Can cinnamon lower your blood sugar?

“Helps promote sugar me­tabolism,” says Tru­nature Advanced Strength CinSulin, a water extract of cinnamon. “Supports healthy blood glucose levels (within the normal range).”

CinSulin? Surely Trunature didn’t mean to imply that its supplement is as effective as insulin? Nah.

“Water extract of cinnamon has been studied in six human clinical trials and a meta-analysis to prove its effectiveness and safety,” says CinSulin’s website.

Why the evidence is unimpressive

CinSulin's claim sounds impressive. Yet in 2012, a rigorous Cochrane Collaboration meta-analysis of randomized trials found that cinnamon had no clear effect on blood sugar.

Most of CinSulin’s trials—which had at least some industry funding or were done by industry consultants—were too short to look at hemoglobin A1c, the best measure of long-term blood sugar.

The largest, which was published in the Journal of Traditional and Complementary Medicine five years after it ended, randomly assigned 173 people in China to take a placebo or two CinSulin cap­sules every day.

When the study started, the average fasting blood sugar level was 157, well above the 126 cutoff for diabetes. After two months, fasting blood sugar fell in the CinSulin takers, but not in the placebo takers. But levels—they averaged 147 for the CinSulin group—were still solidly in the diabetes range.

What’s more, the researchers don’t say how many of the 36 participants who dropped out had to start taking insulin because of sky-high blood sugar levels or even how many people were taking medications (other than insulin) when the study started.

And how do those results back up the label’s claim that CinSulin supports blood glucose “within the normal range”?

The bottom line

Don’t rely on cinnamon supplements to lower your blood sugar.

Photo: TruNaturalSupplements.