February is American Heart Month, a designation intended to remind people to focus on their cardiovascular health. Is it possible to reverse the process of heart disease? Can we make up for the sins of our youth by adopting a healthy lifestyle later in life? This article presents the most current, evidence-based strategies for the prevention of what continues to be the leading cause of death among Americans.

Three Types of Prevention: Primordial, Primary and Secondary

According to the most recent statistics from the American Heart Association, in 2018 nearly 127 million Americans ages 20 years and older were affected by cardiovascular disease (CVD), which includes coronary heart disease (CHD), heart failure, stroke and hypertension. That number represents nearly 50% of that age group. Since 1900, with the exception of 1918 and 1919 when there was a worldwide influenza pandemic, the most common cause of mortality amongst American adults has been CVD. To combat the epidemic of CVD, various preventative strategies have been developed and implemented and they fall into one of the following three categories:

• Primordial prevention refers to measures taken to prevent the development of risk factors. In other words, the focus of primordial prevention is on promoting healthy lifestyle behaviors that will thwart risk factors for CVD from ever arising in the first place.
• Primary prevention refers to actions taken to treat existing risk factors. For instance, a goal of a primary prevention program for an individual who is not meeting physical-activity recommendations, struggles with overweight and has developed hypertension might include increasing physical-activity levels as a way to lower their known CVD risk factors.
• Secondary prevention refers to measures taken to prevent recurrent, clinical CVD-related events. In this scenario, an individual who has experienced a heart attack might be encouraged to attend a cardiac rehabilitation program to change their lifestyle behaviors and help reduce their chances of experiencing another heart attack.      

Primordial Prevention: The Importance of Starting Early

It’s no secret that bad habits, such as smoking, physical inactivity and poor diet, contribute to the development of numerous CVD risk factors, including obesity, high cholesterol, hypertension and type 2 diabetes—a fact that is supported by a considerable amount of research. On the other hand, there is an equal amount of scientific evidence suggesting that adhering to a healthy lifestyle reduces the likelihood of developing these risk factors.

Here are three key pieces of evidence demonstrating the impact of developing risk factors earlier in life versus preventing risk factors altogether in terms of lifetime risk of heart disease: 

• A study focusing on women ages 18 to 39 years found that those with one or more major CVD risk factors (hypertension, high cholesterol, smoking, type 2 diabetes or obesity) were two to 10 times more likely to die from CVD than their same-aged counterparts who had no CVD risk factors.
• According to the results of this study, individuals who reach 50 years of age without any known risk factors have a markedly lower lifetime risk of CVD. Men and women with two or more CVD risk factors had a lifetime risk of 68.9% and 50.2%, respectively. By comparison, men and women with no CVD risk factors had a lifetime risk for CVD of 5.2% and 8.2%, respectively. Moreover, these same researchers reported that men and women who are risk factor-free by the time they reach age 50 live approximately eight to 10 years longer than their same-aged counterparts who have two or more CVD risk factors.
• A research review that combined the results of 18 different studies with a total of a quarter million men and women sought to quantify the lifetime risk of CVD based on risk-factor burden. Among individuals 55 years of age, those with two or more major CVD risk factors had a three- to sixfold increased risk of death from CVD compared to those with an optimal CVD risk-factor profile (i.e., non-smoker, non-diabetic, normotensive and normal cholesterol).

The collective take-home message from these studies is that making it to middle-age without the burden of CVD risk factors is extremely important. Individuals who avoid developing CVD risk factors before they reach middle age are significantly less likely to die of CVD, which underscores the power of primordial prevention. 

Primary and Secondary Prevention Strategies: It’s Never Too Late to Start Making Positive Changes

While ideally everyone would reach 50 without the burden of CVD risk factors, the harsh reality is most individuals in our society will arrive at that age with numerous CVD risk factors in tow, resultant of poor health choices made throughout their life. Now what? Is there any chance for redemption? Next, let’s examine some compelling evidence highlighting that it’s never too late to make up for the health indiscretions of our younger years. 

Eliminate CVD risk factors with the right volume of exercise.

Despite current estimates indicating that more than 40% of American adults have obesity, a substantial portion of these individuals are essentially metabolically healthy. This subset of people who have obesity, often referred to as metabolically healthy but having obesity (MHO), are more resistant to the adverse CVD-related consequences than are those who are considered to have metabolically abnormal obesity (MAO). For example, recent findings from a large prospective study demonstrated that the risks of CVD mortality was 76% lower in those who are considered to have MHO when compared to those who are considered to have MAO. Additionally, research from our laboratory showed that a short-term, 12-week community exercise program can successfully transition individuals from having MAO to MHO by eliminating various CVD risk factors, such as high blood pressure, abnormal blood lipids and elevated blood glucose. We found that a greater volume of personalized exercise is the key to risk-factor elimination, as individuals who performed approximately five hours per week of exercise were nearly 12 times more likely to eliminate CVD risk factors and transition to having MHO than those individuals who only performed one hour per week of exercise. 

The ultimate heart-disease antidote is better cardiorespiratory fitness.

