What is hypertension? 

Hypertension is the medical term for high blood pressure and is a major cause of premature death worldwide.


In this article, we explain the risks associated with developing hypertension, and we look closely at the factors that affect that risk.

  • How do we measure blood pressure?
  • The importance of a blood pressure check
  • Risk factors explained
  • Prevention of hypertension and reducing the risks
  • Exercise as a preventative measure
  • Weight status
  • Summary and practical recommendations

 

How do we measure blood pressure?

Blood pressure is recorded using two numbers, both measured in millimetres of mercury (mmHg):

An ideal blood pressure is considered to be around 120/80 mmHg, while a measurement of 140/90 mmHg or more is considered high blood pressure. A measurement between these values means that you are at risk of developing high blood pressure if you do not take steps to keep your blood pressure under control.

It is important to get your blood pressure checked regularly because typically there are no symptoms of hypertension. Measuring blood pressure is the main way of monitoring changes in hypertension.

 

The importance of a blood pressure check

An estimated 1.28 billion adults worldwide aged 30–79 years have hypertension, and of those, 42% are diagnosed and treated, while 46% of adults with hypertension are unaware of their condition.

Consequently, this not only impacts individuals’ health, it adds significantly to the cost of healthcare. An estimated 10% of global healthcare spending is on hypertension and its complications.

A blood pressure measurement is part of the NHS Health Check and is recommended for all 40–74-year-olds. If left untreated, hypertension can block and damage the arteries, and this can lead to further health complications including: heart failure, kidney failure, heart attack, stroke, and loss of vision.

 

Risk factors explained

Although hypertension has many risk factors, most of these are lifestyle-related factors. This means that improvements in our daily habits can lead to a significant reduction of risk. 

A recent review study examined four of these hypertension risk factors. It focused particularly on evidence-based aspects that could be changed to reduce risk.
 

Age

Although age is not a ‘modifiable risk factor’, it should be taken into account – together with the potential risk of hypertension – with your overall lifestyle. With increasing age, the risk of developing hypertension increases, and the earlier the onset of hypertension the greater the mortality risk.

This was demonstrated in the results of a 2020 study which showed that the onset of hypertension at 45 years old or younger resulted in greater than 2.5 times a greater risk of mortality, compared to an increased risk of 1.3 times if the onset of hypertension occurred at an age of 65 years or more. This emphasises the importance of minimising the risk of early-onset hypertension.

Sodium intake (salt)

Sodium intake demonstrates a clear causal relationship with blood pressure: incremental increases in salt intake result in significant increases in blood pressure.

Conversely, potassium intake can also play an important protective role when it comes to reducing the risk of developing hypertension. Low potassium intake can increase blood pressure, although regular supplementation results in significant reductions of blood pressure.

Alcohol intake

Those who regularly consume alcohol are at an increased risk of higher blood pressure, especially heavy drinkers. A recent review reported that regular consumers of alcohol can expect small improvements by reducing their consumption, while heavy drinkers who cut their intake by 50% can significantly improve their blood pressure. This suggests that the more alcohol an individual regularly consumes, the greater the potential improvement for risk reduction by reducing their alcohol intake.

Overall diet

Both overall diet and levels of physical activity and exercise play an important role when it comes to reducing blood pressure. This is especially relevant when we consider the underlying link between these factors and weight status. Obesity is directly related to increased blood pressure, and weight loss can counteract and even reduce the risk.

 

Prevention of hypertension and reducing the risks

Many lifestyle aspects are linked to hypertension, so making positive lifestyle adjustments over time can lead to improvements in blood pressure and risk of hypertension.

Sodium intake

Being mindful when it comes to salt intake can have significant benefits.

The UK average salt intake is about 8g per day, when it should be about 6g per day. Even then, this should ideally be closer to 4g per day to minimise risk. Small adjustments, such as not adding salt to meals at the table, can reduce intake by 6–20%. Even tasting foods before automatically adding salt can have a notable impact on the level of salt intake at the table.

Potassium intake

Ensuring an adequate intake of potassium is desirable to achieve a lower blood pressure. A 2020 study found that supplementation of 30 mmol/day of potassium reduced participants’ blood pressure, although it highlighted that too much supplementation offset the effect and should be avoided.

