HOW PRODUCTS WERE EVALUATED:
How Products were Selected:
Products were selected to represent those commonly available in the United States. ConsumerLab.com purchased products on the open market through retail stores, on-line retailers, and direct sales or multi-level marketing companies. Products were not accepted directly from manufacturers. For each product, the sample was composed of one or more purchased samples from a lot having an expiration date (if labeled) later than the date of testing.
Testing Methods:
The cancer prevention products were tested for amount(s) of selected key ingredients: green tea (Camellia sinensis L.), caffeine, lycopene and selenium. Analyses included identification of potential contamination with lead in green tea products. All applicable products were also tested for their ability to disintegrate in solution (excluding capsules, chewable and time-release products).
For each ingredient, the following testing method was employed:
- Green tea products were evaluated for specific forms: Total catechin concentration by HPLC. Green tea products were quantitatively analyzed for xanthine alkaloids (caffeine, theophylline and theobromine) by HPLC. Lead contamination was assessed by ICP-MS analyses.
- Selenium products were analyzed using an Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) for total selenium and seleniomethionine forms as claimed or yeast content was measured by a special method.
- Lycopene products were evaluated for cis-lycopene and total lycone content by HPLC.
Disintegration of non-capsule, non-chewable and non-time release formulations was analyzed utilizing USP (United States Pharmacopeia) 2040 recommendations entitled "Disintegration and Dissolution of Nutritional Supplements."
Products not having passing levels of key ingredients or contaminants were then re-tested in a second independent laboratory using similar methods and instrumentation. The identities of the products were not disclosed to the laboratories performing the testing.
Passing Score: *
To achieve a "Pass" in the testing, a product had to meet the following criteria:
Green Tea Products
- Contain a minimum of 100% and no more than 135% of label claim for total catechins or specific catechins (e.g. epigallocatechin gallate (EGCG)). Total catechins are the sum of epigallocatechin, epicatechin, epigallocatechin gallate, gallocatechin gallate, epicatechin gallate and catechin gallate. Green tea extracts with no total catechin or specific catechin label claim should have no less than 10% total catechins (%wt/wt).
- Contain no less than 100% and no more than 120% of label claim for xanthine alkaloids (as caffeine, theophylline and theobromine).
- Must not exceed California Prop 65 levels for lead contamination in a recommended daily serving and, in no event, exceed 2 mcg of lead in a recommended daily serving. (The State of California has established its own strict standards for lead, including 0.5 micrograms of lead per serving per day for foods and most supplements. Products sold in California that exceed these levels are required to bear warning labels).
Selenium Products
Contain a minimum of 100% and no more than 135% of label claim of elemental selenium and seleniomethionine.
Lycopene Products
Contain a minimum of 100% and no more than 135% of label claim of total cis/trans lycopene or specific lycopene isomers.
All Products:
- Meet recommended USP parameters for disintegration for nutritional supplements (excluding capsule, chewable and time-release products).
- Meet FDA labeling requirements.
*Passing scores allow for specific margins of technical error associated with each analysis. ConsumerLab.com reserves the right to disqualify a product at any time from passing its testing if it considers such product to present a safety risk or to provide misleading or inaccurate information in its labeling.
