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. 2022 Apr 29;14(9):1872.
doi: 10.3390/nu14091872.

Is the Brain Undernourished in Alzheimer's Disease?

Roberto Aquilani  1 , Alfredo Costa  2   3 , Roberto Maestri  4 , Matteo Cotta Ramusino  2   3 , Giulia Perini  2   3 , Mirella Boselli  5 , Paolo Iadarola  1 , Daniela Buonocore  1 , Manuela Verri  1 , Maurizia Dossena  1 , Federica Boschi  6
Affiliations

Is the Brain Undernourished in Alzheimer's Disease?

Roberto Aquilani et al. Nutrients. .

Abstract

Cerebrospinal fluid (CSF) amino acid (AA) levels and CSF/plasma AA ratios in Alzheimer Disease (AD) in relation to nutritional state are not known. Methods: In 30 fasting patients with AD (46% males, 74.4 ± 8.2 years; 3.4 ± 3.2 years from diagnosis) and nine control (CTRL) matched subjects, CSF and venous blood samples were drawn for AA measurements. Patients were stratified according to nutritional state (Mini Nutritional Assessment, MNA, scores). Results: Total CSF/plasma AA ratios were lower in the AD subpopulations than in NON-AD (p < 0.003 to 0.017. In combined malnourished (16.7%; MNA < 17) and at risk for malnutrition (36.6%, MNA 17−24) groups (CG), compared to CTRL, all essential amino acids (EAAs) and 30% of non-EAAs were lower (p < 0.018 to 0.0001), whereas in normo-nourished ADs (46.7%, MNA > 24) the CSF levels of 10% of EAAs and 25% of NON-EAAs were decreased (p < 0.05 to 0.00021). CG compared to normo-nourished ADs, had lower CSF aspartic acid, glutamic acid and Branched-Chain AA levels (all, p < 0.05 to 0.003). CSF/plasma AA ratios were <1 in NON-AD but even lower in the AD population. Conclusions: Compared to CTRL, ADs had decreased CSF AA Levels and CSF/plasma AA ratios, the degree of which depended on nutritional state.

Keywords: Alzheimer; CSF amino acid levels; amino acid CSF/plasma ratio; nutritional state.

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Conflict of interest statement

The authors have no potential conflict of interest to declare. Roberto Aquilani is Scientific Consultant of Professional Dietetics, Milano, Italy.

Figures

Figure 1
Figure 1
Scatterplot of Cerebrospinal fluid (CSF) Arginine as a function of Insulin. Spearman’s r and Pearson’s r are also reported with corresponding p-values.
Figure 2
Figure 2
Scatterplot of Cerebrospinal fluid (CSF) Branched-Chain Amino Acids (BCAA)/Total Amino Acids (Total AAs) as a function of Plasma BCAA/Total AAs. Spearman’s r and Pearson’s r are also reported with corresponding p-values.
Figure 3
Figure 3
Some general potential mechanisms underlying brain amino acid overutilization and reduced CSF amino acid levels. formula image increase formula image decrease. BBB: Blood-Brain-Barrier.
See this image and copyright information in PMC

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