title: Effects of exercise with or without blueberries in the diet on cardio-metabolic risk factors: an exploratory pilot study in healthy subjects.
abstract: BACKGROUND
  The improvement of insulin sensitivity by exercise has been shown to be inhibited by supplementation of vitamins acting as antioxidants.
  
  
  OBJECTIVE
  To examine effects of exercise with or without blueberries, containing natural antioxidants, on cardio-metabolic risk factors.
  
  
  METHODS
  Fifteen healthy men and 17 women, 27.6 ± 6.5 years old, were recruited, and 26 completed a randomized cross-over trial with 4 weeks of exercise by running/jogging 5 km five times/week and 4 weeks of minimal physical activity. Participants were also randomized to consume 150 g of blueberries, or not, on exercise days. Laboratory variables were measured before and after a 5 km running-race at maximal speed at the beginning and end of each period, i.e. there were four maximal running-races and eight samplings in total for each participant.
  
  
  RESULTS
  Insulin and triglyceride levels were reduced while HDL-cholesterol increased by exercise compared with minimal physical activity. Participants randomized to consume blueberries showed an increase in fasting glucose levels compared with controls, during the exercise period (blueberries: from 5.12 ± 0.49 mmol/l to 5.32 ± 0.29 mmol/l; controls: from 5.24 ± 0.27 mmol/l to 5.17 ± 0.23 mmol/l, P = 0.04 for difference in change). Triglyceride levels fell in the control group (from 1.1 ± 0.49 mmol/l to 0.93 ± 0.31 mmol/l, P = 0.02), while HDL-cholesterol increased in the blueberry group (from 1.51 ± 0.29 mmol/l to 1.64 ± 0.33 mmol/l, P = 0.006).
  
  
  CONCLUSIONS
  Ingestion of blueberries induced differential effects on cardio-metabolic risk factors, including increased levels of both fasting glucose and HDL-cholesterol. However, since it is possible that indirect effects on food intake were induced, other than consumption of blueberries, further studies are needed to confirm the findings.
authors: Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University , Linköping , Sweden.
authors: Sofia
authors: S
authors: Nyberg
authors: Edvard
authors: E
authors: Gerring
authors: Solveig
authors: S
authors: Gjellan
authors: Marta
authors: M
authors: Vergara
authors: Torbjörn
authors: T
authors: Lindström
authors: Fredrik H
authors: FH
authors: Nystrom
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000737:chemistry; D001786:Blood Glucose / Q000032:analysis; D029798:Blueberry Plants; D002318:Cardiovascular Diseases / Q000517:prevention & control*; D008076:Cholesterol, HDL / Q000378:metabolism; D008078:Cholesterol, LDL / Q000378:metabolism; D018592:Cross-Over Studies; D004032:Diet; D015444:Exercise; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007328:Insulin / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012307:Risk Factors; D014280:Triglycerides / Q000378:metabolism; D020107:Troponin T / Q000097:blood; D055815:Young Adult
chemical_list: D000975:Antioxidants; D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D007328:Insulin; D014280:Triglycerides; D020107:Troponin T
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