Written by Manuel Seraydarian
Dams serve the purpose of holding water back to contain it in a reservoir for use as a water supply or produce electricity, as well as preventing whole-scale flooding during torrential rainfall. After several years of exceptional drought, the Oroville Dam in northern California is blocking the movement of water from the now fully-filled Lake Oroville, which earlier this year threatened the lives of about 188,000 people living near the dam. The threat was caused because of a crater in its main spillway that eroded the ground beneath, but water levels were so high that they seeped over the emergency spillway [1]. In this case a dam is useful in having saved so many lives, but what if there was a similar conceptualization of a dam, but within your artery?
You can think of an artery as a fast-flowing river, circulating oxygenated blood throughout your entire body. But if you dammed up the artery, just like Lake Oroville, it would block the movement of the necessary components needed to nourish your cells, remove wasteful products, and the ability for your immune cells to reach regions compromised by pathogens [2]. But why should humans worry about their arteries potentially being barricaded?
What is the Obstructive Threat? Atherosclerosis affects arterial blood vessels due to the severe thickening of the normally elastic arterial walls, brought on by the accumulation of white blood cells, low-density lipoproteins (LDL), and calcification [2]. A chronic disease that remains asymptomatic until it starts causing physiological consequences, atherosclerosis is caused by decades of arterial damage, mostly because of lifestyle and a fatty diet. It is the pervasive consumption of foods containing high levels of cholesterol and triglycerides, combined with a sedentary style of living that promotes arterial deterioration [3].
Cellularly, What is Happening? The hardening of the arteries is a slowly progressive condition resulting in the accumulation of fatty material underneath the arterial smooth muscle, making the arterial walls bulge out into the blood vessel and interfere with blood flow [3]. Figure 1 depicts the meticulous procedure for which plaque builds up over time [4]. The presence of low-density lipoproteins, which transfer fats, such as cholesterol and triglyceride around the body to be taken up by cells, can be oxidized, thus damaging cell membranes, proteins, and DNA. White blood cells, specifically, monocytes and macrophages, engulf these fatty substances, thus becoming foam cells due to the high lipid content [5]. Attacks by these white blood cells cause severe inflammation and produces a fatty streak. This internal warzone propagates the plaque buildup, especially with the calcification of smooth muscle cells which crystallizes and forms a rigid outer layer that extends into the blood vessel. The fatty deposits, atheroma, release enzymes that further enlarges the artery, risking clotting of the blood vessel, impeding blood flow, and increasing blood pressure [5].
How to Prevent and Treat Atherosclerosis? If left untreated, atherosclerosis becomes a foremost cardiovascular disease that can potentially lead to stroke, aneurysm, myocardial infarction (heart attack), and or claudication, which is insufficient movement of blood to the legs [5]. Prevention is brought through direct individual action by ceasing smoking, dietary restrictions, and a more actively physical lifestyle. Treatment would have to consist of a change in diet, specifically to a more Mediterranean cuisine, surgery if the artery disease is life-threatening, and or adhering to the medication, statins, which inhibit the pathway that converts an intermediate to cholesterol, thus reducing its plasma levels [5].
References:
1. “Oroville Dam Risk: Thousands Ordered to Evacuate Homes.” BBC News. BBC, 13 Feb. 2017. Web. 25 Feb. 2017.
2. “What Is Atherosclerosis?” WebMD. WebMD, n.d. Web. 25 Feb. 2017.
3. “Atherosclerosis.” Atherosclerosis. N.p., n.d. Web. 25 Feb. 2017.
4. “Atherosclerosis.” Wikipedia. Wikimedia Foundation, 24 Feb. 2017. Web. 25 Feb. 2017.
5. National Institutes of Health. U.S. Department of Health and Human Services, n.d. Web. 25 Feb. 2017.