Hypertension: Blame the brain

Daily News Egypt
7 Min Read

Dubbed the silent killer, high blood pressure, or hypertension, creeps up on patients until it is often too late, causing heart attack, stroke and kidney failure. Over 600 million people suffer from high blood pressure worldwide and in over 90% of these cases, the cause of hypertension is unknown. Previous mechanisms of hypertension have focused on the heart, blood vessels and kidney, and current medications used to control hypertension, target various aspects of these organs.

However, research published earlier this week by scientists in the United Kingdom in the journal Hypertension suggests that one of the causes of hypertension may lie in the brain. This study found a new protein, aptly named JAM-1 (junctional adhesion molecule), located in the walls of the blood vessels in the brain of rats, that allowed white blood cells to stick to it, trapping the white blood cells within very fine small blood vessels in the brain stem, and causing inflammation.

This led to obstruction of blood flow and oxygen to the brains of these rats. That this protein can produce high blood pressure and was present in higher amounts in hypertensive rats led these scientists to suggest that hypertension is an inflammatory vascular disease of the brain. Previous research published in 2005 also found the brain to play a role in hypertension; researchers used electrodes to stimulate the brain, initially to control pain in patients, but found that blood pressure could also be controlled with this kind of brain stimulation.

The brain, heart and other organs are all connected through the autonomous nervous system (part of our nervous system that we are not in control of that functions in an involuntary reflexive manner) and so it should come as no surprise that the brain is involved in hypertension. According to the researchers of these studies, their work is expected to point the way forward to future research into this poorly understood disease, and in time, to novel and perhaps more effective treatments. An alarming 60% of patients with hypertension are unresponsive to the current drugs available for this disease and maintain dangerous levels of hypertension.

Hypertension is a dangerous condition to have as it wreaks havoc on your blood vessels over time, causing them to stiffen and harden (atherosclerosis) or tear. As hypertension has few symptoms (some sufferers complain of headaches, nosebleeds, or shortness of breath) this can lead to sudden death, stroke, heart attacks or aneurysm (life-threatening rupture of a large artery, whose wall has weakened).

Furthermore, it is becoming apparent that hypertension can take a subtle toll on your mental faculties, reducing attention, learning, memory and decision-making skills. Recent research published in 2005 in France found that people with high blood pressure are more likely to develop brain abnormalities called white matter hyperintensities (WMH). These WMH were found to be associated with cognitive decline, an increased risk of dementia, and accelerated brain aging in some hypertensive patients. Hypertension can also cause small strokes that may go unnoticed, but which diminish the brain s capacity to function. Some people with chronic hypertension may have small spots on their brain where the tissue is dead.

Clearly, checking your blood pressure at regular intervals is crucial, and the younger you start the better, in order to avoid the debilitating cumulative effects of hypertension.

Normal blood pressure is defined as having a systolic pressure (as the peak pressure in the arteries, which occurs near the beginning of the cardiac cycle) of 120 or below; and a diastolic pressure (the lowest pressure at the resting phase of the cardiac cycle) of 80 or below, measured in millemeters of mercury (mmHg).

High blood pressure is having a reading of 140/90 or higher while a reading of anything between 120/80 and 140/90, means you have prehypertension. Generally, low blood pressure predisposes to a healthier cardiovascular system, unless your levels are so low as to warrant urgent medical attention (due to reduced blood flow to the brain).

Despite hypertension mechanisms being poorly understood, many lifestyle factors have been identified that can affect blood pressure such as; maintaining a diet rich in fruits, vegetables, whole grains and low-fat dairy foods; increasing your potassium intake and avoiding processed foods that are full of salt and avoiding adding salt to foods, especially as many natural foods already contain salt. (Potassium and salt balance each other and a low potassium intake can lead to high salt in cells.

A third of hypertension patients are salt sensitive, which means their blood pressure is increased by salt and these patients should limit their daily salt (sodium) intake to less than 2,400 mg); keeping a healthy weight (obesity increases blood pressure); exercising for at least 30 minutes a day for 5 days a week or more (exercise reduces blood pressure); limiting your alcohol intake to one or two drinks a day; and avoiding tobacco (alcohol and tobacco can increase blood pressure).

Natural remedies of hypertension include garlic, fish oil and hawthorn berry and according to recent studies, cocoa rich dark chocolate and other cocoa-rich products. Prevention is always better than cure; a piece of dark chocolate or cup of hawthorn berry after a good workout surely fairs better than a cupful of medications and a damaged kidney or artery. Wouldn’t you agree?

Dr. May El Meleigyholds a Ph.D in Immunology from the London School of Hygiene and Tropical Medicine, as well as an MSc. (Toxicology/pathology) and a B.Sc in pharmacology) from London University. El Meleigy is a freelance medical/health writer and is currently producing Health Education programs for Egyptian TV.

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