A new study conducted on rats finds that vitamin K could protect against age-related cognitive decline.
Vitamin K comes in two forms: vitamin K1 and vitamin K2. The study, carried out at AlMaarefa University, focussed on vitamin K2 found in animal and fermented foods and how this vitamin may improve cases of dementia.
Dementia is a syndrome associated with an ongoing decline in brain functioning. It can cause symptoms such as memory loss, reduced thinking speed and language problems such as using words incorrectly. Preventive methods for memory decline are important to support the ageing population and ward off dementia.
“Vitamin K2 demonstrated a very promising impact in hindering ageing-related behavioural, functional, biochemical and histopathological changes in the senile ageing brain,” said Mohamed El-Sherbiny, PhD, of AlMaarefa University in Saudi Arabia, the study’s senior author. “Vitamin K2 can be proposed to be a promising approach to attenuate age-related disorders and preserve cognitive functions in ageing individuals.”
The findings were presented at the American Association for Anatomy annual meeting.
Biological pathways of vitamin K2
The research illuminates biological pathways that showcase vitamin K appearing to preserve cognitive functions. The team of researchers investigated the effects of menaquinone-7 (MK-7), a form of vitamin K2, in 3-month-old rats, an age at which rats have reached maturity. One group of rats received supplemental MK-7 for 17 months, while the other group did not.
Using validated tests, including a maze, swim and sociability test, the researchers assessed the cognitive function and depressive-like and anxiety behaviour in rats. The tests highlighted that rats receiving the vitamin K supplement performed better than those that did not. Furthermore, it was associated with reduced evidence of cognitive impairment, depression and anxiety and improved spatial memory and learning ability.
Preventing cognitive decline
Following the completion of the study, the researchers examined the rat’s brain tissues for insights into the biological pathways involved. The results suggest that vitamin K affects pathways involving the proteins NLRP3, caspase-1 and Nrf-2, which are involved in inflammation and antioxidant activity. It appears to promote the expression of tyrosine, an amino acid that helps preserve cognitive functions.
However, the researchers cautioned that more studies are needed to determine whether the new findings translate from rats to humans and to identify the optimal source and dose of vitamin K to reap the potential brain benefits. Furthermore, people taking certain blood thinners and other medications are advised to avoid vitamin K supplements and foods rich in vitamin K.
“Further clinical studies will be required to assess the appropriate dosage for protection against Alzheimer’s, especially in those treated with vitamin K antagonists,” said El-Sherbiny.