It’s worth noting that supplementation is not always necessary. Sufficient potassium levels can be achieved through a balanced diet. Good food sources include; bananas, avocado, spinach, and broccoli.

Dietary fat

Whilst dietary fat is an essential nutrient and can have positive effect when it comes to heart health, consuming too much can be detrimental to health. In particular, eating too much saturated fat can raise our levels of bad cholesterol (LDL), which can block our arteries – a condition known as atherosclerosis. This can lead to raised blood pressure and to stress on the heart.

Foods high in saturated fat include red and processed meats, butter, cheese, chocolate, cakes and pastries. We should aim for a maximum of saturated fats of about 25g per day. So, be aware of these foods and consider eating foods with more unsaturated fats that can lower blood cholesterol. These foods include nuts, oily fish, avocados and olive oil.

Alcohol intake

Repeated over-consumption of alcohol has shown a clear association to hypertension.

A recent study highlighting the exponential increase in the risk for those who are heavy drinkers (more than 15 drinks per week). It is worth noting that reducing alcohol intake lowers blood pressure in a dose-dependent manner. This means that greater reductions in alcohol consumption lead to greater reductions in blood pressure.

Therefore, everyone should consider the guidelines for low-risk drinking. These guidelines advise:

  • drinking no more than 14 units per week to keep health risks from alcohol low
  • choose lifestyle options that support a healthier balance. This may include low or non-alcohol alternatives, drinking less frequently, and avoiding episodes of ‘binge’ drinking.

 

Exercise as a preventative measure

As already highlighted, being physically active can help reduce the risk of hypertension. While minimising prolonged periods of being seated and achieving 10,000 steps per day can benefit us, exercise plays an important role as a preventative measure.

Cardiovascular exercise

A study from 2018 reported that cardiovascular exercise – including walking, running and cycling – and resistance training, involving muscle strength training, had antihypertensive effects. The greatest effects were observed in individuals with higher blood pressure whose hypertension was untreated.

Resistance training – low to moderate intensity

Interestingly, a meta-analysis in 2017 reported that significant reductions in blood pressure in pre-hypertensive and hypertensive individuals can be expected after just eight weeks of resistance training alone. 

A broad recommendation of the analysis is that 30 minutes of moderate cardiovascular exercise at least four days per week, and resistance training involving more than eight exercises per session at least three days per week. This applies across a range of age groups including adults over 60 years at a prehypertensive or hypertensive stage.

Resistance training – moderate to high intensity

A 2023 study provides further evidence for this and shows similar, if not greater, improvements using just resistance-based training, free weights, machines and resistance bands at a moderate to high intensity. This approach led to significant reductions in blood pressure, although training at low intensities is unlikely to be sufficient to generate notable improvements.

 

Weight status

Another aspect is weight status. A recent review study reported a clear linear relationship between weight status and blood pressure. This review highlights another study that found for every kilogram of body weight lost through lifestyle interventions – such as calorie restriction and increased physical activity – a reduction of around 1 mmHg in blood pressure could be expected.

This finding supports the idea that by following a dietary-based and physically active lifestyle, the lifestyle changes mentioned above will promote weight loss and improve blood pressure. This in turn will result in a greater reduction in the risk of developing hypertension.

With each action taken towards each modifiable risk factor, the risk of hypertension can be reduced further and further. This highlights the importance of collective lifestyle changes which can generate a meaningful reduction in the risk of developing hypertension.

 

Summary & Practical Recommendations

  • Hypertension is a result of chronic high blood pressure and can cause severe health complications.
  • There are no obvious symptoms of hypertension, so understanding the risk factors is very important.
  • Risk factors include being over 65 years; being overweight/obese; high salt and alcohol intake; an unhealthy diet; a history of smoking, and the lack of physical activity/exercise.
  • Taking action on these modifiable risk factors and making positive lifestyle changes can reduce blood pressure and therefore reduce the risk of developing hypertension:
    • Dietary actions – limit alcohol and salt intake; eat more fruit and vegetables, and in general, make healthier dietary choices.
    • Physical activities – avoid sedentary behaviours and keep active, e.g., try to reach 10,000 steps daily. Complete 30 minutes of cardiovascular exercise at least four days per week and do some moderate resistance training at least three days per week.

Harrison Prince, March 2024. Next review due February 2028.

 

Here are some other articles on the Age Watch website that are relevant:

 

 

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