Ask the Expert

Blood pressure is the force created by the blood against the walls of the blood vessels and it is pumped around the body. We all have blood pressure, without it blood would not be able to flow around the body and our body would not receive the oxygen and nutrients that are vital to life. But, if the pressure is too high, it puts a strain on your arteries and heart, which will increase the risk of heart attack, stroke and kidney disease

In many cases high blood pressure doesn't cause any symptoms, even when it's dangerously high. In fact most people find out they have blood pressure by accident during a routine checkup. A very small number of people with high blood pressure may suffer from headaches or nose bleeds, but the only way of knowing if your blood pressure is high is to have it measured.

In over 90% of cases, the cause of high blood pressure is unknown, but certain factors such as being overweight, smoking , lack of exercise, excessive alcohol intake and stress can increase the risk. High blood pressure also tends to run in families so if your any other members of your family suffer from high blood pressure the chances that you will also suffer are greater. People of African or Caribbean origin also have a greater risk of suffering from high blood pressure.

Although the risk of developing high blood pressure increases as you get older, you can suffer from high blood pressure at any age.

There are several things you can do.

• Eat a healthy balanced low sodium diet which contains plenty of fruit and vegetables.
• Limit your salt intake to no more than 6g/day
• Exercise regularly - aim for 30minutes at least 5 times a week. (for more information go to http://www.cdc.gov/physicalactivity/everyone/guidelines/)
• Keep your weight in the ideal range (for more information go to www.bdaweightwise.com)
• If you smoke, stop (for more information and help go to to www.lung.org/stop-smoking
• If you drink alcohol, stay within the safe guidelines (for more information on guidelines go to www.cdc.gov/alcohol/faqs.htm

Although sodium is indeed vital in the diet the amount we actually need is tiny. Most of us eat around 2.5 times more that we actually need and far more than experts believe is good for us.

Small amounts of sodium occur naturally in many foods including meat, fish vegetables and even fruit but the main source of sodium in our diet salt.

The average daily sodium intake for Americans aged 2 and older is more than 3400mg, this may not sound like a lot but the recommendation from the American Heart Association is that adults should  eat no more than 2300g salt per day. 

The chemical name for salt is sodium chloride and it's the sodium part of salt which is linked with blood pressure.

1 gram of sodium is equivalent to 2.5grams of salt so in to convert sodium into salt you need to multiply by the figure for sodium by 2.5.

As a general rule of thumb - foods that contain more than 1.5g salt or 0.6g of sodium per 100g are high in salt. Foods that contain less than 0.3g salt or 0.1g sodium per 100g are low in sodium. 

There are alternatives like LoSalt, which is made from potassium chloride rather than sodium chloride, that you can use instead of salt. You can also use other flavourings like fresh herbs and spices and lemon juice and zest to add flavour your food  

Potassium helps you kidneys work more efficiently and one of the jobs that your kidneys do is to help control your blood pressure by controlling the fluid stored in your body. The more fluid, the higher your blood pressure. 

A growing number of scientific studies (see references below) suggest that eating diet which is low in sodium and rich in potassium can help to lower blood pressure.

For more information on how to increase the amount of potassium in your diet,visit

Heart.org 

RefL Q. Yang, T. Liu, E.V. Kuklina, W.D. Flanders, Y. Hong, C. Gillespie, et al."Sodium and Potassium Intake and Mortality Among US Adults: Prospective Data From the Third National Health and Nutrition Examination Survey" Archives of Internal Medicine. 2011. 171 (13), 1183-1191

:L.D. Silver, T.A. Farley. "Sodium and Potassium Intake: Mortality Effects and Policy Implications". Archives of Internal Medicine. 2011. 171 (13), 1191 - 1192

Iodine is an essential trace element and a vital component of thyroid hormones, which affect processes such as heart rate and body temperature, and help convert food into energy to keep the body going. Although iodine is essential in the diet there are other healthier ways, rather than getting it from salt, to ensure that your diet contains enough. The Department of Health says you should be able to get all the iodine you need by eating a varied balanced diet. Good sources of iodine include sea fish and shellfish. Iodine can also be found in plant foods such as vegetables and grains but levels may vary depending on the amount of iodine in the soil in which the plants are grown.

Not at all. Usually there is no need to treat low blood pressure and the good news is that people with low blood pressure tend to live longer than people with high or even normal blood pressure. Like high blood pressure, low blood pressure tends not to have any symptoms. However for some people, especially older people, it can cause dizziness or even fainting after getting up quickly from sitting or lying down.