Arteries are flexible tubes that carry blood from the heart to every region of the body. They have special properties that ensure they perform this task effectively. However, as we age, several changes occur in these tubes, which lead to serious health conditions such as the formation of plaque in arteries. The question we need to ask ourselves is: Can we prevent some of these changes caused by age?
The three layers of the arterial wall
Before we can answer today’s question, let us take a look at the different components of the arteries. Arteries are composed of three layers, each one with different functions.
1.Inner layer. The innermost layer of an artery is called the endothelium. It provides smoothness by forming a continuous glistening layer that coats the collagen and other materials in the arterial wall. In so doing, it permits blood to flow easily without clotting. It also secretes several components, including nitric oxide (*NO) and angiotensin converting enzyme (ACE). Nitric oxide limits the thickening of the blood vessels. It also inhibits the formation of clots and plaque. ACE stimulate vasoconstriction, although the effects of *NO usually dominate, keeping vessels adequately dilated.
2.Middle layer. The middle layer consists of a thick layer of elastic fibers that make the arteries strong. This layer provides elasticity, which allows the arteries to be stretched outward somewhat each time the heart pumps blood into them.
3.Outer layer. This layer consists mostly of loose connective tissue containing soft gel and fibers. This layer attaches the arteries to other body structures, enabling arteries to be shifted as parts of the body move while preventing the arteries from moving too far out of position.
Changes that occur in the inner layer as we age
Many of the functions of the endothelium continue as we age although there is a decline in the ability of this layer to regulate blood vessels and blood pressure. It may be due to the aging of endothelial cells, to the damage caused by free radicals, or to an increase in blood pressure. Nitric oxide reacts with free radicals producing toxic products that further injure the endothelial cells. These changes may contribute to high blood pressure and to atherosclerosis.
Changes that occur in the middle layer with age
Here, many changes occur. The changes we see as we age are in this area of the arteries include breakage, glycation, and accumulation of calcium and lipid deposits. The accumulation of these substances causes thickening and stiffening of the arteries which in turn cause the arteries to be less elastic. Since the arteries are less able to stretch when receiving the blood, systolic pressure tends to rise.
Atherosclerosis: an arterial disease
Atherosclerosis is a serious condition in the arteries; it is responsible for causing most heart attacks and strokes. It is also a major contributor to kidney disease, and problems in the legs.
Atherosclerosis begins with the formation of streaks of fatty tissue in the inner layer of arteries. Gradually, the streaks widen and thicken as they accumulate a variety of other materials, including smooth muscle cells, collagen fibers, cholesterol, and calcium deposits. The resulting mass, plaque, narrows the passage in the artery.
The plaques often grow quite large, causing blood clots which narrow the interior of the arteries. This narrowing leads to a reduction or even a complete blockage of the blood flow. In addition, pieces of plaque sometimes break off and move to areas where the artery branches to form smaller arteries, blocking the passage of blood.
Plaques can also extend to the middle layer of the artery, causing it to stiffen. When this occurs, arteries are less able to stretch to accommodate the strength of the blood sent by the heart, and systolic pressure can skyrocket. It can also cause weakening of the middle layer, in which cases the artery affected begins to bulge outward from blood pressure. Some arteries become so weak that they rupture, causing severe internal bleeding that can lead to serious strokes.
So, can we prevent the formation of plaque in the arteries?
The seriousness of atherosclerosis can be greatly lowered by avoiding or reducing the risk factors such as:
1.Smoking. Inhaling tobacco smoke increases blood pressure and adds substances in the blood that seem to promote the formation of plaque.
2.High blood pressure. High blood pressure seems to cause repeated minor injuries to the arteries. As the arteries try to repair the damage, they form scar tissue and plaque. High blood pressure also makes the heart work harder, increasing the amount of oxygen it needs, and eventually weakening the heart.
3.High LDL cholesterol. When the level of LDL cholesterol is high, it can accumulate in the walls of arteries and contribute to the formation of plaque. On the other hand, HDL cholesterol reduces the accumulation of LDL.
4.Diabetes type 2. This is a disease that alters many aspects of the body, including blood glucose levels and the maintenance and repair of arterial walls. In so doing, it promotes the formation of plaque.
5.Physical inactivity. The heart of people who are physically inactive gets less exercise because it does not have to work hard. Like every other muscle, heart muscle that gets little exercise becomes weaker. Lack of exercise promotes increases in blood pressure and in the ratio of LDL to HDL cholesterol.
6.Obesity. Being very overweight weakens the heart and makes it less efficient because the heart is being overworked and tends to become invaded with fat. Obesity also promotes high blood pressure, high levels of total and LDL cholesterol, and type 2 diabetes.
7.Stress. A constant high level of emotional tension or stress promotes atherosclerosis by causing prolonged periods of high blood pressure.
8.Other risk factors. High blood homocysteine, family history, menopause, personality, high blood iron levels and periodontal disease are also among the risk factors that can contribute to the formation of plaque in arteries.
Final words
While it is true that there is not too much we can do about our age, -changing our date of birth in our passport or driver’s license won’t solve the issue- we can take some steps to minimize some of the risk factors that cause changes in our arteries as we age. Good nutrition, adequate exercise, and limiting our level of stress can work miracles for us in preventing the formation of plaque in our arteries.
To your health!
Emilia Klapp, R.D., B.S
Emilia Klapp has a Bachelor Degree in Nutrition Science and is certified as a Registered Dietitian by the American Dietetic Association. She counsels and teaches patients who have diabetes type 2, high cholesterol, high blood pressure and are overweight. To read her articles and to receive a list of the calories and sodium content in meals at major fast food restaurants visit her at www.TheDiabetesClub.com