What is Blood Pressure?
Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps blood around the body.
How is Blood Pressure Measured?
To measure blood pressure, a healthcare professional will use a blood pressure cuff around your arm that will gradually tighten. Blood pressure was recorded using two numbers made up of systolic pressure and diastolic pressure. Systolic pressure (higher number) is the force at which your heart pumps blood around the body. Diastolic pressure (lower number) is the resistance to the blood flow in the blood vessels. Blood pressure is measured using a millimetre of mercury (mmHg).
An ideal blood pressure reading would be 120/80 mmHg. High blood pressure would be a reading of 140/90 mmHg. For individuals over 80 years old, high blood pressure is 150/90 mmHg.
Effect of Caffeine on Blood Pressure
Consuming around 80-250mg of caffeine daily can acutely raise blood pressure. It will increase diastolic and systolic blood pressure by 4-13mmHg 60 minutes after intake and will persist for 180 minutes on average. There is around 140 mg of caffeine in one mug of filtered coffee, meaning your caffeine intake can quickly creep up.
There is no international standard for caffeine consumption as every country has different caffeine consumption. However, it is recommended that daily caffeine intake should be around 400 mg per day, which equates to 3-4 cups of coffee. Pregnant women should consume less than 200mg, which is why decaffeinated coffee is recommended as it has less caffeine. Children should only consume 45-100 mg of caffeine.
Are there any benefits of drinking coffee?
There are many benefits to drinking coffee. One benefit of coffee is the improvement of mood and stimulation of brain function. Coffee will increase responses from the dopamine and serotonin receptors which are linked to feeling happy.
Another benefit of drinking coffee is significant improvements in physical performance, as it helps you avoid fatigue and improves the supply of substrates, enhancing oxygen uptake.
Finally, moderate caffeinated coffee consumption is associated with a reduction in the relative risk of developing chronic degenerative diseases. Being a coffee drinker can reduce the risk of Parkinson's or delay the onset and Alzheimer's disease and hepatoprotective effects.
Everyone's caffeine sensitivity can vary. If you are not an avid caffeine consumer, you are more susceptible to caffeine sensitivity, which can produce jitteriness, insomnia, nervousness, and anxiety. Sleep quality can be impaired if around 100 mg of caffeine is consumed too close to bedtime. The sensitivity to caffeine may alter if you consistently consume caffeine regularly, so you may be less likely to experience these symptoms.
Decaf Coffee and Blood Pressure
How is decaf coffee made?
Decaffeinated coffee is coffee where most of the caffeine has been removed. Before roasting coffee beans, fresh green coffee beans will steam, or water is pumped into the green coffee beans. The caffeine is extracted from the pumped beans with a solvent, which is repeated until the desired level of decaffeination is achieved, and then the beans are dried and ready for roasting. In decaf coffee, there is around 0.3-0.5mg of caffeine per 100g of ground roasted coffee.
Does Decaf Coffee Raise Blood Pressure?
Decaf coffee does not elevate blood pressure significantly compared to regular caffeinated coffee. There are no haemodynamic effects, so there is no effect on the blood flow dynamic. However, decaffeinated coffee may cause a slight increase in diastolic blood pressure.
Should People with Hypertension Avoid Coffee?
To an extent, people with hypertension (high blood pressure) should avoid caffeine before activities that elevate their heart rates, such as exercise and heavy lifting.
Signs and Symptoms of High Blood Pressure
Signs and symptoms are barely noticeable. They can include blurred vision, nosebleeds, shortness of breath, chest pain, dizziness, and headaches. Many people do not have high blood pressure, and some feel okay even with high blood pressure.
Complications of High Blood Pressure
If untreated, high blood pressure can cause serious problems, such as heart attack and strokes, as there is too much strain on the blood vessels, heart, and other organs. High blood pressure can increase your risk of heart disease, heart attacks, strokes, heart failure, kidney disease, and vascular dementia.
Treatment, Management and Prevention of High Blood Pressure
High blood pressure can be prevented or reduced by having a healthy diet, maintaining healthy body weight, exercising, managing caffeine intake, drinking alcohol in moderation, and not smoking.
- Healthy diet: Cutting down the amount of salt you consume can make a big difference in high blood pressure. Aim to consume no more than a teaspoon of salt per day, which equates to 6g of salt. Eating a high-fibre diet which includes wholegrain rice, pasta, and plenty of fruit and vegetables can help lower blood pressure if done consistently. Finally, drink plenty of water, especially if you have a high salt intake.
- Maintaining a healthy body weight: Having a healthy body weight is critical to maintaining lower blood pressure, and being overweight forces your heart to work harder to pump blood around the body, which can lead to raising your blood pressure. Please seek advice on losing weight safely from a healthcare professional.
- Exercising: Getting active and taking part in regular exercise can lower blood pressure by keeping your heart and blood vessels in perfect condition. Regular exercise can be in the form of walking, cycling, lifting weights, or sports.
- Reducing caffeine intake: Consuming more than 4 cups of caffeinated coffee or 400mg of caffeine daily may increase your blood pressure. Consider cutting down on tea, coffee, energy drinks, or fizzy drinks. If you do not want to cut down the glass you're consuming, there are alternatives to some of these drinks that contain little to no caffeine.
- Drinking alcohol in moderation: Binge drinking and drinking a lot of alcohol regularly can raise your blood pressure over time. Men and women should not consume more than 14 alcohol per week. This is roughly equivalent to 6 pints of beer, seven glasses of wine, or 14 shots. Alcohol contains lots of calories, and drinking it regularly can cause you to gain weight, which will strain your heart and blood flow.
- Reducing smoking: Smoking may not directly cause high blood pressure, but it can increase your risk of a heart attack and stroke. If you have high blood pressure and smoke, it will cause your arteries to narrow and put you at greater risk of heart and lung disease.
When to Call a Doctor or Dial 999
If you take your blood pressure reading home, input the data into the NHS website, and it may recommend you go straight to the doctor, GP, or call emergency services. According to the American Heart Association, reading 180/110mmHg or greater with two readings like that in a row requires immediate attention.
Does decaf coffee raise blood pressure? Yes, it does, but only very slightly. Decaf coffee still does contain caffeine. However, the caffeine levels in decaf coffee are significantly lower than in regular caffeinated coffee. Caffeine in decaf coffee is minimal, but it can cause diastolic blood pressure to rise by up to 13 mmHg. Please seek medical attention if your blood pressure reading is 180/110mmHg or above.
- dePaula J, Farah A. Caffeine consumption through coffee: Content in the beverage, metabolism, health benefits and risks. Beverages. 2019 Jun;5(2):37.
- Smits P, Thien T, Van't Laar A. The cardiovascular effects of regular and decaffeinated coffee. British Journal of Clinical Pharmacology. 1985 Jun;19(6):852-4.