Our circulatory system is how blood reaches our organs and muscles. The necessary blood flow for each organ is precisely adjusted to its needs. Failure in the proper flow of blood may cause many problems in our health and worsen the conditions of our overall wellbeing. The brain and heart are vitally important for our body, so the design of their mechanisms feature even more complexity than any other organ. For example, when you try to solve a difficult mathematical problem, the problem-solving area of the brain starts to work immediately. We can understand this by using fMRI (Functional Magnetic Resonance Imaging) films. Using fMRI, it is possible to see where activity increases in the brain. As activity increases, so, too, does blood flow to that part of the brain. Conversely, when we are asleep, brain blood flow significantly decreases.

At rest, the amount of blood that goes to our muscles is around 1.2 liters per minute. Certain muscles can receive up to 20 times as much during intense sports activity. While doing sports, the organs of the abdomen, the kidneys, and the skin rest, allowing more blood to flow to the muscles, thus reducing the amount of blood they use. While exercising, the amount of blood pumped by the heart, to compensate for the excess blood needed by the muscles, is tripled.

The heart is equipped with mechanisms that can adjust the amount of blood pumped according to the working quantities of the organs – and therefore, their blood needs. This is a complete automatic arrangement; it requires no thought or awareness from us.

If the heart cannot pump enough blood, it is called heart failure, and this means that the heart itself, as well as the brain, liver, kidneys, and all other organs, are not getting enough blood. Failure begins in the liver and kidneys. If the brain does not get enough blood, dizziness, fainting, and other disruptions occur. If the muscles can’t get enough blood, a patient is afflicted by fatigue, weakness, dementia, severe aches, and, of course, the inability to do work.

If the heart pumps too much blood, then many diseases, especially hypertension, appear. This makes the heart tired, as it works too much – and once again, heart failure occurs.

The heart pumps blood to the aorta, which is the largest artery. In the aorta, blood must flow very quickly, ensuring that the organs get the food and oxygen they need. The aorta has the highest blood pressure, since it is the first vessel that receives blood from the heart. The vein wall is created thick, elastic, and robust so that the high blood pressure doesn’t tear it apart. As you move away from the heart, the number of vessels increases, the blood pressure decreases, and the blood starts to flow more slowly; the walls of the veins gradually get thinner.

The capillaries are created with a great structure-function fit. The capillaries, both themselves and their walls, are created to be very, very thin. At the end of arteries, just before the capillary vessels (arteriole), the blood pressure and velocity are reduced. The aim is to prevent the high pressure form damaging these very thin veins. In the capillaries, blood travels slowly. Why? Because these are the shopping veins. The body’s 100 trillion cells get all the oxygen, glucose, fat, protein, vitamins, antibodies, and hormones from these blood vessels. In addition, all cells give their carbon dioxide, urea, creatinine, uric acid, and all other waste products to the blood in the same capillary vessels. If the blood in the capillaries was as fast as in the big arteries, then the vessel could not withstand it, and the blood would tear away the walls without the cells getting their nutrients and without shedding their garbage. And if there was even a little scratch on our vessel, we would not be able to stop the bleeding.

After passing through the capillaries, the blood is accelerated again in the small veins. There is more blood in the veins. The wall of the veins, which are deep below the skin’s surface, is thicker than the capillaries but thinner than the arteries. As the wall is thinner, the internal space is wider; the veins are a kind of bloodstream. The small veins connect to the main veins, which empty blood into the heart. In order to pump blood to the heart, the blood pressure of each pulse must be sufficient for all the blood in the body to be pumped back to the heart. Neither more nor less. The mean blood pressure of the heart is 100 mmHg. At the point where the blood circulating eventually reaches the heart, the mean blood pressure is 0 mmHg. As an example from daily life, it is like you hit a ball with your foot: as the ball reaches its target, its energy finishes and stays at the exact point you want. Our heart reaches the target with every stroke. Thus, at the point where the blood has already completed circulation, the pressure applied to it is zero. Thanks to this incredible adjustment, the heart does not waste power.

