Breaking Health News, November 26, 2002

Redefining a Healthy Diet

< November 26, 2002 > A few simple changes to the federal government's "Dietary Guidelines for Americans" could further reduce the risk of major chronic diseases, Harvard University researchers say.

The trouble with the guidelines is that they do not make a distinction between different types of fat or protein; they lump red meat, chicken, and nuts together as sources of protein; and they place too much emphasis on carbohydrates, the researchers say.

A 15-year study showed that men who ate white meat instead of red, unsaturated rather than saturated fat, and whole grains rather than refined grains lowered their risk of major chronic diseases by 20 percent. The reduction for women was 11 percent, says a report by the researchers in the new issue of the American Journal of Clinical Nutrition.

Marjorie McCullough, a nutritional epidemiologist who was part of the Harvard University School of Public Health team that looked at the US Department of Agriculture (USDA) dietary guidelines with a critical eye, says the recommended changes were prompted by a closer look at specific parts of the guidelines.

For example, the USDA guidelines emphasize lowering intake of all sorts of fats.

"We agree with that in general, but we look at a higher ratio of polyunsaturated fat to saturated fat," says McCullough, who now is a nutritional epidemiologist with the American Cancer Society. That means consuming more liquid vegetable oil and fish oil, she says. The Harvard guidelines—dubbed the Alternative Healthy Eating Index—also recommend lower intake of total trans fats, which come from margarine and vegetable shortening.

Potatoes are out because people generally consume them in the form of fries. Baked potatoes are OK, McCullough says, but "they don't have the same benefit of risk reduction as other vegetables do, such as broccoli."

Four servings of fruit daily, 15 grams a day of cereal fiber, one serving a day of nuts and soy protein, moderate alcohol consumption—one or two drinks a day—and multivitamin supplements are also recommended.

These recommendations are not based on any abstract laboratory study. Instead, the Harvard team had more than 150,000 men and women enrolled in the "Health Professionals Follow-Up Study" and the "Nurses Health Study" give detailed lists of what they were eating, and then looked at the diseases they developed over a 15-year period.

The men whose diet most closely followed the Harvard recommendations cut their risk of cardiovascular disease by 39 percent, compared to those whose diets strayed farthest from the guidelines. For women, the reduction was 28 percent. By comparison, the reduction for those who followed the federal dietary guidelines was 11 percent for men and 3 percent for women. No reduction of cancer risk was found for either set of guidelines.

A USDA spokesperson says the federal dietary guidelines are coming up for review and possible revision. The review will be done in collaboration with the US Department of Health and Human Services. A notice requesting nominations for a committee to do the review will be placed in the Federal Register, possibly as early as next month, according to the spokesperson.

Always consult your physician for more information.

For more information on healthy diets, please visit the Cardiovascular Diseases information module on this Web site.

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American Cancer Society

American Journal of Clinical Nutrition

American Heart Association

Family and Consumer Sciences Research Journal

National Heart, Lung, and Blood Institute

US Department of Agriculture (USDA)

US Department of Health and Human Services

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A Soda a Day Keeps the Vitamins Away

Soft drink consumers less likely to get daily recommended amounts of vitamins

Soft drinks may fill you up, but they let you down when it comes to vitamins and minerals.

A University of Missouri consumer economist, analyzing the results of a national food survey, found that people significantly increased their chances of being deficient in the recommended daily allowances (RDA) for common vitamins and minerals when they consumed a lot of sugared drinks.

RDA deficiencies are not common. In the some 15,000 people who self-reported their food intake for the US Department of Agriculture (USDA) study, from only 1 percent to 8 percent of the participants were not getting the proper amounts of certain vitamins and minerals.

However, says Michael S. Finke, an assistant professor or consumer and family economics at Missouri, the consequences of getting ever more calories from soft drinks or fruit-flavored sugared drinks with no nutrients is a trend that needs attention.

"RDA deficiency is not a major problem because a lot of foods have vitamins and minerals added, but this study shows that more nutrient-rich foods are being replaced by sugar drinks," says Finke, author of the study, appearing in the December issue of the Family and Consumer Sciences Research Journal.

"People haven't really highlighted the consequences of this major food consumption trend," he says.

Part of the problem could be simple economics, he says. Soda is a very cheap way to get calories.

"Soda pop has always been around, but it's so much cheaper now, relatively speaking, than it was 30 years ago that it is an enticing food option for resource-constrained families," Finke says. "A three-liter bottle of soda is 69 cents and contains 1,000 calories."

The only cheaper food source, he says, is vegetable oils.

Between 1970 and 1997, Finke says in his study, there has been a 86 percent increase in annual per capita consumption of carbonated, sugared soft drinks. One 12-ounce can of cola supplies about 150 calories from about 10 teaspoons of sugar.

In the study, Finke reviewed the results of a 1994-1996 survey of the USDA's Food Intakes by Individuals, to see if there were any associations between soda consumption and vitamin and mineral deficiency among participants in the self-reported food survey.

The scientists looked at 14 vitamins and minerals, including: vitamins A, E, C, B6, and B12, thiamin, riboflavin, niacin, and folate, and the minerals calcium, phosphorus, magnesium, iron, and zinc. The study did not include information about any vitamin or mineral supplements taken.

"The results were a little bit more dramatic that I had expected," he says. "I expected the results would be significant for nutrients associated with foods that might be replaced by soda, like calcium in milk, but the results were also significant for every other vitamin and mineral."

Finke and his colleagues found that sugar drink consumption was the most consistent variable—more than gender, race, or income —to signal the probability that people would not meet their RDA requirements.

The problem, he says, is not failure to meet RDA requirements, as only a small proportion of the participants actually failed to do so, ranging from 181 people (1.2 percent) for niacin to 1,168 people (7.8 percent) for vitamin A. However, the trend of increased soda pop consumption could increase the likelihood that more people would fail to meet their RDA requirements down the road.

"If someone drinks two cans of soda daily, which is about 15 percent of daily caloric intake, there is a 1 percent decrease in the probability that the person will meet their RDA requirements in calcium, for instance," Finke says. "So if the trend continues in the future as it has in the past, sugar drink consumption will have an even greater impact on failure to meet RDAs."

Finke says he is an economist, not a nutritionist, "but it seems obvious that we should pay attention to this trend in US food consumption and look at things we can to do reduce sugared drink consumption by making other foods less expensive and more palatable."

Connie Diekman, a nutritionist at the Washington University in St. Louis, agrees that soft drink consumption is a trend threatening to compromise good, nutritional health, especially in young people.

"What this study and others have shown is that adolescents increasingly turn to soft drinks for hydration and then do not need to get those calories from healthier choices," she says. "In addition, the long-term effects of inadequate calcium—maybe not deficient, but less than that needed for bone health—are a major health issue."

Always consult your physician for more information.