Here’s some recent research from Aberdeen University into the antidiabetic properties of cinnamon It concludes that true Ceylon cinnamon is the most effective in slowing the breakdown of starches - which can send blood sugar levels soaring. 

This is an extract from an associated press article which sums up the research:

"It’s the sweet-smelling spice we associate with treats at Christmas time and morish Danish pastries. But far from a luxury that will pile on the festive pounds, cinnamon could help lead the fight against diabetes – but only if it is from Sri Lanka.

Scientists at Aberdeen University’s Rowett Institute have compared the four most widely available varieties of the spice, which is gathered from the bark of the laurel tree.

Cinnamon is widely grown across Asia, with China, Vietnam and Indonesia supplying most of the world’s kitchen cupboards. But researchers found that the rarest of them all – “true”, or Ceylon cinnamon – is the most potent in reducing blood sugar levels, may provide a key to managing diabetes, and helps the body’s defences.

Dr Viren Ranawana, the nutritionist who led the study, said: “We thought it would be interesting to take the main four varieties of cinnamon, used in cooking around the world, and compare their diabetic properties.”

Cinnamon's unique properties come from its essential oils and compounds, particularly cinnamaldehyde. This compound gives cinnamon its flavour and aroma, and is also key to many of its health benefits.

Researchers took the four cinnamon varieties and dissolved them in alcohol to extract the active ingredients. Then they put high-starch bread and cinnamon through an artificial “stomach”.

Dr Ranwana said all four, in particular the Chinese and Indonesian cinnamon, had active antioxidants, which defend cells from damage caused by molecules known as free radicals. Also, all types had a positive effect on starch digestion – up to a thousand times better than some drugs already used to control diabetes. But the Ceylonese variety was particularly effective in slowing the break down of starches – which can send blood sugar levels soaring. It also had a large number of phytochemicals, which are believed to protect cells from cancer.

Dr Ranwana, whose study was published in thePlant Foods for Human Nutrition journal, concluded: “Ceylon cinnamon showed the best results, even though Chinese and Indian cinnamons were better at reducing enzyme activity."