HOW A ‘SELFISH BRAIN’ COULD RAISE YOUR BP
Earlier this week, I was diagnosed with hypertension. My hypertension was borderline, but the doctor chose to put me on low-dose angiotensin II receptor blocker drug to relax my blood vessels to bring down my blood pressure to a healthy 120/80 mmHg.
Uncontrolled hypertension, like diabetes, is a risk factor for a clutch of diseases, including heart attacks, strokes and kidney failure. Globally, 62% of stroke and 49% of heart diseases are linked to hypertension, defined as consistently high blood pressure of more than 140/90 mmHg.
There is no apparent physiological cause for my hypertension and there is little I can do to bring it down on its own. I don’t smoke, my weight is perfect for my height, my cholesterol is optimal, my sugar levels are fine, my kidneys are healthy, I don’t care for salted snacks, I’m not on any prescription medicines, I’m not particularly stressed, and I’m fairly active.
I have what is called essential hypertension, because it has no known cause. I’m told it is genetic, which is highly likely because my dad’s been a hypertensive for as long as I can remember, yet he continues to be sprightly and active at close to 80.
SELFISH BRAIN SYNDROME
Curious about what it is that makes my blood pressure freakishly high without reason, I surfed scientific literature and came across professor Julian Paton’s work exploring the link between high blood pressure and the brain.
His focus is on the hypothalamus, the part of the brain that is the centre of the autonomic or sympathetic nervous system that controls temperature, heart rate, blood pressure, hunger and body weight; and the brainstem, which controls heart and respiratory functions.
Paton’s “selfish brain hypothesis” is the newest theory about unexplained hypertension. According to the hypothesis, when the blood flow to the brain is reduced, the greedy brain activates the sympathetic nervous system to send out messages to constrict blood vessels to raise blood pressure and feed more blood to the brain.
A constant demand from an overactive brain results in hypertension. Identifying triggers within the brain that send out the SOS to increase sympathetic nerve cell activity and developing drugs to reverse this could be a therapy of the future.
Till then, there are always the tried-and-tested ways to lower hypertension without medicine.
Eat yoghurt. Women who have five or more servings (one serving is ¾ cup) of yoghurt a week are less likely to be hypertensive than those who rarely have it, found a study of 170,000 people over 30 years presented earlier this month at the scientific Sessions of the American Heart Association. Eating other dairy products, such as milk and cheese, also has a protective effect, but not as great a one as yoghurt, which contains more calcium, potassium and minerals that lower blood pressure.
Dietary fibre. You can’t have too much of it. Having dietary fibre — found mainly in fruits, vegetables, whole grains, legumes and nuts — lowers both systolic (upper reading) and diastolic (lower reading) blood pressure, showed a review of 25 randomised control trials published in the Journal of Hypertension. Dark chocolate. While too much may widen your waist, eating three to four bars of dark chocolate a week lowers hypertension irrespective of age and family history, but it has no effect on heart rate.
Cut down on salt. While your body needs some amount of salt, lowering dietary salt from the current intake of 9 to10 gm/day to the recommended level of less than 5 to 6 gm/day lowers blood pressure and cuts back on heart attack and stroke risk Too much alcohol is trouble. If you must, stick within the recommended limits of three to four units (one unit is 30 ml of spirits, 15 ml of wine and 330 ml of beer) a day for men and two to three for women.
Get active, lose weight. Doing moderate-intensity activity every day in bouts of 10 minutes to build up to at least 150 minutes a week keeps your blood pressure and weight under control.
Take prescription medication. Don’t stop medication just because you’re feeling better or change medicines on your own just because someone tells you it’s working for them. Many people need to take more than one type of medicine to control their blood pressure, and different permutation-combinations work for different people. Stick to what’s prescribed for you. If you want to change your medication, discuss it with your physician.
Like most things in life, hypertension poses no threat as long as you keep it in check.