The Forgotten Vitamin for Brain Health

 In today’s episode of Daily Value, we explore the possibly underappreciated role of vitamin K in brain health and neuroprotection. Recent research (doi: 10.3389/fnut.2024.1396707) reveals a connection between dietary vitamin K intake and reduced levels of neurofilament light chain, a potential biomarker for neurodegeneration, particularly in middle-aged and older adults. We’ll discuss how vitamin K supports neuronal function, what specific forms of vitamin K are most important, and how this nutrient might help slow cognitive decline as we age.

Episode Talking Points:

*The role of neurofilament light chain as a biomarker for brain health and its association with neurodegeneration.
*Findings from a recent study (doi: 10.3389/fnut.2024.1396707) showing how higher vitamin K intake (and a specific amount) is linked to lower neurofilament light chain levels.
*The potential of vitamin K, and possibly MK-4, to protect neurons through mechanisms like sphingolipid metabolism and anti-inflammatory effects.

https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2024.1396707/full 

Transcript

Vitamin K and Brain Health

Speaker 0 0:00

Hello everyone , welcome back to Daily Value . I'm William Wallace , and today we're looking into what I consider to be a topic that deserves to have some more attention brought to , that found that dietary vitamin K is associated with decreased neurofilament light chain levels , especially in middle-aged and older adults . As for what exactly that is and what it means for brain health with aging , we will get into that momentarily In this episode . We'll talk about neurofilament light chain , what that is and why it's important for brain health and function . We'll discuss vitamin K , specific forms of vitamin K and what role they may play in brain health , as well as structure and function of the brain . We will discuss the results of the study I just mentioned to see what level of vitamin K intake is associated with the most benefit , and we'll discuss the practical implications of these findings in the context of the larger body of research on this topic .

Speaker 0 1:06

So what exactly are neurofilaments ? Well , you can think of neurofilaments as scaffolding inside of the nerve fibers of brain cells . This helps keep these cells shape and structure and allows them to function properly . Neurofilaments are particularly important for supporting the structure of axons . This is the part of axons . This is the part of a neuron that transmits electrical signals between nerve cells . Axons are made up of several components , but neurofilaments are an important component of their cytoskeleton . Neurofilaments are composed of three primary subunits , those being neurofilament heavy chain , neurofilament medium chain and , of course , neurofilament light chain . Neurofilament light chain is the smallest and most abundant subunit of the neurofilaments . Neurofilament light chain is the only of the three that can constitute the backbone of nerve fibers . When brain cells are damaged , neurofilaments can be released into cerebral spinal fluid and blood . Because neurofilament light chain has a very low molecular weight , it's highly soluble . Its levels in cerebral spinal fluid and blood are often considered a biomarker for neurodegeneration . In fact , nervous system diseases are thought to be causal to high peripheral circulating levels of neurofilament light chain . High levels of neurofilament light chain , high levels of neurofilament light chain , are positively associated with stroke risk , as well as dementia and dementia-related mortality . As we age , neurofilament light chain levels naturally increase in our blood , but higher than expected levels can be an early indicator of neuronal damage and cognitive decline . This makes it a unique biomarker for assessing brain health , particularly in older populations .

Speaker 0 2:48

Now enter vitamin K . Vitamin K is traditionally known for its role in blood clotting and bone health , but research in recent years has suggested its use for brain function . Vitamin K exists in two primary forms vitamin K , also called phylloquinone , and vitamin K2 , also called menaquinone . While vitamin K1 is more commonly found in leafy greens , k2 is present in fermented foods and some animal products . Vitamin K1 primarily exists as phylloquinone , but there are several different types of vitamin K2 . Actually , there are up to 15 different menoquinones , ranging from menoquinone 1 , also called MK1 , through menoquinone 15 or MK15 . Although not all vitamin K2 subtypes may play a role in human health , the most studied for their effects in humans are MK4 and MK7 . Mk4 is the most abundant vitamin K2 subtype in the human body . Metaquinones are actually made in the body when bacteria in our guts convert vitamin K1 from our diet to different forms of vitamin K2 . So in this way , gut health is also imperative to health outcomes related to the roles of vitamin K in the body .

Speaker 0 4:02

Vitamin K2 , of vitamin K in the body , vitamin K2 , menaquinone 4 , specifically , is the primary form of vitamin K in the brain . Longer chain menaquinones like MK7 are more bioavailable in the bloodstream , but they do not accumulate in the brain as significantly as MK4 . These forms tend to be more involved in systemic benefits , such as cardiovascular health and bone mineralization and may not have brain-specific functions , at least that we know of . The brain actually has its own enzymatic machinery to convert vitamin K1 and longer-chain menaquinones into vitamin K2 , mk4 . This indicates the brain's specific requirement for MK4 , which explains its dominance in neural tissues and suggests that MK4 has a role in maintaining neurological function , neuroprotection and and myelin synthesis , as vitamin K has been shown to modulate what's called sphingolipid metabolism . Sphingolipids are essential components of myelin , which is the fatty insulating layer that surrounds and protects nerve fibers like axons , which again are structurally held together by neurofilaments , which has led to the hypothesis that vitamin K may influence the stability , health , that vitamin K may influence the stability , health and the release of neurofilaments .

