Sugar-derived substance damages "good" cholesterol, a new study has found.

Researchers at Warwick Medical School have found that methylglyoxal - MG destabilizes High Density Lipoprotein.

HDL is known to protect against heart diseases. The scientists said that elderly and those with diabetes or kidney problems have high levels of MG.

MG is formed from glucose. The substance damages arginine residue (amino acid) in HDL. The loss of an amino acid in a functionally important site leads to a breakdown of the entire fat molecule. The body maintains low levels of MG. However, ageing and diseases lead to a rise in levels of this harmful substance.

"MG damage to HDL is a new and likely important cause of low and dysfunctional HDL, and could count for up to a 10% risk of heart disease," said Dr Naila Rabbani, of the Warwick Medical School, according to a news release.

The body removes this damaged HDL, leading to a loss of good cholesterol in the body. Currently, there is no drug to reverse HDL loss. The researchers say that understanding the mechanism by which MG damages HDL can lead to new treatments that can reduce levels of this sugar.

"By understanding how MG damages HDL we can now focus on developing drugs that reduce the concentration of MG in the blood, but it not only be drugs that can help," Rabbani said in a news release. "We could now develop new food supplements that decrease MG by increasing the amount of a protein called glyoxalase 1, or Glo 1, which converts MG to harmless substances."

 The study is published in the journal Nutrition and Diabetes. It was funded by British Heart Foundation (BHF).