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Food for Thought

Janet Raloff
Food for Thought

Putting Labels on Nutrients

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After all the holiday partying, it's probably time for most people to get back in the habit of checking the labels on food. Which frozen desert has less fat per serving? Which cereal has the recommended amounts of iron and folic acid?

But do those nutrition fact boxes on packaged foods supply the information that people really need? Two new reports suggest that they don't.

Nutrient labeling of food has existed to varying degrees in the United States since 1941, but the nutrition fact box familiar to today's supermarket shoppers was designed in the early 1990s. By federal law, packaged foods must list the number of grams and percent daily value (%DV) of carbohydrates, fats, proteins, minerals, vitamins, and a few other food components in each serving.

The %DV is part of the alphabet soup of terms that nutritionists and Food and Drug Administration officials use to describe different ways of looking at nutritional requirements. It represents the proportion of the recommended amount of a nutrient that's available in each serving.

In 1968, FDA established these recommended amounts, known as Recommended Dietary Allowances (RDAs), for each of 12 vitamins, 7 minerals, and other food components. The RDA is the amount of each component needed to prevent nutritional deficiency in 97.5 percent of the population above the age of 4, not including pregnant and nursing women.

But nutritionists have conducted many studies on the minimums, maximums, and optimal amounts of different nutrients since 1968. Officials from FDA, the Department of Agriculture's Food Safety and Inspection Service, and the Canadian government's Health Canada, wanted to determine how to best use this new science to update the information on food labels. So they asked the National Academy of Science's Institute of Medicine to form a committee to investigate the issue.

"What we wanted, and what the USDA and Health Canada wanted, was for the academy to give us some guiding principles" to develop new %DVs, says Virginia Wilkening, deputy director in the Office of Nutritional Products, Labeling, and Dietary Supplements at FDA.

New guidelines

On Dec. 11, the Institute of Medicine committee recommended that FDA change the way it calculates %DVs but continue using them as a way for consumers to compare foods and put one food product in the context of a whole day's food intake.

"When you use the [current] recommended dietary allowances, you're really overestimating the nutritional requirements and needs for at least 50 percent of the population," says nutritionist Penny Kris-Etherton of Pennsylvania State University in University Park. So instead, the committee recommended that FDA nutritionists calculate %DVs based on Estimated Average Requirements (EARs).

Like an RDA, an EAR is a measure of the amount of a nutrient that people need to avoid dietary deficiencies. The difference is that RDAs cover almost everyone in a population, but EARs target the average person.

Nutritionists determine EARs for thirteen different populations, defined by age and gender, because different population groups have different nutritional requirements: Young boys need more calories than seniors, while women of childbearing age should consume more folic acid than the rest of the population needs, for example.

To simplify things, nutritionists create a single EAR for a given nutrient by factoring in how much of the population each of the 13 groups represents. It's these population-weighted EARs that the committee suggested should be the reference for %DVs.

"What we hope is that this is the best way of capturing the science in a way that will be useful to consumers," says Irwin H. Rosenberg, chair of the Institute of Medicine committee and dean of the Friedman School of Nutritional Science and Policy at Tufts University.

The committee ran calculations of what revised recommended daily nutrient intakes would be if based on the new EARs. For example, iron's current daily intake of 18 milligrams is the amount recommended for women of childbearing age, who need more than the rest of the population. Under the suggested population-weighted, EAR-derived figures, the daily value would drop by two-thirds to 6.1 mg.

This means a serving of spinach that contains 3 mg of iron would fulfill 17 percent of the current recommended daily intake, but under the proposed changes would account for almost 50 percent of the daily intake for iron.

This proposal doesn't sit well with everyone. Michael F. Jacobson, executive director of the Washington, D.C.–based Center for Science in the Public Interest says that this recommendation could result in people consuming inadequate amounts of vitamins and minerals. By following the new recommendations, half the population could assume they're meeting their nutritional needs when they aren't, Jacobson argues. In addition, he says that companies could reduce the amount of vitamins and minerals they add to foods and supplements, yet still be able to claim their product meets the FDA's standards.

"If you want to protect the public's health, I'd rather see some people getting more [nutrients] than they need, than many people getting less than they need," he says.

