Impact of Cocoa Flavanols on Cardiovascular Health: Additional Consideration of Dose and Food Matrix.

Abstract

Keywords: chocolate; flow mediated dilatation; blood pressure. Dear editor,We read with interest the recent article by Vlachojannis and colleagues in which they summarised reviews of the effects of cocoa derived flavanols on cardiovascular function (Vlachojannis et al., 2016). We agree that there is a lack of consistency in findings, particularly in relation to blood pressure (BP), and that better reporting of flavanol content in research reports and on consumer products is needed. There are three aspects of their paper that we feel warrant further discussion.(1) Their assertion that the European Food Safety Authority food claim (EFSA Panel on Dietetic Products, Nutrition and Allergies, 2012) needs review because the requisite intake of total flavanol (200 mg/day) is too low is not fully supported by the evidence. The health claim in question relates specifically to circulatory function (as assessed by flow-mediated dilation [FMD]) in healthy (nonpregnant) people; thus, the two studies cited as evidence that the dose is too low (one in pregnant women and one in people with established peripheral vascular disease) are not relevant to the claim (Hammer et al., 2015;Mogollon et al., 2013). Furthermore, the 200-mg intake requirement has been subsequently validated in healthy men and women: 1 week of supplementation with either 80 or 200 mg total flavanol (17 or 42 mg epicatechin, respectively) significantly increased FMD (Grassi et al., 2015). We accept that the optimal dose may be higher than these levels; nevertheless, the 200mg/day intake appears sufficient to support the claimed health benefits.(2) We consider that their conclusion-"At present there is no evidence that the doses of cocoa flavanols and epicatechins used in the studies included reliably decrease blood pressure" (Vlachojannis et al., 2016) -is not a reasonable interpretation of the literature. The authors point out the variability of responses in individual studies and note that repeat seated clinic measures of BP are inherently variable and therefore an unreliable means to detect change. This variability reduces the likelihood of detecting statistically significant effects in individual studies or at the meta-analytic level. In addition to BP measurement techniques, heterogeneity of study designs, sample populations, flavanol doses, and food matrix will also contribute to the variation of outcomes reported in individual studies. Hence, any significant change in BP is more, not less, likely to be a real effect. The main effects reported at the meta-analytic level therefore should be seen as robust indicators of a BP lowering effect with cocoa consumption (Desch et al., 2010;Hooper et al., 2012). (3) The authors also discuss the impact of food matrix with a particular focus on differences in flavanol content in different types of chocolate. What is missing from this discussion is the apparent differential dose response of BP to consuming the flavanols in the form of chocolate or in a flavanol-rich beverage or supplement. We presented data in a recent...

Sugar and cocoa: sweet synergy or bitter antagonisms. Formulating cocoa and chocolate products for health: a narrative review

“…When considering the effect of sugar on bioavailability of cocoa flavanols, it is important to consider the potential effects of the form, it appears from post hoc analysis of data by Faridi et al . () reported earlier; that being in the form of chocolate may increase bioavailability compared to cocoa and more specifically being associated with greater physiological changes following consumption (Davison & Howe, , ). Although there may be a role for sugar in synergy with fat found in chocolate, there could be relationships in the differences in delivery and bolus formation in the upper gastrointestinal tract.…”

“…No statistical analysis was reported comparing the cocoa beverage to the chocolate; therefore, there is a lack of data to support whether sugar behaves differently in cocoa beverages than in solid chocolate. This is definitely an area warranting further study, as consuming cocoa flavanols in solid chocolate may lead to better bioavailability (Davison & Howe, ). Additionally, human studies with variable sugar content are required as the optimal sugar content in either a cocoa beverage or chocolate is yet to be determined.…”

“…The way in which the cocoa itself if process will impact on its polyphenol content, even before it is being incorporated into a product (Bordiga et al ., ). This is before considering the potentially, large variations in bioavailability and bioactivity between solubilised cocoa or chocolate as delivery vehicles for cocoa flavanols (Mellor, ; Davison & Howe, ). Beyond their food chemistry, there are nutritional considerations linked to the high‐energy content of cocoa and chocolate products, including significant levels of fat (especially saturated fatty acids) and sugar, which could have the potential to reverse any advantageous effects of the cocoa flavanols.…”