British Journal of Nutrition

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British Journal of Nutrition (2010), 103:1746-1754 Cambridge University Press
Copyright © The Authors 2010

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Metabolism and Metabolic Studies

Dietary supplementation with medium-chain TAG has long-lasting cognition-enhancing effects in aged dogs

Yuanlong Pana1 c1, Brian Larsona1, Joseph A. Araujoa2a3, Winnie Laua2, Christina de Riveraa2a3, Ruben Santanaa1, Asa Gorea1 and Norton W. Milgrama2a3a4

a1 Nestlé Purina Research, One Checkerboard Square, 2RS, St Louis, MO 63164, USA
a2 CanCog Technologies, Toronto, Canada
a3 Department of Pharmacology, University of Toronto, Toronto, Canada
a4 Department of Psychology, University of Toronto at Scarborough, Toronto, Canada
Article author query
pan y [PubMed]  [Google Scholar]
larson b [PubMed]  [Google Scholar]
araujo ja [PubMed]  [Google Scholar]
lau w [PubMed]  [Google Scholar]
de rivera c [PubMed]  [Google Scholar]
santana r [PubMed]  [Google Scholar]
gore a [PubMed]  [Google Scholar]
milgram nw [PubMed]  [Google Scholar]


The present study focused on the hypothesis that dietary supplementation with medium-chain TAG (MCT) will improve cognitive function in aged dogs by providing the brain with energy in the form of ketones. Aged Beagle dogs were subjected to a baseline battery of cognitive tests, which were used to establish cognitively equivalent control or treatment groups. The dogs in the treatment group were maintained on a diet supplemented with 5·5 % MCT. After an initial wash-in period, all the dogs were tested with a battery of cognitive test protocols, which assessed sequentially landmark discrimination learning ability, egocentric visuospatial function and attention. The groups were maintained on the diets for 8 months. The MCT-supplemented group showed significantly better performance in most of the test protocols than the control group. The group differences also varied as a function of task difficulty, with the more difficult task showing greater supplementation effects than the easier tasks. The group given the MCT supplement showed significantly elevated levels of β-hydroxybutyrate, a ketone body. These results indicate, first, that long-term supplementation with MCT can have cognition-improving effects, and second, that MCT supplementation increases circulating levels of ketones. The results support the hypothesis that brain function of aged dogs can be improved by MCT supplementation, which provides the brain with an alternative energy source.

(Received August 20 2009)

(Revised November 23 2009)

(Accepted January 04 2010)

(Online publication February 09 2010)

Key Words:Brain ageing; Cognitive functions; Dogs; Medium-chain TAG; Ketone bodies


c1 Corresponding author: Dr Yuanlong Pan, fax +1 314 982 5857, email


Abbreviations: BHB, β-hydroxybutyrate; CBC, complete blood count; MCT, medium-chain TAG