. The panel found no convincing evidence that one form of alcohol, including red wine, was better than another.
But alcohol even at moderate intakes raises the risk of birth defects and breast cancer, possibly because it interferes with folate, an essential B vitamin. And heavy alcohol consumption is associated with several lethal cancers, cirrhosis of the liver, hemorrhagic stroke, hypertension, dementia and some forms of heart disease.
Dairy and Soy Drinks
Here my reading of the evidence differs slightly from that of the panel, which rated low-fat and skim milk third, below water and coffee and tea, as a preferred drink and said dairy drinks were not essential to a healthy diet. The panel acknowledged the benefits of milk for bone density, while noting that unless people continue to drink it, the benefit to bones of the calcium and vitamin D in milk is not maintained.
Other essential nutrients in milk include magnesium, potassium, zinc, iron, vitamin A, riboflavin, folate and protein — about eight grams in an eight-ounce glass. A 10-year study of overweight individuals found that milk drinkers were less likely to develop metabolic syndrome, a constellation of coronary risk factors that includes hypertension and low levels of protective HDLs. To me, this says you may never outgrow your need for milk.
The panel emphasized the need for children and teenagers to drink more milk and fewer calorically sweetened beverages.
“Fortified soy milk is a good alternative for individuals who prefer not to consume cow milk,” the panel said, but cautioned that soy milk cannot be legally fortified with vitamin D and provides only 75 percent of the calcium the body obtains from cow’s milk.