The %DV "is meant to represent guidance for comparison and food planning in a total diet," counters Rosenberg. "It's never been meant to make recommendations to institutions or populations about how many nutrients they should be taking."

Beyond vitamins and minerals

Another question facing the panel was how to display nutritional information for food components that are generally bad for people. Saturated fats are currently listed in the nutrition fact box, and in July, FDA announced that trans fats would be listed by 2006 (see No Hiding Most Trans Fats).

Because there's no minimum healthy amount for such fats–and instead many health risks–there are no EARs on which to base the %DVs. However, because saturated and trans fats are part of most North Americans' diets, food labels should offer people guidance, the committee said. The FDA had proposed that in addition to disclosing the amount of trans fats in a serving size, labels could contain a footnote or a disclosure statement to put the content in perspective, says Wilkening.

The Institute of Medicine committee decided that a combined %DV for saturated and trans fats would be useful and so has recommended that FDA create this new %DV based on a model of a healthy daily menu.

"When you look at menu modeling, you can get saturated fat down to about 5 percent" of energy intake, says Kris-Etherton. She adds, however, that "it's up to the FDA to decide what they're going to use as a standard."

The nutrition committee also made recommendations for how to calculate the %DVs for other fats, proteins, and carbohydrates. Because people often consume more calories from those categories than is physiologically necessary, the committee suggested that labels include ranges for each and a %DV based on a recommended intake set in the middle.

Other recommendations from the committee to the U.S. and Canadian government agencies were to continue to specify 2,000 calories as the standard for a typical day's intake; to use an "adequate intake" value if an EAR isn't available for any particular nutrient; to establish separate daily intake recommendations for infants, toddlers, pregnant women, and nursing mothers; and calculate the %DVs for nutritional supplements such as vitamin capsules in the same way %DVs are calculated for foods.

However, don't expect changes on cookie labels anytime soon. The FDA will reopen the public comment period on the issue of trans fats labeling to allow consumer and industry groups to express their opinions, says Wilkening. Then a comment period will follow for the other recommendations in the Institute of Medicine report. Finally, FDA and Health Canada will together update %DV labeling requirements, based on all the gathered recommendations and comments.

Another opinion

The second major report just out on food labels is from the Federal Trade Commission, the government agency that attempts to ensure that product manufacturers make only truthful claims. The report came in the form of a response to an FDA request for comments on how nutritional labeling might be improved to help consumers make better choices about what they eat.

The commission recommended that the FDA's Obesity Working Group determine whether labels' listing of the standard serving size of food products accurately reflects how people typically eat. The report suggests that FDA may have to mandate changes to make claimed serving sizes more realistic. The commission recommends that FDA look into whether listings of serving sizes are "sufficiently clear and prominent."

The report also recommended that the FDA relax some restrictions that make it hard for companies to put comparative claims, such as "reduced calorie," on their labels. The commission also suggested that companies should be able to label and advertise foods using more comparisons of different food types–making clear, for instance, that cherry yogurt is more nutritious than cherry pie–and more comparisons between different-size portions.

Because the health benefits of a low-calorie diet are so well established, the commission recommended that the FDA allow food manufacturers to display this information on labels. Stating the relationship between diet and health would "clearly further the FDA's objectives of empowering consumers to make better dietary choices," according to the report.

Still, nutritionists and consumers alike will have to wait a few years to see what changes will be made. Whatever happens, nutritionist Kris-Etherton says she hopes that people will use labels to find foods rich in a variety of vitamins and minerals and that meet their individual caloric needs.

Citations

Penny M. Kris-Etherton

271 Henderson South Building

Penn State University

University Park, PA 16802

Michael Jacobson

Center for Science in the Public interest

1875 Connecticut Avenue, N.W.

Suite 300

Washington, DC 20009

Irwin H. Rosenberg

Jean Mayer USDA HNRCA

Tufts University

711 Washington Street

Boston, MA 02111-1524

Virginia Wilkening

Food and Drug Administration

5100 Paint Branch Parkway

College Park, MD 20740
Further Reading

Raloff, J. 2003. No hiding most trans fats. Science News Online (July 19). Available at [Go to].

______. 2001. Brain food. Science News 160(Nov. 3):282-284. Available at [Go to].

______. 1997. FDA helps you identify heart-y oats! Science News Online (Jan. 25). Available at [Go to].

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