How can you keep your heart healthy?

Cardiovascular disease refers to a group of conditions affecting the heart and circulatory system, including coronary heart disease, heart attacks, stroke, abnormal heart rhythms and birth defects that affect the heart. Together, these diseases claim an estimated 20 million lives each year (World Health Organization). Of these deaths, 85% are due to heart attack or stroke.  

The good news is that as many as 80% of heart attacks and strokes can be prevented. Researchers at Oxford Population Health have conducted large-scale studies involving millions of participants to better understand factors that increase the risk of cardiovascular disease and to test different treatments and therapies.

What causes cardiovascular disease?

Cardiovascular disease is mainly caused by a build-up of fatty deposits (plaque) inside the arteries that causes them to harden and narrow. This condition, known as atherosclerosis, makes it harder for blood to flow. If a blood clot forms, it can prevent blood reaching the heart or brain and cause a heart attack or stroke.

What are the risk factors?

There are many factors that can increase your chances of cardiovascular disease. Some, like family history, ethnic background and getting older, are beyond our control, but others, such as smoking, not exercising enough, eating an unhealthy diet, or drinking too much alcohol can be addressed. These behavioural risk factors can lead to raised blood pressure, high cholesterol, diabetes and obesity – all conditions that can increase the risk of heart attack and stroke. 

Researchers at Oxford Population Health have explored the effects of these risk factors and conditions on heart health in different population groups.

What are the links between smoking and cardiovascular disease?

Smoking is one of the biggest risk factors for cardiovascular disease with tobacco use accounting for some 10% of all deaths from heart conditions. The chemicals in cigarettes leave sticky deposits in the walls of arteries, which can cause fatty material to accumulate. Nicotine can also raise heart rate and blood pressure, while carbon monoxide reduces the oxygen-carrying capacity of the blood.  

Research led by Oxford Population Health found that smoking creates a biological imprint in the blood that can be used to predict risk from smoking-related death and illness. The researchers developed an index based on 51 proteins found in the blood that accurately distinguished current smokers from those who had never smoked. They then assigned a smoking impact score to each of the study’s 43,914 participants. 

Among current smokers in the study, a higher index score was significantly associated with six out of 15 major smoking-related health outcomes, including various types of heart disease. It took at least 10 years for most former smokers to recover from the effects of smoking, but some former smokers were found to have a similar index score and lifetime risks to participants who had never smoked, demonstrating the benefits of quitting.

How does alcohol consumption affect heart health?

Regularly drinking too much alcohol can raise blood pressure, increase the risk of heart arrhythmias, and weaken the heart muscle, all of which can damage cardiovascular health. As alcohol is high in calories, it can also lead to weight gain, obesity and an increased risk of type 2 diabetes, creating further risk factors for heart disease.  

There is a popular belief that moderate alcohol consumption can have a protective effect on the heart, but our research has shown that even small amounts of alcohol can increase a person’s risk of cardiovascular disease.  

Oxford Population Health researchers used data from the China Kadoorie Biobank to assess the effects of alcohol use on specific causes of death in men. They used common genetic variants that are present only in East Asian populations and which greatly reduce alcohol tolerability, and therefore alcohol intake, to compare men who drank very little with those who drank about two drinks a day. As few Chinese women drink alcohol, women in the study provided a useful control group.  

The results showed that even moderate alcohol drinking (one-two drinks per day) increased the risk of having a stroke by about 12%. There was no genetic evidence that moderate drinking had a protective effect on any cause of death, including heart disease.

How does poor diet and obesity increase risk for cardiovascular disease?

Eating an unhealthy diet that is high in fat, sugar and salt and low in fruits, vegetables and wholegrains increases cardiovascular disease risk in a number of ways. Consuming foods that are high in saturated and trans fats, such as processed foods and red meat, can increase levels of LDL (‘bad’) cholesterol, which deposits in the arteries and leads to atherosclerosis and an increased risk of heart attack. Diets high in fat, salt, sugar and calories can also lead to obesity, high blood pressure and type 2 diabetes which all come with their own major risk factors for heart attacks and strokes.  

