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Thanks to our Grand Platinum Sponsor: Ventura Foods Thanks to our Platinum Sponsors: Almond Board of California, Kellogg's Food Away from Home, National Peanut Board, Regione Siciliana/Best of Italy Consumer Association, and Tyson Foods Commentary on the 2005 Dietary Guidelines Healthy Menu Research & Development

Drink to Your Health

In the world of nutrition science, what people drink has long been an afterthought. Today there is finally a growing understanding that what—and how much—you drink can have a substantial impact on health and disease.

During a million or so years of human evolution, we've relied almost exclusively on one beverage: Water. Milk, juices, soft drinks, and other beverages are comparatively recent additions.

Primitive:
One million years ago		 Agrarian:
10,000 years ago		 Modern:
Today
Foods Beverages Foods Beverages Foods Beverages
Fruits Water Fruits Water Fruits Water
Vegetables   Vegetables Milk Vegetables Tea, coffee
Nuts   Nuts   Nuts Milk
Insects   Insects   Insects Juices
Small animals   Small animals   Small animals Soft drinks
    Fish, large animals   Fish, large animals Wine, beer, spirits
    Grains   Grains  

Water doesn't seem to satisfy us today. Americans spend more than $200 billion a year on beverages. Some of this is for bottled water. The lion's share, though, is for sugar-sweetened soda and coffee.

Beverages and Health

We drink mainly to replenish fluid lost when we breathe, sweat, and urinate. The beverages you choose to top off your tank can have an impact on health far beyond that physiological function.

Beverage Healthy? Health hazards? Cost per serving Overall impact on health
Water Yes Virtually none < 1¢ Beneficial
Tea Yes   5¢ Beneficial
Coffee Yes   10¢ Beneficial
Milk Mostly   25¢ Uncertain
Juice Uncertain   25¢ - 50¢ Uncertain
Soft drinks No   25¢ - 50¢ Negative

Water

Water is, and should be, the most commonly consumed beverage on the planet. It offers 100 percent of what we need with no calories and at little cost. Evidence for health benefits of water:

  • In one survey of almost 6,000 Chinese adults, the more water an individual drank the lower his or her chances of being overweight. (Stookey, European Journal of Clinical Nutrition, 2001)
  • An even larger study, this one of 20,000 Seventh Day Adventists living in California, found that the group of individuals who drank five or more cups of water a day were 50 percent less likely to have had fatal heart attacks than those who drank two or fewer cups a day. Comparing high versus low intakes of fluids other than water showed increases in risk of fatal heart attack. (Chan and colleagues, American Journal of Epidemiology, 2002)

Adverse effects of water

  • Virtually none

Tea

After water, tea is the world's second most commonly consumed beverage. It is made from the leaves of a bushy evergreen plant named Camellia sinensis. The leaves are prepared in different ways to yield three basic types of tea: green tea, black tea, and oolong. A cup of tea contains mostly water with a smattering of polyphenols, catechins, chlorogenic acid, caffeine, methylxanthines, theobromine, and hundreds of other substances in even smaller amounts.

Evidence for health benefits of tea

  • In a survey of 1,210 adults, those who reported drinking tea daily for 10 years or more had 20 percent less body fat compared to non-tea-drinkers. (Wu and colleagues, Obesity Research, 2003)
  • A 10-year study of 1,500 initially healthy Taiwanese men and women showed that those who drank ½ to 2½ cups a day were 46 percent less likely to have developed hypertension during the study period when compared to those who didn't drink tea. The decrease in risk was even greater, 65 percent, for those who drank more than 2½ cups a day. (Yang and colleagues, Archives of Internal Medicine, 2004)
  • In a careful trial that included 15 volunteers with high cholesterol, drinking five servings a day of black tea reduced LDL (bad) cholesterol by 11 percent and lipoprotein (a) by 16.4 percent compared to a caffeine-free placebo. (Davies and colleagues, Journal of Nutrition, 2003)
  • A study that compared a variety of dietary and lifestyle factors between 340 heart-attack survivors and 340 similarly aged men and women found that those who drank at least one cup of tea a day had a 44 percent lower risk of heart attack. (Sesso and colleagues, American Journal of Epidemiology, 1999)

