Staying abreast of emerging nutrition research studies can be a real challenge for busy wellness professionals. Half the battle is making sense of the terms used to describe new scientific findings. One day “genetics” is making headlines, while the next day everyone is talking about the “glycemic index.”
Things get even trickier when your clients pose questions about these newfangled buzz words and you don’t have a clue as to what they mean. That’s why we devised this primer to explain 10 key terms related to breaking food and nutrition research news. We’ll explore the first five in this issue and the remainder in the May issue of Inner IDEA Body-Mind-Spirit Review.
Topping the list of popular terms used in many studies this year is nutrigenomics, defined as the study of how different foods interact with specific genes to increase or decrease the risk of diseases, such as type 2 diabetes, heart disease or cancers (DeBusk et al. 2005). Because nutrigenomics is still in its infancy, the applications of personalized medical nutrition therapy to human genetics are not yet widely understood. However, as science expands the body of knowledge on this topic, more practitioners will likely begin tailoring meal plans based on individuals’ unique genetic profiles. As more studies confirm the efficacy of this approach, personalized nutrition plans based on nutrigenomics will be used to treat, manage and maybe even cure diet-related diseases. For example, men with a family history of prostate cancer may be encouraged to increase their intake of tomatoes, which contain high levels of the antioxidant lycopene; studies have shown that lycopene can reduce the risk of prostate cancer, in addition to offering protection against heart disease.
2. Daily Values
Intended to help consumers plan healthier diets, the term Daily Value (DV) was coined back in 1994 to comply with the U.S. Food and Drug Administration’s (FDA) Nutrition Labeling and Education Act (USFDA 2005). The DV serves two functions. First, it quantifies the percent of each nutrient (e.g., fat, carbs or fiber) contained within the food product, based on the total daily amount that is recommended for a healthy person on a typical 2,000-calorie-per-day diet. According to current federal guidelines, a 2,000-calorie diet should provide approximately 600 calories from fat, 1,200 calories from carbs and 25 grams (g) of fiber (USFDA 2005). The DV’s second purpose is to help consumers understand descriptive terms used on food packaging, such as low sodium and low fat. Visit http://vm.cfsan.fda.gov/~dms/flg-7a.html for a complete listing of DVs that appear on food labels.
3. Dietary Reference IntakesIn the mid 1990s, the Institute of Medicine established the concept of Dietary Reference Intakes (DRIs). The DRI values expand upon or replace the older Recommended Dietary Allowances (RDAs), which set recommended daily levels of nutrients needed to prevent deficiencies. The DRIs take this one step further by recommending up to four different values for nutrients: the RDAs themselves; Estimated Average Requirements (EARs); Adequate Intakes (AIs); and Tolerable Upper Intake Levels (ULs) (U.S. Department of Agriculture [USDA] 1999). An EAR is the average daily intake level typically used for research purposes to determine the needs of half the people in a particular population, such as older adults. An AI is used by nutrition experts to make a recommendation for a nutrient when there is currently insufficient scientific support to determine an EAR. A UL is the highest average daily nutrient intake level likely to pose no risk of adverse health effects for nearly all individuals in a particular life stage or gender group (USDA 2005).
Here’s a term that is being bandied about often in research studies these days. Phytochemicals are naturally occurring bioactive substances contained in plants. These mighty chemicals perform a host of functions to protect plants from the elements, and those protective properties are passed on to humans when we ingest the plants or plant-based foods. In addition to having protective health properties, phytochemicals impart spectacular color, aroma and flavor to fruits and vegetables and other plant products.
Phytochemicals work in myriad ways. These antioxidants protect cells from damage; boost immunity levels; improve cardiovascular health; slow the aging process; improve eye health; promote cell death of malformed cells; render carcinogens harmless; and repair DNA (Duyff 2002). What an impressive list of reasons to give to your clients when recommending that they consume plenty of fruits, vegetables and whole grains each day!
There are different categories of phytochemicals, such as terpenes, phenols and thiols, and each category contains numerous subgroups of phytochemicals. Clearly, the research behind phytochemicals is in its infancy, so expect much more to come with each passing day. In the meantime, you can learn more about these essential plant compounds by checking the U.S. Department of Agriculture’s phytochemical database at www.ars.usda.gov/Services/docs.htm?docid=8875.
Here’s a term that is raising curiosity and concern in consumers. According to the USDA, irradiation is an emerging technology that uses radiant energy to reduce potentially harmful, disease-causing pathogens and insects in food (USDA 2003). Although the process destroys microscopic germs and other bugs, it does not alter the nutritive value or wholesomeness of the food itself. According to the USDA’s Food Safety Research Information Office, irradiation enhances food quality and safety (USDA 2003). And despite myths about irradiation, the food does not become radioactive in the process.
That said, many nutrition experts (myself included!) caution that irradiation should not be used in place of fundamental safe food-handling practices. Encourage your clients to wash their hands properly prior to handling food, to avoid cross- contamination, and to cook irradiated food to the appropriate internal temperature.
So, how do you know if the food you purchased has been irradiated? Food manufacturers use a radura symbol on the nutrition facts label to show that a particular food has undergone irradiation.
Look for the remaining five key nutrition terms in the May issue of Inner IDEA Body-Mind-Spirit Review.
DeBusk, R.M., et al. 2005. Nutritional genomics in practice: Where do we begin? Journal of the American Dietetic Association, 105, 589-98.
U.S. Food and Drug Administration (FDA). 2005. “Daily values” encourage healthy diet. www.fda.gov/fdac/special/foodlabel/dvs.html; retrieved Dec. 1, 2005.
U.S. Department of Agriculture (USDA). 1999. Dietary reference intakes?new dietary guidelines really are new!
Duyff, R.L. 2002. Complete Food and Nutrition Guide (2nd ed.). Hoboken, NJ: Wiley & Sons.