We have investigated the relationship between diet and cardiovascular disease. For instance, EPIC-Oxford – the Oxford component of the European Prospective Investigation Into Cancer and Nutrition study - found that pescatarians (who eat fish, but no meat) and vegetarians had, respectively, 13% and 22% lower rates of coronary heart disease than meat eaters.   

Numerous other studies have shown that high consumption of fibre (found in fruit, vegetables, cereals, legumes, nuts and seeds) is associated with reduced risk of heart attack or stroke. Data from the Pan-European EPIC study showed that every additional 10g intake of fibre a day was associated with a 23% lower risk of ischaemic stroke.   

Studies carried out by Oxford Population Health researchers have also found a strong association between obesity and heart disease risk. Carrying excess weight forces the heart to work harder, which can eventually lead to heart failure. Having too much body fat, especially the hidden visceral fat that sits around our internal organs, promotes the build-up of plaque in the arteries. 

We demonstrated that both higher body mass index (BMI) and a larger waist circumference were associated with an increased risk of atrial fibrillation (AF) – a condition where the heart beats irregularly and does not contract as it should, which can cause blood clots. This doubles the risk of heart-related death and is associated with a five-fold increase in stroke risk. Measuring body mass and waist circumference can help identify those most at risk of AF. 

What role does exercise play in heart health?

It’s often said that if exercise were a pill, we would all be prescribed it, and it is certainly a factor in keeping our hearts healthy. Physical activity is thought to benefit cardiovascular health through several mechanisms, including strengthening the heart muscle, reducing blood pressure, improving blood sugar regulation and reducing the hardening of arteries.  

Even small increases in daily activity seem to help: a China Kadoorie Biobank study found that every additional hour of brisk walking or cycling led to a 9% lower risk of heart attack, 5% lower risk of stroke and 12% lower risk of death from cardiovascular disease.  

Another study used wrist-worn accelerometers to record the activity of 90,000 UK Biobank participants, then followed them over five years. The results clearly showed that higher amounts of physical activity were associated with lower risk of cardiovascular disease, with no apparent threshold at high levels of activity.

What interventions have proven effective at preventing or treating heart disease?

We have investigated the efficacy of various health interventions for preventing and treating heart disease. For example, a number of large-scale trials over many years have demonstrated the safety and effectiveness of a family of drugs called statins that lower LDL cholesterol levels, significantly reducing the risk of heart attacks and strokes. One study, led by the Cholesterol Treatment Trialists’ (CTT) collaboration, addressed lingering questions about possible side effects associated with statins that have deterred some patients from taking them. Drawing on data from 23 large-scale randomised trials, it found that statins did not cause the majority of possible side effects listed on package leaflets. It also found that statin treatment only marginally increased the frequency of muscle-related symptoms.  

The Active Monitoring for Atrial Fibrillation (AMALFI) trial of a wearable electrocardiogram (ECG) patch found that it increased diagnosis of AF. Participants who wore the patch were diagnosed with AF earlier and were more likely to be prescribed blood-thinning medication. 

Findings from another long-term trial found that carotid artery surgery (the surgical removal of plaque in the arteries) and stenting (inserting a stent to keep artery walls open) were equally protective against stroke in patients with carotid artery disease.   

Our research has also demonstrated the need for better screening of pregnant women for cardiovascular disease. Heart disease is a leading cause of maternal deaths in the UK, accounting for 23% of women who died during pregnancy or up to six weeks afterwards between 2015 and 2017. Pregnancy places additional strain on the heart, but in many cases cardiovascular disease symptoms are misdiagnosed as general symptoms of pregnancy. To address this, we developed Focused Cardiac Ultrasound (FoCUS) Solutions, a training resource to detect cardiac abnormalities, particularly in resource-limited settings. 

Updated on 16 March 2026.