title: The impact of protein supplementation on cognitive performance in frail elderly.
abstract: OBJECTIVE
  Maintenance of cognitive abilities is important for elderly to stay independent. With the aging of the population, the call for modifiable factors is emerging. Dietary protein might improve cognitive performance; however, this has hardly been studied. Therefore, we studied the impact of 24-week dietary protein supplementation on cognitive performance in pre-frail and frail elderly people.
  
  
  METHODS
  Pre-frail and frail elderly subjects, according to the Fried criteria, randomly received a protein drink containing 15 g protein or a placebo drink twice a day. Cognitive performance was measured at baseline and after 24 weeks by means of a sensitive neuropsychological test battery. In addition, reaction time was assessed after both 12 and 24 weeks of intervention. Domain scores were calculated for the domains episodic memory, attention and working memory, information processing speed, and executive functioning. Analyses of covariance were used to determine differences between groups. Linear mixed models were used to determine differences in reaction time over time and per treatment.
  
  
  RESULTS
  In total, 65 subjects (79 ± 8 years) with a median Mini-Mental State Examination score of 28 (interquartile range 26-30) were included. Reaction time improved more in the protein group (68 ms) than in the placebo group (18 ms, P = 0.03). Dietary protein had no significant effect on any of the cognitive domain scores.
  
