October 17, 2018 – Appetite For Life @ Johnson & Wales University-Charlotte
Nutrition information presented by
Steph Saullo, MS, RD, LDN
REGISTERED DIETITIAN
UNC NUTRITION RESEARCH INSTITUTE
THE NRI AND RESEARCH
The science on food and nutrients and their relationship to health is complex. Individuals are unique and there are various factors that influence health outcomes. Researchers at the UNC Nutrition Research Institute (NRI) are working very hard to understand the intricacies of diet and nutrients, and their relationship to disease prevention and progression with the goal that general dietary guidance will be replaced with personalized nutrition recommendations.
FUNCTIONAL FOODS
Quite simply, all foods are considered functional at some level because they provide carbohydrates, proteins, and/or fat – nutrients that are necessary for human physiology. The Academy of Nutrition and Dietetics position statement on functional foods says, “whole foods and fortified, enriched, or enhanced foods, have a potentially beneficial effect on health when consumed as part of a varied diet on a regular basis, at effective levels.”[1] There is no legal definition of functional foods and functional foods are not officially recognized in the U.S., so it is important to be able to evaluate any claim(s) made for a particular food.
Functional foods can be divided into categories:
- Conventional foods. These include all whole foods like fruits, vegetables, grains, and nuts.
- Modified foods. These include fortified, enriched, or enhanced foods like iodized salt, calcium-fortified juice, DHA-fortified milk and margarine, folate-enriched breads, and vitamin- and mineral-fortified cereals.
- Medical foods. These include foods specifically formulated for the dietary management of certain health conditions, like phenylketonuria (PKU), which requires low protein.
- Foods for special dietary use. These would include foods developed for infants, such as formula and hypoallergenic foods (like gluten-free or lactose-free products).1
Fortified and enriched foods are often criticized for being “processed”; however, they can provide nutrients that are often consumed in less than adequate amounts and thus contribute to decreasing the risk of deficiencies. Fortification of food is when a nutrient(s) is added to a food that wasn’t present in its natural form. Enrichment is when nutrients that are lost during processing are added back. These types of foods can also help us to eat nutrients that are not prevalent in the food supply, like docosahexaenoic acid or DHA and eicosapentaenoic acid or EPA (omega 3 fatty acids) which are predominantly found in fatty sources of fish like salmon, herring, mackerel, and tuna. Research has shown that it isn’t simply the quantity of omega-3 fatty acids one consumes, but more the ratio of omega-6 to omega-3 fatty acids that is important. Dr. Carol Cheatham and her team at the NRI have shown that how much omega-3 fatty acids one ate and the omega-6 to omega-3 ratio were related to executive function abilities in children. For more on Dr. Cheatham’s work visit www.cheathamlab.com.
Many refined grains are enriched and fortified. Grains, in their natural form, are made up of three parts – bran, germ, and endosperm. The bran contains antioxidants, B vitamins and fiber; the germ contains B vitamins, minerals, protein, and fat; and the endosperm contains mostly starchy carbohydrates, proteins, and some vitamins and minerals. Foods like oats, wild rice, and whole wheat flour are whole grains. When a grain is refined, one or more of these parts are removed. White flour and white rice are refined grains and contain only the endosperm part of the grain. These food products are traditionally enriched with B vitamins (folic acid, riboflavin, niacin, and thiamine) and iron.
In the U.S., there are some standardized foods like enriched flour that require additional fortification with folic acid. This decision was implemented in order to reduce the risk of neural tube birth defects in infants. Dr. Natalia Krupenko’s research at the NRI is focused on the role of folate (vitamin B9) in promoting health and preventing disease in humans. While folate deficiency has been connected with increased risk for neural tube defects, cardiovascular disease and cancer, recently, concerns have been raised regarding the adverse effects of over-supplementation with the vitamin. Dr. Krupenko’s goal is to determine the best ways to utilize health-protective properties of folate and prevent the possibility of its adverse effects in humans. She also works with Dr. Sergey Krupenko in studying the effects of folic acid supplementation on cancer growth in mice and they have found that limiting folic acid can help suppress the rate of cancer growth. Read more about their work at www.uncnri.org.
