Does cinnamon really lower your blood sugar?
Cinnamon can modestly lower fasting blood sugar in type 2 diabetes, but whether that makes any meaningful difference to long-term health remains unclear. Use it at most as a supplement to proven treatment, and if so prefer Ceylon cinnamon over the common Cassia variety.
Cinnamon probably lowers fasting blood sugar in people with type 2 diabetes by a modest amount. Multiple meta-analyses of randomised trials find an average reduction of roughly 0.5 to 1.4 mmol/L. A recent double-blind study using Ceylon cinnamon extract (1000 mg per day, 12 weeks, n=150) found an average reduction of 8.6 mg/dL compared with placebo. In participants with type 2 diabetes the reduction was as large as 63 mg/dL. That last study was partly funded by a cinnamon manufacturer, which colours the findings.
The crucial caveat lies in the long-term measure of blood sugar control: HbA1c. That is the value doctors use to assess how well blood sugar has been controlled over several months. Older meta-analyses found no improvement in HbA1c with cinnamon. The most recent meta-analysis (24 studies, published up to 2022) did find a modest reduction, but the researchers themselves state that the results are 'not conclusive'. This is because the studies differ widely in dosages, types of cinnamon and study duration.
Cassia cinnamon, the most widely sold variety in supermarkets, contains coumarins. This compound can burden the liver at high daily doses. Ceylon cinnamon contains considerably fewer coumarins and is more often regarded as safer in the research literature. Studies to date are too short and too small to measure rare side effects.
For blood lipids the picture is unclear. Some studies observe a reduction in LDL cholesterol and triglycerides, others do not. No firm conclusion can be drawn here.
Cinnamon is not a replacement for diabetes medication. If you want to try it as a supplement, discuss this with your doctor. Ceylon cinnamon extract has shown a more favourable safety profile in studies than large daily amounts of Cassia cinnamon.
Based on multiple meta-analyses (up to 24 RCTs, n=543 in the largest meta-analysis, n=150 in the most recent RCT) and one RCT with an uncertainty notice (expression of concern). High heterogeneity between studies and variation in cinnamon type/dosage limit generalisability. One RCT partly funded by a cinnamon manufacturer.
Does eating more fibre help against high blood sugar?
Eating more water-soluble fibre probably helps in lowering high blood sugar, but the overall meal composition also plays a role. Choose legumes, vegetables and fruit if you want to increase your fibre intake, and watch out for side effects when making a large increase.
Does a walk after eating help with your blood sugar?
A short walk after eating, or better still several short walking breaks of 2 to 3 minutes spread throughout the day, is a practical and well-supported way to limit blood sugar spikes, especially if you have excess weight or type 2 diabetes.
Does it make sense to limit blood sugar spikes, even without diabetes?
Limiting blood sugar spikes makes sense even without diabetes: the risk of cardiovascular disease appears to rise with spikes that are still officially considered 'normal', and walking immediately after a meal is a simple, evidence-based way to reduce those spikes.
What does alcohol do to your blood sugar and insulin sensitivity?
The effect of alcohol on your blood sugar depends strongly on context: on an empty stomach the risk of low blood sugar is real, whereas with a meal it may temporarily rise instead. If you have diabetes or use blood-sugar-lowering medication, discuss with your doctor how to incorporate alcohol safely.
Does strength training work better against high blood sugar than cardio?
Strength training appears to work better than cardio alone in people with diabetes and a normal weight, but in overweight individuals that advantage is less clear and a combination of exercise with diet helps the most.
Does berberine help against high blood sugar (the natural metformin)?
Be careful with this. Berberine measurably lowers blood sugar, but EFSA could not establish a safe intake level (signs of DNA damage and liver damage), an EU procedure that may lead to restriction is underway, and it interacts strongly with medicines. Do not use it on your own, certainly not alongside diabetes medication or during pregnancy.