Shirataki and konjac based foods are generally recognized as safe (GRAS) by the Food and Drug Administration. As such, it is highly unusual to hear of negative side effects from the use of shirataki noodles and glucomannan based foods, however, some dangers do exist from consuming these foods.
- A typical complaint of dieters taking glucomannan capsules or eating a lot of shirataki noodles is a bloating or overly full feeling. This feeling is typically gone within a week of beginning a glucomannan regimen. It can be caused due to the increase of fiber in the diet.This bloated feeling can be immediately relieved by discontinuing the use of glucomannan, konjac or shirataki products.
- A rare but life threatening side of effect of consuming glucomannan based products is the existence of a choking hazard. Because glucomannan absorbs water, if an insufficient amount of water is consumer after taking a glucomannan capsule, the capsule may begin to expand in the throat or upper digestive track, leading to blockage and potential choking. Simply drinking 8 ounces of water after taking glucomannan should significantly reduce the chance of this occurring.
- In 2001, the FDA did issue a two general warnings against consuming mini-cup gel candies that contain konjac. These multi-fruit-flavored candies are typically packaged as individual, mouth-sized servings, and often feature an embedded piece of preserved fruit.
The FDA and the Consumer Product Safety Commission staff consider this type of candy to pose a serious choking risk, particularly to infants, children and elderly. There have been reports of choking deaths related to consuming these candies since they do not readily dissolve in the mouth. Some products that remain in Asian markets have an increased size, unusual shape, and more delicate consistency than the round plug-like gels that were associated with the choking incidents. The snacks usually have warning labels advising parents to make sure that their children chew the jelly thoroughly before swallowing.
Although konjac is generally considered to be safe, it is not recommended that pregnant or nursing women as well as children consume these products without a doctor’s authority and supervision.