What is high blood pressure?
High blood pressure is a common risk factor for a variety of heart-related conditions, such as a heart attack or stroke. High blood pressure is often referred to as ‘hypertension’, and it means that the amount of pressure to help force blood around the body is too high. A blood pressure reading can tell you how high or low your blood pressure is and reading consists of two types of blood pressure measures; systolic and diastolic. Systolic pressure is a measure of pressure in the arteries when the heart contracts and therefore is always the highest number, and diastolic pressure is a measure of pressure in the arteries when the heart relaxes. A reading of around 120/80 mmHg (systolic/diastolic) is usually considered ‘normal’. (1)
Hypertension is classified into 3 different stages, depending on its severity. Generally, lifestyle recommendations and/or medications are measures used to control hypertension.
There are several reasons why someone may suffer from high blood pressure. Non-modifiable risk factors include age, genetics and ethnicity. Modifiable risk factors are related to lifestyle choices such as high alcohol, poor diet and being overweight. The good news, however, is that this means lifestyle changes can be made to help lower your blood pressure. (2)
The World Health Organisation states that almost half of adults with high blood pressure are unaware they have the condition. This is large because there are often no symptoms to indicate anything is wrong. Sometimes, particularly if hypertension is severe, symptoms such as fatigue, chest pain or muscle tremors may occur. (3) For many people, this means the only way of detecting whether they suffer from high blood pressure is with a blood pressure monitor.
If you are worried you may have high blood pressure or are simply curious, you can get your blood pressure checked at the doctor’s clinic or the pharmacy. Some people suffer from what is called White coat syndrome, where your blood pressure rises due to the stress of being in a health care setting. In this case, you may feel it is worthwhile investing in your blood pressure monitor. Simple monitors are relatively inexpensive. It is important not to diagnose yourself with hypertension, and if you have any concerns about your blood pressure, it is a good idea to seek medical advice. (4)
Effect of diet on blood pressure
Studies have shown that a highly effective method of lowering blood pressure both without medication and alongside medication, is by implementing the DASH diet. DASH stands for Dietary Approach to Stop Hypertension. (5)
Foods to avoid
Salt/sodium
When we eat food containing salt, the body digests the food in the stomach, it is then filtered by the kidneys and some components of the food such as salt (sodium) are reabsorbed by the body and into the blood. When we eat too much salt, the kidney is unable to adequately filter out sodium, causing our blood sodium levels to rise. The body tries to compensate for the salt in the blood and to counteract it by absorbing water. Essentially the body is trying to ‘dilute’ the blood to bring the concentration of sodium down. This, in turn, increases blood pressure and puts a strain on the heart as it now has to work harder to pump the blood around the body.
The WHO suggests that reducing salt intake to less than 5g a day can help lower the risk of developing hypertension. (3) Although salt naturally occurs in many foods, it is the added salt that needs particular monitoring. Himalayan pink salt is better for your health than regular table salt as it contains less sodium and many trace minerals that table salt does not contain, which are necessary for general health. There are limited studies to demonstrate the exact health benefits of Himalayan pink salt, however, there are many resources and anecdotal references to its benefits.(3)
Sugar
Sugar can be found naturally in fruits, but the real problem is consuming products with refined sugars, such as sugary drinks, cakes and biscuits. Eating foods rich in refined sugar can cause weight gain and lead to obesity. Obesity is linked to cardiovascular problems as well as high blood pressure. It is also thought that sugar directly plays a role in causing high blood pressure. (6)
Red meat
Red meats such as lamb and beef are known to contain higher levels of saturated fat than white meat, therefore they should be eaten in moderation. Saturated fats can raise cholesterol levels in the blood. Cholesterol is a fatty substance; some types of cholesterol are good for you, as they help build healthy cells. However, the cholesterol derived from saturated fats is deemed to be “bad” cholesterol. Over time, cholesterol can build up in the blood vessels as fatty deposits and can become hardened. This makes the blood vessels narrower and less able to stretch. Because of this, blood pressure can increase as the blood now has to flow through a narrowed vessel. (7)
Processed and prepackaged foods
Although a convenient food choice, processed and pre-packaged food such as crisps, pastries and some breakfast cereals contain lots of added salt to give the food the desired taste. It means you have less control over how much salt you are putting in your body, and left unchecked, it can be easy to exceed the daily salt intake limit. Processed food also contains high levels of saturated fat, which leads to an increase in bad cholesterol in the body and leads to high blood pressure.
Condiments
Condiments include soy sauce, tomato ketchup, mayonnaise and mustard. They aren’t necessarily all bad, however, it is important to check the nutrition content on the labels and use them in moderation, as they can contain high levels of sodium and sugar.
Caffeine
Caffeine is a substance found in beverages such as coffee, tea and certain energy drinks. Studies have shown that caffeine can cause temporary rises in blood pressure for up to 3 hours after consumption. (2) Although there is little evidence to suggest caffeine has long-term effects on blood pressure, the fact that caffeine causes fluctuations in blood pressure means that its consumption should be moderated. Many suggest a maximum of four cups of coffee a day.
Foods to include
Whole grains
Whole grains are great for your health as they release their sugars slowly. This means that whole grains are less likely to cause a sharp rise in insulin release. This can protect you from later becoming insulin resistant (which can lead to type 2 diabetes).
