by Marion Nestle
Jun 3 2019

Industry-funded study of the week: blueberries again

I love blueberries and grow two different kinds on my 12th-floor Manhattan terrace, both delicious if I can get to them before the voracious birds do.

I wish the blueberry industry could just accept delicious and leave it at that, but no such luck.  It is desperate to get research it can use to promote blueberries as a superfruit (I wrote about the history of blueberry-funded research in Unsavory Truth).

Here’s the latest.

The study: Blueberries improve biomarkers of cardiometabolic function in participants with metabolic syndrome—results from a 6-month, double-blind, randomized controlled trial.  Peter J Curtis, et al. Am J Clin Nutr 2019;109:1535–1545.

Method: Participants were fed powdered blueberries equivalent to a half or full cup a day, compared to placebo.

Conclusions: Despite insulin resistance remaining unchanged we show, to our knowledge, the first sustained improvements in vascular function, lipid status, and underlying NO [nitric oxide] bioactivity following 1cup blueberries/d. With effect sizes predictive of 12–15% reductions in CVD risk, blueberries should be included in dietary strategies to reduce individual and population CVD risk.

Funder: Supported by the US Highbush Blueberry Council (USHBC) with oversight from the USDA and the Biotechnology and Biological Sciences Research Council (BBSRC, UK). AC and ERB both act as advisors to the USHBC grant committee. The funders of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report.

Comment: The press picked this one up:  “Study: Blueberries benefit heart health.”  This study used powdered blueberries.  Trust me, the fresh ones are much better.  You can tell this is an industry-funded study because the published study is open access, which somebody has to pay for—a clue that it is about marketing.  And what about the comment that funders had no influence?  They didn’t have to.  The study did not compare blueberries to any other fruits.  The science here provides some interesting information about how anthocyanins in this fruit might work, but wouldn’t they work the same way in any other fruit?  Are blueberries the only fruit that contains these particular anthocyanins?   This questions suggest that this study is not about the science, it is about demonstrating that there is something special about blueberries.  Dietary advice?  Eat whatever fruits you like.  And vegetables.  And nuts.  They all have something good about them.