Other potential health benefits of drinking tea include

Adverse effects of tea

  • The plant from which tea is made, Camellia sinensis, can concentrate minerals such as fluoride and aluminum. Drinking a lot of tea can lead to a mottling of the teeth known as dental fluorosis and theoretically can cause aluminum toxicity. (Graham, Preventive Medicine, 1992; Cao, Food and Chemical Toxicology, 2003)

Coffee

Although we can't say for certain exactly when humans began eating or brewing coffee beans, there is good evidence that coffee trees were being cultivated almost 1,000 years ago. According to the National Coffee Association, Americans drink about 400 million cups of coffee a day, or enough to fill the Empire State Building every 10 days.

A cup of coffee delivers mostly water. Taken black without sugar, it's almost calorie free. In addition to some vitamins and minerals, it contains polyphenols, chlorogenic acid, caffeine, and smaller amounts of hundreds of other substances.

Evidence for health benefits of coffee

  • Among 120,000 initially healthy men and women, individuals who drank six or more cups of coffee a day were one-half to one-third less likely to have developed diabetes over the 12 to 18 years of follow-up than those who didn't drink coffee. (Salazar-Martinez and colleagues, Annals of Internal Medicine, 2004)
  • The onset of Parkinson disease was 80 percent lower among men who drank three or more cups of coffee a day in a study that followed 8,000 Japanese-American men for 30 years. (Ross and colleagues, Journal of the American Medical Association, 2000)

Other potential health benefits of drinking coffee include:

Adverse effects of coffee

In general, drinking coffee is safe. However, caffeine is mildly addictive, and many coffee drinkers must get their daily "fix" or face headaches or grogginess. Drinking unfiltered coffee such as espresso can increase levels of total and LDL (bad) cholesterol, while filtered coffee does not appear to influence cholesterol levels. (Jee and colleagues, American Journal of Epidemiology, 2001) One report suggests the possibility that people with epilepsy who drink a lot of coffee may put themselves at risk for seizures, and that cutting down on coffee or eliminating it altogether may help prevent seizures. (Bonilha, Seizure, 2004)

Milk

Archeological excavations in Britain suggest that humans have been drinking milk from non-human mammals for at least 6,000 years. In different parts of the world, milk is obtained from cows, sheep, goats, camels, horses, donkeys, and buffaloes. Milk is a dietary staple in some parts of the world and uncommon in others. Per capita milk consumption ranges from a high of 43 gallons a year in Ireland to half a gallon per year in China. The United States is somewhere in the middle, with a per capita consumption of 25 gallons per year.

A cup of whole milk is a significant source of calories, fat, and other nutrients. It delivers 156 calories, eight grams of protein, 11 grams of sugar, and nine grams of fat (5.5 of them saturated fat), along with 290 milligrams of calcium, 227 milligrams of phosphorous, some vitamin B 12, riboflavin, beta carotene, and other micronutrients. Because milk and other dairy products are such good sources of calcium, the latest Dietary Guidelines for Americans, not to mention the ubiquitous "got milk?" ads, urge us to get at least three servings a day to prevent the bone-thinning disease osteoporosis. That, however, isn't the best advice.

Evidence for health benefits of milk

  • In a 10-year study of 3,000 initially healthy young adults, each daily serving of milk decreased the risk of obesity by 17 percent and the risk of the insulin resistance syndrome by 25 percent. (Pereira and colleagues, Journal of the American Medical Association, 2002)
  • A national study that included 3,300 white women showed that those who drank at least one cup of milk a day during childhood and adolescence had higher bone mineral density than those who drank less milk. Higher levels of milk intake during adolescence were also associated with 50 percent lower risk of breaking a hip, spine, or forearm. (Kalkwarf and colleagues, American Journal of Clinical Nutrition, 2003)
  • Decreased colorectal cancer is another possible benefit of consuming dairy products (Hjartker and colleagues, International Journal of Cancer, 2001; Davies, British Journal of Cancer, 1996; Ma and colleagues, Journal of the National Cancer Institute, 2001)

