Jan 29, 2015Up, Up, and Away
Research shows that certain “superfoods” can help improve athletic performance. The University of Texas is using them to reach new heights.
By Amy Culp
Amy Culp, RD, CSSD, LD, is an Assistant Athletics Director and the Sports Dietitian at the University of Texas. She has been coaching athletes on all aspects of fueling for optimal performance and health for more than a decade and can be reached at: [email protected].
The author would like to thank her graduate student assistant, Katie McInnis, RD, for her research assistance on this article.
Clark Kent may not look much different from anyone else, but beneath the surface he has super powers waiting to be unleashed. So it is with certain foods. They don’t necessarily stand out, but these “superfoods” offer dietary and healing potential that, given the right circumstances, can help an athlete step up and save the day. Basically, superfoods are whole foods such as cherries and flaxseed that serve as rich sources of various vitamins, minerals, antioxidants, essential fatty and amino acids, and other nutrients. They may be capable of directly influencing athletic performance by aiding muscle recovery after exercise, increasing oxygen consumption during physical activity, or improving cardiac efficiency. As I educate athletes on how the right mix of fuel can help them perform better, I make sure the student-athletes at the University of Texas know all about these superfoods and how to incorporate them into their fueling plans. I also teach them how superfoods have benefits that extend well beyond the athletic realm, positively affecting blood pressure, heart health, and cognitive function. I prefer to build fueling plans around whole foods instead of supplements because studies show a diet of nutrient-rich foods working together synergistically produces more health benefits than supplements containing isolated nutrients. Plus, whole foods are more delicious and fun to eat!
To ensure I’m providing the best guidance, I keep up with the latest scientific research on whole foods and whole-food components that may offer performance or health benefits. When searching for information, I look for double-blind, placebo-controlled studies conducted on a population comparable to our student-athletes. I make sure claims made about an item are properly supported and that there are no major side effects or other safety issues. I also run through the following questions to determine if something could benefit our student-athletes. Does the food or food component: – Speed recovery? – Decrease fatigue? – Assist with muscle growth/repair? – Decrease muscle soreness/inflammation? – Support the immune system? – Support overall health?
When I feel comfortable with an item’s efficacy and safety and believe it would be a great addition to our program, I start looking for ways to introduce it. I may incorporate it into menus I develop at our training table or into our pre- or post-competition meals, or, if NCAA compliant, I may offer it at our fueling stations. The following are some of the superfoods that I have incorporated into the performance nutrition plans of our student-athletes.
Cherries are rich in phytochemicals, which have potent anti-inflammatory and antioxidant properties. Research has shown that this superfood can reduce soreness associated with strenuous exercise, while lessening the time needed to recover isometric muscle strength. In addition, cherries have been linked to improvements in the duration and quality of sleep, which may indirectly improve performance. Strenuous exercise results in increased inflammation and oxidative stress in the muscles, which are contributing factors to fatigue and soreness. Cherries have been shown to reduce inflammation on a scale comparable to that of NSAIDs, such as aspirin and ibuprofen. A category of phytochemicals in cherries known as anthocyanins are the agents thought to provide the fruit’s antioxidant and anti-inflammatory effects. A number of studies have demonstrated how cherry consumption can reduce pro-inflammatory agents and decrease reactive oxygen species, molecules which, at high levels, can cause significant damage to cell structures. In one of these studies, a 25 percent reduction in serum inflammatory markers–proteins released into the bloodstream from sites of inflammation–was demonstrated after participants consumed 280 grams of sweet cherries per day for 28 days. In another study, marathon runners were given 480 milliliters of tart cherry juice per day for a six-day period leading up to a race. Researchers found decreased exercise-induced inflammation in the runners who consumed cherry juice–evidenced by decreased levels of interleukin-6 and C-reactive protein, which are released into the bloodstream in response to inflammation. In addition, their oxidative stress levels were lowered and their total antioxidant status increased by approximately 10 percent. The ability of cherries to accelerate the recovery of isometric muscle strength following strenuous exercise has been demonstrated in several studies. In one trial, participants consumed either cherry juice or a placebo before and after eccentric exercise. Post-exercise testing showed that those who consumed the cherry juice averaged a four percent decrease in muscle strength compared with a 22 percent loss for those who received a placebo.
Research has shown sleep can have a big effect on athletic performance, so identifying foods that enhance sleep is valuable. In one of the first studies to use objective measurements of sleep quality, researchers demonstrated that the consumption of 30 milliliters of tart cherry juice twice a day produced exogenous melatonin, a hormone that is thought to boost sleep. There is no definitive evidence on when it’s best to incorporate cherries into an athlete’s training program, but at Texas, we generally use them as part of a recovery regimen after workouts, competitions, injuries, and surgeries. We have our athletes consume tart cherry juice, as well as dried, frozen, and fresh tart and sweet cherries. For example, frozen whole cherries make a great addition to breakfast or recovery smoothies. When adding cherries to a fueling plan, we consider the caloric and carbohydrate amounts in the juice and calculate serving sizes accordingly.
