To the common man sugar is blood sugar and blood pressure is high blood pressure. Sugar causing high blood pressure is a concept one cannot even dream of. For ages now salt has been blamed for raising blood pressure. Doctors have advised people suffering from high blood pressure to reduce salt consumption. Since the sodium present in the salt was held responsible in raising blood pressure low sodium varieties of salt were being sold in the market.
Recent research has however pointed out that blaming salt for raising blood pressure is not evidence based. It is sugar which in fact is more responsible for raising blood pressure.
So before understanding how the mechanism works let us understand the basics of high blood pressure.
What Is High Blood Pressure?
High blood pressure is also known as hypertension. It is a condition in which the pressure of the blood is higher than normal against the arteries. The amount of blood pumped by the heart and the resistance the artery walls provide against the blood determines the level of blood pressure.
When the heart pumps more blood than needed, or when the arteries become narrow or inflexible blood pressure increases.
Normal blood pressure is considered to be 120/80 mmHg where 120 is the systolic blood pressure value. This is the pressure of blood when the heart pumps out blood. 80 is the diastolic blood pressure, that is, the pressure of the blood when the heart is relaxed.
When the systolic blood pressure is found to be more than 140 mmHg (millimetre mercury) or the diastolic blood pressure is found to be more than 90 mmHg (millimetre mercury) it is considered to be high blood pressure. This pressure must be measured at two intervals six hours or more apart. Only one measurement is not reliable because the high pressure might be a transient event because of:
- Fight/ Flight/ Fear.
Untreated high blood pressure can pose several health risks like narrowing and bulging of blood vessels; heart diseases such as coronary artery disease, left ventricular hypertrophy and heart failure; Glomerulosclerosis (scarring of the kidney from damaged renal blood vessels), kidney failure (from extensive kidney scarring); Transient Ischaemic Attacks or TIA (ministrokes), strokes(due to reduced blood flow to the brain and hypoxia); Retinopathy(retina damage), Choroidopathy (choroidal damge), Optic neuropathy (optic nerve damage).
Symptoms Of High Blood Pressure
High blood pressure is a fairly common problem these days. Many people who suffer from high blood pressure have no overt symptoms. Only during a routine check-up, their high pressure is detected. For this reason it is very important that a person gets his blood pressure checked regularly.
Some people experience certain symptoms if their blood pressure increases above the normal level. They are as follows:
- Feel jittery and anxious
- Facial flushing or a burning sensation of the face
- Nasal bleeding
- Shortness of breath.
Waiting for these symptoms to appear is quite risky. Moreover, they might not be good markers of high blood pressure as well. These symptoms generally appear in case of a hypertensive crisis which can be life threatening. A hypertensive crisis is when the systolic blood pressure is above 180 and the diastolic blood pressure is above 110. If this is the case then the person needs emergency medical care.
Why Was Salt Blamed For Raising Blood Pressure?
Previously it was believed that excess amount of salt is responsible for altering the homeostasis of the body. This could lead to long term health hazards like high blood pressure, cardiovascular diseases, etc. Research studies were conducted where a person’s normal diet was replaced by fruits and vegetables. It was found that blood pressure could be kept in check after executing this diet plan. However, the results are now being reconsidered. It is true that a diet rich in fruits and vegetables does not contain added salt but at the same time it does not contain any added sugar too. Moreover, the role of sugar was overlooked while interpreting the results.
Contrary to popular belief salt has various health benefits. They are as follows:
- It is responsible to maintain the concentration of blood, plasma, and other body fluids.
- Salt is responsible for carrying various nutrients into the cells and out of it.
- Blood pressure is maintained and regulated.
- Salt can increase the glial cells of the brain.
- Useful in the generation of action potential to help in neural communication within the body.
- Salt loss can lead to fainting.
- Low levels of sodium can lead to a condition called hyponatremia. The symptoms of hyponatremia are as follows-
- Change in appetite
- Reduced energy level
- Urinary incontinence
- Problems relating to mood
- Muscular weakness, spasms, cramps
How Is Sugar Responsible For Raising Blood Pressure?
Recent reports emphasize that added amounts of sugar can raise blood pressure. Fructose in particular is to be blamed for this rise. In addition, it has also been found that fructose is highly responsible for raising cardiovascular risk among patients. However intake of a solution of glucose did not lead to the same findings.
Ingestion of fructose changes the homeostasis of the body. The hypothalamus, a key region of the brain, is affected due to the changes in the homeostasis. The hypothalamus is connected to the pituitary gland. When the hypothalamus is activated, it send signals the pituitary gland to produce various hormones that reach various other glands like thyroid, adrenal, etc. which then starts releasing more amounts of hormones that these glands are supposed to produce. Moreover, hypothalamus is also responsible for stimulating the sympathetic nervous system. When the sympathetic nervous system is stimulated various changes start happening in the body. They are as follows:
- Metabolism is affected in the body.
- Pupils dilate
- Heart rate increases and contractions are forceful
- Rate of respiration increases as myocardial oxygen demand increases
- Sweat glands start secreting
- Peristalsis is inhibited in the digestive tract
- Renin secretion increases in the kidneys
- Blood vessels dilate in the skeletal muscles and blood pressure increases.
Thus, the various hormones which are at an imbalanced state and the various bodily changes that occur as a result of activation of the sympathetic nervous system due to the stimulation of hypothalamus causes increase in heart rate, secretion of renin, more sodium retention by the kidney, and vascular resistance increases. All these conjointly lead to the increase of blood pressure in the individual.
Sugar also raises the insulin levels of the blood. Increased levels of insulin lead to storage of body fat giving rise to obesity, which again is a primary risk factor for diabetes and hypertension.
Furthermore, fructose metabolism leads to an increase in uric acid. The raised uric acid is also responsible for raising blood pressure.
Foods That Are Rich in Fructose and Increases Blood Pressure
The food which are high in fructose and added sugar are carbonated drinks and beverages, fruits and vegetables like banana, kiwi, cherry, blackberry, mango, tomato, dates, asparagus, beans, broccoli, etc., processed foods like barbeque and pasta, dried fruits, etc.
Thus a person who is at increased risk and also those who are already suffering from hypertension must be cautious about the intake of added sugar or fructose in their diet. These people must also try to avoid the processed and packed foods which are generally very high in added sugar. Moreover, in contrary to the earlier belief, they should include salt in their diet so as to utilize its positive effects on the body. However, the quantity must not exceed the limit.