Adverse effects of milk:

Consumption of dairy products has been linked with a number of health problems. These include:

Juice

Just less than one-half of all fruit in the US is consumed as juice. Orange juice accounts for two-thirds of all juice consumed. About one-quarter of four-month-old infants and one-half of eight-month-old infants drink juice regularly. One cup of fresh-squeezed orange juice delivers 112 calories, 26 grams of carbohydrate, almost two grams of protein, a half-gram of fat, and almost double the daily recommended intake of vitamin C.

Evidence for health benefits of fruit juice

  • About the best that can be said for juice as a beverage is that it supplies some vitamin C and a variety of antioxidants. True fruit juices also deliver some fiber. Fruit-flavored juices deliver little more than sugar water enriched with a few vitamins. There is little data to support health benefits for juices.

Adverse effects of juice

  • Some (but not all) studies show an increased risk of short stature and obesity in children who drink a lot of juice. (Dennison and colleagues, Pediatrics, 1997)
  • Excess juice consumption has been identified as a possible cause of failure to thrive in children. (Smith and colleagues, Pediatrics, 1994)
  • Drinking juice has also been linked with an increase in cavities. (Grobler and colleagues, Clinical Preventive Dentistry, 1989)

Soft Drinks

Approximately half of all Americans have at least one soft drink a day. Over 80 percent of these are sugar-sweetened, not diet. Soft drinks make up the major source of added sugar in children's diets.

These are generally empty calories—calories without healthful nutrients. A 12-ounce can of Coca-Cola, for example, gives you 110 calories (most of them from sugar), no protein, no fat, no vitamins or minerals, and 34 milligrams of caffeine.

Evidence for health benefits of soft drinks

  • There really aren't any. About the most that can be said for soft drinks is that they provide a "way to prevent dehydration." That's from the Web site of the American Dietetic Association, which receives financial support from the soft drink industry.

Adverse effects of soft drinks

  • Children who have at least one soft drink a day take in about 200 calories more each day than those who don't have soft drinks. They also have lower protein, calcium, and vitamin intakes. (Harnack and colleagues, Journal of the American Dietetic Association, 1999)
  • In middle-school children, every additional serving of soft drinks a day increased the risk of obesity by 60 percent. (Ludwig and colleagues, The Lancet, 2001)
  • Adults given 3½ servings a day of regular soda for three weeks gained weight, mainly due to the extra daily calories. (Tordoff and Alleva, American Journal of Clinical Nutrition, 1990)
  • Women who drink at least one soft drink a day have an 83 percent increased risk of developing diabetes. (Schulze and colleagues, JAMA, 2004)

Alcoholic beverages

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Over the past three decades, scores of different types of studies from different parts of the world have indicated that alcohol in moderation protects against heart disease and the most common kind of stroke (ischemic) and may also help ward off type 2 diabetes and gallstones.

Before going any further, two definitions are in order:

  1. What's "a drink?" The Dietary Guidelines for Americans, and many scientists who study alcohol, have traditionally defined a drink as 12 ounces of beer, 5 ounces of wine, or 1½ ounces of spirits.
  2. How many drinks is "moderate?" For men, moderate alcohol consumption means one to two drinks a day. For women, defining moderate is a bit trickier. Women, like men, benefit from alcohol's ability to prevent heart attack and stroke. But the Nurses' Health Study and others have shown that, compared with one drink a day, two a day increase the chances of developing breast cancer by 20 to 25 percent—that's the difference between 12 of every 100 women developing breast cancer during their lifetimes (the current average risk in the United States) and 14 to 15 of every 100 women developing the disease (Smith-Warner and colleagues, JAMA, 1998). Interestingly, getting plenty of one type of B vitamin, folic acid, can limit or even negate this increased risk.

