ON Heart Health Survey delivered this week's grim discovery that four in five adults in England have hearts that are more damaged than they should be for their age.
Public Health England's "Heart Age Test," made by 2 million people in England, paints a bleak picture of the country's health and has drawn new attention to the most potent risk factors for heart disease – and how people can avoid it. Over 80% of heart attacks and strokes in people under the age of 75 could be prevented according to the NHS.
But a persistent complaint among those taking the test has been getting inflated ages because they do not know their cholesterol or blood pressure levels. Those who did not reach blood pressure (50% of participants) and cholesterol (79%) received the UK average, which is outside the safe range for both.
"Part of the effort is to encourage people to know their numbers," said Matt Kearney, National Clinical Director for the Prevention of Cardiovascular Disease at Public Health England and NHS England, who conducted the test. "40% of people with high blood pressure – over 5 million people in England – are undiagnosed and unaware."
According to Kearney, the age test is based on a risk calculator, which is commonly used in family practices to assess the risk of heart disease to an individual and make decisions about whether to prescribe medicines that lower blood pressure or cholesterol. The assessment aims to capture as much information as possible about a person's risk.
For example, the test asks about a person's weight, blood pressure and cholesterol level – factors that directly affect cardiac health – but not how many hours a person trains, a factor that has a more indirect health impact. Smoking, one of the most serious risks for heart disease, is being asked. However, the test ignores alcohol consumption, which, perhaps surprisingly, has at most a weak effect.
We talked to five experts about the different ways in which our way of life affects the health of the heart.
Matthew Walters, Professor of Clinical Pharmacology at the University of Glasgow
Diet is an important risk factor for the development of diseases such as heart attack, stroke and type 2 diabetes, and nutritional factors are involved in a significant proportion of deaths from these diseases. A high intake of salt and sugary drinks and a low intake of vegetables have a particularly strong association with deaths from cardiovascular disease. Although there is a link between an unhealthy diet and obesity, an unhealthy diet can cause problems even in people who are not obese.
The question of how diet and obesity contribute to poor cardiovascular health is of great interest, as obesity is a growing health problem. In essence, as more fat develops in the body, there are a number of complicated hormonal changes. The fat cells release a number of hormones called adipokines, which can affect blood sugar levels, blood pressure and the amount of fat in your blood. Some inflammatory changes in the blood vessels may also occur, and the combined effect is to cause progressive hardening of the arteries, which can lead to the development of heart attacks and strokes.
Emily McGrath, senior nurse at the British Heart Foundation, London
More than 20 million people in the UK are physically inactive, according to a British Heart Foundation report. The report defines "not active" as not meeting the government's physical activity guidelines of 150 minutes moderate intensity of physical activity per week and strength activities on at least two days per week. Proving that exercise is physically active can reduce the risk of cardiovascular disease by up to 35% and the risk of early death by up to 30%.
One of the most important health benefits of exercise is that it helps keep glucose, insulin and cholesterol levels within the normal range.
As you exercise, your heart rate increases with physical activity to deliver more oxygenated blood to your muscles, and the fitter you are, the more efficiently your heart can do this, allowing you to work longer and harder. Since your heart is a muscle, the more you can, the stronger it gets. As a side effect, this increased efficiency also reduces your resting heart rate and reduces your blood pressure by creating new blood vessels. Exercise lowers blood pressure and relieves the heart.
Smoking and drinking
Dr. James Rudd, Lecturer in cardiovascular medicine at the University of Cambridge
Smoking cigarettes triples the risk of heart attack. And for young people, the influence of smoking is even more noticeable – in people under the age of 50, smoking leads to an eightfold increase in risk. Smoking is the most important "modifiable" risk factor for a heart attack – so the risk can be reduced by quitting. In fact, 10-15 years after stopping, the risk of a person is that of a non-smoker again. The evidence for this link is extremely robust and is not disputed by tobacco companies.
The reason why smoking is so dangerous is because it makes the blood "stickier" and tends to block the arteries of the heart. Cigarettes also damage the delicate lining of the arteries and promote inflammation. All of these effects increase the risk of a heart attack caused by a blood clot in the coronary arteries.
Alcohol has much weaker evidence – it probably has a neutral effect on heart attack risk. Certainly drinking up to 14 units a week does not increase the risk of heart attacks.
Dr. Nay Aung, cardiologist at Queen Mary University of London
Air pollution is a known risk factor for cardiovascular disease, although awareness of this relationship may not be as strong as other risk factors such as high blood pressure or lack of physical activity. According to a very well-conducted study, Global Burden of Disease, a component of air pollution known as particulate matter, is among the top five risk factors for increased risk of death. Most deaths or injuries are caused by heart attacks and strokes.
There are now several controlled studies in which volunteers were exposed to the air with diluted diesel particulates. The results showed that even short-term exposure to air pollutants at a similar level as on a busy road resulted in increased heart stress caused by a reduction in blood supply and an increased risk of clot formation. Airborne pollutants have been shown to increase an inflammatory stress response in the body that can trigger a cascade of harmful biological effects, including increased plaque buildup in the arteries.
Prof Andrew Steptoe, director of Behavioral Research and Health at University College London
There is evidence that various forms of chronic stress contribute to risk, as well as depression and, to a lesser extent, hostility. However, the impact is much greater for people at high risk for cardiovascular disease than for the general population. The best studied type of stress is at work, where the presence of workload (high demands combined with low control) is toxic. We estimate that in 550 middle-aged people, we need to perform treatment (eliminating stress at the workplace) to prevent a cardiac event over five years. By contrast, if we make physically sedentary people physically active, we would only need to treat 195 people to prevent a cardiac event. There is a risk of stress in the general population, but it is not big. Where the effects are much greater is among people who have a high cardiovascular risk, or those who already have a diagnosis of heart disease.
We now know a great deal about the biological mechanisms by which stress can affect heart disease. There are various processes, including changes in the autonomic nervous system, increased stress hormones, activation of immune reactions and inflammation and increased stickiness of the blood.