Published on 08/20/2007

High Blood Pressure

What is high blood pressure (hypertension)?

The heart's function is to pump blood through the arteries, around the body. When the heart pumps, the blood presses against the walls of the blood vessels. The pressure in the blood vessels depends on how much resistance there is from the arteries. Therefore slight narrowing of the arteries increases the resistance to blood flow, which in turn increases the blood pressure. In this respect, people who suffer from hypertension have an abnormally high blood pressure.

What causes high blood pressure?

Blood pressure is usually divided into two categories, primary and secondary. Primary hypertension is high blood pressure that is not due to another underlying disease. The precise cause is unknown, but a number of definite risk factors have been identified.

These include cigarette smoking, lack of exercise, stress, obesity, high cholesterol levels, excessive use of stimulants such as coffee or tea, drug abuse, being male, diabetic, high sodium intake and a strong family history of heart disease or stroke. Because too much water retention can exert pressure on the blood vessels, those who consume foods high in sodium may be at a greater risk for high blood pressure. Elevated blood pressure is also common in people who are overweight. Blood pressure can rise due to stress as well, because stress causes the walls of the arteries to constrict. When persistently elevated blood pressure arises as a result of another underlying health problem, such as hormonal abnormality or an inherited narrowing of the aorta, it is called secondary hypertension.

A person may also have secondary hypertension because the blood vessels are chronically constricted or have lost elasticity from a build up of fatty plaque on the inside walls of the vessel, a condition known as atherosclerosis. Arteriosclerosis and atherosclerosis are common precursors of hypertension. The narrowing and/or hardening of the arteries makes circulation of blood through the vessels difficult. As a result, blood pressure is elevated. Secondary hypertension can also be caused by poor kidney function, which results in the retention of excess sodium and fluid in the body. This increase in blood volume within the vessels causes elevated blood pressure levels. The kidneys may also elevate blood pressure by secreting substances that cause blood vessels to constrict.

What are normal and high blood pressure values?

Blood pressure is measured in millimetres of mercury (mmHg) and is recorded as two figures, for example 140/85 mmHg. The first number is the systolic pressure and this is the pressure in the arteries when the heart contracts. The second number is the diastolic pressure and this is the pressure in the arteries when the heart rests between each heartbeat.
Normal blood pressure is less than 140/90 mmHg, mildly high blood pressure is 140/90 mmHg or above, but below 160/100 mmHg, and high blood pressure is 160/100mmHg or above.

How common is high blood pressure?

In the UK, above half of people over 65, and about 1 in 4 middle-aged adults have high blood pressure. It is less common in younger adults.

What are the symptoms of high blood pressure?

High blood pressure usually causes no symptoms. However, over the years, high blood pressure may do some damage to the arteries and put strain on the heart. If blood pressure is elevated, the heart must work harder to pump adequate amounts of blood to all the tissues of the body, and ultimately, sooner or later, the excess stress on the heart will take its toll on our health. In general, the higher your blood pressure above normal, the greater the health risks. Warning signs associated with advanced hypertension may include headaches, sweating, rapid pulse, shortness of breath, dizziness, and visual disturbances.

What are the health risks associated with high blood pressure?

If you have high blood pressure you may have an increased risk of developing health risks such as heart disease, stroke, vascular disease, and kidney damage. It is estimated that reducing a high diastolic blood pressure by 6 mmHg reduces your relative risk of having a stroke in the future by about 35-40%, and reduces your relative risk of developing heart disease by about 20-25%.

What can you do to lower your high blood pressure?

In some cases blood pressure can be reduced by:

Losing weight:

May reduce the amount of blood-circulating fats that lead to the constriction of the blood vessels caused by the build up of fatty plaque on the inside walls of the vessels (atherosclerosis).

Regular exercise:

Can lower blood pressure by lowering blood lipid levels and reducing stress levels. Try and get 30 minutes of exercise a day by brisk walking, cycling, swimming or dancing. Avoid strenuous exercise that may increase blood pressure, such as intensive training and sprints.

Eat a healthy diet:

Plenty of vitamins, fibre and other nutrients will lower cholesterol, control your weight and so help prevent hypertension.

Here are a few recommendations:

1.	Lower your salt intake. The more salt we eat, the higher our blood pressure. Salt also causes other health problems such as water retention, osteoporosis, and kidney disease. Therefore follow a low salt diet. This is essential for lowering blood pressure. Everybody should try and cut down their salt intake to 5 to 6 grams a day or less. Most salt in our diet comes from processed foods and people are unaware of how much salt is present in these foods. Read labels carefully and avoid those food products that have "salt", "soda", "sodium" or the symbol "Na" on the label. Do not add salt to your food at the table or whilst cooking. Use herbs and spices to flavour food rather than salt. Avoid stock cubes, gravy, soy sauce and salted dried fish, all of which are very high in salt.
2.	Eat a high fibre diet and take supplemental fibre. Oat bran is a good source of fibre. (Always take supplemental fibre separately from other supplements and medication.) Eat grains like brown rice, buckwheat, millet and oats.
3.	Eat plenty of fruits and vegetables, such as apples (apple pectin aids in reducing blood pressure), asparagus, bananas, broccoli, cabbage, cantaloupe, eggplant, garlic, grapefruit, green leafy vegetables, melons, peas, prunes, raisins and sweet potatoes.
4.	Avoid animal fats such as bacon, beef, chicken, liver, corned beef, dairy products, gravies, pork, sausage, and smoked or processed meats. You may eat white fish and skinless turkey or chicken in moderation.
5.	Use low fat, monounsaturated or polyunsaturated spreads. If you do fry, choose a vegetable oil such as sunflower, rapeseed or olive oil.
6.	Avoid foods such as aged cheeses, aged meats, anchovies, avocados, chocolate, pickled herring, sherry, sour cream, wine, and yoghurt.
7.	Avoid the artificial sweetener aspartame, which contains phenylalanine.
8.	Reduce alcohol intake to 1-2 units per day and reduce your caffeine intake, as caffeine drinks such as tea, coffee and cola can cause a small increase in blood pressure.
9.	Include 2-3 portions of fish per week, at least one of which should be 'oily' (such as herring, mackerel, sardines, kippers, pilchards, salmon, or fresh tuna). Use fresh fish rather than canned or processed. Oily fish are rich in omega 3 fatty acids which, if eaten regularly, can reduce blood pressure. One study showed that 3g of fish oil supplement taken on a daily basis can reduce blood pressure. Therefore supplementation would be a good alternative for people who do not like consuming oily fish. Oily fish can also lower cholesterol levels, therefore reducing another risk factor that is associated with high blood pressure.

Have your blood pressure checked:

At least every four to six months. Because hypertension often shows no signs, regular blood pressure checks by a professional are important.

Because high blood pressure usually causes no symptoms until complications develop, it is known as the 'silent killer'. Therefore, to avoid the health risks, you should go for a routine check up with your GP, who can easily diagnose high blood pressure by using a sphygmomanometer. Some risks of hypertension cannot be changed, such as a family history of the disease for instance. However, many risk factors can be avoided by making simple changes in the diet and lifestyle.

© Samar Tarabay, Quest Nutritionist.

For further information on the Quest range of products or for other nutritional information contact the Quest nutritionists on 0121 359 0056 or email nutrition@questvitamins.co.uk

Acknowledgement.

This article has been supplied by Today’s Therapist Magazine – the Uk’s leading trade journal for today’s therapist. Visit: http://www.todaystherapist.com