Speaker 0 5:23

Now a recent study published last year , conducted using data from the National Health and Nutrition Examination Survey , otherwise known as NHANES , aimed to explore the potential relationship between dietary vitamin K intake and serum neurofilament light chain levels in middle-aged and older adults . The study included over 1,500 participants and used highly sensitive amino assays to measure serum neurofilament light chain levels . The findings showed that participants with higher dietary vitamin K intake had significantly lower serum neurofilament light chain levels , particularly those who consumed more than 200 micrograms per day of vitamin K from either food or supplements , or both . The association was stronger in middle-aged and older adults , suggesting that vitamin K might play a protective role in neurodegenerative processes as we age . The dose-response relationship showed that as vitamin K intake increased , neurofilament light chain levels decreased rapidly , but this effect plateaued at intakes above 200 micrograms per day . In other words , after reaching a certain threshold , higher vitamin K intake did not significantly lower neurofilament-like chain levels further , but it also didn't hurt them . Of note , the authors did not specifically distinguish between vitamin K1 and vitamin K2 intake .

Speaker 0 6:36

This study was interesting for several reasons . First , it adds to the growing body of evidence that diet , and specifically vitamin K intake , can have a profound impact on brain health . Second , it highlights the potential of vitamin K as a neuroprotective agent which could be particularly beneficial for aging populations at risk of neurodegenerative diseases . Neurofilament light chain is an easily measurable biomarker in blood , meaning that it can be used to monitor brain health over time . If future studies confirm that increasing dietary vitamin K can help lower neurofilament light chain levels , it might become a simple , non-invasive way to mitigate the risk of neurodegeneration . But as of now , I do think that a more likely scenario is that vitamin K intake may help to prevent the increase in neurofilament light chain levels as we age .

Speaker 0 7:25

But how exactly does vitamin K do this ? There are a few potential explanations . One , which I mentioned earlier sphingolipid metabolism . Vitamin K plays a role in the synthesis of sphingolipids , which I mentioned earlier . Sphingolipid metabolism Vitamin K plays a role in the synthesis of sphingolipids , which , again , are critical for maintaining the structural integrity of neuronal membranes . Disruption in sphingolipid metabolism has been linked to neurodegenerative diseases , so maintaining proper levels through adequate vitamin K intake might help protect neurons from damage .

Speaker 0 7:54

Two , there are anti-inflammatory effects of vitamin K . Chronic inflammation is obviously a hallmark of many neurodegenerative diseases . Vitamin K does have anti-inflammatory properties due to its function as a coenzyme for different enzymes in the body , like growth arrest , specific 6 or protein S . These proteins play a role in proliferation of cells and prevent programmed cell death in some cases , which may make them protective proteins . So what does this all mean for you ? Well , first and foremost , it reinforces the importance of a diet rich in vitamin K .

Speaker 0 8:30

Foods like leafy green vegetables for vitamin K1 and fermented foods like natto for vitamin K2 are excellent sources . Of course , supplements can also provide concentrated sources of vitamin K in the form of vitamin K1 or vitamin K2 . You can even find supplements that will provide concentrated doses of different metaquinones , like MK4 and MK7 , which are the most common . Remember that MK4 is the form of vitamin K that is the most prevalent in the brain and , although the study we just discussed did not differentiate between different forms of vitamin K , we can theorize that this form of vitamin K plays the largest role in directly supporting brain structure , health and cognitive function . That being said , also remember that your body manufactures MK4 from dietary vitamin K1 . Brain cells can make MK4 through the conversion of vitamin K1 or other metaquinones . Your microbiota can also convert vitamin K1 into different metaquinones , which highlights a potentially massive role of gut health in maintaining vitamin K status and brain health .

Speaker 0 9:36

Do you need to supplement with MK4 to get the potential benefits of vitamin K in

Vitamin K and Brain Health Benefits

Speaker 0 9:41

the brain ?

Speaker 0 9:41

Well , no , not necessarily .

Speaker 0 9:43

If you've taken enough dietary vitamin K and take care of your gut health , you are likely making enough of the various different vitamin K subtypes .

Speaker 0 9:50

Worth noting is that there is not an actual recommended dietary allowance of vitamin K , but there is an adequate intake , or AI as it's known , that AI is 120 micrograms a day for adult men and 90 micrograms a day for adult women and 90 micrograms a day for adult women . The study found that neurofilament light chain levels were lowest in individuals who consumed more than 200 micrograms of vitamin K per day , which is above the current adequate intake set for vitamin K for men and women by approximately two-fold . To wrap things up , this new research highlights a very fascinating link between vitamin K intake and lower levels of neurofilament light chain , a key biomarker for neurodegeneration . While more studies are needed to fully understand this relationship , the findings suggest that increasing dietary or supplemental vitamin K may be a simple and effective way to support brain health , particularly in aging populations . Thank you for tuning in to Daily Value . If you found today's episode insightful , be sure to subscribe and share with others who might benefit . Until next time , stay sharp and please stay healthy .