Mangoes and Exercise Inflammation

Overview

Vigorous exercise bouts result in significant inflammation and muscle soreness. Our research group has published several papers showing that ingestion of various types of fruits enhances inflammation resolution after exercise. Mangoes have a unique nutrient profile (carotenoids, polyphenols, sugars, vitamins) that we hypothesize will mitigate post-exercise inflammation and muscle soreness. This study will examine the effect of 2 cups/day frozen mango ingestion (2 weeks, 330 g/day) in moderating exercise-induced (2.25 h cycling) inflammation and muscle soreness in a randomized crossover trial. Participants will include 20 male and female young adult cyclists (ages 18-60 years) who are capable of cycling 2.25 h in the laboratory on trainers. In random order, the cyclists will supplement their diets with 2 cups/day mangoes with 1 cup water or 1 cup water alone for two weeks, followed by the 2.25-h exercise challenge. Blood and urine samples will be collected pre- and post-2 weeks supplementation. Additional blood samples will be collected immediately post-exercise, and then 1.5-h, 3-h, and 24-h post-exercise. Urine samples will be analyzed for mango-related metabolites to confirm compliance to the supplementation regimen and to establish statistical relationships with inflammation-related outcomes. The blood samples will be analyzed for novel, cutting-edge outcomes related to inflammation including 70 oxylipins, inflammasome activation, and pro-inflammatory cytokines that we have previously shown are sensitive to exercise and nutrition-based interventions. If the data support our hypothesis, mango ingestion will be viewed as a nutritional strategy to counter exercise-induced inflammation by fitness enthusiasts and athletes who exercise vigorously on a regular basis.

Subjects will come to the lab for orientation/baseline testing, pre-and post-supplementation (2 weeks mango ingestion compared to water alone) blood and urine sample collections with 3-d food records, two 2.25 h cycling sessions, and additional lab visits to provide 1-day 7:00 am recovery blood samples) (thus 7 total lab visits). The total amount of time subjects will be asked to volunteer for this study is about 20 hours at the Human Performance Laboratory (over a 6-week period). A. Orientation/Baseline Testing (Visit #1): After voluntarily signed IRB-approved consent forms, study participants will be tested for maximal aerobic capacity (VO2max) during a graded, cycling test with continuous metabolic monitoring with the Cosmed CPET metabolic device (Cosmed, Rome, Italy). Body composition will be measured with the seca BIA and Bod Pod body composition analyzer (Life Measurement, Concord, CA). Demographic and training histories will be acquired with questionnaires. A symptom inventory will be conducted using a 2-week retrospective questionnaire. 3-day food records and 24-h urine collection kits will be supplied with thorough instructions. B. Pre-Supplementation Lab Visit #2 and 2-Week Mango Supplementation Protocol: Two weeks prior to the first running session, subjects will report to the Human Performance Laboratory at approximately 7:00-8:00 am. A blood sample will be collected in an overnight fasted state to coincide with the same time of the day for the post-supplementation blood draw. Urine samples and 3-d food records will be turned in after review. A 2-week supply of frozen mangoes in date/time labeled freezer bags (1 cup or 165-gram amounts) will be given to the participants randomized to the mango trial, with instructions to consume 1 cup each with the first and last meals of the day (for two weeks). Participants will be given the frozen mangoes in cold containers and then instructed to store these in their home freezers. Subjects will be instructed to consume the mangoes in a variety of ways including in smoothies, with yogurt, or as is. Bottled water will be supplied to both groups with instructions to consume 1 cup each with the first and last meals of the day. Subjects will be instructed to store and then bring the freezer bags to their next lab visit. To assess potential adverse effects, a symptom inventory will be conducted using a 2-week retrospective questionnaire (before and after the 2-week supplementation period). Rationale for the mango dosing regimen: The amounts of carotenoids and polyphenols in 2 cups/d mangoes are similar to amounts we have used successfully in prior studies to mitigate post-exercise inflammation and muscle soreness. We recommend a 2-week supplementation period because our experience is that this is a sufficient time period for bioactive effects to emerge as the gut microbiome and tissues adapt. We recommend using water as the control condition to allow the full array of nutrient components found in mangoes (carbohydrate, carotenoids, polyphenols, vitamins C and A) to be tested when compared to just water. C. 2.25 h Cycling Session (Lab Visit #3): During the 3-day period prior to the 2.25-h cycling session, subjects will taper exercise training and ingest a moderate-carbohydrate diet using a food list restricting high fat foods, visible fats, and polyphenols. Subjects will record all food and beverage intake during the 3-day period, with macro- and micro-nutrient intake assessed using the Food Processor dietary analysis software system (ESHA Research, Salem, OR). We will also measure total flavonoid intake (and 6 flavonoid subgroups) using the USDA flavonoid database that we have incorporated into the Food Processor database. Study participants will report to the Human Performance Lab in an overnight fasted state and provide a blood sample, ingest 1 cup mango with 1 cup of water, or 1 cup of water alone, and then cycle 2.25 h at high intensity (70% VO2max) while ingesting water alone (3 ml/kg every 15 minutes). Blood samples will be collected at 0 h, 1.5 h, 3.0 h, and 24 h post-exercise. Testing protocol during the lab sessions with the 2.25-h cycling session: 1. 7:00 am: Provide blood sample, delayed onset of muscle soreness (DOMS) rating (1-10 scale), profile of mood states ratings (POMS), and turn in the 24-h urine sample and 3-day food record. Fill in the 2-week retrospective symptom log. 2. 7:10 am: Ingest 1 cup mangoes with 1 cup water or 1 cup water alone. 3. 7:30 am: Start the 2.25 h cycling session. Subjects will cycle on trainers in the lab at 70% VO2max (\~race pace) for 2.25 hours. Oxygen consumption, carbon dioxide production, respiratory exchange ratio, and ventilation will be measured using the Cosmed Quark CPET metabolic cart after 15 minutes and then every 30 minutes. Subjects will consume 3 ml/kg water every 15 min. No other beverage or food containing energy or nutrients will be allowed during the 2.25-h cycling sessions. 4. \~10:00 am to 1:00 pm: Blood samples will be taken via venipuncture immediately after completing the cycling session, and then 1.5-h and 3.0-h post-exercise. Subjects will be allowed to shower and change clothes. The DOMS and POMS questionnaires will be administered each time blood samples are collected. Subjects will ingest no food or beverage other than water (7 ml/kg during the 1.5 h post-exercise period). After the 1.5 h post-exercise blood draw, subjects in the mango group will consume 1 cup mangoes with 1 cup of water. Subjects in the water group will consume a calorie-matched volume of Gatorade (0.45 liters). Another blood sample will be collected 3-h post-exercise. Afterwards, subjects will be allowed to leave the lab with instructions to adhere to the food list requirements, and to keep exercise training moderate. 5. 7:00 am, next morning: 24-h blood sample and DOMS and POMS ratings (Lab visit #4). D. Washout/Crossover/Repeat Subjects will engage in a 2-week washout period without the mango supplements, crossover to the opposite treatment arm, and then repeat all procedures (Lab visits #5,6,7).