Heart attack risk even to casual users of cannabis
CANNABIS users are three times as likely to die from high blood pressure, even if they do not smoke it frequently.
The danger rises for every year someone uses the drug, a study found.
Marijuana’s effects on the cardiovascular system are already known from people taken to hospital with heart attacks and angina after use. But the new findings raise fears over high blood pressure, which puts extra strain on the blood vessels, heart and other organs such as the brain.
Left untreated, it can kill people by causing strokes or kidney disease, as pressure on the small blood vessels stops the organs working properly.
The latest study of 1,213 people by Georgia State University in the US found those who had used marijuana were 3.42 times as likely to die from high blood pressure.
Lead author Barbara Yankey said: ‘Marijuana stimulates the sympathetic nervous system, leading to increases in heart rate, blood pressure and oxygen demand.’
Smoking marijuana can double someone’s heart rate for up to three hours afterwards. The main psychoactive, mindaltering ingredient in the drug, tetrahydrocannabinol (THC), has been found to
‘It stimulates the nervous system’
lead to strokes, dizziness and fainting. That is because cannabinoid receptors, which deliver the high when someone smokes the drug, are also part of the cardiovascular system.
To investigate how this affects blood pressure, the researchers carried out a follow-up study of adults aged 20 and over involved in a national health survey. The average length of use for those considered marijuana users was 11.5 years.
This group’s triple risk of dying from high blood pressure included deaths from kidney disease.
Dr Amitava Banerjee, honorary consultant cardiologist at University College London, said the study added to previous evidence that found ‘the link between marijuana and strokes was stronger than for any other cardiovascular diseases.’
However British experts said the study published in the European Journal of Preventive Cardiology is small and it was criticised for assuming past users had continued smoking the drug when they may not have done so.