Could you improve your health with chocolate? Despite widespread skepticism that chocolate could have health benefits, researchers keep uncovering additional evidence. We’ll summarize some of that below. First, though, we’ll address readers’ concerns about potential hazards, especially contamination with heavy metals.
How Safe Are Cocoa Supplements?
Q. I subscribe to ConsumerLab.com to make sure I am informed about dietary supplements. There was recently an update on cadmium and lead in cocoa and chocolate. While that was discouraging, I was heartened to read good news. Some products with high cocoa flavanols have low levels of heavy metals.
A. ConsumerLab.com cited a study in Food Research International (July, 2024). The Tulane University investigators found disturbing levels of cadmium in some chocolates from Central and South America.
With a subscription to ConsumerLab.com, a reader can identify the products you mention with high levels of cocoa flavanols and low levels of toxic metals. The overall top pick from ConsumerLab.com is a dietary supplement: CocoaVia Brain Health Memory +. (CocoaVia is a sponsor of our radio show and podcast.)
Are Some Brands Safer Than Others?
Q. I am a chocolate lover. I try not to overdo, so I limit myself to a small piece or two almost every day. The recent news reports on heavy metals in chocolate have me worried. Are some brands better than others?
A. In 2023, two different consumer-oriented organizations came out with reports on chocolate or cocoa products within a short time of each other. The bad news is that a number of brands, including some very popular ones, are contaminated with cadmium or lead. On the other hand, both reports found some brands that are not too high in heavy metals.
ConsumerLab.com Looks at Cocoa Flavanols:
If you are looking for maximum cocoa flavanols per serving, ConsumerLab.com found that CocoaVia supplements top the list (without heavy metal contamination). For dark chocolate, their choices are Montezuma’s Absolute Black 100%, Ghirardelli Intense Dark 72% and Baker’s Unsweetened 100%. Montezuma’s and Ghirardelli were also on the list as chocolate bars with the least cadmium, along with ChocZero and Lily’s 70%. ConsumerLab.com did not find excessive levels of lead in any of the supplements or chocolates that they tested.
Consumer Reports Looks at Heavy Metals:
Consumer Reports did not look at flavanols, but they did analyze chocolate bars for cadmium and lead. The five bars they identified as safer choices include Ghirardelli Intense Dark, both 72% and 86%; Mast Organic Dark Chocolate; Taza Chocolate Organic Deliciously Dark Chocolate and Valrhona Abinao Dark Chocolate. With all these choices, you should be able to find something to satisfy your chocolate cravings without endangering your health.
Keep reading for the evidence on how to improve your health with chocolate. Your idea on moderation is a great principle for starters.
Lower Risk of Type 2 Diabetes or Elevated Liver Enzymes:
An observational study demonstrated that people who eat a small portion of chocolate daily are less likely to develop type 2 diabetes or elevated liver enzymes (British Journal of Nutrition, May 2016). The Observation of Cardiovascular Risk in Luxembourg study included results from more than 1,000 adults. The researchers found that the more chocolate people reported eating (up to 100 grams a day, about the amount in a large candy bar), the less likely they were to have insulin resistance.
This study relied on a one-time questionnaire and blood test. This cross-sectional study design makes it harder to sort out what might be due to other unrelated factors such as age, activity level, education and other dietary patterns, including tea, coffee, vegetables and fruits or alcohol. Because of this potential confounding, it is difficult to argue that this study shows conclusively that you can improve your health with chocolate. Not surprisingly, the scientists call for randomized controlled trials to explore how chocolate affects insulin resistance and metabolic health.
Other Studies on Whether You Can Improve Your Health with Chocolate:
A review of previous studies (cohort and cross-sectional studies like this one, rather than experiments called randomized controlled trials) found that people consuming more chocolate were less likely to suffer cardiovascular complications (a 37 percent lower chance of heart disease and a 29 percent reduction in stroke). These investigators also call for randomized controlled trials to confirm this observation (BMJ, Aug. 26, 2011).
Australian researchers actually did computer modeling that suggests having people consume dark chocolate rich in polyphenol compounds could be cost effective as a way to reduce the risk of heart disease (BMJ, May 30, 2012). This study is even further removed from a randomized controlled trial, however.
Given the many observations that cacao products such as chocolate are associated with better health, some health experts speculate that a low-sugar high-flavanol chocolate added to metformin might improve the treatment of people with type 2 diabetes (Medical Hypotheses, June, 2016). Unfortunately, however, this is a thought experiment instead of a randomized controlled trial.
The COSMOS Cocoa Flavanol Trial:
One randomized controlled trial has produced some interesting results, however. The COcoa Supplement and Multivitamin Outcomes Study (COSMOS) (funded by Mars and Pfizer) ran for four years to test whether taking cocoa flavanols can reduce the risk of heart attack or stroke. You may wish to listen to our interview with the lead investigator, Dr. JoAnn Manson of Harvard Medical School. It is Show 1307: Cocoa Compounds and the COSMOS Trial. The researchers published their findings that cocoa flavanols reduced cardiovascular deaths in 2022 (American Journal of Clinical Nutrition, June 7, 2022).
This trial used standardized cocoa flavanols (500 mg) supplied by Mars, very similar to the flavanols in CocoaVia CardioHealth. CocoaVia has underwritten The People’s Pharmacy radio show and podcast for years, but the company did not influence our reporting on this important clinical trial.
