Vitamin K status and inflammation are associated with cognition in older Irish adults

Kiely, Annemarie; Ferland, Guylaine; Ouliass, Bouchra; O’Toole, Paul W.; Purtill, Helen; O’Connor, Eibhlís M.

doi:10.1080/1028415x.2018.1536411

Cited by 37 publications

(38 citation statements)

References 35 publications

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“…In line with previous studies, Kiely et al described that elderly with poor cognitive functions, evaluated with MMSE, had the lowest dietary vitamin K intake (assessed with FFQ). Similar results were observed correlating MMSE scores and phylloquinone serum levels measured with HPLC ( 66 ).…”

Section: Vitamin K and Cognitive Declinesupporting

confidence: 83%

The Relationships Between Vitamin K and Cognition: A Review of Current Evidence

et al. 2019

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Vitamin K is a fat-soluble nutrient discovered in 1935 and its role in blood coagulation has been thoroughly explored. In recent years, studies conducted in vitro and on animals highlighted vitamin K involvement in brain cells development and survival. In particular, vitamin K seems to have an antiapoptotic and anti-inflammatory effect mediated by the activation of Growth Arrest Specific Gene 6 and Protein S. Moreover, this vitamin is involved in sphingolipids metabolism, a class of lipids that participate in the proliferation, differentiation, and survival of brain cells. An altered expression in sphingolipids profile has been related to neuroinflammation and neurodegeneration. This review stems from a growing interest in the role of vitamin K in brain functions, especially in cognition, also in view of an expected increase of prevalence of Alzheimer's disease and other forms of dementia. It collects recent researches that show interesting, even though not definitive, evidence of a direct correlation between vitamin K levels and cognitive performance. Moreover, vitamin K antagonists, used worldwide as oral anticoagulants, according to recent studies may have a negative influence on cognitive domains such as visual memory, verbal fluency and brain volume. The aim of this review is to analyze the evidence of clinical studies carried out up to date on the relationship between vitamin K intake and cognitive performances. The involvement of vitamin K antagonists (VKAs) in declining cognitive performances is also addressed separately.

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Section: Vitamin K and Cognitive Declinesupporting

confidence: 83%

The Relationships Between Vitamin K and Cognition: A Review of Current Evidence

et al. 2019

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“…Green leafy and cruciferous vegetables are an important food source of vitamin K, and its levels in serum can provide information about dietary patterns (Ferland et al, 2020). Reduced vitamin K status has also been associated with poor cognitive function in older adults (Presse et al, 2013;Kiely et al 2020). We observed a small between-group effect on serum Vitamin K levels, however this appears to have been driven by a regression in Vitamin K levels toward the mean among the EX+ED group.…”

Section: Preliminary E Cacycontrasting

confidence: 47%

Feasibility and Preliminary Efficacy of the Lifestyle, Exercise and Diet (LEAD) Study: A Cluster Randomized Controlled Trial of a Combined Exercise and Diet Intervention in Older Adults with Vascular Risk Factors and Early Dementia Risk

