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Did you know that the leading cause of death in the general population is heart disease? There are several risk factors for heart disease and high blood pressure (BP), known as hypertension, is the leading preventable risk factor.2 High BP negatively impacts almost every organ in the body, especially the heart, blood vessels and kidneys.2 Let’s take a look at the definition of hypertension, its causes, and what we can do to mitigate its negative effects on the body.

Definition of hypertension

Firstly, it is important to define what a high BP is. Hypertension was defined as a systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg. In 2010, the global age-standardised prevalence of hypertension was around 30%. Meaning that a whopping 30 out of every 100 individuals had a high BP.1 In 2017, hypertension was redefined as systolic BP ≥130 mmHg and/or diastolic BP ≥80 mmHg.3  The change in definition was based on findings from several studies that showed increases in the risk of heart disease with increasing BP.1

Looking at the results of 123 clinical trials and over 600 000 participants, a 10 mmHg drop in systolic BP is associated with a 20% relative risk of major heart disease events. Breaking it down, the risk for ischemic heart disease was reduced by 17%, stroke by 27%, heart failure by 28%, and all-cause mortality by 13%.1

Uncovering the culprits of hypertension

Complex interactions between genetic and environmental factors raise BP.2 Aging populations and poor lifestyle is leading to an increase in the prevalence of hypertension globally. As we age, BP tends to increase. Once you reach the age of 35, systolic BP becomes more important than diastolic BP in terms of the risk of heart disease. Men seem to have higher BP at younger ages than women, however, the increase per decade for women is higher than for men. That said, women appear to have a better awareness of high BP, treatment, and control than men!2

Men and women in Sub-Saharan Africa have been found to have higher BP than high-income regions. This could be a result of several social and environmental factors.1 In low-income countries like South Africa, people living in rural areas have lower BP, whereas the opposite is true for high-income countries.1 Urban living in South Africa is associated with a poor lifestyle that drives the increase in BP. I’m not sure what is happening in the rural lives of those in high-income countries to be raising their BP though!

Race and ethnicity also dictate the risk for high BP, where Black people tend to have higher levels compared to White people. It is unlikely that genetics plays a role in this observation, and it is rather due to sociodemographic, environmental, and behavioural factors associated with the various population groups.1

Age, gender, and race are all considered to be non-modifiable risk factors. Unfortunately, we can’t do anything about these risk factors and should rather focus on what we can change. Modifiable risk factors for high blood pressure include:1

• Unhealthy diet
• High sodium intake
• Low potassium intake
• Excessive alcohol consumption
• Obesity
• Lack of physical activity

Power up your prevention and treatment game against hypertension

For individuals with hypertension, modifying lifestyle is strongly recommended as a first-line intervention to lower BP.4 Exercise, the DASH diet, sodium restriction, reducing alcohol intake, and weight reduction have all been shown to benefit the risk of hypertension.5

Dietary Approaches to Stop Hypertension, or DASH diet, involves reducing sodium intake to lower blood pressure.1 The DASH diet is an eating pattern that emphasises large amounts of fruits and vegetables and is high in fibre and potassium. It also consists of whole-grains, low-fat dairy products and limited amounts of red meat.4,5 Sodium intake is limited to 2000 mg per day, which is about 5 g (1 tsp.) of salt.4

In a systematic review and meta-analysis, it has been found that the DASH diet reduces SBP by an average of 3.2 mmHg, and DBP by an average of 2.5 mmHg. The DASH diet has a greater effect on lowering BP in diets with a sodium intake > 2400 mg/day compared with a sodium intake below this. Furthermore, it is more effective in people <50 years.2

The beneficial effects of the DASH diet seem to be more pronounced when accompanied by physical activity.5 Physical activity, even at modest levels, is associated with reduced blood pressure in people with high as well as normal blood pressure.1 People with and without hypertension should engage in 30 – 60 minutes of moderate-intensity dynamic exercise (such as walking, jogging, cycling, or swimming) 4 – 7 days per week on top of routine daily activities. Resistance exercise does not adversely affect blood pressure.4

If consuming large amounts of alcohol, decreasing alcohol intake lowers BP.5 Moderate alcohol intake appears to offer benefits for the heart.5 However, this should be interpreted with caution. If you are not a drinker, it may be best to keep it that way. If you do drink alcohol, consumption should be limited to 1 drink/day for women and 2 drinks/day for men (1 standard drink is the equivalent of 340 ml of beer, 120 ml of wine, and 25 ml of spirits).

Maintaining a healthy body weight is important to prevent the development of hypertension. If an individual with hypertension is obese, weight loss should be promoted. Distribution of excess fat is also important, so aim to keep your waist circumference below 102 cm if you are male and below 88 cm if you are female.4

Stress can also contribute to rising BP levels, and appropriate techniques for managing stress should be utilised.4