Due to their high concentration of nitrates, which the body converts into nitric oxide, beets are a potent vasodilator that helps the body use oxygen more effectively. Research has shown that nitrates in beets can lower blood pressure, improve oxygen consumption during exercise, and elevate performance endurance. In a 2010 study, researchers provided eight subjects with beet juice (0.5 L/day; 5.2 mmol of NO3/day) and found that the systolic and diastolic blood pressures of the subjects were reduced by four percent compared to the placebo group, which experienced no significant changes. Oxygen consumption (VO2) levels measured two and a half hours after exercise also decreased by four percent, with the placebo group experiencing no change. Since the effects remained consistent on days five and 15, the conclusion was drawn that as long as supplementation is continued, the vasodilation effects of beet juice can continue for up to two weeks after exercise. Similar results regarding the effects of beet juice on oxygen consumption during walking, moderate running, and intense running were seen in a 2011 study. The placebo for the study was whole beet juice with the nitrates selectively removed, so any effects of the juice could be attributed to the nitrate concentration in the beets, not their other phytochemical or nutritive properties. The average oxygen intake across the three activities increased in both the placebo and nitrates study groups but was 12 percent greater in the latter. Absolute VO2–which does not take body weight into consideration–was seven percent lower in the nitrates group than in the placebo group during the final 30 seconds of moderate running, and a four percent greater reduction in the amplitude of the pulmonary VO2 response was seen in the nitrates group. Beet juice in moderate quantities is well-tolerated and can be taken in one sitting. Whole beets can be consumed in a variety of ways, such as being roasted as a side dish, sliced on top of salad, and incorporated into a host of different recipes. However, the dosage of nitrates in whole beets is lower than in beet juice supplements, so equivalent servings should be calculated. We use a beet juice powder that is mixed with water prior to workouts and competitions. Though plenty of scientific evidence supports eating beets for improved health, if over-consumed, the high levels of nitrates in beet juice may produce symptoms of hypotension. Athletes with cardiovascular disorders may wish to consult their physician before consuming the juice to ensure safe use. Also, GI tolerance is variable, so athletes should be tested prior to consumption to determine their tolerance.
Berries such as blueberries, raspberries, and blackberries contain antioxidants like vitamin C and are a good source of folate, selenium, and carotenoids. They are also high in anthocyanins, which are potent inhibitors of lipid peroxidation and cell damage with very high antioxidant potential. Anthocyanins have been shown to improve cognitive function and preserve brain and eye health and DNA integrity. Berries have also demonstrated cardioprotective capabilities, and they can decrease inflammation and reduce oxidative damage. In addition, they’ve been shown to facilitate strength recovery following exercise. These health benefits have been confirmed in a number of studies, including one that produced results that have important implications for athletes. In this study, ingesting a blue-berry smoothie prior to strength training was shown to reduce exercise-induced muscle damage. There was also a faster rate of decrease in oxidative stress–statistically significant even 36 hours post-exercise–and a small increase in plasma antioxidant capacity. A 2007 study demonstrated the antioxidant effects of berries and their cytotoxic effects on H. pylori bacteria. Another epidemiological study showed an association between berry consumption and inhibited inflammatory markers, which was eventually confirmed by data from the National Health and Nutrition Examination Survey program. At least one study showed that the benefits increased when berry consumption reached two or more times per week, so this is a good initial intake recommendation. Also, consuming different combinations of whole berries has proven more effective than eating a single type of berry. Berries can be added to a variety of foods, like salads, entrees, desserts, oatmeal, yogurts, breakfast cereals, and smoothies. They are also great on their own! Berry extracts and juices deliver a more concentrated dose of anthocyanins than whole berries, so they may provide the most benefit. At Texas, we like to use berries as part of the post-workout smoothies to aid student-athletes in their post-workout recovery. To make these, we generally blend a berry mix with other fruit and fruit juices and an NCAA-compliant protein powder. We also serve a variety of fresh berries at our student-athlete training table and stock fruit cups at our fueling stations.
