TOKYO -- It has emerged that a significant proportion of dietary supplements may be ineffective, after over 40% of 100 types of the products that were tested by the National Consumer Affairs Center of Japan were found not to dissolve in water within time limits prescribed for conventional medicines.
The findings show that people's bodies may not be absorbing the concentrated nutrients packed into supplements' pills and tablets. The center called for caution, saying, "It's not always the case that supplements are of the same quality as medicinal products."
Supplements are classed as food items. Standards exist for displaying nutritional information on those deemed Food with Nutrient Function Claims, and Foods with Function Claims must be submitted to the Consumer Affairs Agency, but such foods are not subject to the same strict requirements as pharmaceutical products. They also do not need national government permission to go on sale.
In 2000, the Ministry of Health, Labor and Welfare relaxed controls over the shapes that medication can come in, and approved the production of food products that resemble medicinal ones. These decisions appear to have fostered an expansion in the market for supplements in pill and tablet form.
Over September and October 2018, the center selected a total of 100 products consisting of 10 different types of supplement, including multi vitamins, GABA, black vinegar and Coenzyme Q for testing. They were chosen based on investigations by the center into which were most often seen available in storefronts and on the internet.
Pharmaceutical products must dissolve in water within 30 minutes if they are hard, uncoated tablets. Those coated in sugar or other solutions have within 60 minutes to break down, and capsules must dissolve within 20 minutes.
But the tests by the center showed that 42 products didn't dissolve within the time limits. The uncoated tablets posted particularly bad results, with 14 of the 26 that were chosen not breaking down on time.
Also, of some 64 products tested which had already been opened and had some of their contents used, half did not dissolve within the time limits required for pharmaceutical items. The rate of success was somewhat worse than for unopened products.
However, in a survey conducted during the same period on around 10,000 consumers, 74% of respondents said that they believed supplements have strict oversight and stable product quality, and 20% said that they take them to ease or relieve symptoms when sick. Close to 10% appeared to be confused about the distinction between medicine and supplements.
Satoshi Ono, head of the clinical research center at Shimane University Hospital, said, "If supplements exit the body just as they did upon entering, then it's a betrayal of consumer expectations. The makers of these products should show evidence that its effective components thoroughly dissolve and are absorbed."
Organizations related to the production of the supplements have accepted the results with varying levels of enthusiasm. The Japan Health and Nutrition Food Association, an industry body, responded by saying that tests of supplements' dissolution time should be made mandatory, and that it will proceed with developing its own voluntary standards.
But while another industry body, the Japan Alliance of Health Food Associations, is considering whether to develop such voluntary standards, it opposed the way the tests were carried out. It said, "It makes it appear that they (supplements) must be judged on the same level as drugs, which causes consumers to misunderstand the differences."
(Japanese original by Reiko Oka, Lifestyle and Medical News Department)