Koblinsky

Anderson

Ajwani

et al. 2021

Preprint

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Background: Healthy diet and exercise are associated with reduced risk of dementia in older adults. Evidence for the impact of clinical trials on brain health is less consistent, especially with dietary interventions which often rely on varying intervention approaches. Our objective was to evaluate the feasibility and preliminary efficacy of a 6-month intervention combining exercise with a novel dietary counselling approach among older adults with vascular risk factors (VRFs) and early dementia risk. Methods: Participants with VRF’s and SCD or early MCI were cluster randomized into the intervention (exercise + Baycrest Brain-healthy Eating Approach (EX+DIET)) or control group (exercise + brain health education (EX+ED)). Both groups participated in 1-hour of supervised exercise per week and were prescribed additional exercise at home. EX+DIET involved 1-hour per week of group-based dietary counselling comprising didactic education focused on brain healthy eating recommendations, goal setting and strategy training. Whereas, EX+ED involved 1-hour per week of group-based brain health education. The primary outcome was change in hippocampal volume from baseline to 6 months. Secondary outcomes included fitness, diet, cognition, and blood biomarkers. Recruitment challenges and early discontinuation of the trial due to COVID-19 necessitated a revised focus on feasibility and preliminary efficacy. Results: Of 190 older adults contacted, 14 (7%) were eligible and randomized, constituting 21% of our recruitment target. All participants completed the intervention and attended 90% of exercise and diet/education sessions on average. All 6-month follow-up assessments pre-COVID-19 were completed but disruptions to testing during the pandemic resulted in incomplete data collection. No serious adverse events occurred and all participants expressed positive feedback about the intervention. Mean improvements in peak oxygen consumption were observed in both EX+DIET (d = .98) and EX+ED (d =1.15) groups. Substantial improvements in diet and HbA1c were observed in the EX+DIET group compared to EX+ED (d = 1.75 and 1.07, respectively). Conclusions: High adherence and retention rates were observed among LEAD participants and preliminary findings illustrate improvements in cardiorespiratory fitness and diet quality. These results indicate that a larger trial is feasible if difficulties surrounding recruitment can be mitigated. Trial Registration: ClinicalTrials.gov identifier: NCT03056508

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“…The primary finding of this study is that, irrespective of all measured potential confounders, variation in the MK biosynthesis concentration is associated with significant differences in MMSE scores (Table 2 and Table 4) driven by certain MK chain isoforms (Table 6) and steps of the MK pathway (Table 8). Positive associations between cognition and PK have been assessed based on FFQ information (50), and lower serum PK concentrations have been reported in patients with severe Alzheimer disease (21, 22). However, the potential interaction of the genes involved in MK biosynthesis, the encoded MKs, and cognition has never been examined.…”

Section: Discussionmentioning

confidence: 99%

Exploratory analysis of covariation of microbiota-derived vitamin K and cognition in older adults

McCann

Jeffery

Ouliass

et al. 2019

The American Journal of Clinical Nutrition

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BackgroundVitamin K has multiple important physiological roles, including blood coagulation and beneficial effects on myelin integrity in the brain. Some intestinal microbes possess the genes to produce vitamin K in the form of menaquinone (MK). MK appears in higher concentration in tissues, such as the brain, particularly MK4, than the dietary form of phylloquinone (PK). Lower PK concentrations have been reported in patients with Alzheimer disease while higher serum PK concentrations have been positively associated with verbal episodic memory. Despite knowledge of the importance of vitamin K for various health parameters, few studies have measured MK concentration and biosynthesis by gut commensals.ObjectiveThe aim of the current study was to investigate the relation between genes involved in gut-microbiota derived MK, concentrations of MK isoforms, and cognitive function.MethodsShotgun metagenomic sequencing of the gut microbiome of 74 elderly individuals with different cognitive ability levels was performed. From this, gene counts for microbial MK biosynthesis were determined. Associations between clusters of individuals, grouped based on a similar presence and prevalence of MK biosynthesis genes, and cognitive ability were investigated. Fecal MK concentrations were quantified by HPLC to investigate correlations with subject clusters.ResultsSeparation of subject groups defined by banded quantification of the genetic potential of their microbiome to biosynthesize MK was associated with significant differences in cognitive ability [assessed using the Mini-Mental State Examination (MMSE)]. Three MK isoforms were found to be positively associated with MMSE, along with the identification of key components of the MK pathway that drive this association. Although the causality and direction of these associations remain unknown, these findings justify further studies.ConclusionsThis study provides evidence that although total concentrations of MK did not covary with cognition, certain MK isoforms synthesized by the gut microbiome, particularly the longer chains, are positively associated with cognition.

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Vitamin K status and inflammation are associated with cognition in older Irish adults

Cited by 37 publications

References 35 publications

The Relationships Between Vitamin K and Cognition: A Review of Current Evidence

The Relationships Between Vitamin K and Cognition: A Review of Current Evidence

Feasibility and Preliminary Efficacy of the Lifestyle, Exercise and Diet (LEAD) Study: A Cluster Randomized Controlled Trial of a Combined Exercise and Diet Intervention in Older Adults with Vascular Risk Factors and Early Dementia Risk

Exploratory analysis of covariation of microbiota-derived vitamin K and cognition in older adults

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