5 reasons you’re more likely to have a heart attack in winter

The cold, dark days of winter might be depressing, but did you know they can seriously affect your heart health, too? You’re twice as likely to have a heart attack or stroke during a cold spell.

Research by scientists at the University of Bristol and University College London found the number of heart attacks and strokes in people aged over 60 doubled during periods of at least four days which were particularly cold compared to the rest of the month.

The British Heart Foundation (BHF), which funded the study, says each year in the UK there are thousands of additional deaths from heart and circulatory disease in the winter months.

“The cold weather makes your heart work harder to keep your body warm,” explains Chloe MacArthur, a senior BHF cardiac nurse. “This can present specific risks for people with heart conditions as it can exacerbate symptoms.”

Dr Gosia Wamil, a cardiologist at Mayo Clinic Healthcare in London, says a combination of factors including extra stress on the body caused by the cold, plus inflammation from winter respiratory infections and even vitamin D deficiency because of the lack of sunlight, can all lead to the increased number of heart attacks in winter.

“The heightened probability of experiencing a heart attack during winter stems from various factors,” she explains. “Cold temperatures induce physiological stress, leading to vasoconstriction, elevated blood pressure, and increased strain on the heart, especially during physically demanding activities like snow shovelling.”

But she adds: “It’s crucial to note that while these factors contribute to seasonal variations in heart attack rates, individual health and lifestyle choices play a significant role in determining cardiovascular risk.”

Here’s why you’re more likely to have a heart attack in winter…

1. Narrowing of blood vessels

The BHF says cold temperatures cause blood vessels to narrow (vasoconstriction) in parts of the body like the skin, fingers and toes, so less body heat is lost and more blood and oxygen are re-routed to essential organs like the heart and brain. “This narrowing creates more pressure in the rest of the circulation, meaning the heart must work harder to pump blood around the body, increasing the heart rate and blood pressure,” explains MacArthur.

2. Changes in the blood

Wamil says that as well as the blood vessels narrowing, the blood itself may also change during a cold snap. “The cold weather may induce changes in blood composition, promoting coagulation and clot formation, contributing to cardiovascular events, although it’s not supported by strong scientific evidence,” she says.

3. Infections

Winter flu could have more serious implications than you think, and Wamil explains: “Winter is characterised by a surge in respiratory infections, such as influenza, which can trigger inflammation and put additional pressure on the cardiovascular system.”

4. Vitamin D deficiency

Wamil says vitamin D deficiency, prevalent in the UK winter due to reduced sunlight exposure, has been associated with an increased risk of cardiovascular diseases.

5. Poor diet

The cold, dark days of winter can lower our mood, and the BHF says this can lead to emotional comfort eating of indulgent, unhealthy food, which is often full of artery-clogging fat. Plus, we’re more likely to be snacking in front of the TV – and seeing adverts for rich, unhealthy food over the festive season.

Wamil warns: “The holiday season further compounds the cardiovascular disease risks, with unhealthy dietary habits, heightened alcohol consumption, and increased stress.”

Reduce your risk

Although the risk of heart attack is higher when it’s cold, it doesn’t mean you can’t do anything to minimise the risk, and MacArthur says: “The BHF is encouraging people with heart conditions to take precautions, such as wrapping up warm, staying active, maintaining a healthy diet and getting the flu jab, to minimise potential health risks during cold snaps.