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Hypertension – more commonly known as high blood pressure – is one of the most common diseases in industrialised countries. Forty percent of people over the age of 25 are affected by the disease, which, in turn, is a major risk factor for cardiovascular and renal diseases. A diet based on vegetarian or vegan food is suitable for both the prevention and treatment of hypertension.
The cardiovascular system
The cardiovascular system is one of the most important organ systems in the human body. It allows blood to distribute all necessary nutrients, hormones, the oxygen we breathe, and many other chemical compounds from and to all cells and organs in the body. In this way, it also helps with regulating, stabilising, and maintaining body temperature, pH, and homeostasis, as well as fighting diseases. The cardiovascular system consists of the blood, heart, and blood vessels. Blood pressure is one of the body’s key vital signs and describes the pressure of the circulating blood on the walls of the blood vessels. Normal blood pressure is considered to be less than 120/80 mmHg.1
Systolic and diastolic blood pressure
The muscle activity of the heart can be divided into two phases: In the systolic phase, blood is pumped from the heart chambers into the body’s and the lungs’ circulatory system; in the diastolic phase, the heart chambers fill with blood again. Both phases of muscle activity can be mapped using a blood pressure monitor. The first reading indicates the maximum pressure the heart exerts when it beats (systolic). Diastolic blood pressure refers to the pressure in the arteries between heartbeats.2
What is hypertension?
Hypertension is a cardiovascular disease. High blood pressure is defined as systolic blood pressure above 140 mmHg or diastolic blood pressure above 90 mmHg (see table 1). Blood pressure is commonly measured in millimetres of mercury (mmHg).3 Depending on the development of the disease, a distinction is made between primary (essential) and secondary (symptomatic) hypertension. About 90% of all patients suffer from primary hypertension, which – unlike secondary hypertension – is not caused by another underlying disease.4
Classification of Hypertension
High blood pressure is divided into one of two categories, depending on the severity of the condition (see Table 1). It should be taken into account that systolic blood pressure increases with age. The reason for this is that the elastic walls of our blood vessels become more rigid as we grow older. If blood pressure values are elevated, that is, above 120/80 mmHg, there is a high risk of hypertension developing. Values above 140/90 mmHg, meaning a systolic blood pressure higher than 140 and a diastolic pressure of more than 90, are considered to be the markers of high blood pressure. A precise classification can be made using the following table.5 6
|Category of blood pressure||Systolic blood pressure (mmHG)||Diastolic blood pressure (mmHG)|
|Stage 1 hypertension||140-159||or||90-99|
|Stage 2 hypertension||≥160||or||≥100|
Table 1: Classification of blood pressure levels in adults 7
Frequency of hypertension
Hypertension, also called ‘the silent killer’, often develops slowly and is sometimes asymptomatic. Worldwide, four out of 10 adults over the age of 25 are affected by arterial hypertension – high blood pressure in the arteries. According to the Global Burden of Disease (GBD) study, hypertension is the second most common risk factor for premature death worldwide.8 The World Hypertension League (WHL) estimates that approximately 10% of 2016’s global healthcare costs were due to high blood pressure.9 In low and middle-income countries, the treatment of people with high blood pressure could save 4.7 million lives over the course of a decade.10
Effects and symptoms of hypertension
Hypertension poses several health risks. It is estimated that the risk of dying from cardiovascular disease doubles with every 20 mmHg added to systolic blood pressure or every 10 mmHg increase in diastolic blood pressure.11 The increased pressure on the arteries can lead to them becoming damaged or constricted. This, in turn, can develop into arteriosclerosis. In addition, aneurysms (bulges in the arterial walls) may develop. In the worst-case scenario, an aneurysm will tear and cause internal bleeding. People suffering from high blood pressure are also at greater risk of vascular dementia, strokes, nerve damage to the eyes, and sexual dysfunction. Additionally, hypertension is also considered one of the most common causes of kidney failure, since high blood pressure can damage the kidneys’ small blood vessels, preventing waste products from being expelled.12 13
Causes of Hypertension
Diet and lifestyle have a major influence on the development of hypertension. In addition to genetic predisposition and pre-existing conditions such as diabetes mellitus type 2 and kidney disease, a high consumption of alcohol, tobacco, salt, and saturated fatty acids play a role as risk factors. On the other hand, regular exercise, a body weight in the ideal range, and an adequate supply of potassium can reduce blood pressure. A well-planned diet can therefore guard against the development of hypertension and be used to treat the condition.
Hypertension and animal products
Several studies have shown that there is a correlation between the consumption of red meat and high blood pressure.14 15 In addition to foods containing large amounts of saturated fatty acids, a high consumption of sodium, salt, or cholesterol also has a negative effect on blood pressure. Cholesterol can accumulate on the walls of blood vessels, resulting in a loss of flexibility.16 17 Processed animal products, in particular, such as cheese, sausage, other meat products, and ready meals, are often very rich in salt, fat, and cholesterol.
Vegetarians and vegans are less likely to suffer from high blood pressure
According to several studies, vegans have lower blood pressure levels compared to people who eat meat.18Some studies have shown that a high potassium intake, as found in a balanced vegetarian/vegan diet, lowers hypertension.19 Sources of potassium include fruit, vegetables, and nuts.20 Since potassium also has a physiologically antagonistic effect on sodium, this nutrient improves the function of blood vessels.21Magnesium and calcium also have a positive effect on high blood pressure. Both are found in kale, fennel, and spinach. However, seeds and nuts, such as hemp seeds, pumpkin seeds, and sunflower seeds, contain greater concentrations of magnesium than is found in vegetables.22 23 24
Rapeseed oil, linseeds, and linseed oil, can also reduce blood pressure25due to the presence of alpha-linolenic acid. Alpha-linolenic acid is a polyunsaturated omega-3 fatty acid, and as such, has a vasodilative effect (like all unsaturated fatty acids).26 Studies have shown that consuming 2.8% more calories in the form of vegetable protein is associated with reduced levels of systolic blood pressure (−2.14 mmHg) and diastolic blood pressure (−1.35 mmHg).27
People who do not consume meat and other animal products usually have a healthy body weight, are physically active, and follow a varied diet high in fruits and vegetables.28Vegetarian/vegan lifestyles are therefore not only suitable for preventing high blood pressure, but also for treating it.29 Switching to a plant-based diet is a natural way to lower blood pressure.
ProVeg tips for the prevention and therapy of hypertension
Hypertension can be treated and counteracted with a healthy diet and lifestyle:
- Eat a diet rich in fruit and vegetables, particularly those containing high levels of potassium and magnesium.
- Try to choose vegetable protein.
- Reduce the intake of saturated fatty acids and cholesterol. Instead, aim for a higher amount of monounsaturated and polyunsaturated fatty acids.
- Switch to a plant-based diet.
- Reduce salt consumption.
- Avoid cigarettes and alcohol as far as possible.
- Maintain a healthy weight.
- Engage in sufficient physical activity.
Should blood pressure reach stage 1 or 2 and it is not possible to reduce it to the desired extent with a change in diet and lifestyle, medication should be administered by a doctor.30