According to the Health Sciences Authority (HSA), health supplements can be imported and sold without a licence.
These are also not subjected to pre-market approval by the HSA.
However, with the proliferation of these products, coupled with an insatiable consumer appetite for them, perhaps it may be worthwhile to reconsider this position.
As it is, some of these health supplements may potentially be harmful to individuals with certain health conditions.
Manuka honey is an example that comes to mind. It is commonly available at local pharmacies and supermarkets.
The active ingredient in this supplement is a chemical called methylglyoxal.
As a highly reactive dicarbonyl molecule, methylglyoxal readily reacts to certain amino acids as well as to nucleic acids.
Apart from Manuka honey, very little methylglyoxal is consumed in the diet.
Low amounts of it are produced in the body as a by-product of the normal cellular process of glycolysis, in which glucose is broken down to provide energy.
As it is a dangerous molecule, the human body rapidly detoxifies methylglyoxal using various enzymes.
However, for people with certain medical conditions, such as diabetes, eating Manuka honey may increase the level of methylglyoxal beyond the detoxification capacity of the enzymes.
As a result, advanced glycation end-products (AGEs) are formed when methylglyoxal reacts and damages proteins and nucleic acids.
Indeed, a large volume of scientific literature has implicated AGEs as a major mechanism in the development of diabetic complications, particularly diabetic retinopathy, the leading cause of blindness in adults.
Besides diabetes, methylglyoxal is thought to play an important role in the process of ageing and in the development of several age-related diseases, including obesity, cancer, disorders of the central nervous system, hypertension and atherosclerosis.
Clearly, it is sensible for individuals with such health conditions to avoid this supplement or at least get advice from their doctors before consuming such products on a prolonged basis.
The HSA can also do its part by reviewing its stance on such health supplements.
Daniel Ng Peng Keat (Dr)