A five-year study found people treated in the summer were on average 8% more likely to see their blood pressure come down to healthy levels. The US Department of Veterans Affairs team analysed data on 443,632 veterans treated for hypertension.

The study, reported to the American Heart Association, suggests a more active summer lifestyle may be the key.

Lead researcher Dr Ross Fletcher said: “People gain weight in the winter and lose weight in the summer. People tend to exercise more in the summer and less in the winter.”

The researchers said it was also possible that people might eat more salty foods in winter. Salt is strongly linked to raised blood pressure.

People with a blood pressure reading of more than 140 mm Hg systolic or more than 90 mm Hg diastolic on three separate days were identified as hypertensive.