No food or nutrient has been found to prevent or cure any disease. Current research suggests following an overall healthful diet, rich in plants, that emphasizes fruits and vegetables, whole grains, lean protein, and unsaturated fats, and staying physically active may best support good health and lower risk for many chronic diseases such as cardiovascular disease, type 2 diabetes, and cancer.
CREATE A COLORFUL PLATE
Include an array of colors when putting meals together to help obtain a wide variety of nutrients. Each color family contains various antioxidants unique to that class. The typical color families and common foods include:
- Red/Purple, like blueberries, blackberries, eggplant, and red pepper.
- Red, like cranberries, tomatoes, and watermelon.
- Orange, like carrots, cantaloupe, and sweet potatoes.
- Orange/Yellow, like butternut squash, oranges, pineapple, and yellow grapefruit.
- Yellow/Green, like avocado, green or yellow pepper, kiwi, and spinach.
- Green, like kale, broccoli, and Swiss chard.
- White/Green, like apples (the flesh), garlic, chives, and artichokes.
Butternut squash is a type of winter squash. It is tan-yellow in color and has a bright orange flesh which is indicative of beta-carotene. Beta-carotene, an antioxidant, is one group of red, orange and yellow pigments called carotenoids. Beta-carotene along with other carotenoids provide roughly 50% of the vitamin A needed in the American diet.[2] Vitamin A is most notably known for its importance in eye health and immune function. Since butternut squash is a fat-soluble vitamin, pairing it with a source of fat like olive oil or coconut milk (as done in the bisque recipe) helps the body absorb the nutrient.
Dark leafy green vegetables tend to be considered powerhouses of nutrition. They are mostly water and therefore when cooked their nutrient content becomes more concentrated. Kale, along with other leafy greens pack in a hefty amount of nutrients like fiber, vitamins A, C, and K, and manganese. They also contain calcium, iron, and potassium. Lutein and zeaxanthin, pigments and carotenoid antioxidants, are found in many leafy greens like kale and have been found to support eye health and cognitive function. It is recommended to try and get in at least 1½ cups of dark green vegetables each week. For those taking blood thinners, it is recommended to consult with your physician or a registered dietitian, as a large amount of leafy greens may interfere with medications like warfarin due to their high vitamin K content.
There are thousands of varieties of apples resulting in various tastes, textures, and a range of culinary uses. Apples don’t contain a large quantity of any vitamin or mineral but have a small amount of many. With apple, we can look to its white, colorless flesh for various flavonoids (a type of antioxidant) including quercetin.
Cranberries get their red color from anthocyanins. (Anthocyanin pigments also contribute to the color of wild rice.) To date, there is not much research to support this antioxidant’s relationship with any disease risk reduction. Cranberries also contain tannins which prevent bacteria growth and give cranberries their likely most notable attribute—prevention of urinary tract infections in women. While other dried fruits like raisins, apricots, and prunes provide iron to the diet, dried cranberries do not.
A diet that includes many fruits and vegetables is important for overall health, and intake has been linked to protecting against various chronic diseases like cancer and heart disease. While research looks at various fruits, vegetables, and some of their components like individual phytochemicals, there is not one fruit or vegetable that can provide an adequate amount of all the nutrients required for health so it is important to include a variety of produce in your diet each day. Most of the American population have intakes below recommended levels for fruits and vegetables (75 percent and 87 percent, respectively) so we could all benefit from increasing our consumption of fruits and vegetables.
[1] Hasler CM, Brown AC. Position of the American Dietetic Association: functional foods. J Am Diet Assoc. 2009;109:735-46.
[2] National Institutes of Health. National Library of Medicine. Beta-carotene. Available at https://www.nlm.nih.gov/medlineplus/druginfo/natural/999.html.
Posted: October 17, 2018
