Red Blood Cell Fatty Acid Profiles Are Significantly Altered in South Australian Mild Cognitive Impairment and Alzheimer's Disease Cases Compared to Matched Controls.

Nutritional imbalances have been associated with a higher risk for cognitive impairment. This study determined the red blood cell (RBC) fatty acid profile of newly diagnosed mild cognitive impairment (MCI) and Alzheimer's disease (AD) patients compared to age and gender-matched controls. There was a significant increase in palmitic acid ( p < 0.00001) for both MCI and AD groups. Saturated fatty acids were significantly elevated in the MCI group, including stearic acid ( p = 0.0001), arachidic acid ( p = 0.003), behenic acid ( p = 0.0002), tricosanoic acid ( p = 0.007) and lignoceric acid ( p = 0.001). n-6 polyunsaturated fatty acids (PUFAs) were significantly reduced in MCI, including linoleic acid ( p = 0.001), γ-linolenic acid ( p = 0.03), eicosatrienoic acid ( p = 0.009) and arachidonic acid ( p < 0.00004). The n-3 PUFAs, α-linolenic acid and docosahexaenoic acid, were both significantly reduced in MCI and AD ( p = 0.0005 and p = 0.00003). A positive correlation was evident between the Mini-Mental State Examination score and nervonic acid in MCI (r = 0.54, p = 0.01) and a negative correlation with γ-linolenic acid in AD (r = -0.43, p = 0.05). Differences in fatty acid profiles may prove useful as potential biomarkers reflecting increased risk for dementia.