A recently concluded workshop on communicating research hosted by Malaysian Biotechnology Information Centre (Mabic) and Monash University Malaysia, found potential “science journalists” among researchers. The article published here is also a testimony of the success of the first home-grown science communication teaching module created by Mabic. The writer was given an opportunity to write popular science stories. The Petri Dish and Mabic will continue to support scientists in their attempts to bridge science and society. 

MANY are not aware that pure honey, if kept for a long time, produces a substance that can cause cancer. The substance is known as 5-hydroxymethylfurfural (HMF) and is also another important indicator of honey purity based on the International Honey Commission (IHC) criteria. HMF is an organic compound that is produced when some sugars like honeys are dried during processing.

The study conducted by a team of scientists at Monash Unversity Malaysia was published in Food & Chemical Toxicology (2010) and have received 110 citations to date.

According to Prof Gan Siew Hua, Deputy Head (Research), School of Pharmacy, HMF is mostly absent in fresh products but is naturally-formed in sugar-containing foods including honey especially during heating or processing. High HMF content in honey is associated with overheating, poor storage conditions and old honey.

“My grandmother always says that old honey is better. However, we found it not to be true. Now I am excited that I have some proof to debunk this myth.

“We found that its concentrations increased over time which is a major concern since it is potentially carcinogenic (cancer-causing).

“We found that honey stored for 3–6 months has acceptable HMF levels (2.80–24.87 mg/kg) i.e. within the internationally recommended value of 80 mg/kg for tropical honeys.

“However, when fresh Malaysian honey was stored for longer periods (12–24 months), it contained much higher HMF concentrations (128.19–1131.76 mg/kg) that is above the recommended value,” said Gan.

The team however did not conduct a study to confirm the carcinogenic effect of old honey consumption since some other substances present in honey may act synergistically and suppress the activity of the other.

Nevertheless, the presence of the compound released in high amounts in old honey is still a major concern, the team noted.

Gan and her team recommend that honey should be consumed within one year of its processing.

Additionally, the scientists also caution that honey should be kept in a glass bottle since honey kept in plastic containers are found to contain some plasticisers like phthalate.
Studies in rodents confirmed that phthalates can alter the levels of hormones in the body or lead to birth defects.

“Similar to HMF, the amount of plasticisers also increases if honey is stored in high temperatures.

“Therefore, in addition to the duration of storage, the manner in which it is stored is also important to ensure good quality honey,” said Gan.