By Robert Nordstrom, Contributor

In part one of “Tea and Weight Loss,” WTN reviewed some research on tea’s effects on weight loss. While researchers have found that tea has interesting and potential benefits on weight management, particularly with regard to increased energy expenditure, most conclude that larger randomized controlled studies are needed.

With the message out, tea businesses regularly field questions from customers about tea’s weight loss properties. So, how should they answer? Only after arming themselves with information, experts say.

Contents Are King

As the health benefits of tea and its constituent properties become increasingly well known to the public, unscrupulous manufacturers have learned to manipulate their products’ ingredients lists.

Navindra P. Seeram and colleagues’ 2006 study, published in the Journal of Agricultural and Food Chemistry, evaluated 19 commonly available green tea dietary supplements and found that “label claims may not correlate with actual phytochemical content or antioxidant capacity, nor provide information about the presence and levels of caffeine.”

David J. Weiss and colleagues analyzed green tea extract dietary supplements and found that the “amount of catechins varies greatly among manufacturers, between capsules of the same manufacturers and between batches” (published in the June 2006 issue of the Journal of Chromatography).

According to Sage Group’s Tea Ingredients Annual 2008, “‘spiking’ of tea ingredients with caffeine and antioxidants … will likely occur as demand for more costly tea ingredients expands, specific constituents are deemed more desirable and shortcuts are sought to optimize profits.”

Sage Group’s founder Brian Keating added: “A few suppliers of tea ingredients use very diluted and watery extracts that contain minimal or no tea constituents. That’s why it’s important for product manufacturers to obtain a certificate of analysis performed by an independent laboratory that documents the existence of even minimal levels of basic tea constituents, such as polyphenols and caffeine.”

Knowing contents is important, because research about tea and weight loss hypothesizes that green tea’s catechin polyphenols raise thermogenesis (the rate at which calories are burned), and thus increase energy expenditure.

For tea extracts, specifically, it is important to know the catechin content. Use this as a reference point: A September 2003 Agricultural Research article (“Brewing Up the Latest Tea Research”) stated that “one 6-ounce cup … of green tea has about 235 milligrams of catechins.” So, if a manufacturer boasts that each serving of its product is equivalent to six or seven cups of tea, read the ingredients list and do the math to determine whether this is true.

Manufacturers Beware

Jim Prochnow, an attorney in the Denver office of Greenberg Traurig, said, “Those who market and sell tea or tea-containing conventional food or dietary supplement products must be aware of the laws, regulations and enforcement policies of the FDA and the FTC.”

The compliance and enforcement policies of the FDA do change, added Prochnow, who specializes in laws governing botanical products, including tea. As an example, he said the FDA now generally allows teas that are sold as conventional foods to be accompanied by claims about the non-disease health benefits of tea consumption, just as Congress has expressly allowed such claims for dietary supplements, including those that have tea as a dietary ingredient.

“If tea is an ingredient in a dietary supplement,” he explained, “the product manufacturer is within its legal rights to make weight-loss claims for that product, as long these claims are supported by competent and reliable research, the product is labeled as a dietary supplement, the list of ingredients are presented, and a disclaimer stating that the product has not been evaluated by the FDA is displayed.”

When working up marketing materials, however, product distributors must choose their language carefully. For example, obesity, according to Prochnow, is considered a disease condition, and a dietary supplement cannot claim that it affects a disease condition. Only products classified as drugs can make such claims.

Back Up Those Claims

Coca-Cola Co. and Nestle, which produce Enviga through a joint venture, recently reached a $650,000 settlement with the District of Columbia and 27 states regarding label clarification of Enviga tea. Enviga’s marketers claimed that drinking Enviga burned more calories than the drink contained, resulting in weight loss, and that consuming three cans in a day would result in burning up to 100 extra calories per day.

The research cited to support these claims was weak, however. The three-day study included only a small group of normal-weight, healthy 18-35 year olds. While some participants experienced additional calorie burning by drinking Enviga, they did not experience weight loss. The study did not establish that any of the calorie-burning effects could be sustained over time.

A printed statement on Enviga cans now reads: “Enviga burns calories but is not by itself a guaranteed weight loss solution. Remember, weight loss requires a reduced calorie diet and regular exercise. Individual results may vary. Drinking more than three cans per day will not have an additional effect.”