Can Cola Give You Cancer? Its Food Coloring Might

However, they also found that Pepsi variants and Malta Goya (particularly from the New York area) boasted worrying concretions. Interestingly, these concentrations dropped as the test went on. [View the full results and an accompanying chart.]

"The fact that we found lower amounts of 4-MEI in our last round of tests suggests that some manufacturers may be taking steps to reduce levels, which would be a step in the right direction," said Urvashi Rangan, toxicologist and executive director of Consumer Reports' Food Safety & Sustainability Center.

"There's no reason why consumers should be exposed to an avoidable and unnecessary risk that can stem just from coloring food brown," he concluded, citing that there are perfectly viable alternatives to 4-MEI-heavy food colorings that can achieve a caramel color.

[You can watch a video about the Consumer Reports study here.]

Still, the fact that manufacturers seem to be lowering 4-MEI concretions secretly could certainly raise some eyebrows.

Building on this report, the latest analysis of 110 soda brand samples, led by a team at the Johns Hopkins Center for a Livable Future (CLF), set out to see how much progress has really been made. There is currently no federal limit for 4-MEI in food or beverages.

Researchers discovered two very important things, which could further a dialogue with the Food and Drug Administration (FDA) to establish consumer limits. Firstly, they found a greater difference in levels between states than the Consumer Report tests. (Scroll to read on...)

This could show that the 2013 study had a greater impact in some states than imagined. The California Attorney General's office, for instance, took action using the state's Proposition 65 law aimed at reducing consumers' exposure to toxic chemicals.

The law only requires manufacturers to label a product if it contains a potential toxin at notable concretions, but the apparent result was a change of heart concerning 4-MEI use.

"Some of the soft drink products sold in California that we sampled had lower levels of 4-MEI than the samples we looked at of the same beverages sold outside the state, particularly in our earlier rounds of testing," Keeve Nachman, senior author of the study, explained in a statement. "It appears that regulations such as California's Proposition 65 may be effective at reducing exposure to 4-MEI from soft drinks, and that beverages can be manufactured in ways that produce less 4-MEI."

The researchers were also curious about the average consumer's soda-drinking habits. After all, the 2007 study that sparked all this had the mice ingesting 4-MEI every day. Unfortunately, Americans sometimes really do reflect the stereotype of chugging Big-Gulps with every lunch. The researchers found that between 44 and 58 percent of people over the age of six typically drink at least one can of soda per day - usually more.

And while it remains unclear how much 4-MEI a human would have to ingest to tip the scales towards cancer, "daily consumption" of a potential carcinogen never sounds good.

Nachman added that "an FDA intervention, such as determining maximum levels for 4-MEI in beverages, could be a valuable approach to reducing excess cancer risk attributable to 4-MEI exposure in the US population."

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