Chapter 5. Lipids

Cardiovascular Disease and Hypertension

Cardiovascular Disease

Cardiovascular disease is the second leading cause of death in Canada after cancer.[1]

The disease generally starts with atherosclerosis, or a hardening of the arteries, a chronic condition so common that most people show signs of it by the time they turn thirty. Arteries start to narrow and harden when fats accumulate along their inner walls and form plaques. A plaque is made of fat, cholesterol, calcium, and other substances found in blood.

Plaque formation causes arteries to narrow and harden, which elevates blood pressure because the vessels can’t expand effectively to accommodate blood pulses. Higher blood pressure strains the heart and causes more damage. Arterial walls can become so weakened due to high blood pressure that they balloon and form what is known as an aneurysm. If the aneurysm bursts, it becomes a life-threatening event. The plaques themselves can also rupture due to a spike in blood pressure or a tremor along an arterial wall, and the body responds to this perceived injury by forming blood clots. These clots are serious health threats, whether they are stationary (a thrombus) or moving (an embolus). A stable clot can slowly kill off surrounding tissue, or grow so big that it blocks blood circulation and causes thrombosis. When a moving clot becomes stuck in an artery too small for its passage, it cuts off blood flow and causes cell death. This is referred to as an embolism. Blood clots in heart and brain arteries can cause heart attacks or strokes.

Table 5.1 The Risk Factors for Cardiovascular Disease

Unmodifiable Risk Factors Modifiable Risk Factors
  • Age. Risk increases for men at forty-five, and for women at fifty-five.
  • Sex. Men have a higher risk than women, though the risk for women steeply rises after menopause.
  • Family history. The more family members who have heart disease, the greater the risk.
  • Cigarette smoking. Nicotine constricts blood vessels, and carbon monoxide damages their inner lining, which increases the risk of atherosclerosis.
  • Obesity. Excess weight worsens other risk factors.
  • Diabetes. This condition is associated with an increased risk of heart disease. Both types have certain risk factors in common, including obesity and high blood pressure.
  • Physical inactivity. Lack of exercise is associated with heart disease.
  • Cholesterol levels. High levels of blood cholesterol can increase the risk. A high level of low-density lipoprotein (LDL), or the “bad” cholesterol, is a common contributing factor. However, a low level of high-density lipoprotein (HDL), or “good” cholesterol, can also promote atherosclerosis.

Steps to Reducing the Risk of Cardiovascular Disease

Diet and nutrition can play a significant role in reducing the risk of cardiovascular disease. It is helpful to lower sodium intake, increase consumption of dietary fiber, and limit consumption of saturated fat, which promotes plaque formation. In addition, it is important to replace refined starches and added sugar, which can boost triglycerides, with whole grains, fruits, and vegetables. Eating foods rich in omega-3 fatty acids, especially fish, using alcohol in moderation, and opting for low or no-fat dairy products can all help reduce your cardiovascular disease risk. Emphasizing vegetable-based sources of protein, such as beans and legumes, can be beneficial, as well as consuming more soy products. It is also important to maintain a healthy weight and avoid smoking or chewing tobacco.

Hypertension

Chronic high blood pressure, also known as hypertension, is a significant health hazard affecting one out of four adults in Canada.[2] This chronic condition is a major cause of heart attacks and strokes, yet it has no symptoms until blood pressure reaches very high levels, which is why it is known as “the silent killer.” The only way to find out if you have high blood pressure is to get an accurate reading of your resting blood pressure rate, which is best done by a medical professional and should be monitored regularly.

High blood pressure is such an important factor in cardiovascular disease, that keeping it within a healthy range is vitally important. Blood pressure readings consist of two numbers. The top number measures systolic pressure (when the heart contracts) and the bottom number measures diastolic pressure (when the heart is at rest). The key blood pressure numbers to keep in mind are:

  • Ideal. 120 over 80 or below
  • Prehypertension. Higher than 120 over 80 and lower than 139 over 89
  • Hypertension. Greater than 139 over 89

Table 5.2 The Risk Factors for Hypertension

Unmodifiable Risk Factors Modifiable Risk Factors
  • Age. After fifty-five, the risk of developing high blood pressure is 90 percent.
  • Race. African-Americans are more likely to develop hypertension, manifest it at a younger age, and have higher blood pressure readings.
  • Family history. There is a strong genetic component to high blood pressure, and an individual’s risk goes up along with the number of family members who have hypertension.
  • Weight. Roughly 60 percent of people with hypertension are obese.
  • Sodium consumption. The more salt in a person’s diet, the more likely they are to have high blood pressure.
  • Alcohol. Drinking more than two drinks per day for men and one drink for women increases the likelihood of hypertension.
  • Diet. In addition to salt and alcohol consumption, other dietary factors increase chances of developing hypertension.

Steps to Reducing the Risk of High Blood Pressure

Although it is not possible to change one’s age or genetics, there are actions that people can take to decrease their risk of hypertension. Techniques to reduce blood pressure include becoming physically active, maintaining a healthy weight, reducing sodium intake below 2,400 milligrams per day (or below 1,500 milligrams if you are in a high-risk group or already have been diagnosed with hypertension), using alcohol moderately, and following the DASH diet. Additionally, vitamin C, calcium, and potassium have all been shown to promote healthy blood pressure. It is also vital to monitor your blood pressure levels on a regular basis. Prompt intervention when readings rise above the ideal level (120 over 80) can save lives, which is why everyone should know the status of their blood pressure.

  1. Statistics Canada. Deaths and causes of death, 2017. https://www150.statcan.gc.ca/n1/daily-quotidien/181129/dq181129g-eng.htm. Updated November 11, 2018. Accessed July 3, 2019. ↵
  2. DeGuire J, Clarke J, Rouleau K, Roy J, Bushnik T. Blood pressure and hypertension. Health reports. 2019 Feb 1;30(2):14-21. DOI: https://www.doi.org/10.25318/82-003-x201900200002 ↵

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