Hypertension – A Silent Killer
Hypertension, the Silent Killer, is a Top Cause of Mortality in Adults
Hypertension remains the most crucial risk factor for cardiovascular disease. Close to six million adult Australians have hypertension (>140/90 or taking medication). This represents 33.7% of adult Australians.
Hypertension is the top cause of mortality in U.S adults, and despite the fact that nearly one third of adults live with hypertension, even more concerning is that almost half of them are unable to successfully manage it. Nearly 7.5 million deaths (or 12.8 percent) of the total of all annual deaths worldwide occur due to high blood pressure. If the number of individuals with prehypertension (120–139 mmHg systolic blood pressure [BP] and 80–89 mmHg diastolic BP) were included in these statistics, the number of individuals with less-than-optimal blood pressure rises significantly.
Hypertension is a Precursor to more Serious Cardiovascular Conditions
Although on a broader view hypertension leads to chronic heart disease, stroke, and coronary heart disease, more specific outcomes of hypertension include heart failure, peripheral vascular disease, renal impairment, retinal hemorrhage, and visual impairment. In some ways, hypertension can be a more dangerous condition than initially assumed because it is a silent killer in that the traditional symptoms of headaches, lightheadedness, vertigo, altered vision, or fainting episodes are rarely experienced by the majority of those with abnormal blood pressure.
Since the prevalence of hypertension has been steadily rising, potential causes have been identified but primarily point to progressive changes in lifestyle, including rapid urbanization, mechanization, sedentary life, dietary changes, and also an increasing elderly population. Obesity is clearly the greatest risk factor of hypertension but is also correlated with more urbanized lifestyles. With lifestyle changes being primary roots of hypertension, it should follow that lifestyle changes are also a significant part of the solution. Further, medications are not always effective at controlling hypertension, leading to resistant hypertension.
Exercise Supports Management of Hypertension
Evidence from numerous randomized controlled trials shows that exercise is an effective means of managing resistant, arterial hypertension. As stated in a 2018 review in Integrative Blood Pressure Control,
“There is a general consensus that aerobic exercise training reduces SBP and DBP of hypertensive patients; a meta-analysis of randomized controlled trials lasting ≥4 weeks concluded that aerobic exercise significantly decreases office SBP (−8.3 [range −10.7 to −6.0] mmHg) and DBP (−5.2 [range −6.9 to −3.4] mmHg) in hypertensive patients.”
In another meta-analysis of 64 controlled studies involving a total of 2,344 adults with hypertension, reductions in systolic BP were as great as −16.0 mmHg among adults with untreated hypertension when they engaged in more than 8 resistance exercises per session with an average of 3 sessions for a duration of 6 to 48 weeks. Exercise does not have to be limited to traditional forms of aerobic or resistance in order to receive the benefits of a lowered blood pressure. Combination (aerobic and resistance) exercise also improves blood pressure.
Sunlight and the Vitamin D Deficiency Epidemic
Our urban lifestyles have also moved a greater portion of society indoors, whether that be the home or office, and out of the bright sunlight. As a result, we are witnessing epidemic numbers of individuals with a vitamin D deficiency. Low levels of vitamin D have been directly associated with elevations in blood pressure, due to its association with dietary calcium and phosphorus absorption, regulation of the renin-angiotensin-aldosterone system (RAAS) and renin gene expression, modulation of immune and inflammatory pathways, and activity in endothelial function – all of which influence blood pressure.
Systematic reviews and meta-analyses cannot confirm that a vitamin D deficiency alone is responsible for rises in blood pressure. Not all studies using vitamin D supplementation were able to show a positive association with blood pressure; however, exposure to sunlight was positively associated with lower systolic blood pressure. Some studies suggest that exposure to UVA/UVB rays in sunlight could induce a transient vasodilatory effect and increase circulating amounts of nitric oxide, which will lower blood pressure.
Fresh Potassium Rich Foods are Important
Dietary potassium is directly associated with blood pressure. As our diets have become increasingly processed with a focus on convenient food options (even among “healthy” foods), the quantity of fresh fruits and vegetables, which are the richest sources of potassium, have declined. Frozen fruits and vegetables have limited potassium compared to their fresh counterparts. The potassium:sodium ratio is a strong influencer of blood pressure. But we have focused so much attention on improving this ratio by lowering sodium without giving proper attention to increasing potassium. In one study, when hypertensive patients increased dietary potassium, 81 percent of the subjects needed less than half of the baseline medication and 38 percent required no antihypertensive medication. In the DASH trial, a diet rich in fruits and vegetables reduced systolic pressure in the 133 hypertensive subjects by 7.2 mm Hg and diastolic pressure by 2.8 mm Hg, at a constant level of sodium intake, indicating potassium alone can modulate blood pressure.
Hypertension is certainly a multi-faceted issue and some cases are more complex than others, but it is also a highly prevalent condition, contributing heavily to our mortality rates, and one that is can be addressed in most individuals with attainable lifestyle changes. Committing to an active lifestyle, getting outdoors more often, and eating adequate amounts of fresh fruits and vegetables are changes that should be fully encouraged in order for individuals to reduce their risk of hypertension.
By Designs for Health Australia and USA research teams
By Designs for Health Australia and USA research teams