Whole flaxseed provides a good source of protein, calcium, magnesium, and phosphorus, and it contains three compounds that carry cardioprotective qualities: omega-3 fatty acids, fiber, and lignans. These compounds also have antioxidant, anti-inflammatory, and hormonal effects. The omega-3 fatty acids in flaxseed are helpful for athletes because not only do they help with inflammation, they boost immunity, produce anti-arrhythmic effects, improve cardiac pumping, reduce muscle oxygen consumption, and increase fat oxidation. One study of omega-3s and exercise demonstrated significantly lower heart rates at increasing workloads and significantly lower oxygen consumption. With flaxseed supplementation, greater health benefits are gained when consuming freshly ground flaxseed instead of whole flaxseed or flaxseed oil. Whole flaxseeds can go through the digestive system intact, without many of the health-promoting properties being released, and flaxseed oil is lacking in lignans, soluble and insoluble fiber, and protein. It is recommended to purchase whole flaxseeds and grind them in a coffee grinder prior to use, and any unused ground flaxseed should be refrigerated in an airtight container to maintain freshness. Here at Texas, ground flaxseed is added to granolas, cereals, breads, and many recipes, or sprinkled on top of yogurt, cottage cheese, salads, pastas, or other dishes. When mixed with water, ground flaxseed can also substitute for egg whites, and it’s a great vegan binding agent for baking.
While most proteins can provide some benefit to either muscle hypertrophy or recovery, whey protein goes a step further. Whey provides a rich source of essential amino acids, including branched-chain amino acids such as leucine, which research has shown plays a critical role in stimulating muscle protein synthesis. It is also digested at a faster rate than other protein sources so blood leucine levels peak soon after ingestion, making it particularly useful for building muscle mass and reducing recovery time following a workout. Several studies have demonstrated that whey protein isolate can enhance muscle recovery following eccentric exercise. While most evidence suggests it’s more beneficial if taken post-exercise instead of pre-exercise, articles have been written in support of each position. Further research shows that whey is most effective when taken in combination with carbohydrate, so for maximal benefit and to meet individualized recovery needs, it should be consumed with the appropriate mix of carbohydrate within 30 minutes following intense activity. Dairy is rich in whey and a great way to introduce the protein into a nutrition plan. Lactose-intolerant athletes can find whey in lactose-free dairy products and whey protein isolate, but whey protein concentrate contains lactose. If using whey protein powder in supplement form, look for third-party verification, such as Informed Choice or NSF, to help ensure the safety of the product. Research shows that ingesting approximately two grams of leucine daily–which can be obtained from about 20 grams of whey protein–is effective in assisting with muscle protein synthesis. It’s important to teach student-athletes that normal-sized “doses” are better utilized than very large doses, and that more than 30 grams a day cannot be effectively utilized by the body. Many of the foods we serve at our student-athlete training table and fueling stations contain whey, such as dairy products. We also utilize NCAA-compliant whey protein powders in recovery shakes and ready-to-drink recovery beverages. In addition, we provide a tart cherry juice drink and a number of sports nutrition bars that contain whey. However, I also teach student-athletes to consume a variety of protein sources at regular intervals throughout the day, which ensures they get a range of amino acids that they can absorb with maximum efficiency.
READY TO EAT
For many student-athletes, trying a new food isn’t their idea of a good time, so simply adding beets or flaxseed to their salad bar choices may not do the trick. The key to getting them on board is education. I’ve found that letting them taste a food while at the same time explaining its importance can take away some of the “risk” associated with trying new foods. It’s always very exciting when I see athletes enjoying one of the superfoods. I know the dietary choices they make now will not only affect their athletic career, it may also have a big impact on their health down the road.
Teaming up with our executive chef and a culinary student, we have come up with two recipes to work some of the superfoods into athletes’ diets.
Power Pancakes Makes 8-10 pancakes
2 cups buckwheat flour 2 tsp baking powder 2 scoops whey protein 2 Tbsp flaxseed 2 1/2 cups almond milk 1/4 cup applesauce 2 tsp vanilla extract
Beet cherry syrup:
1 cooked beet 1/4 cup agave 1/4 cup water 12 pitted cherries
1. For the pancake batter, combine all the ingredients listed into a medium-sized bowl and mix until fully incorporated. Let the batter rest while you prepare the syrup. 2. For the syrup, grate the beet into a small sauce pan, then add the agave and water. Simmer until the consistency of syrup, then add the cherries and cook for 10 minutes. Strain into a serving container and set aside. 3. Ladle 1/4 cup of batter per pancake into a hot, non-stick pan and cook on medium heat. Flip when edges look cooked and bubbles appear on surface. Remove when bottom is cooked.
4. Cover pancakes with syrup.
1/2 cup frozen strawberries 1/2 cup frozen blueberries 1 Tbsp flaxseed 8 ounces tart cherry juice 1 scoop whey protein 4 ounces beet juice or cubed beets
Combine all ingredients into a food processor or blender and blend on medium until fully incorporated.