Capitalizing on Popular-Science Views of Antioxidants

Over the last several years, chocolate and cacao products have undergone a dramatic image change. These foods, which were once marketed as sweet indulgences, are now having their potential health benefits extolled far and wide. Perhaps the most widespread of these claims about chocolate’s supposed healthfulness is the fact that it contains high levels antioxidants. Take, for example, Navitas Naturals, a company whose byline is “The Superfood Company”, and that advertises its cacao nibs as an “antioxidant powerhouse”. They boast, “Navitas Naturals Cacao Nibs are loaded with antioxidants. In fact, cacao is one of the most antioxidant-rich foods on the planet!” However, they never explain why

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Source: navitasnaturals.com

antioxidants should be considered beneficial, or why we should want large quantities of them in our cacao. The same can be seen on Hershey’s packaging for their range of “Antioxidant Milk Chocolate”, shown below. The word “antioxidant” is splashed in large font across the packaging, but no specific health claims are present. What is it, then, that the consumer is meant to understand as the benefits of these antioxidant rich

hersheysantioxidant
Source: fallontren

foods? It must be that chocolate companies are drawing on a popular-science conception of the benefits of antioxidants that they expect the consumer to be primed with. In this way, they can draw upon what consumers already believe about antioxidants without making any potentially fallacious medical claims. Because, as Navitas Naturals’ page stipulates, “Cacao is a healthy food, not a miracle drug. These statements herein have not been reviewed by the FDA. [Cacao] products are not intended to treat, diagnose, cure or prevent any disease.” In the following paragraphs, I will discuss what it seems likely the average consumer associates with the term “antioxidant”, and review the science behind this perception.

 

 

“Antioxidant” is an umbrella term for any number of chemical species that protect cells from damage by free radicals. Free radicals are chemicals that pose a threat to our wellbeing, as they pull electrons off of nearby molecules, which can cause damage to cells and DNA. Antioxidants neutralize the threat caused by free radicals by freely donating their electrons while remaining stable themselves (“Antioxidants” Beyond the Hype”).   Antioxidants became a pop-science mainstay in the 1990s, when researchers identified free radical damage as a possible contributing factor in diabetes (Giugliano D), cardiovascular disease, and cancer (Dreher, Don) etiology, among others. Despite this laundry list of possible health benefits attributable to antioxidants, it seems that the general public has latched onto one of these in particular: cancer prevention.

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Source: Free Radical Biology and Medicine

There are several ways in which we can establish the strong association between antioxidants and cancer in the mind of the layperson. The first is to use Google’s “Ngram Viewer”, a resource that allows the user to plot the frequency of use of a word or phrase in a huge database of books. This provides a good proxy for the relevance of words to the average person, due to the very broad nature of the corpus from which Google draws. Using the “Ngram Viewer”, we can generate usage graphs for the words “cancer” and “antioxidants”. We can see that the frequencies of these two words are strikingly

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similar to one another, with usage increasing steeply for both beginning around 1940. This provides supporting evidence to the theory that these two words and concepts are closely linked in the mind of the average person. Additionally, the antioxidant/cancer association gains support from Google’s Autofill feature, which completes your search based on terms that are most often searched together. If I enter “antioxidants and” into the Google search bar on a browser with no related search history, Google suggests “cancer” as the top term

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Source: Google

to complete my search. This indicates that “antioxidants” is most frequently searched for when paired with “cancer”. So, taken together, these two pieces of evidence suggest that when advertising for antioxidant content, chocolate companies are implicitly appealing to the pop-science notion of antioxidants as a way to prevent cancers. In the coming paragraphs, I will assess the validity of this theory, and the implications for the chocolate industry.

 

The first question we need concern ourselves with when considering the anti-cancer effects of antioxidants in chocolate and cacao products is what sorts of antioxidants are found in cacao, and at what levels are they present? Indeed, it does seem to be the case that raw cacao has notably high levels of a certain class of antioxidants, namely polyphenolic antioxidants, and more particularly flavonoids (Ramiro-Puig E). Cacao powder contains up to 70mg of polyphenols per gram (Ramiro-Puig E), meaning that a single serving of cacao-rich foods has more antioxidants than a serving of tea, red wine, or blueberries (Lee, K. W.), all of which are considered antioxidant-rich foods. It is notable, however, that antioxidant content is a function of how much cocoa powder or “nonfat cocoa solid” is present in the chocolate (see below), making milk chocolates, such as

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Source: Journal of Agricultural and Food Chemistry

Hershey’s “Antioxidant Milk Chocolate” far lower in polyphenols than dark chocolate or raw cacao products. Indeed, as many of Hershey’s own dark chocolate products would presumably contain higher levels of antioxidants than do their “Antioxidant Milk Chocolate” range, it does seem a bit disingenuous of Hershey’s to market this product in this way. Additionally, although the types of polyphenols in cacao do have high antioxidant capacity (Gu, Liwei), the vast majority of studies on the anti-cancer effects of antioxidants in humans have not used polyphenols. Instead, most studies to date have been done using antioxidant vitamins, such as vitamins C and E (Aviram, M). This lack of placebo-controlled in vivo studies on the relevant chemicals poses a serious threat to cacao company’s claims of antioxidant-related health benefits.

