New research deepens the understanding of how vitamin K influences the health of the brain

While scientists try to unravel the complicated potential connections between nutrition and the aging brain, a new study by researchers from the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) can shed light on Tufts University on how insufficiently consumption of vitamin K has.

The study, conducted in middle -aged rodents, suggests that a lack of vitamin K can increase inflammation and increase proliferation of neural cells in the hippocampus, part of the brain that is able to generate new cells and is central to functions such as learning and memory.

Vitamin K is found in green leafy vegetables such as Brussels sprouts, broccoli, green peas, kale and spinach. It is already known that it plays an essential role in clotting blood, and research suggests that it can also have positive effects on cardiovascular health and joint health, says Sarah Booth, director of the HNRCA and senior author of the study. Booth is also a professor at Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy at Tufts University.

“There is also research that indicates that vitamin K contributes to brain function and that the function of the brain decreases during the aging process,” says Tong Zheng, main author of the study and a research scientist at the HNRCA. “Vitamin K seems to have a protective effect. Our research tries to understand the underlying mechanism for that effect, so that one day we can focus on those mechanisms specifically.”

Learning and memory influences

In the new research, published in The Journal of NutritionResearchers have carried out a six-month nutrition intervention to compare the cognitive performance of mice that received a low-vitamin K K diet and people who received a standard diet.

The research team concentrated on Menaquinon-4, a form of vitamin K that prevails in brain tissue, and found considerably lower levels of this nutrient in the brain of vitamin K-deficiency mice. This deficit is associated with noticeable cognitive decline as measured in a series of behavioral tests that are designed to assess their learning and memory.

In such a test, the new object recognition test, the vitamin K-deficient mice showed a reduced ability to distinguish between known and new objects, a clear indication of reduced memory. In a second test, to measure spatial learning, the mice had to learn the location of a hidden platform in a pool of water. The vitamin K-deficient mice took considerably longer to learn the task compared to their counterparts with sufficient vitamin K levels.

When the researchers then investigated the brain tissue of the mice, they found significant changes within the Hippocampus, a brain area crucial for learning and memory. In particular, they saw a reduced number of proliferating cells in the dentate gyrus of the hippocampus in the vitamin K-deficient mice.

This decrease translated into less newly generated immature neurons, a process known as neurogenesis. “Neurogenesis is supposed to play a crucial role in learning and memory, and its disorder could immediately contribute to the cognitive decline that was observed in the study,” says Zheng.

By adding a new layer of complexity, the researchers also found proof of increased neuro inflammation in the brain of vitamin K-deficient mice.

“We have found a higher number of activated microglia, the most important immune cells in the brain,” says Zheng. Although microglia play a crucial role in maintaining the health of the brain, their overactivation can lead to chronic inflammation, which is increasingly recognized as a key factor in age -related cognitive decline and neurodegenerative diseases.

A healthy diet

Both Booth and Zheng emphasize that their research does not mean that people have to hurry and take vitamin K supplements.

“People have to eat a healthy diet,” says Booth. “They have to eat their vegetables.”

Booth noted that the Tufts team works closely with Rush University Medical Center in Chicago, where the Rush team carries out observational studies in people of brain health and cognition, while Tufts focuses on models to study specific mechanisms.

“We know that a healthy diet works and that people who do not eat healthy diet do not live for so long or do so well cognitive,” says Booth. “By choreographing animal and human studies together, we can do better to improve brain health in the long term by identifying and focusing specific mechanisms.”