What serious health condition do you know of that affects one in three South African adults? It is responsible for one in two strokes and two in every five heart attacks, according to the Heart and Stroke Foundation of South Africa.
Yes, you guessed right – high blood pressure.
How can our incredibly well-designed body go wrong in such a high percentage of people? Is this because of genetic changes over which we have no control, or is it related to environmental and personal behaviours that can be modified? What is high blood pressure? Every heartbeat creates pressure in our vascular system. This drives life-giving blood around our 100 000 km of blood vessels. This system is vastly more complex than the water reticulation system of a large city.
However, if all the blood vessels were fully open, the pressure would be too low to perfuse all our body cells. Muscles lining these blood vessels are controlled by nerves and hormones to open or restrict blood to certain areas through highly complex mechanisms. These blood vessels are lined by endothelial cells which provide a super smooth surface. Endothelial cells also produce nitric oxide, a powerful relaxant of blood-vessel muscles. One of the main precursors of nitric oxide comes from our diet, especially green leafy vegetables, carrots and beetroot.
The main contributing factors to high-blood pressure include being overweight, too much salt and too little potassium intake (mostly obtained from fruits and vegetables), lack of exercise, drinking too much alcohol and caffeine-based beverages, smoking, uncontrolled stress, family history of high blood pressure and belonging to certain ethnic groups. Certain diseases can bring on high blood pressure, kidney disease, diabetes, sleep apnoea, certain hormonal problems and auto-immune conditions and medications like contraceptive pills, steroids, anti-inflammatory pain killers, and liquorice-containing medicines.
Understanding these causes offers opportunities for patients to reduce modifiable risks. This is accomplished through lifestyle behaviour change. In many cases it may be possible to restore normal blood pressure, with sufficient commitment. But even adopting some changes can reduce risks. This is not to undermine the secondary role of medications.
The most researched lifestyle intervention is the DASH (Dietary Approaches to Stop Hypertension) eating plan. This promotes eating vegetables, fruits and whole grains; low-fat or fat-free dairy, fish, poultry, beans, nuts and vegetable oils, reducing saturated fats, found in meats and tropical oils, and limiting sugar-sweetened beverages. The DASH eating plan is also low in sodium, and high in potassium. Beneficial effects can already be measured within one week. And in the long term it reduces the risk of heart disease mortality.
Lifestyle-behaviour changes are recommended in the SA National Guidelines for Hypertension as the foundation of managing the disease. But work with your doctor and, if necessary, use medication.
V This health column is written by Dr Dave Glass, a retired obstetrician/gynaecologist living in Somerset West for just over a year. He is also chairperson of the South African Lifestyle Medicine Association (Salma).
V Glass, with an MBChB, FCOG(SA) and DipIBLM, has a passion for preventing and addressing the root causes of chronic diseases.
