Abstract
Dogs demonstrate an age-related cognitive decline, which may be related to a decrease in the concentration of omega-3 polyunsaturated fatty acids (n-3 PUFA) in the brain. Medium chain triglycerides (MCT) increase fatty acid oxidation, and it has been suggested that this may raise brain n-3 PUFA levels by increasing mobilization of n-3 PUFA from adipose tissue to the brain. The goal of the present study was to determine whether dietary MCT would raise n-3 PUFA concentrations in the brains of aged dogs. Eight Beagle dogs were randomized to a control diet (n = 4) or an MCT (AC-1203) enriched diet (n = 4) for 2 months. The animals were then euthanized and the parietal cortex was removed for phospholipid, cholesterol and fatty acid determinations by gas-chromatography. Dietary enrichment with MCT (AC-1203) resulted in a significant increase in brain phospholipid and total lipid concentrations (P < 0.05). In particular, n-3 PUFA within the phospholipid, unesterified fatty acid, and total lipid fractions were elevated in AC-1203 treated subjects as compared to controls (P < 0.05). Brain cholesterol concentrations did not differ significantly between the groups (P > 0.05). These results indicate that dietary enrichment with MCT, raises n-3 PUFA concentrations in the parietal cortex of aged dogs.
This is a preview of subscription content, access via your institution.

Abbreviations
- MCT:
-
Medium chain triglycerides
- PUFA:
-
Polyunsaturated fatty acids
References
Freemantle E, Vandal M, Tremblay-Mercier J, Tremblay S, Blachere JC, Begin ME et al (2006) Omega-3 fatty acids, energy substrates, and brain function during aging. Prostaglandins Leukot Essent Fatty Acids 75:213–220. doi:10.1016/j.plefa.2006.05.011
Reger MA, Henderson ST, Hale C, Cholerton B, Baker LD, Watson GS et al (2004) Effects of beta-hydroxybutyrate on cognition in memory-impaired adults. Neurobiol Aging 25:311–314. doi:10.1016/S0197-4580(03)00087-3
Boutet I, Milgram NW, Freedman M (2007) Cognitive decline and human (Homo sapiens) aging: an investigation using a comparative neuropsychological approach. J Comp Psychol 121:270–281. doi:10.1037/0735-7036.121.3.270
Studzinski CM, Araujo JA, Milgram NW (2005) The canine model of human cognitive aging and dementia: pharmacological validity of the model for assessment of human cognitive-enhancing drugs. Prog Neuropsychopharmacol Biol Psychiatry 29:489–498. doi:10.1016/j.pnpbp.2004.12.014
Bach AC, Babayan VK (1982) Medium-chain triglycerides: an update. Am J Clin Nutr 36:950–962
Kawakita E, Hashimoto M, Shido O (2006) Docosahexaenoic acid promotes neurogenesis in vitro and in vivo. Neuroscience 139:991–997. doi:10.1016/j.neuroscience.2006.01.021
Beltz BS, Tlusty MF, Benton JL, Sandeman DC (2007) Omega-3 fatty acids upregulate adult neurogenesis. Neurosci Lett 415:154–158. doi:10.1016/j.neulet.2007.01.010
Bazan NG (2007) Omega-3 fatty acids, pro-inflammatory signaling and neuroprotection. Curr Opin Clin Nutr Metab Care 10:136–141. doi:10.1097/MCO.0b013e32802b7030
van Gelder BM, Tijhuis M, Kalmijn S, Kromhout D (2007) Fish consumption, n-3 fatty acids, and subsequent 5-y cognitive decline in elderly men: the zutphen elderly study. Am J Clin Nutr 85:1142–1147
Beydoun MA, Kaufman JS, Satia JA, Rosamond W, Folsom AR (2007) Plasma n-3 fatty acids and the risk of cognitive decline in older adults: the Atherosclerosis risk in communities study. Am J Clin Nutr 85:1103–1111
Folch J, Lees M, Sloane Stanley GH (1957) A simple method for the isolation and purification of total lipides from animal tissues. J Biol Chem 226:497–509
Adams ML, Sullivan DM, Smith RL, Richter EF (1986) Evaluation of direct saponification method for determination of cholesterol in meats. J Assoc Off Anal Chem 69:844–846
Cunnane SC, Armstrong JK (1990) Long-chain fatty acid composition of maternal liver lipids during pregnancy and lactation in the rat: comparison of triglyceride to phospholipid. J Nutr 120:338–345
Demar JC Jr, Ma K, Chang L, Bell JM, Rapoport SI (2005) alpha-Linolenic acid does not contribute appreciably to docosahexaenoic acid within brain phospholipids of adult rats fed a diet enriched in docosahexaenoic acid. J Neurochem 94:1063–1076. doi:10.1111/j.1471-4159.2005.03258.x
