Stress: A risk factor for heart disease and stroke
While February brings to mind red hearts and Valentine’s Day, it’s also the month we draw attention to cardiovascular health. Originating in 1964 by Presidential Proclamation, February as American Heart Month was established to bring awareness to the increasing problem of heart and vascular disease. Nearly 60 years later, according to the WHO and CDC, heart disease is the leading cause of death worldwide and in the US. A report from the American Heart Association in 2016 stated that as of 2013 cardiovascular disease accounted for nearly 1/3 of all deaths in the US.
Maybe you or someone you know have high blood pressure, high cholesterol, or have gone through a major cardiovascular event like a heart attack or stroke. In the last few years sudden cardiac events have gone up significantly. Fortunately, with proper medical attention these conditions can be detected and treated, however in cases of a severe cardiovascular event without immediate medical attention the consequences are dire.
These unfortunate statistics reflect a dilemma of modern life; cardiovascular disease (CVD) is largely a matter of lifestyle. You may already be aware of risk factors such as smoking, lack of exercise, and a poor diet, but there is an often-overlooked contributor that deserves more attention. There is an increasing body of research implicating psychosocial stress, the stress we feel mentally and emotionally, to be an independent risk factor for heart disease and stroke. A very eye-opening study that demonstrated this occurred in Germany during the 2006 football (soccer) World Cup where they studied cardiovascular events in conjunction with the immensely popular playoff games in Europe. They found that on days of very suspenseful games, cardiac events doubled!
To explain how stress affects the heart and blood circulation let’s start with an overview of how the body’s stress system works. As the body constantly senses our internal and external environments, the brain processes this data and transmits a response through a special part of the nervous system called the autonomic nervous system or ANS. The ANS is composed of two parts, the parasympathic (PNS) that activates rest and recovery; and the sympathetic (SNS) that activates the stress response. While both systems are working all the time, often one is more dominant. For example, when we sleep the PNS is more active and when we are upset or physically active the SNS dominates. It’s important to note that when the SNS and stress response are activated, the PNS is suppressed, thereby impairing rest and recovery. Both the PNS and SNS are necessary, however when the stress response is activated for prolonged periods, is when problems can occur.
To further explain the stress response, we must talk about how the nervous system connects to our hormones. When stress activates the SNS, it signals the release of stress hormones from our adrenal glands. These hormones include adrenalin, noradrenaline, and cortisol. Among other effects, these hormones wake us up, release stored glucose, and stimulate our muscles including the heart. We feel the effects as mental alertness, pounding in the chest or sometimes anxiety.
An example of how extreme emotional stress can affect the heart is “broken heart syndrome” or takotsubo cardiomyopathy. This is where the heart muscle becomes severely weakened from extreme emotional stress such as grief. This very high emotional state can literally cause heart failure.
While not as drastic; moderate prolonged stress depletes energy at a cellular, tissue, and organ level. Our most important muscle, the heart, needs a constant supply of energy, oxygen, and nutrients; while requiring the constant removal of wastes. With prolonged stress and less time in a restful state, metabolic balance is impaired. Since the heart and vessels supply the entire body, you can imagine that a circulation problem will affect many other areas.
Another way stress impacts cardiovascular health is blood glucose homeostasis. As mentioned above, stress hormones increase the release of stored glucose into the blood. These hormones can increase sugar cravings, driving someone to consume more sugar, compounding the problem. Elevated blood sugar or hyperglycemia damages blood cells, vessel walls, impairs circulation and contributes to artery disease. Through these effects and other mechanisms, stress also increases vasoconstriction (narrowing of vessels) and an increased tendency for blood to inappropriately clot. These issues also contribute to increased blood pressure and heart rate, further straining our circulatory system.
One of the most important areas of research on cardiovascular disease relates to stress’ effect on our immune system. During stress the immune system is partially suppressed and activates a more inflammatory state. A number of studies have identified some of the pathways that lead to these changes. For instance, the bone marrow is signaled to make more pro-inflammatory neutrophils and monocytes. At the same time, the immune system is impaired from fighting infection or searching for pre-cancerous cells. Stress also effects are genes, impairing proper DNA replication by affecting our telomeres that control how many times we can copy our genetic code. This is thought to determine our overall lifespan. Stress can literally accelerate the aging process.
Besides direct cardiovascular effects, stress can also lower sex hormones, contribute to weight gain, and increase physical and mental fatigue.
The human body is an integrated system. Evidence demonstrates the benefit of a multifaceted approach to most matters of health. While quitting smoking and starting an exercise program are worthy goals, we should pause and evaluate our personal stress status. Here are five categories to consider on improving your heart health and addressing the “stress” in your life.
Decrease exposure to external stressors: Life can be unpredictable, but we often worry about things out of our control or may have unnecessary fears. In this electronic age we have 24/7 access to news and communication with the world. Take time to turn off and focus on nature and your immediate surroundings. Limiting your exposure to the news cycle and the sometimes stress-inducing social media might be a worthy goal. If you are struggling with interpersonal relationships seek to find resolution. Don’t be shy about seeking help.
Find a personal practice that relieves stress: Consider meditation, breathwork, prayer, journaling, and healthy social activities. Focused breathing alone can lower your stress hormones. Pick one area to focus on this month.
Add something new and nourishing to your diet: Try a new recipe, include colorful vegetables, while reducing sources of concentrated sugar and refined grains.
Consider checking your stress response system: Adrenal function testing can help determine why you may struggle with anxiety, mood imbalance, sleep trouble, high blood pressure and other health concerns related to the body’s stress system.
Check cardiovascular and inflammation status: While a standard blood test and doctor visit can help screen for cardiovascular disease there are additional inflammation and lipid markers such as cholesterol particle size and C-Reactive Protein that more comprehensive testing can provide.
As you think about the ones you love this month, think about caring for your own heart and managing the stress in your life.
**Medical Disclaimer** Please note that the information provided in this blog post is for educational and informational purposes only. It is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read in this blog post.