Kobayashi Pharmaceutical’s growing scandal over its red yeast supplements has reignited debate on Japan’s “functional food” labels, which have been criticized for years over the lack of sufficient scientific proof of safety and efficacy accompanying their use.

The Osaka-based drugmaker on Friday confirmed another death associated with its line of beni kōji red yeast rice dietary supplements, bringing the reported fatality count to five, and the number of hospitalizations to 114. While the company has yet to pinpoint the cause of the health problems, it has said its beni kōji products may have unintentionally contained a yet-to-be-identified toxic substance.

Kobayashi Pharmaceutical is among many firms that utilize the kinōsei hyōji shokuhin label, or Foods with Function Claims (FFC). This functional food label was introduced in 2015, giving manufacturers a third way to advertise the health-enhancing ingredients in their products separately from two other health food labels.

The functional food label was intended as a middle ground between those two labels: Tokuho, short for tokutei hokenyō shokuhin (food with specified health uses) and eiyō kinō shokuhin (food that boosts nutrient functions).

Tokuho allows manufacturers to make certain health claims on their products if the government determines there's enough scientific evidence on their benefits and safety, but its certification system is tightly regulated, and is viewed by market players as too costly and time-consuming.

Eiyō kinō shokuhin, on the other hand, is a label that manufacturers can freely use as long as the products contain designated vitamins and minerals.

Functional foods are similar to tokuho in that manufacturers can make specific health claims, but unlike tokuho, the government does not review or guarantee the safety and efficacy of individual products.

The government explicitly states that it is not responsible for verifying the health claims made by the businesses, urging consumers to judge the foods' risks and benefits themselves by reading up on information on the label and on the agency's website.

In the case of Kobayashi Pharmaceutical’s Beni Koji Koresute Herupu (Cholesterol Help), which was registered as a functional food until it was withdrawn on Tuesday, information on the agency’s food database shows the firm’s claim that the product is considered safe because it had a history of marketing the beni kōji materials since 2007 with no health damage reported by consumers.

On the product’s health benefits, the firm said it relied on one peer-reviewed study showing the effects of the active ingredient “red yeast rice polyketide” on reducing LDL (low-density lipoprotein) or “bad” cholesterol. The information, however, cited no source for the research or the details of the study, including its size, location and period.

In the wake of the scandal, Kobayashi Pharmaceutical has withdrawn the registration of the functional food label from a total of eight supplement products containing beni kōji that claims to lower cholesterol, blood pressure and visceral fat.

Another firm, Zero Plus, which had used Kobayashi Pharmaceutical’s beni kōji for its cheese rice crackers marketed as being able to help reduce bad cholesterol, has also canceled its functional food label.

Consumer rights groups have for years argued that the functional food label, supposedly modeled after U.S. regulations on dietary supplements, is thin in scientific evidence and potentially harmful to health.

The scandal has reignited criticism of the government’s regulatory policy over these health foods.

Yuko Kamimura, a medical doctor and an executive board member of the Japan Medical Association, said the system needs an overhaul.

“At present, no screening is conducted and no permission is required for the manufacturing and sales of functional foods. It is unclear how functional and safe they are,” Kamimura told a news conference in Tokyo on Thursday. “(Some functional foods) are advertised in ways that are similar to medical drugs. It is presumed that there are not a few cases of people taking them excessively and suffering health damage.”

The Consumer Affairs Agency has begun an emergency inspection of 7,000 food products that carry the FFC label, which are marketed by 1,700 businesses. The agency is asking these businesses to report by April 12 if they have received health complaints from consumers and whether they have a mechanism in place to investigate reports of health issues.

Agency chief Yutaka Arai told reporters Thursday that, following an emergency check of existing practices, the agency will weigh measures to address regulatory issues.

“We are facing a serious situation that has raised questions over the safety of FFCs,” Arai said. “We understand that before this incident (involving Kobayashi Pharmaceutical), many groups have expressed opinions on the foods, so (the emergency inspection) would be a starting point for examining them.”