March 27, 2026

expert reaction to study looking at maltol, a caramel food additive, and bone fragility in diabetic mice

A study published in Cell Metabolism looks at a food additive (maltol) and bone fragility in mice.

Prof Tom Sanders, Professor emeritus of Nutrition and Dietetics, King’s College London, said:

“This is an interesting study stimulated by an exploratory metabolic profiling of neck tissues from people with type 2 diabetes with neck fractures that suggested maltol may have a role in regulating bone turnover. They found a trend for higher levels of maltol levels in bone tissues of 11 patients with type 2 diabetes compared to 11 controls.

“The investigators then fed diabetic mice maltol added to their drinking water 48 and 100 micromol/litre (equivalent to 6 to 12 parts per million).  They found evidence of increased bone turnover in diabetic miced that were hyperglycemic compared with control animals that did not receive maltol, as well as in normal mice.

“However, it is difficult to translate the amount of maltol given to mice with that usually consumed in human diets. The mice received the maltol in drinking water.  My estimates are that an average mouse weighs about 20 g but consumes a lot of water daily (5 ml) in relation to its body water compared to 75 kg man who would consume 2500 ml/d.  Consequently, the mice would be receiving roughly 30-60 micrograms maltol per day which is the equivalent of 1.5-3.0 mg/kg body weight.  So, my estimate is that the equivalent dose for a 75 kg man would be 112.5-225 mg per day.  Maltol is added to provide caramel flavour particularly in cola drinks and the average level is 80 mg/L and about 111 mg/kg in caramel flavour bakery products.  This would indicate that the doses fed to the mice were not excessive and were reasonable.

“Maltol is found naturally (larch bark, pine needles, ginseng).  Maltol as the name implies was first isolated from malt.  The source of maltol in many diets is from food processing notably the browning reaction (Maillard reaction) when food is heated for example during baking or toasting bread (Guan et al, 2026).  Other sources are from roasting coffee beans, beer (where it is derived from malt) and soya sauce and tea (from fermentation) and wine kept in in oak aged barrel.

“This is an innovative piece of research that deserves follow-up but is insufficient to justify changes in dietary advice regarding maltol intake.  Further research is needed to confirm the relationship between higher maltol levels in patients with diabetes and neck fractures in a larger sample.  At this stage there is no evidence that restricting maltol intake would have any benefit and this can only be demonstrated by a controlled trial.”

‘Maltol induces diabetic fragility fractures by disrupting the balance of bone remodeling’ by Jinyang Wang et al. was published in Cell Metabolism at 15:00 UK time on Friday 27 March 2026. 

DOI: 10.1016/j.cmet.2026.03.001

Declared interests

Prof Tom Sanders: “I was Chair of the British Nutrition Foundation Report on Nutrition and Development: Short and Long term consequences for Health.

I have received grant funding for research on vegans in the past.  I have been retired for 10 years but during my career at King’s College London, I formerly acted as consultant for companies that made artificial sweeteners and sugar substitutes.

I am a member of the Programme Advisory Committee of the Malaysia Palm Oil Board which involves the review of research projects proposed by the Malaysia government.

I also used to be a member of the Scientific Advisory Committee of the Global Dairy Platform up until 2015.

I did do some consultancy work on GRAS affirmation of high oleic palm oil for Archer Daniel Midland more than ten years ago.

My research group received oils and fats free of charge from Unilever and Archer Daniel Midland for our Food Standards Agency Research.

I was a member of the FAO/WHO Joint Expert Committee that recommended that trans fatty acids be removed from the human food chain.

Member of the Science Committee British Nutrition Foundation.  Honorary Nutritional Director HEART UK.

Before my retirement from King’s College London in 2014, I acted as a consultant to many companies and organisations involved in the manufacture of what are now designated ultraprocessed foods.

I used to be a consultant to the Breakfast Cereals Advisory Board of the Food and Drink Federation.

I used to be a consultant for aspartame more than a decade ago.

When I was doing research at King’ College London, the following applied: Tom does not hold any grants or have any consultancies with companies involved in the production or marketing of sugar-sweetened drinks.  In reference to previous funding to Tom’s institution: £4.5 million was donated to King’s College London by Tate & Lyle in 2006; this funding finished in 2011.  This money was given to the College and was in recognition of the discovery of the artificial sweetener sucralose by Prof Hough at the Queen Elizabeth College (QEC), which merged with King’s College London.  The Tate & Lyle grant paid for the Clinical Research Centre at St Thomas’ that is run by the Guy’s & St Thomas’ Trust, it was not used to fund research on sugar.  Tate & Lyle sold their sugar interests to American Sugar so the brand Tate & Lyle still exists but it is no longer linked to the company Tate & Lyle PLC, which gave the money to King’s College London in 2006.”