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Market values - updating the recommended dietary allowances - includes related article on food supplements

Men's Fitness, Oct, 1998 by Christie Knudsen

After years of confusion at the grocery store, we're finally getting new RDAs

If your level of nutrition knowledge is on a par with Norm's from Cheers, your sole exposure to Recommended Dietary Allowances (RDAs) is most likely limited to boxes of Cap'n Crunch. If, on the other hand, you do know a lot about fueling your body to make it perform at peak efficiency, you're probably familiar with RDAs but completely disregard them.

Billed by the nutritionists who developed them as the most authoritative source of information on nutrient allowances for healthy people, the RDAs haven't been updated since 1989. Unless you've been living under a rock since then, you know there have been plenty of new nutrition developments in the past decade.

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The National Academy of Sciences (NAS) established the first RDAs during World War II to ensure that soldiers ate well. Unfortunately, World War II-era thinking has dominated the thought-process of the nutritionists who formulated the current RDAs. Their emphasis on getting nutrients from food, not supplements, ignores a lot of current scientific research and fails to acknowledge the frenetic pace of modern life. Is it desirable to get all of your nutrients through food? Sure. Is it possible? Only if you have Alice the housekeeper making every single meal for you. Fortunately for you - if not Alice - the NAS is in the process of releasing new RDAs, along with a more practical view of supplementation.

New and improved

Since the inception of the RDAs, the NAS has updated them periodically, basing their recommendations on the belief that an adequate diet prevents a vitamin- or mineral-deficiency disease. Increasingly, however, health-minded men and women haven't been willing to settle for adequate, as demonstrated by the billions of dollars spent on supplements and fortified foods each year. Furthermore, nutritionists and experts in the food industry have been increasingly vocal in demanding modification of the RDAs to reflect current research. For instance, the RDA for vitamin C is currently 60 milligrams a day; that's basically just enough to keep you from getting scurvy. Yet many doctors, cancer specialists and longevity experts often prescribe a daily vitamin C dose of 100 times the RDA or more, believing it will significantly improve their patients' lives.

In the wake of all this clamor, the NAS has finally created a new system based on an entirely different assumption: that Americans should strive to eat an optimal diet, one that not only prevents deficiencies but also promotes health. In fact, the new guidelines offer three times more information than the old RDAs. They're based on the latest nutritional studies and acknowledge that supplements can be a valuable, even essential, addition to one's diet. Janet King, PhD, RD, professor of nutrition at the University of California, Berkeley, and a member of the Dietary Reference Intakes Committee at the NAS, calls the recent changes "a whole new paradigm in nutrition," saying they will better enable individuals to design diets for optimal health and vitality.

You may be thinking, Why should I care? Here's a reason: The new RDAs are expected to improve everyone's nutrition, whether you're aware of it or not. RDAs are the standard for anything to do with food; schools, hospitals, the military, various other institutions and even some restaurants use them to plan and develop meals. The government uses them to help decide which nutrients should be added to foods. Finally, the food industry uses RDAs to develop foods attractive to buyers, like cereals fortified with folic acid and other hard-to-get nutrients.

Loosely based on the RDAs are food and supplement labels sporting "Percent Daily Values" information about vitamins and minerals. Unfortunately, the Food and Drug Administration isn't expected to change labeling requirements to reflect the new RDAs any time soon, according to Virginia Wilkening, a nutritionist in the FDA's Office of Food Labeling. So don't rely on "Percent Daily Values" printed on labels to help you figure out whether you're getting an optimal amount of nutrients. Instead, calculate what you're getting in actual amounts (listed in units such as grams or milligrams) [TABULAR DATA OMITTED] and count it toward your daily requirement.

RDAs vs. DRIs

To help people design their optimal diet, the NAS rolled the updated RDAs into a new, more informative system called the Dietary Reference Intakes (DRIs). The DRI system contains three categories for each nutrient: the minimum daily intake, the new RDA, and the "maximum" daily intake.

You should get at least the "minimum" amount of any vitamin or mineral to cover your bases (see chart above). Better yet, get the new RDA. Even better, get an amount somewhere between the RDA and the maximum allowance, taking into account your activity level, body size and disease risk factors.

Here's an example using folic acid: Let's say Bob is a pretty fit 210-pound, 30-year-old guy with elevated levels of homocysteine, a naturally occurring amino acid in the blood that may contribute to heart disease. Folic acid may reduce the risk of heart disease by lowering homocysteine. To prevent deficiency, Bob must consume at least 320 micrograms of folic acid each day. To satisfy his physiological need and improve his health he would want to get between 400 micrograms - the new RDA and the maximum of 1,000 micrograms each day. To more closely approximate his optimal daily dose, Bill should consider his size, the fact that he works out three days a week and his high homocysteine levels. Hence, he would probably be wise to consume close to the maximum of folic acid every day.

Market values - updating the recommended dietary allowances - includes related article on food supplements

Men's Fitness, Oct, 1998 by Christie Knudsen

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