The world hypertension statistics

Almost a quarter (26 percent) of the world’s adult population suffers from high blood pressure. It is estimated that this number will reach 29 percent by the year 2025. These average statistics based on the adult population of the world includes people of various age groups and from different countries. The risk of hypertension increases with age. While the figure for 20–29 year old males is 13 percent, it increases to 40 percent between the ages of 50–59, and reaches over 60 percent after the age of seventy. Although there are slight variations in women, many of the figures are almost the same (Figure 1).

These figures are quite striking; one out of every two people over the age of sixty suffers from high blood pressure. As for those in their seventies, the figures have already reached almost 70 percent and are expected to increase even further as this group ages. Many diseases in the adult population remain at 1–2 percent; therefore, these figures convey just how common and serious hypertension really is.

The regional distribution of hypertension figures

In contrast with the estimated numbers given above, the figures for hypertension in the different regions present significant variations. Statistically, the number of hypertension cases increases according to the welfare status of the society. In economically developed countries, 37 percent of the adult population has high blood pressure, which is a considerably elevated number in comparison with the world average of 26 percent. Furthermore, 70 percent of the males and 80 percent of the females over the age of seventy living in economically developed countries suffer from high blood pressure. However, in economically underdeveloped countries, the number of hypertension cases is very low.

The hypertension rates in China and India are well below the world averages, with males at 17 percent and females at just 14 percent (Figure 2). In some societies, for example in the Amazon’s catchment areas, the Yanomami Red-Indians, and tribes in the highlands of Papua New Guinea, few cases of hypertension can be found, and blood pressure among these groups does not tend to increase with age.

The reasons for the increase in hypertension

There is a genetic disposition to develop hypertension. The recent studies reveal that high calorie foods, a high level of salt intake, the lack of physical activity, and alcohol intake all play a significant role in the increase of hypertension. By examining these reasons alone, we clearly see how important the prohibition of alcohol is and the Prophet’s words of wisdom advising us to eat less bear on our lives and prosperity in both this world and the hereafter.

Excess of body fat (obesity)

Another recent health phenomenon is the huge increase in people suffering from obesity, mainly due to excessive eating and the lack of exercise. Studies related to disease outbreaks (epidemiological studies) show that obesity is clearly associated with hypertension. These studies also reveal a significant increase in people suffering from both obesity and hypertension. According to these studies, 78 percent of the male and 65 percent of the female cases of hypertension are connected to obesity. Similar studies carried out in various countries confirm that a large number of people with high blood pressure were overweight and that losing weight substantially reduced their blood pressure levels. In fact, the blood pressure in some was reduced by losing weight alone, without the need of any medication.

Many studies also evaluated the connection between obesity and hypertension by measuring the level of the leptin, the hormone that controls the appetite, in the body. High levels of leptin induce stimulation in the sympathetic nervous system and shrink the veins (causing an increase in blood pressure). Another reason for the increase in the activity of the sympathetic nervous system of overweight people is the rise in insulin levels, which in most people can be controlled by diet. Finally, the kidneys of overweight people retain greater levels of salt and water, which causes an increase in blood pressure. These conditions, which on many occasions can prove to be very serious, are in fact contrary to the intended physical state of human creation, as the Prophet Muhammad, peace be upon him, declared in these words of warning: “What I fear most for my followers is a large stomach, excessive sleep, idleness, and the lack of certainty (in faith).”

Excessive salt and alcohol

Evidence from both experiments on animals and clinical studies proves that the excessive intake of salt increases blood pressure. In animal experiments, a high intake of salt in the diet of rats showed a rise in blood pressure, which resulted in strokes. In another experiment, more than 0.50 ounces of salt was added to the diet of several chimpanzees for a period of twenty months. The studies showed an increase of 33 mmHg in the systolic blood pressure and 10 mmHg in the diastolic blood pressure, and when the salt was removed from the diet, the chimpanzees’ blood pressure returned to normal levels. Indeed, salt is an important nutrient for the human body. Sodium, potassium, and calcium salts are essential for all nerve cell activity, for muscle movement, and for the osmotic balance of body fluids. Medical science of today stresses the importance of natural foods, and bread, an important part of our diet, meets the body’s daily requirement of sodium. Thus adding salt to our food and exhausting the kidneys is not necessary.

