Cider vinegar to cut your risk of a stroke? Better evidence is needed

Taking 60ml of cider vinegar every day can reduce levels of cholesterol in the blood by 13 per cent, according to research carried out on the BBC series Trust Me, I’m a Doctor.

The researcher who made the discovery, Dr James Brown from Ashton University in Birmingham, said the acetic acid in cider vinegar had a ‘protective effect’.

The researchers split 30 volunteers into three groups. The first group was asked to drink 30ml (two tablespoons) of cider vinegar diluted in 200ml of water twice a day before meals. The second group was asked to do the same with malt vinegar and the third group was given a placebo.

The cider vinegar group experienced a 13 per cent reduction in total cholesterol levels, and a ‘significant’ reduction in triglycerides, a dietary fat found in meat, dairy and cooking oils. The malt vinegar group experienced no such reduction.

Dr Brown said: ‘Britain has among the highest cholesterol levels in the world. Anything that might help bring them down is worth considering.

‘Bringing cholesterol levels down like this can significantly reduce your chances of having a heart attack in the future. So we were really excited to see that finding.’

Mail Online went further, reporting the study with the headline: ‘Cut the risk of stroke or a heart attack — with a dash of cider vinegar every day.’

Instant analysis
This study, which hasn’t been published, was carried out by the BBC’s Dr Michael Mosley in conjunction with Dr James Brown. It was conducted on 30 healthy volunteers and was placebo controlled but was not randomised or blinded. Ten volunteers drank cider vinegar, 10 malt vinegar and 10 drank coloured water for three months. Their main finding was that there was a 13 per cent reduction in total cholesterol in those that drank cider vinegar.

No comment is made on the palatability of ingesting two tablespoons of cider vinegar diluted in water, but dropout would be expected. Similarly, while the placebo group drank coloured water, unless this was similarly flavoured to the vinegar water, it would be obvious this was not the treatment arm of the study. Those studied had a healthy level of cholesterol that was then reduced further. The meaning of this in clinical terms is unclear. At the same time these ‘healthy volunteers’ also have diseases such as arthritis and eczema, so perhaps are not so healthy, which of course may influence the results.

This study would need to be repeated in a much larger group, with a proper placebo, and both volunteers and scientists randomised as to which intervention they received, using unhealthy individuals at significant risk of a heart attack or stroke (that is, with elevated cholesterol) and followed up for years to see what impact it could have on heart attacks and strokes, before we could draw any firm conclusions of the therapeutic effectiveness of cider vinegar.

Other studies on the subject have had similar findings but also low scientific value.
DW
Research score: 2/5