Alcohol and heart disease

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More than 30 large, long-term studies including more than one million volunteers have investigated a possible connection between alcohol and heart disease. The findings from these studies offer extremely solid evidence that something in alcoholic beverages helps prevent heart disease and stroke. For example, in a 14-year study of almost 40,000 male health professionals, men who drank alcohol were less likely to have had a heart attack or died of heart disease than non-drinkers. (Mukamal and colleagues, New England Journal of Medicine, 2003)

Scientists aren't exactly sure how alcohol fights heart disease. One thing it does is raise levels of HDL, the protective form of cholesterol. Numerous studies indicate that higher HDL translates into less heart disease. Alcohol also helps prevent the formation of blood clots inside arteries. This is important because heart attacks and strokes occur when such clots block blood flow in the arteries that nourish the heart or feed the brain.

Potions and Patterns

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A lively debate rages in medical journals and the popular press over which alcoholic potion is better at preventing heart disease. Wine supposedly has a lead over beer and spirits, fueled in part by the so-called French paradox—the French aren't as plagued by heart disease as Americans, even though they smoke, exercise very little, and eat plenty of artery-clogging saturated fats. They do, however, drink red wine.

It's a cute idea, and one that American wine sellers love to perpetuate. But wine hasn't cornered the heart-protection market. There are almost equal numbers of studies showing cardiovascular benefits for wine, beer, and spirits (Rimm, American Journal of Epidemiology, 1996).

Drinking patterns are probably more important than the type of alcoholic beverage. Having one drink a day is quite different from having four drinks on Friday, three on Saturday, and none during the rest of the week, even though your weekly intake is about the same. Frequent binge drinking increases the chances of having a bleeding stroke (Longstreth and colleagues, Stroke, 1992). In the other direction, drinking small amounts of alcohol daily seems to offer greater protection than drinking once or twice a week. (Mukamal and colleagues, New England Journal of Medicine, 2003)

Hazards of Alcohol

Alcohol, of course, has hazards as well as benefits. It is implicated in about one-third of all fatal traffic accidents in the United States. Alcohol contributes to liver disease, a variety of cancers, high blood pressure, so-called bleeding strokes, a progressive weakening of the heart and other muscles, depression, and a host of other conditions. Alcohol abuse can devastate families and relationships. In other words, heavy drinking is a major cause of suffering, illness, and preventable deaths.

Even moderate drinking carries some risks. Alcohol can disrupt sleep and judgment. It can interact in potentially dangerous ways with a variety of medications, including acetaminophen, antidepressants, anticonvulsants, painkillers, and sedatives. It is also addictive, especially among people with a family history of alcoholism.

The bottom line

  • Alcohol in moderation (1-2 drinks/day for men, no more than 1 drink a day for women) decreases the risk of heart disease by 25 to 40 percent.
  • The benefits of alcohol are stronger for those who drink small amounts frequently.
  • Wine, beer, and spirits all seem to be equally effective at preventing heart disease.
  • If you don't drink, don't feel compelled to start. You can get similar benefits by exercising more, improving your diet, or losing weight.

Calcium and Dairy

Calcium — No Emergency

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If milk could help Cal Ripken break Lou Gehrig's record, it's got to be good for the rest of us. Add in the recommendation from the latest national Dietary Guidelines for Americans to have three servings a day of milk or other dairy products and you've got a nutrition home run, right? Not necessarily.

We are urged to include more dairy products in our diets ostensibly to prevent osteoporosis. This bone-thinning condition affects more than 10 million Americans, and another 34 million are on the road to it. In older Americans, it's a key cause of broken bones, which can lead to disability, loss of independence, and even death.

The more calcium you get, so the thinking goes, the stronger your bones will be and the smaller your chances of developing osteoporosis. That hypothesis, though, isn't shored up by strong data. In fact, the connection between dietary calcium and bone health is on the weak side. A survey of daily calcium intake and hip fractures across 10 countries showed no real link between the two. In fact, broken bones were the least common in Hong Kong and Singapore, two of the countries with the lowest calcium intakes, and were much more common in the United States and New Zealand, which had comparatively high calcium intakes (Hegsted, Journal of Nutrition, 1986).

