Fiber ingredient suppliers and food companies have been waiting with interest for a few years, but finally, here come the "fiberworks." The FDA defined the term dietary fiber in May as part of its efforts to update the Nutritional Facts panel of food products since its debut more than 20 years ago. The agency now restricts fiber to naturally occurring fibers and those with a physiological benefit. It also increased the Dietary Reference Values (DRV) of dietary fiber, which includes both soluble and insoluble fiber, from 25 to 28g.
For ingredient suppliers and food companies, the definition could add the challenges of having to identify their food ingredients as starch, oats and fiber on a package label. Manufacturers concerned about how the changes will affect the updated Nutrition Facts panel have additional issues. With the changing definition, certain fiber claims on products are at risk, as are some products themselves. Any "newly isolated or manufactured dietary fiber" would need to deal with additional evaluations before being allowed to be listed as dietary fiber on food packaging.
Until this year, FDA regulations didn't define dietary fiber, and instead relied on analytical methods for measuring levels of dietary fiber present in food. This meant an isolated or synthetic, non-digestible carbohydrate could be added to foods and quantified as a dietary fiber, even if it didn't necessarily provide a beneficial physiological effect to human health.
The FDA-approved health claims recognize that soluble fiber as part of a diet low in saturated fat and cholesterol plays a major role in reducing heart disease risks. A fiber-rich diet has been well documented to have numerous benefits supported by substantial scientific research.
According to the new FDA plan, manufacturers adding fiber to foods—either by isolating it from other foods or synthesizing it—will need to demonstrate one beneficial physiological effect to human health to meet the definition's requirements.
So what existing carbohydrates can be considered dietary fiber content? And for those not yet recognized as dietary fiber, what physiological benefits have to be demonstrated?
First, to be considered a dietary fiber that may be declared on a food package label, a carbohydrate must exhibit certain physiological effects to be eligible: Lowering blood glucose and cholesterol levels; lowering blood pressure; improving laxation and bowel function; increasing mineral absorption in the intestinal tract; reducing energy intake (for example, from the fiber promoting a feeling of fullness). Other physiological values can be added to the list if scientific evidence supports their inclusion, the agency states.
Second, the FDA issued guidance to the industry on how to submit proof to demonstrate physiological benefits to human health (see the guidance document). Manufacturers with $10 million or more in annual food sales must comply with the new dietary fiber declaration requirements by July 26, 2018; manufacturers selling less than $10 million annually must comply by July 26, 2019.
Seven so far
The FDA determined and was able to assess seven non-digestible carbohydrates that meet its definition of dietary fiber:
- Beta-glucan soluble fiber (soluble)
- Psyllium husk (mostly soluble)
- Cellulose (insoluble)
- Guar gum (soluble)
- Pectin (soluble)
- Locust bean gum (soluble)
- Hydroxypropylmethcellulose (soluble)
Other fibers, such as inulin, can be added to a product, but they may not be included in the dietary fiber total. Publicly available clinical trial data is also being identified and summarized for non-digestible carbohydrates, including inulin, bamboo fiber, soy fiber, pea fiber, wheat fiber, cotton seed fiber, sugar cane fiber, sugar beet fiber and oat fiber.
Additionally, other fibers are included in the Total Carbohydrate total.
Naturally occurring fibers in foods include those in vegetables, whole grains, fruits, cereal bran, flaked cereal and flours. According to the FDA, fiber is considered to be "intact" in these because the fibers haven't been removed from the food.
The agency has also identified and reviewed an additional 26 types of isolated or synthetic non-digestible carbohydrates, beyond the first seven it already deemed the most common added to food and declared on the Nutrition Facts label as dietary fiber. Interested parties are invited to submit scientific data, information and comments to the FDA on the physiological benefits of the 26 fibers they believe qualify for the fiber definition. Manufacturers who want the agency to amend the definition of dietary fiber to include one of the 26 are asked to submit a citizen petition.