The Cognitive Effects of a Ketogenic on HIV-Associated Neurocognitive Impairment in Older Adults with HIV

Background: Approximately 30-50% of adults with HIV experience some form of HIV-associated neurocognitive disorder that can impair everyday functioning (i.e., medication adherence, driving) and quality of life. As people age with HIV, the prevalence and severity of such cognitive impairments are likely to increase. Unfortunately, pharmacological interventions to address cognitive impairments are not effective in this population, a population that already has a high pill burden with a high prevalence of renal and hepatic complications. Recent work has shown that a ketogenic diet (KD; a low carbohydrate (< 50 grams/day) & high fat diet) improves brain metabolism and cognition for those with a range of neurodegenerative diseases. We hypothesis that the KD will improve cognition in older adults with HIV with such cognitive impairments. Methods: In this pre-post two-group experimental study, 14 older adults (Mage = 55.50 years) with HIV experiencing cognitive problems were recruited from a university HIV/AIDS clinic. They were randomized either to a: 1) 12-week KD or 2) 12-week patient choice diet (PCD); this was followed by a 6-week washout period. A standardized cognitive battery was administered to participants at baseline, 12 weeks, and 18 weeks. Results: The KD and PCD groups were similar at baseline across all cognitive domains. At week 12, between group analyses indicated that the KD group performed significantly better on the Trails A (a measures of psychomotor function) and Trails B (a measure of executive function) assessments (p=0.035 & 0.039, respectively) in comparison to the PCD group. No other between group differences were observed at week 12. As anticipated, there were no between-group differences observed at week 18; this suggests the cognitive gains observed in the KD group at week 12 were not sustained after resuming their normal diet. Discussion: This feasibility study provides preliminary support of the potential efficacy of a KD to treat of HIV-associated neurocognitive impairment. Among those in the KD, participants reported satisfaction with the food taste, quality, and satiety. With only a single exception, KD group participants received their weekly food delivery without incident. How these observed cognitive gains translate to daily functioning, quality of life, more optimal medication adherence, or other indicators of successful cognitive aging are unknown.