 

The next point of consideration is how bioavailable these polyphenols are when ingested—in other words, what happens to these antioxidants once we eat them? Do they remain in our system long enough to fight free radicals, or are they simply flushed out of our bodies or degraded in our digestive tracts? Again, the results are a bit of a mixed bag. It does seem clear that the polyphenols present in cacao are indeed stable in the human gut, and are not broken down by our stomach acid (Rios LY). This means that the antioxidants will be able to reach the small intestine unchanged, where they can then be absorbed into the bloodstream. In in vitro experiments in humans eating plain cocoa, antioxidant capacity (as measured by blood samples) was most increased one to two hours after ingesting the cocoa, and had returned to baseline after about six hours (Ramiro-Puig, Emma). So, ingesting pure cacao powder can indeed increase an individual’s antioxidant capacity, albeit only briefly. The issue is that this result does not seem to generalize to manufactured chocolate bars. Specifically, studies have suggested that when the cocoa is eaten alongside dairy, as it would be in the case of milk chocolate, antioxidant absorption is compromised (Ramiro-Puig, Emma). It seems that some interaction with the milk proteins makes it more difficult for the intestine to absorb the polyphenols, and as a result, less antioxidants end up circulating in the bloodstream. So, not only does milk chocolate have lower antioxidant levels in the first place, but even the amount that is there may not be able to become fully bioavailable. If we truly want to realize any potential antioxidant-related benefits from our chocolate consumption, then we would realistically want to avoid milk chocolate in favor of raw cacao or very dark chocolate.

Lastly, although we currently have an elegant and coherent model of how antioxidants could neutralize free radicals, preventing damage to DNA, and so protecting against cancer-causing mutations, there is truly little evidence that this actually occurs. As a 2011 review article bluntly put it “none of the completed trials [to date] produced convincing evidence to justify the use of traditional antioxidant-related vitamins or minerals for cancer prevention” (Goodman, Michael).  Although the oxidative-stress theory of cancer is coherent and sensible, and despite the success of many in vitro assays in demonstrating the protective effects of antioxidants, the article emphasizes that “definitive evidence about the effects of agents on human health can only be established from human studies” (Goodman, Michael). Despite the commonly held belief that antioxidants can prevent carcinogenesis, there is simply not enough evidence to support this claim in vivo. While the area certainly merits further research, it is by no means clear that antioxidant-rich diets are at all protective against cancer.

Companies that advertise their chocolate as being antioxidant-rich capitalize on pop-science rhetoric, a commonly held but unproven association between cancer and antioxidants. Although these companies do not make explicit claims about any anti-cancer effects of their products, it is unlikely that this is not the intended interpretation. As discussed previously, the fact of the matter is that the average consumer likely equates the word “antioxidants” with the notion of cancer prevention. By advertising their products in this way, they are leveraging the consumer’s ill-founded beliefs in a way that benefits their sales. They are co-opting the media’s portrayal of antioxidants in a way that allows them to rebrand chocolate as a “superfood”, despite at best limited evidence that this is the case.

 

 

 

 

Works cited:

“Antioxidants: Beyond the Hype.” The Nutrition Source. Harvard T.H. Chan School of Public Health. Web. 02 May 2016.

Aviram M (Nov 2000). “Review of human studies on oxidative damage and antioxidant protection related to cardiovascular diseases”. Free Radical Research.

Dreher, Don, and Alain François Junod. “Role of oxygen free radicals in cancer development.” European Journal of cancer 32.1 (1996): 30-38.

Giugliano D, Ceriello A, Paolisso G (Mar 1996). “Oxidative stress and diabetic vascular complications”.Diabetes Care 19 (3): 257–67.

Goodman, Michael, Roberd M. Bostick, Omer Kucuk, and Dean P. Jones. “Clinical Trials of Antioxidants as Cancer Prevention Agents: Past, Present, and Future.” Free Radical Biology and Medicine 51.5 (2011): 1068-084. Web.

Gu, Liwei, Suzanne E. House, Xianli Wu, Boxin Ou, and Ronald L. Prior. “Procyanidin and Catechin Contents and Antioxidant Capacity of Cocoa and Chocolate Products.” J. Agric. Food Chem. Journal of Agricultural and Food Chemistry 54.11 (2006): 4057-061. Web.

Lee, K. W.; Kim, Y. J.; Lee, H. J.; Lee, C. Y. Cocoa has more phenolic phytochemicals and a higher antioxidant capacity than teas and red wine. J. Agric. Food Chem. 2003, 51, 7292-7295.

Ramiro-Puig E, and Margarida Castell. “Cocoa: Antioxidant and Immunomodulator.” BJN British Journal of Nutrition 101.07 (2009): 931. Web.

Rios LY, Bennett RN, Lazarus SA, et al. (2002) Cocoa procyanidins are stable during gastric transit in humans. Am J Clin Nutr 76, 1106 –1110.

 

 

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