  
  CONCLUSIONS
  Protein supplementation might improve reaction time performance in pre-frail and frail elderly, but did not improve other cognitive functions.
authors.affiliation: Division of Human Nutrition, Wageningen University, P.O. Box 8129, 6700 EV, Wageningen, The Netherlands, Nikita.vanderzwaluw@wur.nl.
authors.forename: Nikita L
authors.initials: NL
authors.lastname: van der Zwaluw
authors.forename: Ondine
authors.initials: O
authors.lastname: van de Rest
authors.forename: Michael
authors.initials: M
authors.lastname: Tieland
authors.forename: Jos J
authors.initials: JJ
authors.lastname: Adam
authors.forename: Gert Jan
authors.initials: GJ
authors.lastname: Hiddink
authors.forename: Luc J C
authors.initials: LJ
authors.lastname: van Loon
authors.forename: Lisette C P G M
authors.initials: LC
authors.lastname: de Groot
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D001288:Attention; D001628:Beverages; D003071:Cognition; D060825:Cognitive Dysfunction / Q000517:prevention & control*; D004311:Double-Blind Method; D056344:Executive Function; D005260:Female; D016330:Frail Elderly; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D062407:Meals; D008568:Memory; D008894:Milk Proteins / Q000627:therapeutic use*; D009426:Netherlands; D009483:Neuropsychological Tests; D011930:Reaction Time
chemical_list: D008894:Milk Proteins
references.citation: J Nutr Health Aging. 2008 Oct;12(8):520-9
references.pmid: 18810298
references.citation: Neurochem Res. 2007 Apr-May;32(4-5):893-904
references.pmid: 17342414
references.citation: J Am Coll Nutr. 2004 Dec;23(6 Suppl):627S-630S
references.pmid: 15640517
references.citation: Am J Clin Nutr. 1985 Aug;42(2):366-70
references.pmid: 4025206
references.citation: Am J Clin Nutr. 2002 Jun;75(6):1051-6
references.pmid: 12036812
references.citation: Psychopharmacology (Berl). 2005 Jun;179(4):761-8
references.pmid: 15696331
references.citation: Am J Clin Nutr. 1997 Jan;65(1):20-9
references.pmid: 8988908
references.citation: Diabet Med. 1998 Jul;15(7):539-53
references.pmid: 9686693
references.citation: Nutr Rev. 1986 May;44 Suppl:61-70
references.pmid: 2980858
references.citation: Exp Brain Res. 2005 Aug;164(4):541-8
references.pmid: 15864565
references.citation: J Nutr Health Aging. 2011 Aug;15(8):690-4
references.pmid: 21968866
references.citation: J Gerontol B Psychol Sci Soc Sci. 2012 May;67(3):317-24
references.pmid: 21918122
references.citation: Nat Rev Cardiol. 2010 Dec;7(12):686-98
references.pmid: 20978471
references.citation: J Psychiatr Res. 1975 Nov;12(3):189-98
references.pmid: 1202204
references.citation: PLoS One. 2012;7(2):e30582
references.pmid: 22347387
references.citation: Geriatrics. 1991 Jul;46(7):54-8, 63, 66
references.pmid: 2060803
references.citation: Am J Clin Nutr. 2001 Nov;74(5):687-93
references.pmid: 11684539
references.citation: Physiol Behav. 2002 Mar;75(3):411-23
references.pmid: 11897269
references.citation: J Nutr. 2007 Jun;137(6 Suppl 1):1539S-1547S; discussion 1548S
references.pmid: 17513421
references.citation: J Intern Med. 2011 Jan;269(1):107-17
references.pmid: 20831630
references.citation: Lancet Neurol. 2007 Jan;6(1):56-62
references.pmid: 17166802
references.citation: J Clin Exp Neuropsychol. 1985 Jun;7(3):281-91
references.pmid: 3998092
references.citation: J Am Med Dir Assoc. 2012 Oct;13(8):720-6
references.pmid: 22889730
references.citation: Biogerontology. 2010 Oct;11(5):527-36
references.pmid: 20683658
references.citation: J Am Geriatr Soc. 2010 Jun;58(6):1063-71
references.pmid: 20487071
references.citation: J Gerontol A Biol Sci Med Sci. 2008 Dec;63(12):1344-9
references.pmid: 19126847
references.citation: Brain Res Bull. 1989 Apr;22(4):759-62
references.pmid: 2736402
references.citation: Int J Sport Nutr Exerc Metab. 2010 Oct;20(5):409-17
references.pmid: 20975109
references.citation: J Gen Psychol. 1985 Apr;112(2):201-10
references.pmid: 4056765
references.citation: Am J Clin Nutr. 1995 Jul;62(1):30-9
references.pmid: 7598064
references.citation: Psychopharmacology (Berl). 1991;103(2):143-9
references.pmid: 2027916
references.citation: Psychol Sci. 2003 Mar;14(2):125-30
references.pmid: 12661673
references.citation: Am J Clin Nutr. 1990 Jul;52(1):93-102
references.pmid: 2360555
references.citation: Am J Clin Nutr. 2008 May;87(5):1551S-1553S
references.pmid: 18469285
references.citation: J Alzheimers Dis. 2012;32(2):329-39
references.pmid: 22810099
references.citation: J Nutr Health Aging. 2006 Sep-Oct;10(5):386-99
references.pmid: 17066210
references.citation: Clin Nutr. 2011 Jun;30(3):303-11
references.pmid: 21239090
references.citation: J Gerontol A Biol Sci Med Sci. 2001 Mar;56(3):M146-56
references.pmid: 11253156
references.citation: J Nutr Health Aging. 2008 Jan;12(1):29-37
references.pmid: 18165842
references.citation: Eur J Nutr. 2005 Dec;44(8):465-84
references.pmid: 16331357
references.citation: Psychosom Med. 2007 Jun;69(5):483-9
references.pmid: 17556640
references.citation: Nephrology (Carlton). 2006 Feb;11(1):53-7
references.pmid: 16509933
references.citation: Neurosci Biobehav Rev. 2006;30(1):1-23
references.pmid: 15935475
references.citation: Amino Acids. 2013 Sep;45(3):419-30
references.pmid: 22677921
references.citation: J Exp Psychol Hum Percept Perform. 1982 Apr;8(2):273-96
references.pmid: 6461722
references.citation: JAMA. 1983 Jun 3;249(21):2917-21
references.pmid: 6842805
references.citation: J Nutr. 2004 Oct;134(10 Suppl):2807S-2811S; discussion 2818S-2819S
references.pmid: 15465790
references.citation: J Psychopharmacol. 2006 Jul;20(4):526-35
references.pmid: 16174675