High blood pressure affects an estimated 30 per cent of adults worldwide. Photo / Andrey Popov
Yesterday, the world was saddened to hear about the death of Tina Turner, at the age of 83. The legendary singer spent the latter part of her life battling chronic kidney disease, ultimately requiring her to have a kidney transplant in 2017.
What many will have found surprising is that Turner’skidney transplant was linked to her high blood pressure (or hypertension). “If I had known how high blood pressure and kidney disease are connected, I would have been spared a lot of suffering,” she revealed on Instagram, adding that she regretted the fact she’d stopped taking her medication and turned to homeopathy.
High blood pressure affects an estimated 30 per cent of all adults worldwide. Age, smoking, high cholesterol and a diet high in salt are known risk factors, while some people are more genetically susceptible.
A blood pressure reading is always given as two numbers – the first and higher reading is systolic pressure, or the pressure when your heart pushes blood out, while the second and lower reading is diastolic pressure – the pressure when your heart rests between beats. The NHS defines high blood pressure as a reading in excess of 140/90.
“Elevated blood pressure over time hardens arteries all over the body, increasing the risk of generalised cardiovascular disease,” says Dr Arjun Ghosh, consultant cardiologist at The London Clinic.
According to Dr Ghosh, it is vital to address high blood pressure through lifestyle changes such as cutting your salt intake, eating a lower-fat diet, losing weight and exercising more. Hypertension can also be treated with medicines such as ACE inhibitors.
Here are the surprising health benefits of keeping your blood pressure in check.
1. To protect your kidneys
One of the biggest problems with uncontrolled blood pressure is it can exert extreme pressure on the fragile structures within the kidneys.
“Basically, your kidneys are made up of millions of little sieves, which are made up of tiny blood vessels,” says Tom Oates, a consultant physician at Barts Health NHS Trust in London. “So if you have high blood pressure, it will chip away at your kidney function because these sieves are working less well.”
Once kidney damage begins, says Oates, it initiates a vicious cycle that is very hard to stop, as the kidneys themselves are integral to maintaining normal blood pressure. A malfunctioning kidney will lead to higher blood pressure, causing more damage, and so on.
2. To decrease your risk of stroke and heart attacks
High blood pressure is the biggest single risk factor for a stroke and, in fact, is thought to play a role in half of all strokes. It’s also a contributory factor to heart attacks.
According to Oates, the stroke risk is due to a number of reasons. Hypertension can lead to blood clots in the brain, as well as damaging the tiny blood vessels deep inside.
“High blood pressure means it is much more likely the blood vessels will become blocked off,” he says. “Or you can have a hemorrhagic stroke, where the blood vessels can burst due to the pressure.”
Left unchecked, high blood pressure can also damage arteries and cause them to become blocked, preventing blood flow to the heart muscle, putting you at greater risk of cardiac arrest.
3. To preserve your sight
Persistent high blood pressure can damage the fragile blood vessels in the retina, the layer of tissue at the back of the eye that converts light into electrical signals sent directly to the brain, enabling sight.
According to Andrew Lotery, professor of ophthalmology at the University of Southampton, high blood pressure can push fluid out of the blood vessels and into the eye’s tissues. “If blood pressure is very high, it can cause fluid to gather in the back of the eye, leading to swelling of the optic nerves and blurred vision,” he says. “This is a medical emergency as it shows there is a high risk of stroke or heart attack if this blood pressure is not treated quickly.”
Professor Lotery says that over time, elevated blood pressure can also damage the nerves in the eye due to poor blood flow, cause blockages in the arteries that supply blood to the retina and block the veins that carry blood away from the retina, leading to vision loss and ultimately blindness.
4. To reduce your risk of breast cancer
After the age of 65, women are more likely than men to develop high blood pressure - a consequence of birth control medication, pregnancy and the hormonal shifts induced by menopause.
Doctors have found that it is particularly vital for women to keep track of their blood pressure in later life, because when it is elevated, they have a 15 per cent greater risk of developing breast cancer.
Four years ago, researchers at the University of Virginia School of Medicine identified a common link between the two conditions: a protein called GRK4. Increased levels of GRK4 predispose women to developing high blood pressure, while it is also found in breast cancer cells, but not normal breast cells.
Scientists are continuing to investigate this link in case it could lead to new treatment approaches for both conditions.
“Lifestyle measures that improve high blood pressure can also reduce the risk of cancer,” says Dr James Good, clinical oncologist at independent cancer care provider GenesisCare.
5. To prevent tinnitus
Around 15-20 per cent of people experience tinnitus, or persistent ringing, buzzing or clicking noises in one or both ears, causing them considerable distress. Again, people are more vulnerable to developing tinnitus as they age, and high blood pressure can be one of the causes.
According to the Anderson Audiology clinics in Nevada, this is because your ears are a fragile system, relying on an intricate network of blood vessels and fine hairs to help you hear. Just as in the eye, hypertension can cause pressure to build inside these blood vessels, leading to tinnitus. If your tinnitus symptoms are characterised by beating, pulsing or pumping sounds, they may be related to your blood pressure, and could be alleviated by treatment.
High blood pressure can also lead to hearing loss in general, with studies finding that 45- to 64-year-olds with elevated blood pressure were more likely to experience issues with their hearing.
6. To keep your brain healthy
In March, a study of more than 30,000 people found that high blood pressure damages nine parts of the brain linked to memory, language, reasoning and personality.
One of these regions is the putamen, a round structure at the base of the front of the brain which helps with learning. The researchers also found that high blood pressure damages the white matter, which connects different parts of the brain.
Scientists believe this is why chronically high blood pressure can increase your risk of eventually developing conditions such as vascular dementia and Alzheimer’s disease.
“By identifying specific areas of the brain that are damaged by high blood pressure, researchers have taken a significant step forward in our understanding of the concerning link between elevated blood pressure and cognitive decline,” says Professor James Leiper, associate medical director at the British Heart Foundation. “The nine brain areas identified can become new points of focus for further research on how high blood pressure causes damage.”