Higher K intakes linked to benefits for late-life depression
A team of international researchers recently examined the relationship between vitamin K intake and the presence of depressive symptoms in elderly people and found a positive relation between higher intake of vitamin K and lower risk of presenting depressed mood. Results of this study that has been conducted in a large cohort of older North American People appeared in a special issue of the Nutrients journal – Diet and Mental Health.
Medical burden and disability that many elderly people have to face significantly decreases the quality of life and may be one of the causes of late life depression. 4,375 participants aged 45–79 years with a high risk of knee osteoarthritis or having knee osteoarthritis were enrolled for the purpose of this study from the Osteoarthritis Initiative database. Dietary vitamin K intake was collected through a semi-quantitative food frequency questionnaire and arbitrarily categorized in four quartiles. Depressive symptoms were diagnosed using the 20-item Center for Epidemiologic Studies-Depression (CES-D) ≥ 16. To investigate the associations between vitamin K intake and depressive symptoms, logistic regression analysis were run, which adjusted for potential confounders. Overall, 437 (=10%) subjects had depressive symptoms. The researchers concluded that after adjusting for 11 confounders, persons with higher dietary vitamin K intake had a lower risk of presenting depressive symptoms. This result was only present in people not taking vitamin D supplementation. The directionality of this association should be further explored in longitudinal research.
“The authors of this paper did not aim to look specifically at vitamin K2, since the vitamin K intake that they calculated was the sum of vitamin K supplementation (if any) and of dietary intake of vitamin K, as assessed by the diet recall questionnaire,” says Dr. Katarzyna Maresz, president of the International Science and Health Foundation. “Nonetheless there are a lot of papers which show that vitamin K2 is important for the brain function,” she adds and cites some important observations that have already been made by Ferland (2013), “[…] vitamin K-dependent proteins (VKDPs), not associated with blood coagulation, also contribute to the brain function. In addition to the VKDPs, vitamin K participates in the nervous system through its involvement in sphingolipid metabolism, a class of lipids widely present in brain cell membranes. […] Also, there is growing evidence that [K2] the K vitamer, menaquinone-4, has anti-inflammatory activity and offers protection against oxidative stress.”2 “Finally, although limited in numbers, reports point to a modulatory role of vitamin K in cognition,” Dr. Maresz emphasizes. “In one of the studies higher dietary phylloquinone intake was associated with better cognition and behavior among older adults,3 a rat model in another study provides further evidence that targeted depletion of MK4 in brain is associated with cognitive impairment,4 and yet another study highlights the importance of dietary vitamin K as a potentially protective cognitive factor; it also provides evidence for the correlation between cognition and inflammation,5” she further mentions.
- Bolzetta F, Veronese N, Stubbs B, Noale M, Vaona A, Demurtas J, Celotto S, Cacco C, Cester A, Caruso MG, Reddavide R, Notarnicola M, Maggi S, Koyanagi A, Fornaro M, Firth J, Smith L, Solmi M (2019) The Relationship between Dietary Vitamin K and Depressive Symptoms in Late Adulthood: A Cross-Sectional Analysis from a Large Cohort Study, Nutrients 11(4):787, doi: 10.3390/nu11040787
- Ferland G (2013) Vitamin K and Brain Function, Semin Thromb Hemost 39(08): 849-855, doi: 10.1055/s-0033-1357481
- Chouet J, Ferland G, Féart C, Rolland Y, Presse N, Boucher K, Barberger-Gateau P, Beauchet O, Annweiler C (2015) Dietary Vitamin K Intake Is Associated with Cognition and Behaviour among Geriatric Patients: The CLIP Study, Nutrients 7(8): 6739–6750. doi:10.3390/nu7085306
- Tamadon-Nejad S, Ouliass B, Rochford J, Ferland G (2018) Vitamin K Deficiency Induced by Warfarin Is Associated With Cognitive and Behavioral Perturbations, and Alterations in Brain Sphingolipids in Rats, Front. Aging Neurosci. 10:213, doi: 10.3389/fnagi.2018.00213
- Kiely A, Ferland G, Ouliass B, O’Toole PW, Purtill H, O’Connor EM (2018) Vitamin K status and inflammation are associated with cognition in older Irish adults, Nutritional Neuroscience, doi: 10.1080/1028415X.2018.1536411