David Nieman and Mary Pat Meaney (2016). Ingesting 25 g/day Milled Chia Seeds for Two Weeks Does Not Affect Exercise Performance. The FASEB Journal, 30(1).
Appalachian State University, North Carolina Research Campus, Kannapolis, NC
Milled chia seed contains 4.4 grams of α-linolenic acid (ALA; 18:3n-3) per 25 gram serving; previous research in our laboratory indicates that plasma ALA increases significantly within 2 h after ingestion, and chronically within the first week of regular intake. Human studies suggest that 60–85% of ALA is utilized by tissues for energy, higher than the 50% conversion shown for other plant oils. The purpose of this project was to study the effects of increased alpha linolenic acid (ALA) intake through two-weeks of supplementation with 25 gm/day milled chia seed on exercise performance in endurance athletes. This study utilized a randomized, crossover research design, with 18 trained cyclists (age 34.9±1.6 years, 351±9.6 wattsmax) operating as their own controls. Participants added 25 g/day milled chia seeds to their normal diet for two weeks, or maintained their own regular diets (randomized order). After the supplementation period, participants rode on their own bicycles on CompuTrainers for 1.75 hours (3:00–4:45 pm) at 70–75% VO2max (or ~60% wattsmax) followed by a 15-km time trial, and then crossed over to the opposite condition. Blood samples were collected before and after the 2-week supplementation periods, and plasma samples were analyzed for ALA, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) using an HP 6890N gas chromatograph (Agilent Technologies, Palo Alto, CA USA) equipped with a 5975B Inert XL MSD mass spectrometer detector. A DB-23 GC column (60 m × 250 μm × 0.15 μm) from Agilent Technologies (Palo Alto, CA USA) was used to separate the methyl esters of the extracted fatty acids. After 2-weeks of supplementation with 25 gm/day milled chia seed, plasma ALA and EPA increased 46.1±11.0 (183±37.5%) and 4.56±1.74 μg/ml (36.9±14.7%), respectively, compared to −2.43±1.21 and −1.98±1.53 μg/ml, respectively, when not ingesting chia seeds (P<0.001, P=0.004), with no trial differences for plasma DHA. After the 1.75-h pre-load at 60% wattsmax, the time to complete the 15-km trial and average power output did not differ between the milled chia seed and no chia seed treatments (28.32±2.22 and 28.30±2.29 min; 251±39.7 and 247±55.2 watts, respectively, P=0.970, 0.641). In summary, despite significant increases in plasma ALA and EPA, these data do not support that 2-weeks supplementation with 25 gm/d milled chia seed has an influence on 15-km cycling time trial performance.