Various clinical studies on humans have shown that excessive salt in the diet increases blood pressure levels. Salt has been used in the human diet for the past 8000 years, since the beginning of agriculture and animal farming. A human’s normal requirement of sodium is 8–10 mmol/per day. However, in economically developed countries, the daily sodium intake of most people has risen to 140–150 mmol per day (8–9 grams), almost 14–15 times more than the normal physiological requirement. In a study carried out on the subject, 10,000 blood pressure sufferers in 32 countries were closely monitored, and the results showed that as the salt intake was reduced, blood pressure levels dropped. In another study, 24 hour urine samples were analyzed, and here too, a low sodium diet showed a decline in blood pressure.

One of the many health risks of alcohol is its serious affect on blood pressure. Clinical studies have proved that the excessive intake of alcohol causes high blood pressure. The frequent cases of high blood pressure in societies of the former socialist countries and economically developed countries of the present are mainly connected to the excessive intake of alcohol.

As a result, the number of high blood pressure cases in the world has exceeded that of contagious diseases, and this is closely connected to our eating and drinking habits. If humans continue to excessively eat and drink as they are at the present, most people will be suffering from high blood pressure in the very near future.

Hypertension is one of the most widespread dangerous diseases of this century affecting the young as well as the elderly. It can lead to other, more dangerous conditions, coronary and brain diseases among them.

The two main causes of hypertension are stress and being overweight conditions associated with the life-style of the materially wealthy, industrialized nations. (We may note in passing that Islam forbids excessive consumption whether in or in goods, and it requires the believers to halt their daily routines at least five times a day for prayer – and prayer, standing or sitting in the presence of the All-Mighty, gives due proportion to all human affairs, enabling the worshipper to obtain or recover calm of body and mind.) .

Doctors nowadays recommend patients with hypertension to eat less salty foods, to avoid becoming overweight and to keep fit by doing light but regular, frequent exercise. But; before that, doctors ask them to give up drinking and smoking if they indulge in these habits. (Again, we note in passing that the life-style being recommended makes up a prescription as familiar to Muslims as the Qur’an and Sunna.)

Hypertension adversely affects blood pressure; to keep the pressure at normal level, the blood vessels constrict. That constriction may, in turn, cause damage when it passes beyond certain limits. It can overload the heart, soon leading to coronary vascu1ai diseases. On the other hand, excessive blood pressure not reduced by constriction of the blood vessels may damage the vessels and, subsequently, lead on to brain and liver diseases.

The first measurement of human blood pressure was taken in 1834. An apparatus like the type most commonly used today was introduced in 1896, with some operative improvements in 1906 (Weinstein, 1976). We meet the first accurate descriptions of what we now know as ‘essential hypertension’ in a series of clinical papers by F. A. Mohammed between 1874 and 1881 (Page, 1988).

It comes as a surprise to learn that hypertension was first recognized as a serious health problem only in the late 1930s. During the 1920s, the textbooks used in leading medical schools throughout the world made no mention of hypertension as a problem, let alone as a disease. The association of hypertension with stroke, heart failure and renal failure was still nebulous (Page, 1988).

A research group under Irvine Page were trying to demonstrate the connection between hypertension and coronary heart diseases and to convince the authorities of the time about the importance of treatment for hypertension. When this group announced, with another group of researchers, that they had found a hormone which is very important in the regulation of blood pressure, there was little or no interest. Page’s group had named the hormone ‘angiotonin’, while the others had named it ‘hypertension’. The two groups got together and agreed on the name ‘angiotensin’ for the hormone. Page suggested that angiotensin was one of the important factors in blood pressure regulation. The active form of this hormone, Axigiotensin-2, caused the blood vessels to constrict so that the blood pressure could be kept at a certain level. Therefore, hypertension could be relieved by preventing the synthesis of this hormone.

