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Maricel V. Maffini, PhD’s Blog

EGCG: Not my cup of (green) tea

Maricel V. Maffini, PhD

Posted August 26, 2014

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Last week, the Washington Post published an exposé of the US Food and Drug Administration (FDA) food additive regulatory program; it concluded that

The explosion of new food additives coupled with an easing of oversight requirements is allowing manufacturers to avoid the scrutiny of the Food and Drug Administration, which is responsible for ensuring the safety of chemicals streaming into the food supply. And in hundreds of cases, the FDA doesn’t even know of the existence of new additives.”  

In the Post article, FDA Deputy Commissioner for Food and Veterinary Medicine, Michael Taylor, admitted that:

“We simply do not have the information to vouch for the safety of many of these chemicals.”

By “many of these chemicals”, Deputy Commissioner Taylor was referring to substances that are “generally recognized as safe” or GRAS — chemicals that companies can independently certify are safe without any obligation to inform the agency (for more information on GRAS, check out this report and one of my earlier blog posts).  One such GRAS chemical, as highlighted by the Post article, is epigallocatechin-3-gallate or EGCG. 

EGCG is a chemical extracted from green tea leaves and has become a popular ingredient in beverages such as flavored water, sport drinks, and soft drinks. Because the extract is produced from green tea leaves, it’s usually touted as natural or “just like green tea”, but this is far from the reality. Extracts contain the active ingredient(s) of a plant that it’s been concentrated and purified; therefore, the extract is a new product with its own identity. FDA itself has called EGCG a cause of concern – though, unfortunately for consumers, concerns about the safety of EGCG were never made public by the company or FDA.

We learned about FDA’s concerns through a Freedom of Information Act (FOIA) request to the agency, which you can read for yourself here (pages 188 to 200). Among the many concerns raised by the FDA scientists was the potential contribution of EGCG to infant leukemia due to its ability to break the DNA strands in the gene associated with this disease.

More recently, I also found EGCG in the list of additives tested in the Tox21 program — a multi-agency (including FDA) effort to quickly and efficiently identify potential toxic effects for thousands of chemicals that lack toxicity information. EGCG had biological effects in 71 cell-based assays. Fully 30 of these tests were performed at the National Institutes of Health laboratory; among them are:

  • Thyroid receptor antagonist (EGCG inhibits the thyroid hormone from binding to its receptor and inducing a biological response; thyroid hormone is fundamental for fetal and childhood brain development)
  • Androgen receptor antagonist (ECGC  prevents androgen -the main male hormone- from binding to its receptor and inducing a biological response such as controling male reproductive organ development)
  • DNA polymerase beta inhibitor (DNA polymerase’s function is to make DNA from nucleotides, the building blocks of DNA; EGCG inhibits this function).

This new information adds even more potential concern about the safety of EGCG. When FDA’s scientists related their concerns to the manufacturer in 2007, they also made another important observation. They said that “although the subject of the notice is a purified substance [EGCG], much of the discussion in the notice is about green tea/green tea extract.” In other words, the manufacturer cloaked the chemical identity and potential toxicity of EGCG by referring to it as though it were simply green tea.

A common marketing practice in the food industry is to portray highly purified extracts as the equivalent of the original plant, fruit or herb. In other words, many products in the market are advertising ‘green tea extract’ as the ingredient rather than EGCG. However, according to the FDA notes, EGCG is the most predominant chemical in the extract (page 195).

FDA is trying to deal with this issue, and last January released a guidance for industry stating that:

We have seen a growth in the marketplace of beverages and other conventional foods that contain novel substances, such as added botanical ingredients or their extracts. Some of these substances have not previously been used in conventional foods and may be unapproved food additives. Other substances that have been present in the food supply for many years are now being added to beverages and other conventional foods at levels in excess of their traditional use levels, or in new beverages or other conventional foods. This trend raises questions regarding whether these new uses are unapproved food additive uses.” [Emphasis added].

In other words, if you extract a component of a plant, its concentrated form is a new substance and does not represent the original source. Even though EGCG is a component of brewed green tea that has been in the food supply for hundreds of years or more, it is NOT comparable to green tea. Therefore, EGCG must meet the “reasonable certainty of no harm” safety standard to be allowed in the food supply. Based on FDA’s review, and the new data from Tox21, I have my doubts that it does.

Though just one example, peering into the way that FDA has handled a chemical like EGCG reveals a broken regulatory system that cannot ensure the safety of the food supply, safety decisions made in secret mainly by those profiting from the chemical’s sales, an agency that has it hands tied and is unable to demand safety information, and questionable claims about the “natural origin” of purified extracts.  What a mess! Michael Taylor was quoted saying: “We aren’t saying we have a public health crisis. But we do have questions about whether we can do what people expect of us.” And we, the consumers, need FDA to answer why they can’t protect the food supply and the public from potentially harmful chemicals.

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