In a recent study published in the Journal of Alzheimer's Disease, researchers investigated the mild cognitive impairment (MCI) outcomes of pomegranate seed oil (PSO) interventions. The study included 80 participants divided between cases (PSO + Mediterranean Diet [MeDi]) and controls (only MeDi), all subjected to an extensive set of neurological assessments following a year of their respective interventions. Study findings revealed that participants consuming PSO display significantly better global cognition, memory, information processing, and executive functions than their MeDi-only counterparts. These findings highlight the use of PSO by people with MCI due to its safety, ease of availability, and cost-effectiveness compared to synthetic pharmaceutical interventions.
Study: The Effects of Pomegranate Seed Oil on Mild Cognitive Impairment. Image Credit: Tim UR / Shutterstock
Pomegranate – an understudied natural food with untapped modern medical potential
'Pomegranate' (Punica granatum) is the common name of a fruit-bearing deciduous shrub belonging to the family Lythraceae, subfamily Punicoideae. It is rich in polyphenols and fatty acids with known anti-inflammatory and antioxidant properties and has been used in traditional medicine for centuries. Unfortunately, modern research on the plant remains lacking, with only a handful of papers discussing its medical potential, all of which have researched the benefits of pomegranate juice.
Encouragingly, the limited clinical evidence of pomegranate's effectiveness has been positive, especially in the neurological sphere, with studies finding that pomegranate juice consumed consistently for 12 months resulted in significantly improved verbal memory performance compared to abstaining from the juice. Cellular studies using murine models have further revealed that pomegranate juice can inhibit and even reverse neurotoxicity induced by aluminum chloride (AlCl3), resulting in better body weight, learning, spatial memory, and neurotransmitter outcomes. Surprisingly, these effects were noted even at low concentrations of pomegranate juice, attesting to its potent neuroprotective effects.
Mild cognitive impairment (MCI) refers to a period characterized by subtle memory loss and cognitive decline that does not interfere with daily functioning and is thus hard to detect without specialized clinical assessments. It precedes the much more significant cognition loss associated with dementia and Alzheimer's Disease (AD) and forms a critical transition point during which time the onset of dementia and AD can either be delayed or hastened. Despite intensive recent research broadening our understanding of these neurological conditions, no cure for these conditions has hitherto been discovered, highlighting prevention as the best means to combat these diseases.
Oxidative stress has been identified as crucial in the pathology of most neurological and cognitive conditions. An increased adherence to suboptimal health behaviors, particularly diet (e.g., the Western Dietary Pattern), has hence been implicated in the rising global prevalence of AD. Science is increasingly turning to food and dietary patterns as potential prevention interventions against cognitive decline. The Mediterranean Dietary Pattern (MeDi) is one such intervention – characterized by a predominantly plant-based diet rich in healthy fats and low in processed foods and red meats; it has been shown to improve physical and cognitive parameters significantly in preclinical trials.
Elucidating the effects of pomegranate seed oil (PSO), the part of the plant richest in potentially beneficial, antioxidant-containing nutraceuticals (conjugated fatty acids such as linolenic acid), would allow for yet another preventive intervention to combat and delay the onset of these devastating diseases. Unfortunately, no studies have yet explored the benefits of PSO in human models.
About the study
The present study aims to evaluate the potential impact of PSO on the age-associated cognitive outcomes of people with clinically diagnosed MCI. The study cohort initially comprised 100 Greek participants with neurologist-validated MCI as per the MCI definition of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V 2013). Unfortunately, 20 participants failed to complete the study during follow-up and were hence removed from the analyses.
Data collection comprised demographic records (gender, age, education), blood collections, clinical examinations, neuropsychological assessments, and laboratory imaging procedures carried out by neurologists from the Greek Association of Alzheimer's Disease and Related Disorders (GAADRD). Individuals with hearing deficits, visual impairments, and those currently prescribed antipsychotic medication were excluded from the study. The remaining participants were divided into case (five drops of PSO per day + MeDi) and control cohorts (only MeDi), each with 40 participants.
Extracted blood was used for blood marker discovery and included evaluations of Aβ, tau protein, and phospho-tau protein, known biomarkers for brain damage. Baseline neuropsychological assessments were presented in two 2-hour-long sessions, repeated after six and 12 months to compare within- and between-group cognitive performance changes over these time durations. These assessments were selected to evaluate attention, memory (working and episodic), visuospatial, executive, and functional performance and were computed using the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-cog), the Mini-Mental State Examination (MMSE), and the Montreal Cognitive Assessment (MoCA).
Memory, in particular, was estimated using the Rivermead Behavioral Verbal Learning Test (for episodic memory), the Rey Auditory Verbal Learning Test (RAVLT; for immediate and delayed recall), and the Rey-Osterrieth Complex Figure Test (for visuospatial memory and executive function).
"The Functional Cognitive Assessment Scale (FUCAS) was used to assess functionality in daily living. However, this test was used only to support that our patients had no problems in activities of daily living."
Study findings and conclusions
Demographic data revealed that the 80 participants included had a mean age of 69.53 years and were 60% female. Comparing demographic data between case and control cohorts showed no statistically significant difference, allowing for between-group comparisons.
Five drops of PSO consumed along with MeDi over a year were found to protect against cognitive decline significantly and, in some cases, even improve cognitive performance in the case-cohort. In contrast, the control cohort (only MeDi) displayed either no change from baseline or cognitive reductions over the same period, highlighting the neurological benefits of PSO.
PSO improved visuospatial abilities, executive function, processing speed, learning, verbal episodic memory, and, importantly, global cognition. ADAS-cog, TMT B, and RAVLT scores were all found to improve statistically over baseline values in the case-cohort. Even more encouragingly – with MoCA presenting the sole exception, all neurological parameters measured showed improvements over baseline, albeit these were not statistically significant. This highlights the role of PSO in both protecting against cognition loss and in improving some neurological parameters, thereby reversing MCI.
In contrast, with FUCAS being the sole exception, all neurological parameters measured in the control cohort displayed declines in mean scores over the 12-month period. FUCAS results were consistent between both cohorts and remained indistinguishable from baseline measures. This, however, is expected because MCI's cognitive deficits do not typically interfere with day-to-day activities.
"In conclusion, because of the absence of clinical trials regarding the effects of PSO on cognition of patients with MCI or other cognitive disorders, the aim of the present study was to identify the potential benefits of PSO in MCI. After one year of treatment, it is proved that the PSO can be beneficial for people with MCI improving different domains of cognition. So, the innovation of the present study is that these results can expand the research in this field and encourage the use of PSO in holistic approaches that can be helpful even in the stage of MCI and lead to prevention of dementia."