Avocado Consumption Increases Macular Pigment Density in Older Adults: A Randomized, Controlled Trial
Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA
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Nutrients 2017, 9(9), 919; https://doi.org/10.3390/nu9090919
Received: 9 May 2017 / Revised: 17 August 2017 / Accepted: 21 August 2017 / Published: 23 August 2017
Lutein is selectively incorporated into the macula and brain. Lutein levels in the macula (macular pigment; MP) and the brain are related to better cognition. MP density (MPD) is a biomarker of brain lutein. Avocados are a bioavailable source of lutein. This study tests the effects of the intake of avocado on cognition. This was a six-month, randomized, controlled trial. Healthy subjects consumed one avocado (n = 20, 0.5 mg/day lutein, AV) vs. one potato or one cup of chickpeas (n = 20, 0 mg/day lutein, C). Serum lutein, MPD, and cognition were assessed at zero, three, and six months. Primary analyses were conducted according to intent-to-treat principles, with repeated-measures analysis. At six months, AV increased serum lutein levels by 25% from baseline (p = 0.001). C increased by 15% (p = 0.030). At six months, there was an increase in MPD from baseline in AV (p = 0.001) and no increase in C. For both groups, there was an improvement in memory and spatial working memory (p = 0.001; p = 0.032, respectively). For AV only there was improved sustained attention (p = 0.033), and the MPD increase was related to improved working memory and efficiency in approaching a problem (p = 0.036). Dietary recommendations including avocados may be an effective strategy for cognitive health.
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Keywords:
lutein; avocado; macular pigment; bioavailability; cognition; older adult
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MDPI and ACS Style
Scott, T.M.; Rasmussen, H.M.; Chen, O.; Johnson, E.J. Avocado Consumption Increases Macular Pigment Density in Older Adults: A Randomized, Controlled Trial. Nutrients 2017, 9, 919. https://doi.org/10.3390/nu9090919
AMA Style
Scott TM, Rasmussen HM, Chen O, Johnson EJ. Avocado Consumption Increases Macular Pigment Density in Older Adults: A Randomized, Controlled Trial. Nutrients. 2017; 9(9):919. https://doi.org/10.3390/nu9090919
Chicago/Turabian StyleScott, Tammy M., Helen M. Rasmussen, Oliver Chen, and Elizabeth J. Johnson 2017. "Avocado Consumption Increases Macular Pigment Density in Older Adults: A Randomized, Controlled Trial" Nutrients 9, no. 9: 919. https://doi.org/10.3390/nu9090919
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