Fraser DD, Whiting S, Andrew RD, Macdonald EA, Musa-Veloso K, Cunnane SC (2003) Elevated polyunsaturated fatty acids in blood serum obtained from children on the ketogenic diet. Neurology 60:1026–1029
Taha AY, Ryan MA, Cunnane SC (2005) Despite transient ketosis, the classic high-fat ketogenic diet induces marked changes in fatty acid metabolism in rats. Metabolism 54:1127–1132. doi:10.1016/j.metabol.2005.03.018
Studzinski CM, MacKay WA, Beckett TL, Henderson ST, Murphy MP, Sullivan PG et al (2008) Induction of ketosis may improve mitochondrial function and decrease steady-state amyloid-beta precursor protein (APP) levels in the aged dog. Brain Res 1226:209–217. doi:10.1016/j.brainres.2008.06.005
Barcelo-Coblijn G, Hogyes E, Kitajka K, Puskas LG, Zvara A, Hackler L Jr et al (2003) Modification by docosahexaenoic acid of age-induced alterations in gene expression and molecular composition of rat brain phospholipids. Proc Natl Acad Sci USA 100:11321–11326. doi:10.1073/pnas.1734008100
Sun GY, Samorajski T (1973) Age differences in the acyl group composition of phosphoglycerides in myelin isolated from the brain of the rhesus monkey. Biochim Biophys Acta 316:19–27
Prasad MR, Lovell MA, Yatin M, Dhillon H, Markesbery WR (1998) Regional membrane phospholipid alterations in Alzheimer’s disease. Neurochem Res 23:81–88. doi:10.1023/A:1022457605436
Soderberg M, Edlund C, Kristensson K, Dallner G (1991) Fatty acid composition of brain phospholipids in aging and in Alzheimer’s disease. Lipids 26:421–425. doi:10.1007/BF02536067
Greiner RS, Moriguchi T, Hutton A, Slotnick BM, Salem N Jr (1999) Rats with low levels of brain docosahexaenoic acid show impaired performance in olfactory-based and spatial learning tasks. Lipids 34:S239–S243. doi:10.1007/BF02562305
Moriguchi T, Greiner RS, Salem N Jr (2000) Behavioral deficits associated with dietary induction of decreased brain docosahexaenoic acid concentration. J Neurochem 75:2563–2573. doi:10.1046/j.1471-4159.2000.0752563.x
Dullemeijer C, Durga J, Brouwer IA, van de Rest O, Kok FJ, Brummer RJ et al (2007) n 3 fatty acid proportions in plasma and cognitive performance in older adults. Am J Clin Nutr 86:1479–1485
Morris MC, Evans DA, Tangney CC, Bienias JL, Wilson RS (2005) Fish consumption and cognitive decline with age in a large community study. Arch Neurol 62:1849–1853. doi:10.1001/archneur.62.12.noc50161
Wu PY, Edmond J, Auestad N, Rambathla S, Benson J, Picone T (1986) Medium-chain triglycerides in infant formulas and their relation to plasma ketone body concentrations. Pediatr Res 20:338–341. doi:10.1203/00006450-198604000-00016
Edmond J (1974) Ketone bodies as precursors of sterols and fatty acids in the developing rat. J Biol Chem 249:72–80
Webber RJ, Edmond J (1979) The in vivo utilization of acetoacetate, d-(−)-3-hydroxybutyrate, and glucose for lipid synthesis in brain in the 18-day-old rat. Evidence for an acetyl-CoA bypass for sterol synthesis. J Biol Chem 254:3912–3920
Farasat S, Kossoff EH, Pillas DJ, Rubenstein JE, Vining EP, Freeman JM (2006) The importance of parental expectations of cognitive improvement for their children with epilepsy prior to starting the ketogenic diet. Epilepsy Behav 8:406–410. doi:10.1016/j.yebeh.2005.12.002
Pulsifer MB, Gordon JM, Brandt J, Vining EP, Freeman JM (2001) Effects of ketogenic diet on development and behavior: preliminary report of a prospective study. Dev Med Child Neurol 43:301–306. doi:10.1017/S0012162201000573
Acknowledgments
We would like to thank Dr. Christa M. Studzinski for her assistance and Dr. David W.L. Ma for his support and expert advice. Financial support for this study was provided by the Natural Sciences and Engineering Research Council and Accera Inc. A.Y.T is a recipient of the Canadian Institutes of Health Research Doctoral Research Award (Fredrick Banting and Charles Best Canada Graduate Scholarships). The authors declare no conflict of interest.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Taha, A.Y., Henderson, S.T. & Burnham, W.M. Dietary Enrichment with Medium Chain Triglycerides (AC-1203) Elevates Polyunsaturated Fatty Acids in the Parietal Cortex of Aged Dogs: Implications for Treating Age-Related Cognitive Decline. Neurochem Res 34, 1619–1625 (2009). https://doi.org/10.1007/s11064-009-9952-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11064-009-9952-5