How we rate
“Strong” = several concordant meta-analyses or systematic reviews. “Moderate” = one synthesis, or several controlled trials. “Limited” = early trials only. The rating is about the quality of the studies, not about how useful the supplement is.
Cider vinegar
It has become a social media sensation. Its effect on blood sugar levels after a meal is real and has been measured; as for the weight-loss claims, however, they are based on just one trial.
Benefits
- Lowers blood glucose and insulin levels after a meal: an effect confirmed by a meta-analysis of clinical trials, and already achieved simply by using a vinaigrette dressing on a mixed meal
- Lowers fasting blood glucose, glycated haemoglobin and total cholesterol in adults (meta-analysis of randomised trials) — but has no effect on LDL, HDL or fasting insulin
- In people with type 2 diabetes, 30 ml a day for eight weeks improves fasting blood glucose levels, glycated haemoglobin, total cholesterol and LDL
- Increases glucose uptake by the forearm muscles in people with type 2 diabetes, thereby reducing postprandial hyperglycaemia and hypertriglyceridaemia
- In obese people, 15 to 30 ml a day for 12 weeks reduced weight, body fat and blood triglycerides
Precautions
In patients with type 1 diabetes suffering from gastroparesis, 30 ml of apple cider vinegar significantly slowed gastric emptying — which may hinder rather than help their blood sugar control. Medical advice is required for those with treated diabetes, as vinegar also affects blood sugar levels. It is also worth noting that when vinegar curbs the appetite, it is largely because it is unpleasant to drink. The reduction in appetite observed in healthy adults was accompanied by a significant increase in nausea, which was all the more pronounced as the preparation was considered unappetising. With regard to weight, only one trial yielded a clearly positive result; another, involving eight weeks of daily vinegar intake in adults at metabolic risk, improved blood sugar levels and insulin levels without affecting body fat. A 2020 systematic review concluded that the quality of the available research was insufficient to draw any conclusions. As for the topical applications popularised online: diluted vinegar baths did not improve either the integrity of the skin barrier or the skin microbiome in atopic dermatitis, with most participants also reporting irritation.
Recommended dosage
In clinical trials, 15 to 30 ml per day was used, taken with meals. As regards the effect on post-prandial blood glucose levels, a small amount in a salad dressing proved sufficient in healthy subjects: it is the acidity that has the effect, not the dose.
How to take it
- Dose: 15 to 30 ml per day in trials on blood sugar and weight, for 8 to 12 weeks.
- At mealtime: added to a meal, even in small quantities in a vinaigrette, it reduced the subsequent blood sugar spike. Its acidity is what acts.
- On appetite: the decrease in appetite is mainly due to the nausea it causes, according to studies on its tolerance.
- With gastroparesis: 30 ml further slowed stomach emptying in type 1 diabetics, which could hinder their blood sugar control.
- On the skin: in a diluted bath against atopic eczema, no benefit, and most participants experienced irritations.
Did you know?
Although it improves blood glucose control, red wine vinegar consumed daily for 8 weeks did not result in a significant reduction in adiposity (body fat, weight, BMI or waist circumference).
What the studies say
A systematic review and meta-analysis of randomised clinical trials evaluated the effect of apple cider vinegar (ACV) on blood lipids and glycaemic parameters in adults. ACV consumption significantly decreased total cholesterol, fasting blood glucose, and HbA1C. However, no significant effect was found on LDL cholesterol, HDL cholesterol, fasting insulin, or HOMA-IR.
Hadi A, Pourmasoumi M, Najafgholizadeh A, Clark CCT, Esmaillzadeh A. — BMC complementary medicine and therapies (2021) — View the source study
For information only: not a substitute for medical advice. Dietary supplements are not a replacement for a varied, balanced diet. Learn more