Glucomannan flour has been used in China as a food source as well as a traditional medicine for many centuries (Liu, 2004), dating back as early as the time of the Western Han Dynasty (206 BC–08 AD).
A wide range of clinical studies (endorsed by the European Food Safety Authority) have demonstrated that supplementing the diet with konjac fibre significantly improves glycaemic control, lowers plasma cholesterol, and enhances bowel movement. There may also be beneficial appetite suppression associated.
Obesity is a global pandemic that is driving a surge in type 2 diabetes as well as a whole host of other obesity-related morbidities. Several groups of researchers have evaluated the safety and efficacy of konjac fibre use in weight loss in overweight and obese.
Konjac fibre has been proven to improve satiety by delaying gastric emptying caused by the mass effect of its gel-like & viscous nature. A study in 2015 reported that konjac fibre improved satiety by increasing the bulk effect of food & the time taken by the slow digestion of a konjac-containing meal, given konjac is not digestible itself; this in turn slows down the rate of any post-prandial glucose uptake, which would reduce the total glycaemic index of the meal, and subsequent insulin spike.
Another recent study evaluated the effects of konjac fibre on body weight and BMI in otherwise healthy obese children and adults. The authors concluded that the short-term use of konjac fibre would help to reduce body weight.
A study by Huang et al. investigated the effect of konjac fibre on blood glucose levels in patients with diabetes. Results show that both, fasting blood glucose and 2h post-prandial glucose level, were significantly reduced 7. Similar results were achieved by a study comparing the viscosity of a range of soluble fibres .
In summary, konjac fibre is an emerging alternative nutritional therapy for the treatment of type 2 diabetes, with clinical efficacy similar to lifestyle changes. The hypoglycaemic effects of the fibre have been attributed to the inhibition of carbohydrate absorption from the gut resulting in a decrease in the post-prandial insulin response. Not only does konjac fibre improve glycaemic control & insulin resistance, but it also reduces associated risk factors such as dyslipidaemia and hypertension.