They are also great sources of fibre, and minerals such as potassium, iron and magnesium. They can help you lose weight as they make you feel fuller for longer. Examples include whole-wheat bread, whole-wheat pasta, quinoa and oats.
Fruits and vegetables, such as leafy greens, avocados, berries, and citrus fruits
Fruits and vegetables have a plentiful supply of minerals which help protect the heart and maintain good blood pressure. Examples are:
Potassium
Is a mineral that is vital for the normal functioning of the heart. Potassium can help widen the blood vessels which means that blood can flow through more easily and there is less strain on the heart to pump the blood through these vessels.(2) Sources of potassium include potatoes, lentils and kidney beans. (8)
Calcium
helps maintain blood pressure by controlling the width of the blood vessels and causing them to dilate or constrict depending on the needs of the body. Sources are mainly dairy products such as milk, however, vegetables such as kale and broccoli also contain calcium. (9)
Magnesium
Works by helping blood vessels to relax. Foods rich in magnesium include green leafy vegetables such as spinach, seeds like pumpkin and chia seeds, and whole grains. (10)
Lean meats, including grilled chicken, chicken breast, and fish
Lean meats are a great source of protein and good for a DASH diet as they contain less saturated fats.
Other protein sources, such as lentils, nuts, quinoa, and tofu
Legumes and beans can be an excellent source of fibre, and are full of minerals; a great addition to the DASH diet as they can lower blood pressure and help you lose weight.
Sample daily meal plan
Even though it’s great to eat foods rich in minerals and nutrients to help maintain normal blood pressure, it’s important to eat a balanced diet as too much of one mineral can cause imbalances in the body. Some great resources and recipes online can help you create a balanced and nutritious meal plan.
One example is the Eatwell guide. It is a guide that splits food categories into 5 main groups; fruit and vegetables, carbohydrates, protein, dairy and oils and spreads. It helps to identify how much of each portion you should eat daily to eat a balanced meal. The link can be found here:
Tips to reduce high blood pressure
Supplementation could be considered to ensure a good vitamin and mineral intake level is being reached. Calcium and Magnesium intake are linked with a reduction in blood pressure (2)
Other than consuming blood-pressure-reducing foods, exercise can also help maintain blood pressure. Regular moderate-vigorous exercise helps to strengthen the heart muscle and therefore reduces the risk of cardiovascular disease and high blood pressure.
Stress is also linked to high blood pressure. (2) Whilst it isn’t always possible to avoid stressful situations in our lives, there are tools that we can employ to help deal with difficult situations in a way that won’t negatively impact our health. Getting enough sleep, regular exercise and healthy eating are great stress modulators. Making time to do things you enjoy as well as confiding in others can also help with stress.
Obesity is a risk factor for hypertension, therefore measures to undo obesity or reduce the risk of its occurrence will also help combat hypertension.
Alcohol can contribute to high blood pressure, and should therefore be taken in moderation.
Smoking can also lead to high blood pressure, so measures to quit smoking will not only benefit the lungs but will also have benefits for the entire cardiovascular system. Although quitting smoking can be tough, there is lots of support and advice available, as well as a wide variety of nicotine replacement therapies. Visiting your local pharmacist may be a great way to get some more advice, as many pharmacies offer smoking cessation programmes.
Summary
It may be difficult to make changes at first, but by making small and realistic changes, it will be easier to maintain a healthier lifestyle over a long period. Whilst prevention is always better than cure, it is never too late to make healthier lifestyle choices.
References
- Desai AN. High blood pressure. JAMA [Internet]. 2020 Sep 22 [cited 2022 Jun 4];324(12):1254–5. Available from: https://doi.org/10.1001/jama.2020.11289
- Samadian F, Dalili N, Jamalian A. Lifestyle modifications to prevent and control hypertension. Iran J Kidney Dis. 2016 Sep;10(5):237–63.
- Hypertension [Internet]. [cited 2022 Jun 3]. Available from: https://www.who.int/news-room/fact-sheets/detail/hypertension
- Office of dietary supplements - calcium [Internet]. [cited 2022 Jun 3]. Available from: https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/
- Moschonis G, Karatzi K. Novel dietary approach for controlling high blood pressure. Nutrients [Internet]. 2020 Dec 21 [cited 2022 Jun 4];12(12):3902. Available from: https://www.mdpi.com/2072-6643/12/12/3902
- High blood pressure diet: dash, foods to avoid, and more [Internet]. Healthline. 2021 [cited 2022 Jun 4]. Available from: https://www.healthline.com/health/high-blood-pressure-hypertension/foods-to-avoid
- High cholesterol - Symptoms and causes [Internet]. Mayo Clinic. [cited 2022 Jun 4]. Available from: https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/symptoms-causes/syc-20350800
- Desai AN. High blood pressure. JAMA [Internet]. 2020 Sep 22 [cited 2022 Jun 4];324(12):1254–5. Available from: https://doi.org/10.1001/jama.2020.11289
- Moschonis G, Karatzi K. Novel dietary approaches for controlling high blood pressure. Nutrients [Internet]. 2020 Dec 21 [cited 2022 Jun 4];12(12):3902. Available from: https://www.mdpi.com/2072-6643/12/12/3902
- Office of dietary supplements - magnesium [Internet]. [cited 2022 Jun 3]. Available from: https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/