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Lower Vitamin K Levels Associated with Impaired Learning and Memory in Mice
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Key Takeaways
- Insufficient vitamin K intake is linked to cognitive decline, inflammation, and reduced neural proliferation in the hippocampus.
- Vitamin K is crucial for brain health, found in green leafy vegetables, oils, fruits, meat, cheese, eggs, and soybeans.
Rather than turning to vitamin K supplements, individuals should incorporate more vegetables into their diets.
Insufficient consumption of vitamin K could adversely impact cognition as individuals age, according to research published by investigators in the Journal of Nutrition. The findings suggest that a lack of vitamin K could be linked to increased inflammation and obstruct proliferation of neural cells in the hippocampus.1,2
Image credit: pkproject | stock.adobe.com
In the next decade, researchers estimate that more US adults aged 65 years and older will develop age-related complications, emphasizing the need for prevention strategies. While vitamin K is known for its roles in blood coagulation and bone formation, further research demonstrates the vitamin also impacts brain function.1
Phylloquinone is the primary form of dietary vitamin K and is often found in green leafy vegetables, such as spinach, kale, broccoli, and lettuce. However, the vitamin is also found in vegetable oils; certain fruits, such as blueberries and figs; meat; cheese; eggs; and soybeans. Despite its natural consumption in various foods, most individuals do not consume the recommended quantity for adequate intake.1
“There is also research that indicates vitamin K contributes to brain function and that brain function declines during the aging process,” said Tong Zheng, lead author of the study and a research scientist at the HNRCA, in a news release. “Vitamin K seems to have a protective effect. Our research is trying to understand the underlying mechanism for that effect so that we might one day be able to target those mechanisms specifically.”2
The researchers conducted a 6-month dietary intervention in mice that were fed a low-vitamin K diet and mice receiving a standard diet to compare cognitive performance. The study focused on menaquinone-4, a type of vitamin K abundant in brain tissue.2
Following the investigation of menaquinone-4, initial results demonstrated considerably reduced amounts of this nutrient in the brains of mice lacking vitamin K. The study authors noted that this menaquinone-4 deficiency relates to significant cognitive decline.2
In a novel object recognition test, vitamin K-deficient mice demonstrated a reduced ability to distinguish between familiar and new objects. Additionally, in a second test that measured spatial learning, the vitamin K-deficient mice took longer to learn the task compared to mice in the adequate vitamin K group—all of which contribute to impaired memory.2
Examining the brain tissue, researchers discovered significant changes in the hippocampus of vitamin K-deficient mice. They observed fewer proliferating dentate gyrus, resulting in reduced neurogenesis, the production of new, immature neurons. Zheng suggests this impairment that is vital for learning and memory likely contributes to the cognitive decline observed.2
“We found a higher number of activated microglia, which are the major immune cells in the brain,” Zheng said in a news release. “While microglia play a vital role in maintaining brain health, their overactivation can lead to chronic inflammation, which is increasingly recognized as a key factor in age-related cognitive decline and neurodegenerative diseases.”2
Despite the results, the researchers note that individuals should not immediately turn to vitamin K supplements and should instead begin to eat healthier, incorporating more vegetables into their diets.2
“We know that a healthy diet works, and that people who don’t eat a healthy diet don’t live as long or do as well cognitively,” Sarah Booth, director of the HNRCA and senior author of the study, said in a news release. “By choreographing animal and human studies together, we can do a better job of improving brain health long-term by identifying and targeting specific mechanisms.”2
