Circulatory Function and Vascular Integrity

Supporting vascular integrity to enhance circulatory function

References

Cholesterol is the focus of the majority of research and product development in the cardiovascular category. However, there are many integrated facets of heart health beyond just cholesterol reduction. Consider blood and the vessels that transport it throughout the body. The systemic circulatory system provides nourishment to the entire body, a conduit of arteries and veins, with microscopic capillaries enabling the exchange of water and chemicals between the blood and tissues. It is estimated that the average human body contains enough blood vessels that, if laid end to end, they would stretch more than 60,000 miles. Blood vessels do not actively transport blood, but the diameter of their interior endothelial lining is regulated by contraction of the blood vessels’ muscular layers. Vasoconstriction occurs when the vascular muscles flex, narrowing the tubing; vasodilation is the opposite, a relaxation of the muscles. The most well-known vasoconstrictors include prostaglandins, hormones such as vasopressin and angiotension, and neurotransmitters like epinephrine. On the dilation side, nitric oxide (NO) is the most prominent player.

Endothelial cells are also involved in blood clotting, both thrombosis and fibrinolysis. In addition, the body employs a process known as haemostasis to control bleeding in the vessels. A combination of vascular spasm, which cuts off blood flow to the area, and clotting are employed to protect vessel integrity. The platelets, specialized blood cells, release granules that contain clotting factors and growth factors, while signaling aggregation (sticking other platelets together) to create a plug or clot.

In order to prevent the clot from getting too large, the chemical fibrin works to absorb and inactivate clotting factors, keeping the plug localized. Fibrinolysis is the process of dissolving a clot, in which plasminogen in the clot is activated by the endothelium to become plasmin or fibrinolysin to digest the fibrin and inactivate clotting factors.

Just keeping the vessels and blood healthy is a complex task for the body. The endothelium should be reactive and elastic to allow passage of blood, while the blood itself cannot be too sticky or viscous, which could impede circulation and undermine vascular health. Fortunately, there are a host of nutritional compounds that can support the structure of the blood vessels, enhance the reactivity of the vessels, and address blood viscosity to avoid thrombosis.

Not surprisingly, the health of the vascular system begins with the diet. Studies consistently show following a more Mediterranean-style diet—high in fruits and vegetables, whole grains, polyunsaturated fats and fish—is beneficial to the circulatory system. German reviewers noted such a diet has synergistic activity on haemostasis, endothelial function and vascular inflammation.¹ Further, a review out of Pennsylvania State University, University Park, examined the impact of antioxidant foods on vascular health and found dietary consumption of fruits and vegetables, red wine, tea, chocolate and olive oil may improve vascular reactivity and positively impact endothelial function.²

Population and intervention studies support the theory. Boston researchers examined data from 690 women in the Nurses’ Health Study and found higher diet quality scores—particularly on the Mediterranean Diet Index—were associated with lower concentrations of markers of endothelial dysfunction and inflammation.³ A team out of Spain examined the chronic effect of three diets—Western, Mediterranean or low-fat enriched in alpha-linolenic acid (ALA)—on postprandial endothelial function and inflammation in 20 healthy men.⁴ The Mediterranean diet, rich in monounsaturated fatty acids (MUFAs), had the greatest positive effect on endothelium-dependent vasodilatory response and NO bioavailability, while also significantly lowering plasma levels of vascular cell-adhesion molecule. Similar findings were reported by another Spanish team, which found adding walnuts (rich in MUFAs) to a high-fat meal could improve flow-mediated dilation (FMD) and decrease plasma concentrations of inflammatory cytokines and adhesion molecules.⁵