Nourish my glycocalyx? I don’t think that’s legal in my state… *ba dum dum.*

But seriously folks, in case you weren’t aware, you definitely have a glycocalyx – a term for the vastly complex protective lining of all of your capillaries, which in turn touch and surround each and every one of the trillions of cells in your body (Möckl, 2020).

Also referred to as the paracellular matrix, its literal translation from Greek is way more fun: it means “sweet husk” due to its composition of complex sugars that provide a slick inner lining for the intricate vascular system (Mead, 2020) (Li, 2016).

If you’ve never heard of your glycocalyx, don’t be too surprised. It existed solely as a theory for many years prior to its first on-camera appearance via an electron microscope in the 1950’s (Li, 2016). 

The gossamer hairs of the glycocalyx. This is a healthy, happy example. High-sugar meals tend to mash it flat against the blood vessel wall, and recovery can take hours. Do it too often and the damage is permanent. Image from ResearchGate with Creative Commons license CC BY-NC.

And even after it was initially visualized, this slippery gel-like substance with wispy, hair-like tendrils was, well, slipping through the fingers of researchers, since the glycocalyx vanishes when exposed to air, instantly dehydrating and disappearing (Reitsma, 2011). However, thanks to improved technology and micro-camera imaging, we can begin to understand what its structure and function are, and why they matter so much to our health.

As its fibrous strands sway with the pulsing of blood like seaweed in the ocean, the glycocalyx behaves as its own complex and fascinating internet of communication, blood flow regulation, stimulant of nitric oxide, antioxidant storehouse, and gatekeeper for healthy cells. Importantly, the thickness and resilience of the glycocalyx is increasingly recognized as an elegant marker for arterial health (Kim, 2017).

Now for the sweet stuff: what exactly does our endothelial glycocalyx do? Well, a lot of things, but for the purposes of this article, we’ll keep it succinct. Its gel-like structure is anti-adhesive, a sort of biochemical nonstick coating. Since it lines every artery, vein, and capillary in the body, protecting the walls of our vasculature known as the endothelium (Nieuwdorp, 2005). The vascular endothelium is the largest organ in the body, and lines the inside of all blood vessels. (Yilmaz, 2019).

Despite long being underestimated as a passive lining of blood vessels, the endothelium is now known to be a major player in the control of efficient blood flow, cell clumping, and vessel strength (Rovas, 2020). It’s also a major factor in regulating immune health, inflammation, growing new blood vessels, and creating hormones (Feletou, 2011).

Blockages start in a damaged glycocalyx

Endothelial damage precedes the development of atherosclerosis, or plaque build-up (Hadi, 2005). It’s pretty much exactly what most of us who spend significant energy and attention regarding our diet and exercise routine are looking to avoid. And key to preventing that is your marvelous glycocalyx - in fact, it is believed to be your first line of defense against arterial disease (Noble, 2008).

The glycocalyx functions as a natural trigger for nitric oxide production - which is a soluble gas continuously produced by the endothelium, and vital for controlling blood blow and blood pressure. Not to be confused with nitrous oxide, or the laughing gas you get from your dentist, nitric oxide increases blood flow on demand when organs require it, regulates local cell growth, and maintains healthy vascular tone. Diminished production of nitric oxide can lead to vascular damage and oxidation of cholesterol, leading in turn to the dreaded plaque buildup known as atherosclerosis (Cannon, 1998).

The glycocalyx also behaves as sort of a control center due to many signaling molecules’ dependence upon it, so it helps to reduce oxidative stress, thus protecting the endothelium and by extension, your heart (Reitsma, 2007).

Basically, the thicker and more robust your glycocalyx is, the better for your circulatory health!

Keep it happy – skip the sugar!

Conversely, the degeneration of the glycocalyx seems to accompany - or even perhaps, hasten - the cluster of risk factors known as metabolic syndrome, which can be a first step to type 2 diabetes. In fact, once the gatekeeping glycocalyx takes on damage, the doorway is open for all sorts of risk factors that may be the “first step” in blood vessel damage and blockage (Noble, 2008).

While oxidative stress, age, and infection are all known culprits that contribute to glycocalyx degradation, one factor that is profoundly responsible for damaging it is hyperglycemia, or high blood sugar. Some studies have concluded that both acute and chronic hyperglycemia cause significant shedding and thinning of the glycocalyx. That, in turn, sets off the cascade of endothelial damage so disruptive to cardiovascular health (Yilmaz, 2019).

Fortunately for fish-lovers, not only do we have myriad evidence that high fish intake is associated with healthy circulating fatty acid levels, but also that a diet high in healthy fats like EPA and DHA can support healthy blood sugar levels and mitigate against the cluster of syndromes that leads to metabolic and circulatory disruption (Albert, 2014).

In other words, fatty fish appears to contribute to a happy glycocalyx. As if you needed another reason to get your daily seafood fix!


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