The health of the endothelium, that thin layer of cells lining the blood vessels, is the front line for cardiovascular health. And a variety of food and supplement ingredients are showing promise in supporting the function of this vital tissue.
Researchers say about 60 to 70% of the population of the United States over the age of twenty is affected by obesity, metabolic syndrome or has high blood pressure. This raises their risk for heart attacks, strokes and other cardiovascular illnesses.
And one of the harbingers of these conditions is dysfunction in the endothelium. This layer performs many functions including maintaining the suppleness of blood vessels and regulating the activity of neutrophils, white blood cells that form a key part of the immune system.
It all starts in the endothelium
Dysfunction in the endothelium leads to arteries with little suppleness, contributing to high blood pressure, and arteries that are chronically inflamed, leading to an overabundance of adhesion molecules.
Addressing these issues calls for a understanding the complex interplay of interactions and molecules at that layer, experts say.
“What’s needed in epithelial cells is a reasonable supply of especially DHA, because a lot of the cell wall structure incorporatse DHA,” said Rudi Moerck, PhD, CEO for Eustis, FL-based ingredient supplier Valensa.
“The other thing we have in veins are lipoproteins, LDL, HDLs and fats and oils. These things are very susceptible to oxygenation, especially in that side of your heart that is the red side of the heart, the oxygenated part.
“If lipoproteins and lipids get exodizeationed they polyermize and they form plaques,” Moerck said. It’s not all that different to the thickened, varnish-like ooze that forms when smear of oil, on the lip of a bottle or the rim of a pan, is exposed to air for a while, he said.
“If DHA oxidizes in the cell walls, then the cell walls become more brittle and become what I would say leather like. When that happens you have less flexibility of the veins,” Moerck said. The hardened blood vessels can’t stand up to the rhythm of 70 pressure pulses or more per minute, especially in the highest pressure areas closest to the heart. “You get injury, you cracking of the veins and you get the development of scar tissue. And that’s where plaques start to form,” Moerck said.
This sets up a viscous feedback loop in which more injury leads to more scar tissue and so forth, he said.
Getting the word out
So, omega-3s obviously have a role to play in endothelial health, one that has been long supported by research and is reasonably well understood by consumers. But other ingredients have a story to tell here, too, by quelling the activity reactive oxygen species and calming inflammation. ORAC value hucksterism may be passé, but the antioxidant story—what these compounds actually do as opposed to which one has the gaudiest number—is alive and well in the endothelial layer.
“As in most chronic diseases, inflammation also plays a key role in affecting the functioning of endothelium, the inner wall of blood vessels, thus increase in inflammation due to circulating cholesterol (more importantly oxidized LDL), free radicals, may effect its function in regulating blood pressure, clotting, barrier function and overall cardiovascular function,” said Dr Anurag Pande, PhD, vice president of scientific affairs for New Jersey-based ingredient supplier Sabinsa Corp.
“For general consumers, the term ‘endothelial health’ or ‘endothelial dysfunction’ doesn’t carry much information on their cardiovascular health, for which they still consider blood pressure numbers as a marker. However the awareness is definitely increasing at the level of formulators and manufacturers who are focusing on products for improving and maintaining endothelial function,” Pande said.
Among the functional food and dietary supplement ingredients that are beneficial along these lines are carotenoids and polyphenols. Among carotenoids are beta carotene, lutein and lycopene. But one stands a top the pyramid for endothelial health, Moerck said.
“All carotenoids, and most of them are fat soluable, will protect lipids from oxidizing,” Moerck said. “It’s well known in the literature that astaxanthin is much more powerful than the other carotenoids” for antioxidant activity.
Asxtaxanthin is not widely available in the diet, Moerck said, with wild-caught salmon being the most common source. Valensa and several other suppliers offer astaxanthin extracted from red algae.
Polyphenols step up
Extracts of grapes, grape seeds, berries and other polyphenol-bearing plant sources have shown promising results in supporting endothelial health.
“Resveratrol and Pterostilbene are both stilbene polyphenols. Resveratrol, primarily found in red wine, is often related with the French paradox, while pterostilbene, present in several berries, has also shown health benefits. Recent research demonstrated that the chemo-preventive effect of pterostilbene is more potent than resveratrol such as in reducing inflammation and modulation of antioxidant signaling pathways. With inflammation playing central role in causing endothelial dysfunction, pterostilbene may be a product to look for as a cardiovascular health ingredient,” Panda said.
Sabinsa offers a natural pterostilbene extract branded as Silbinol which it obtains from a traditional Ayurvedic source, the Indian Kino Tree (Pterocarpus marsupium).
In addition to these ingredients, other functional food and supplement ingredients have shown interesting results in clinical trials.
Curcumin, a derivative of the spice turmeric, is in the phenolic family of compounds and has many trial results showing good results in quelling inflammation via its modulating effect on the NfKB pathway. A recent review of 17 studies showed a small but positive effect of soy isoflavones on endothelial health. And good old olive oil showed a protective effect on the lining of blood vessels in a recent study from the US and Italy.
Another Ayurvedic ingredient has shown a surprisingly result in this area, one that comes a little from left field. A recent, yet-to-be published study on Sensoril, an extract of the root and leaves of the ashwagandha plant (Withania somnifera) marketed by Brattleboro, VT-based ingredient supplier NutraGensis, showed good results in improving endothelial function. The result was surprising, because ashwagandha has little demonstrated antioxidant activity, which is often thought to be the price of entry for an ingredient seeking to play in this space. This suggests that, as so often is the case with the internal affairs of the human body, the story of endothelial health does not yield to simple explanations.