As the years passed, the number of researchers and organizations working in the field (as well as funding) increased dramatically. Drugs like ‘captopril’ and ‘enalapril’ were developed, which would block the production of angiotensin and hence give some temporary relief to sufferers of hypertension. Today, hypertension is a major medical research area usually carried on under the broad category of brain and cardiovascular research.

When Dr Ibrahim Benter, A Muslim chemist and doctor, came to the Cleveland Clinic to work as a research scientist. Dr Ferrario was the head of the brain and cardiovascular research department. Having worked with Irvine Page at the Cleveland Clinic earlier, Dr Ferrario had been interested in angiotensin for several years.

He had previously shown that Angiotensin 1-7 a trimmed version of the hormone Angiotensin-2, was synthesized in various sites in the human body. However, he was somehow unable to show its effects via live-animal experiments. Despite his reputation, his articles on this particular subject were rejected everywhere. One reason for this was the consensus of the research community that submolecules of Angiotensin-2 were ineffective. After several years of fruitless research, Dr Ferrario had begun to lose hope.

The story of Angiotensin 1-7 attracted Dr Benter’s interest. He had a simple and sound principle: ‘The All-Mighty would never create something that is useless.’ Since angiotensin was synthesized in various places in the body, it should have a definite function. He decided to do some experiments in his own lime during his stay in the Cleveland Clinic. When he mentioned his idea to colleagues some of them smiled and told him not to waste his time. Briefly, they were saying ‘We spent several years and got nothing out of this research; you should not make the same mistake.’ Everybody seemed to have convinced themselves that Angiotensin 1-7 was useless.

However, Dr Benter was determined. He began his experiments using his own set-up and techniques in the expectation of turning up something missed or neglected in previously used methods. Dr Ferrario, having noticed Dr Benter’s efforts, visited him from time to time to see if anything new had turned up. When several trials yielded no positive findings, Dr Ferrario gave up all hope. Not so Dr Benter. I us determination was grounded on his belief that all scientific research is like a prayer to the All-Mighty, and that discoveries are part of the results of the acceptance of these prayers. Since God is the One who makes all progress possible our duty is to work with faith in a systematic way.

Shortly afterwards, he received the reward for his patience, faith and determination. Angiotensin 1-7 was not useless at all. It was a hormone with a function of profound importance – it was just that certain mechanisms in the body hid its effects from being easily observed. When he determined those mechanisms and disabled them, he clearly observed the effects of Angiotensin 1-7. The results were very significant. When acting alone, Angiotensin 1-7 lowered the blood pressure considerably; it could therefore be used as the basis For a new medicine against hypertension, one with fewer side- effects (sec Renter. 1992).

On learning about Ibrahim Benter’s findings, Dr Ferrario gathered all the researchers in the department in Ibrahim’s lab: he wanted them all to see the results. As his colleagues watched the gauges with awe and surprise. Ibrahim was silently thanking his Lord for the success He had bestowed.

They quickly prepared an article, sent grant proposals to relevant institutions and requested support for further research. The response was positive. They were given a research fund of approximately 1.5 million dollars to continue their study. When the official from the funding institution visited them, he said privately to Ibrahim Benter ‘without your findings, this grant would not be possible’.

Dr Ibrahim Benter is probably even now continuing his research on Angiotensin 1-7. When interviewed on the subject, he explicitly asked the following comment to be made public:

This achievement, for which many other more experienced and skilled researchers worked fruitlessly was made possible only by God’s help.’

The story we have just told, is perhaps one example among countless others which demonstrate the role of faith and determination in achievement. If it was successful in bringing an important fact to our attention, or refreshing our confidence in it, then our telling the story has served its purpose. 

REFERENCES

• BENTER IBRAHIM (I 993) ‘Cardiovascular Actions of Angiotensin 1-7’, Peptides, Vol.14. pp.679-89
• PAGE, Revise n. (1988) Hypertension Research: a memoir. Pergamon Press. NewYork.
• WEINSTEIN, MILTON C. (1976) Hypertension: A Policy Perspective. Harvard University Press. Cambridge MA.