Higher Vitamin K Intake Associated with Reduced Risk of Dementia-Related Cognitive Impairment

by | Jul 5, 2022 | 2022, Brain Health, Cognitive Health, Vitamin K

Written by Taylor Woosley, Staff Writer. Results of the MAP longitudinal study show that higher brain MK4 concentrations in all four brain regions resulted in a 17% to 20% lower chance of dementia or mild cognitive impairment occurrence (ORs 0.80 to 0.83, all P-values < .014). 

vitamin KThe global population is aging at an accelerated rate, with people over the age of 65 years expecting to increase by 12% (about 1 billion) by 2030 1. As older individuals live longer, the incidence of mild cognitive impairment (MCI), or the loss of cognitive domain functions, begins to increase, which can eventually lead to dementia-related disorders 2. Alzheimer’s disease (AD) is the most prevalent form of dementia, contributing to 60-70% of cases, with one new case of dementia being diagnosed every 3 seconds 3. Research has shown that modifiable cardiometabolic risk factors, such as hypertension and diabetes, and following an unhealthy lifestyle, are associated with an increased risk of dementia 4.

Vitamin K, a group of fat-soluble compounds involved in coagulation, bone development, and cardiovascular health, has shown promising results related to cognitive health 5. Vitamin K compounds are classified into two forms, vitamin K1 (phylloquinone) which is found in leafy green vegetables and vitamin K2 (menaquinone) which is found primarily in fermented foods 6. Additionally, MK-4 is obtained through the conversion of K1 or K2 and is found mainly in meat and animal by-products 7. Research from community-based studies of older adults has shown an association of higher vitamin K intake with slower cognitive decline and better cognitive functioning 8.

Booth et. al conducted a study using data from the Rush Memory and Aging Project (MAP), an ongoing community-based longitudinal study focused on determining risk factors for AD and related dementias and cognitive decline. Study inclusion consisted of being free of known dementia, with clinical evaluations being completed annually, along with organ donation upon death. At each yearly visit subjects (n=325) partook in 19 cognitive tests to determine global cognitive function. At the time of death, a neurologist made a final cognitive diagnosis (classified as dementia, MCI, or no cognitive impairment) and after death brains were dissected and examined histologically for AD pathology. The last evaluation of global cognitive functions for participants before death occurred an average of 1.3 (SD = 1.5) years before death. Plasma phylloquinone was obtained an average of 2.1 (SD = 1.9) and 3.3 (SD = 2.1) years before the last global cognitive function assessment.

Significant findings of the MAP longitudinal study include:

  • Odds of dementia occurrence or MCI at the last cognitive assessment before death were 17% to 20% lower per doubling of MK4 in all four brain regions measured (ORs 0.80 to 0.83, all P-values < .014).
  • Higher brain MK4 concentrations in the mid-frontal and mid-temporal cortexes and the anterior watershed were also associated with better ante-mortem global cognitive function scores and a decreased rate of cognitive decline (all P-values < .040).
  • Higher brain MK4 concentrations in the cerebellum was associated with better ante-mortem global cognitive function (P-value = .036).
  • For neuropathologically related outcomes, the odds of Braak stage ≥ IV were 14% to 16% lower per doubling of MK4 in the mid-frontal and mid-temporal cortexes, anterior watershed, and cerebellum (ORs 0.84 to 0.86, all P-values < .045).
  • The odds of developing Lewy bodies were 13% to 18% lower per doubling of MK4 in the mid-frontal and mid-temporal cortexes and cerebellum (ORs 0.82 to 0.87, P < .045).
  • Ante-mortem measures show that higher plasma phylloquinone at the last clinical evaluation was associated with better cognitive function (global cognitive function β [SE] = 0.229 [0.072], P-value = .002, n = 295), and a slower rate of cognitive decline (slope of cognitive function β [SE] = 0.017 [0.006], P-value = .004, n = 295).

Study findings suggest that vitamin K plays a significant role in cognitive functioning, with higher levels of MK4 in all four brain regions being associated with lower incidence of dementia. Researchers emphasize the importance of preclinical research to better understand the exact mechanisms by which vitamin K has neuroprotective benefits. Limitations of the study include the lack of inferring causation due to the observational design of the study and the lack of diversity of the cohort resulting in uncertainty regarding generalizability to other race-ethnic groups.

Source: Booth, Sarah L., M. Kyla Shea, Kathryn Barger, Sue E. Leurgans, Bryan D. James, Thomas M. Holland, Puja Agarwal et al. “Association of vitamin K with cognitive decline and neuropathology in community‐dwelling older persons.” Alzheimer’s & Dementia: Translational Research & Clinical Interventions 8, no. 1 (2022): e12255.

© 2022 The Authors. Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring published by Wiley Periodicals, LLC on behalf of Alzheimer’s Association

Click here to read the full text study.

Posted July 5, 2022.

Taylor Woosley studied biology at Purdue University before becoming a 2016 graduate of Columbia College Chicago with a major in Writing. She currently resides in Glen Ellyn, IL.

References:

  1. Wang RS, Wang BL, Huang YN, Wan TTH. The combined effect of physical activity and fruit and vegetable intake on decreasing cognitive decline in older Taiwanese adults. Sci Rep. Jun 14 2022;12(1):9825. doi:10.1038/s41598-022-14219-5
  2. Alharbi EA, Jones JM, Alomainy A. Non-Invasive Solutions to Identify Distinctions Between Healthy and Mild Cognitive Impairments Participants. IEEE J Transl Eng Health Med. 2022;10:2700206. doi:10.1109/jtehm.2022.3175361
  3. Yuan F, Sadovnik A, Zhang R, Casenhiser D, Paek EJ, Zhao X. A simulated experiment to explore robotic dialogue strategies for people with dementia. J Rehabil Assist Technol Eng. Jan-Dec 2022;9:20556683221105768. doi:10.1177/20556683221105768
  4. Han X, Wang Y, Jiang Z, et al. Association of Cardiovascular Health Metrics with Dementia in Rural Chinese Older Adults: A Population-Based Study. Clin Interv Aging. 2022;17:947-956. doi:10.2147/cia.S356910
  5. Eden RE, Coviello JM. Vitamin K deficiency.[Updated 2019 Mar 29]. StatPearls [Internet] Treasure Island (FL): StatPearls Publishing. 2019;
  6. Popescu A, German M. Vitamin K2 Holds Promise for Alzheimer’s Prevention and Treatment. Nutrients. Jun 27 2021;13(7)doi:10.3390/nu13072206
  7. Bellone F, Cinquegrani M, Nicotera R, et al. Role of Vitamin K in Chronic Kidney Disease: A Focus on Bone and Cardiovascular Health. Int J Mol Sci. May 9 2022;23(9)doi:10.3390/ijms23095282
  8. Booth SL, Shea MK, Barger K, et al. Association of vitamin K with cognitive decline and neuropathology in community-dwelling older persons. Alzheimers Dement (N Y). 2022;8(1):e12255. doi:10.1002/trc2.12255