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Results from the Nurses' Health Study show no connection between dietary calcium and hip fractures. Over an 18-year period, women who got the most calcium (above 1,100 milligrams a day) had the same rate of hip fractures as women who got the least calcium (under 400 milligrams a day) (Feskanich and colleagues, American Journal of Clinical Nutrition, 2003). There wasn't a connection between milk consumption and hip fractures, either. Other studies have yielded similar results.

At the same time, a number of studies have shown that the higher the calcium intake, the stronger or denser bones become.

This conflicting information indicates that there is real uncertainty over how much calcium the average adult needs each day. This is reflected in the recommendations that different countries have made about calcium. The World Health Organization says you need 400–500 milligrams of calcium a day to prevent osteoporosis. In the United Kingdom, everyone over age nineteen is urged to get 700 milligrams a day. In the United States, the recommended intakes are 1,000 milligrams per day from ages 19 to 50 and 1,200 milligrams per day after that. In Canada, the target for adults is 1,000 milligrams per day up to age 50 and then 1,500 milligrams per day after that.

Dairy's Darker Side

When it comes to preventing disease, it's important to take steps that will stop something bad—like osteoporosis—from happening without causing other bad things to occur. Dairy doesn't appear to prevent osteoporosis and broken bones. At the same time, dairy products may pose some health hazards of their own. The first of these is the saturated fat they can deliver. Drinking three glasses of whole milk a day is like eating twelve strips of bacon or a Big Mac and an order of fries. A one-ounce serving of cheese made from whole milk delivers about two-thirds the calcium as a glass of milk and the same amount of saturated fat. You can limit or avoid this wallop of saturated fat by using skim milk and non- or low-fat dairy products.

Adverse effects of milk

Consumption of dairy products has been linked with a number of health problems. These include:

If Not Calcium, What?

Getting extra calcium isn't the only way to keep bones strong. Several other strategies have been shown to have strong and positive influences on bone health. These include:

  • Be as physically active as possible. Brisk walking and other weight-bearing activities gently stress bones. This stimulates a flurry of bone-building activity. Activity doesn't build or strengthen all bones, just those that are stressed, so you need to engage in a variety of activities that stress different bones and that keep your muscles strong.
  • Get enough vitamin K. This vitamin, once thought to be involved only in the blood clotting process, also regulates calcium and bone formation. Vitamin K is mainly found in green vegetables such as dark green lettuce, broccoli, spinach, Brussels sprouts, and kale. Eating one or more servings of green leafy vegetables a day should give you enough vitamin K.
  • Take a vitamin D supplement. In addition to helping the body absorb calcium and phosphorus, this fat-soluble vitamin also inhibits the breakdown of bone and boosts bone-building activity. Several studies have shown that vitamin D deficiencies are more common among older people with broken bones than those without them. In the Nurses' Health Study, older women who got at least 500 IU of vitamin D a day were one-third as likely to have broken a hip than women who got under 200 IU a day. The current official target for daily vitamin D intake is 200 IU (5 micrograms) between the ages of 19 and 50; 400 IU (10 micrograms) between the ages of 51 and 70; and 600 IU (15 micrograms) after age 70. Yet many lines of evidence point to a higher level—800 IU per day—to get the full benefits of vitamin D.
  • Don't get too much extra preformed vitamin A (retinol) unless prescribed by your doctor. Too much vitamin A can weaken bones. It can also interfere with the activity of vitamin D. Keep your daily dose from supplements under 2,000 IU.

The Bottom Line on Calcium

  • Calcium is essential, but daily intakes of 1,000 milligrams or more probably overstate how much most adults need.
  • Few Americans are likely to lower their chances of breaking a bone by taking in more calcium.
  • Consuming a lot of dairy products could have negative effects on overall health.
  • Supplements that combine calcium and vitamin D may be a good option for women.
  • Calcium supplements may not be advisable for men.
  • Other ways to keep bones strong and prevent osteoporosis or fractures include exercising more, eating more green leafy vegetables, getting plenty of vitamin D (800–1,000 IU per day), and trying not to get too much preformed vitamin A.