While hypertension, high cholesterol and obesity undoubtedly contribute to heart-disease risk, the most powerful predictor is cardiorespiratory fitness. In fact, research highlights that low levels of cardiorespiratory fitness better predicts an individual’s risk of developing heart disease and heart-disease mortality compared to the previously mentioned CVD risk factors. It’s worth noting that previous ACE-sponsored research found that personalized exercise programming that adheres to the ACE Integrated Fitness Training^® (ACE IFT^®) Model consistently improves cardiorespiratory fitness by 15% in most individuals. Similarly, another ACE-sponsored study showed that personalized reduced-exertion, high-intensity interval training (REHIT) increased  participants’ cardiorespiratory fitness by 12%. These improvements provide substantial heart-health protection, as the scientific literature indicates that for each 10% improvement in cardiorespiratory fitness, there is a corresponding 15% risk reduction for mortality from CVD. Furthermore, an approximately 10% increase in cardiorespiratory fitness has also been linked in previous studies to an increase in lifespan by about two years.

Stop smoking to increase longevity.

A landmark study that followed more than 34,000 physicians for 50 years revealed that lifetime smokers (from adulthood onward) died an average of 10 years sooner than nonsmokers. However, this study also showed that individuals who quit smoking at the ages of 40 and 60 years improved their life expectancy by approximately nine and three years, respectively. Significantly, those who stopped smoking at the age of 30 erased nearly all risk of premature mortality related to their nicotine habit. Regrettably, smoking continues to be the leading cause of preventable disease, disability and death in the US, accounting for more than 480,000 deaths every year, or about one in five deaths. Nevertheless, these statistics do offer some encouraging news: Primary and secondary prevention, in the form of smoking-cessation programs, even when taken up later in life, leads to increased longevity. 

Replace sedentary time with activity.                 

A classic study conducted in the 1950s first brought attention to the insidious health outcomes associated with excessive sedentary behavior. London-based researcher Professor Jeremy Morris showed that the risk of heart attack was more than two times greater in bus drivers compared to bus conductors. A typical day for bus drivers consisted of long periods of sitting during their work shifts. By comparison, conductors engaged in less sitting time throughout their workday because they frequently walked up and down the stairs of double-decker buses and collected the tickets from passengers. This pioneering work proved to be prescient, as an ever-growing body of modern-day research links increased sedentary behavior with poor cardiovascular health. Recent research demonstrated that replacing just 30 minutes of sedentary time with the equivalent of light- or moderate-intensity physical activity reduces the risk of cardiovascular disease mortality by 15% and 45%, respectively.

Healthy lifestyle behaviors reverse heart disease.

Researchers followed heart-disease patients who made widespread lifestyle adjustments to determine how these secondary prevention strategies impacted the progression of heart disease. A total of 48 participants with moderate-to-severe CHD were divided into a usual-care group (who followed the advice of their personal physicians) and an experimental group (who consumed a 10%-fat vegetarian diet, quit smoking and participated in moderate aerobic physical activity, stress-management training and group psychosocial support). Five years later, participants were given angiograms. Individuals in the experimental group experienced a regression in their CHD relative to the control group (in which researchers observed disease progression). Additionally, there were twice as many cardiac events in the control group versus the experimental group over the five-year period.   

Greater energy expenditure leads to coronary artery disease stabilization and regression.

In the early 1990s, researchers completed a milestone study aimed at determining whether the process of coronary artery disease (CAD) could be modified through a lifestyle intervention in patients with known heart disease. After one year, the investigators found an important link between the amount of weekly energy expenditure and the status of CAD in patients. Specifically, those individuals who accumulated approximately 1500 kcal per week of physical activity (which was equivalent to about three hours per week) showed no further blockage of the coronary vasculature. More excitingly, individuals who burned approximately 2200 kcal per week (which was equivalent to about six hours per week) showed a regression in their CAD. This means that at the conclusion of the study, these individuals had less plaque blocking blood flow through the coronary vessels compared to when they started the research trial. These results are compelling and encouraging, particularly for those who have been diagnosed with heart disease, because they suggest that this chronic condition can be successfully managed with secondary prevention if the client is willing to do enough exercise.

It’s worth noting that the volume of exercise required to elicit CAD stabilization equates to current national physical-activity guidelines (i.e., 30 minutes of moderate-intensity exercise most days of the week). However, if a client is hoping to regress their CAD, the volume of exercise must be doubled to one hour per day virtually every day of the week.          

Summary

As a health and exercise professional, you recognize the tremendous upside of promoting primordial prevention of heart disease in clients whenever possible. However, given the current widespread prevalence of obesity, diabetes and heart disease, you are more likely to work with clients who require primary and secondary prevention strategies. Nevertheless, regardless of the “health sins” committed by your clients in their earlier decades, it is reassuring to know that it is never too late to seek redemption by adopting healthy lifestyle behaviors. 

Expand Your Knowledge

	Case Study: A Healthy Lifestyle Get a first-hand look into the struggles and successes of physical-activity and health-related lifestyle changes.
	Cardiovascular Training for Clients Who Have Obesity: A Trainer’s Guide to Analysis, Design and Execution This course features an informative, step-by-step how-to cardiovascular programming guide you can use to support clients who have obesity.
	Practical Tools for Cardiorespiratory Training Gain practical tools to deliver individualized cardiorespiratory programs—in-person and virtually—that facilitate adherence and goal attainment.