What is cardiovascular disease?
There are a huge number of issues which can potentially affect the health of the heart and many circulatory issues are linked to heart health and vice versa. Some of these conditions can be inherited, but many develop over time, particularly in relation to lifestyle factors and well as genetics and other diseases.
The umbrella term of cardiovascular disease (CVD) encompasses any condition which affects the heart or circulation including stroke, vascular dementia and high blood pressure.
Coronary heart disease (CHD) is the most common of the four types of CVD and is defined by a narrowing of the arteries (sometimes called atherosclerosis) due to a build-up of fatty material, and the pain felt from this is angina. If the artery then becomes blocked, this will cause a heart attack. This category also covers heart failure, as this can often occur after a heart attack as the ability of the heart to pump effectively is compromised. There is often some hardening of the blood vessels walls making them less flexible and restricting blood flow.
High blood pressure and heart health: Causes and risks
High blood pressure or hypertension is strongly linked to the health of the heart. It is expressed with two figures: systolic blood pressure/diastolic blood pressure. Systolic blood pressure is the higher number as this represents the blood pressure during a heartbeat, whereas diastolic is the pressure measured between beats when the heart is relaxed.
Normal blood pressure can vary depending on activity, stress and emotional state but high blood pressure is defined by The National Institute of Clinical Excellence (NICE) to be a reading of 140/90, confirmed by further readings of 135/85.
Public Health England have identified that 1 in 4 people in England have high blood pressure and it is a significant contributory factor to early death and disability, only behind smoking and diet in its significance. Worryingly, for every 10 people with diagnosed hypertension, there are a further 7 who are undiagnosed.
Early warning signs of high blood pressure include headaches, nosebleeds and buzzing in the ears, but as many GP surgeries and pharmacies now have facilities to check your own blood pressure, it is advisable to do this before symptoms develop.
High blood pressure has been shown to cause physical changes in the heart, reducing its ability to pump and increasing blood pressure further. Studies suggest that every 10mm reduction in systolic blood pressure, the risk of a stroke, CHD and heart failure all decreased alongside the overall risk of death.
Lifestyle risk factors for high blood pressure
There are several risk factors for the development of high blood pressure and whilst some, such as gender, age, genetics and ethnicity cannot be changed, there are a number of risk factors which can be changed. These include smoking, excess salt intake, sedentary lifestyle, obesity and stress.
Salt intake is a key factor, as a high intake will increase blood pressure to allow the body to excrete the excess via the kidneys, preventing toxicity. Studies do confirm that reducing sodium supports a reduction in blood pressure.
Regular exercise has been shown to improve the strength of the heart, allowing it to beat more effectively, thus reducing the overall blood pressure. Longer term benefits of exercise also include weight and fat loss and changes in body composition which can reduce the other risk factors for CVD.
LDL and HDL cholesterol: Impact on coronary heart disease
Since the 1960s we have also known of the link between high cholesterol and CHD. Around 60% of adults in the UK are thought to have raised cholesterol, although many remain undiagnosed and therefore untreated.
However, to understand the effects of cholesterol on the health of the heart, it is important to understand the 'types' of cholesterol present in the body.
Cholesterol is made by the liver and is essential for cell development and maintenance, the production of hormones and for the functioning and insulation of nerve cells. We also obtain cholesterol from animal-based foods such as meat, eggs and dairy produce.
LDL cholesterol is responsible for carrying cholesterol to the cells of the body. However, when cholesterol levels are higher than required it is LDL which causes the deposition of cholesterol in the blood vessels, narrowing the vessel walls and increasing the risk of heart attack or stroke.
HDL cholesterol, often referred to as 'good' cholesterol, carries cholesterol away from the blood vessels and back to the liver for removal.
Obesity, smoking and cardiovascular disease risk factors
Obesity and an increased fat mass have been shown to affect cholesterol levels, especially if waist measurement is high. Higher body fat is also associated with inflammation which can damage the heart and blood vessels.
There is also a condition known as familial hypercholesterolaemia (FH), which causes LDL and total cholesterol to be higher than normal. The NHS estimates that up to 1 in 250 people in the UK have this condition.
Smoking is another major risk factor. Cigarette smoke constricts blood vessels, increases inflammation and raises LDL while lowering HDL cholesterol levels.
Smokers are also more susceptible to blood clots as smoking increases compounds involved in clot formation and causes thicker blood.
Homocysteine levels and cardiovascular disease risk
Another element which influences the risk of heart disease development is the level of a compound called homocysteine. This is an amino acid naturally found in the body and the level is normally low.
However, raised levels may occur due to deficiencies in B6, B12 and folate, certain health conditions such as diabetes and thyroid disease, or lifestyle factors such as smoking, caffeine or alcohol intake.
High homocysteine levels have been linked to damage to blood vessel walls, stiffening of arteries and changes in blood clotting.
Diet and heart health: The Mediterranean approach
Dietary advice related to heart health has changed over time as new research has emerged. Very low-fat diets and the omission of eggs were once recommended, but these guidelines have evolved.
Low-fat 'diet' foods are often best avoided due to their reliance on sugar for flavour, and research has now linked excessive sugar intake and insulin resistance with an increased risk of heart disease.
A Mediterranean-style diet is widely regarded as one of the best options for heart health. It focuses on fruits and vegetables, nuts and seeds, olive oil, lean meats and oily fish such as salmon, mackerel and sardines.
This dietary pattern emphasises fresh, minimally processed foods that are naturally lower in sugar, salt and trans fats.
Key nutrients for heart health
Several nutrients are associated with cardiovascular health. Adequate intake of B vitamins, particularly B6, B12 and folic acid, as well as minerals such as magnesium, potassium and calcium, can help support normal homocysteine levels and blood pressure.
Magnesium intake is strongly associated with heart health due to its role in muscle function and blood pressure regulation. However, dietary intakes often fall short of recommended levels.
Omega-3 fatty acids, particularly EPA and DHA found in oily fish and algae, are widely recognised for supporting heart health.
A daily intake of around 250mg EPA and DHA contributes to normal heart function, while higher intakes may support the maintenance of normal blood pressure.
Plant sterols have been shown to support healthy cholesterol levels by inhibiting cholesterol absorption in the gut.
Garlic has also been studied extensively for its effects on both blood pressure and cholesterol levels and may help relax blood vessels and support circulation.
Other compounds including lecithin and globe artichoke have also been investigated for their potential effects on cholesterol metabolism.
Co-enzyme Q10 (CoQ10) plays an important role in cellular energy production, and the heart muscle has one of the highest energy demands in the body.
Research suggests CoQ10 supplementation may support heart health and blood pressure regulation. It is also particularly relevant for individuals taking statin medications, as these can reduce CoQ10 production.
Fat-soluble vitamins including vitamins D, E and K may also play a role in cardiovascular health.
Vitamin K2 helps direct calcium into bones rather than arteries, vitamin E supports antioxidant protection, and vitamin D has been linked to blood vessel function and blood pressure regulation.