- Sven J van der Lee et al. Circulating metabolites and general cognitive ability and dementia: Evidence from 11 cohort studies. Alzheimers Dement. 2018 Jun;14(6):707-722.
Circulating metabolites were consistently associated with cognition, dementia, and lifestyle factors, opening new avenues for prevention of cognitive decline and dementia
- Juho Tynkkynen et al. Association of branched-chain amino acids and other circulating metabolites with risk of incident dementia and Alzheimer’s disease: A prospective study in eight cohorts. Alzheimers Dement. 2018 Jun;14(6):723-733.
In conclusion, our large prospective study identified lower BCAA levels to be associated with an increased risk of incident dementia, independent of other conventional risk factors. If corroborated in other studies, these biomarkers may help in early identification of persons at risk of dementia and initiation of preventive and treatment measures.
- Carmen Peña-Bautista et al. Early neurotransmission impairment in non-invasive Alzheimer Disease detection Sci Rep. 2020 Oct 2;10(1):16396.
In conclusion, some amino acids and derivatives involved in neurotransmission impairment could be potential biomarkers in early and non-invasive AD detection.
- Charleen D Adams. Circulating Glutamine and Alzheimer’s Disease: A Mendelian Randomization Study Affiliations expand. Clin Interv Aging. 2020 Feb 10;15:185-193.
Modifications to exogenous glutamine may be worth exploring in future efforts to prevent and/or treat Alzheimer’s disease.
- Gaetano Corso et al. Serum Amino Acid Profiles in Normal Subjects and in patients with or at Risk of Alzheimer Dementia. Dement Geriatr Cogn Dis Extra. 2017 May 4;7(1):143-159.
Amino acids contribute to a characteristic metabotype during the progression of AD along the continuum from health to frank dementia, and their monitoring in elderly individuals might help to detect at-risk subjects.
- Roberto Aquilani et al. Mini Nutritional Assessment May Identify a Dual Pattern of Perturbed Plasma Amino Acids in Patients with Alzheimer’s Disease: A Window to Metabolic and Physical Rehabilitation? Nutrients. 2020 Jun 21;12(6):1845
Stratifying patients with AD for MNA may identify a dual pattern of altered AAs, one due to AD per se and the other linked to nutritional state. Significant correlations were observed between several AAs and cognitive tests.
- Fekkes D. Abnormal amino acid metabolism in patients with early-stage Alzheimer dementia. J Neural Transm. 1998;105(2-3):287-94.
The reported findings suggest that abnormal amino acid metabolism is present in the early stages of AD. We hypothesize that this abnormality could play a role in the pathogenesis of behavioural changes occurring in later stages of AD.
- Ravaglia G. Plasma amino acid concentrations in patients with amnestic mild cognitive impairment or Alzheimer disease. Am J Clin Nutr. 2004 Aug;80(2):483-8.
The plasma amino acid profiles of elderly patients with aMCI or AD show abnormalities in aromatic and basic amino acids that potentially affect neurotransmitter biosynthesis.
- Gueli MC. Alzheimer’s disease: amino acid levels and brain metabolic status. Neurol Sci. 2013 Sep;34(9):1575-9.
- Yang An et al. Evidence for brain glucose dysregulation in Alzheimer’s disease. Alzheimers Dement. 2018 Mar;14(3):318-329.
Impaired glucose metabolism due to reduced glycolytic flux may be intrinsic to AD pathogenesis. Abnormalities in brain glucose homeostasis may begin several years before the onset of clinical symptoms.
- Juliette Le Douce et al. Impairment of Glycolysis-Derived l-Serine Production in Astrocytes Contributes to Cognitive Deficits in Alzheimer’s Disease. Cell Metab. 2020 Mar 3;31(3):503-517.e8.
Altogether, these data raise the prospect of L-serine supplementation as a treatment option for AD and possibly other neurodegenerative diseases.
- Baruh Polis et al. Role of the metabolism of branched-chain amino acids in the development of Alzheimer’s disease and other metabolic disorders. Neural Regen Res. 2020 Aug;15(8):1460-1470.
Tau and deposited amyloid-beta proteins are just hallmarks or epiphenomena, but not the ultimate causes of Alzheimer’s disease. Therefore, approaches targeting amyloid-beta or Tau are not adequate to cure the disease. Accordingly, the modern scientific vision of Alzheimer’s disease etiology and pathogenesis must reach beyond the hallmarks, and look for alternative strategies and areas of research.
- Fonteh AN. Free amino acid and dipeptide changes in the body fluids from Alzheimer’s disease subjects. Amino Acids. 2007 Feb;32(2):213-24.
Since our data show changes in antioxidants, neurotransmitters and their precursors or FAA associated with urea metabolism in pAD compared with CT, we propose that manipulation of these metabolic pathways may be important in preventing AD progression.
- Hestad K, Alexander J, Rootwelt H, Aaseth JO. The Role of Tryptophan Dysmetabolism and Quinolinic Acid in Depressive and Neurodegenerative Diseases.Biomolecules. 2022 Jul 18;12(7):998.
- Degrell I. Amino acid concentrations in cerebrospinal fluid in presenile and senile dementia of Alzheimer type and multi-infarct dementia. Arch Gerontol Geriatr. 1989;9:123–35.