The 2002 study was a sixteen-week randomized, multicenter, crossover trial involving 100 participants and positive and placebo controls. The protocol included four 4-week steps: baseline measurement, treatment period 1, treatment period 2, and post-treatment follow-up.
To begin the study, Connecticut residents were invited to public meetings at the New Fairfield and Mansfield Senior Centers, and to the study web site at BlueberryStudy.com. Recruitment ended approximately 30 days after newspaper, radio and television announcements were made.
Participants were randomly assigned to receive individually quick frozen wild Maine blueberries (1 cup/day or 10 lbs/month), rice powder (500 mg/day), coenzyme Q10 (30-mg/day) or an antioxidant mixture containing mixed tocopherols (500 IU total/day) plus lipoic acid (25 mg/day). To equalize blueberry and control group expectations, participants were sent email messages citing evidence of health benefits from vitamin E, lipoic acid and our other control supplements. Participants conducted weekly measurements of single-choice decision speed, provided estimates of their aches and pains, energy-level, mood, sharpness, peacefulness, sleep quality, and overall health, and made three separate decision-speed predictions each week to allow expectations and motivation to be measured. Errors and decision speed were recorded before and also after predictions during each measurement session, to provide additional measures of participant expectations and motivation.
Ninety seven participants completed the protocol. Among those receiving wild blueberries, significant improvement occurred in decision speed (t-test p = 0.025) and self-reported aches and pains (p = 0.017), energy level (p = 0.002), sharpness (p = 0.001), sleep quality (p = 0.017), mood (p = 0.010), peacefulness (p = 0.005) and overall health (p = 0.001). Blueberry group response times improved by 4.2%, decreasing from 39.96 to 38.27 centiseconds, more than twice the improvement in the control group. Actual decision speeds were not displayed during the study so speed improvement could not influence self-reported health. Adjustments to balance decision speed predictions, error rates and within-measurement decision-speed improvement (our measures of expectation and motivation) in blueberry and control groups did not significantly change these results. Two blueberry recipients reported hearing improvement that was confirmed by an independent observer, and three reported their prostate serum antigen level declined. Significant changes were not observed in any control group.
Results of this study indicate that blueberries consumed regularly for four weeks can improve a number of health indicators related to aging, including decision speed, aches and pains, and energy level.
We greatly appreciate assistance provided by Bill Holme, Phil Fichandler, Kathy Hull, Marilyn Gerling and many others at the New Fairfield and Mansfield Senior Centers.
Citations: Joseph et al. (1999) J Neurosci. 19(18):
8114-21. Pappas et al. (2001) 30th Ann. Mtg. Amer. Aging Assoc.,
Abstr. 106.
Key words:
blueberries health reaction time aging
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