Microwave ovens are no longer a novel or unusual technology. In many offices and some homes, they are the primary or only way to heat things. Still, some people are unsure about their safety. We strongly urge people not to use plastic containers for heating, because that could lead to excessive leaching of undesirable compounds such as BPA into food. But does the microwave have an impact on the food itself? That is the question this reader asked.
Will the Microwave Harm Nutrients in Cocoa?
Q. Some time ago, a reader mentioned not wanting to use the microwave to heat cocoa. I frequently heat coffee, cocoa and other foods in my microwave. Should I be concerned about destroying nutrients when I use a microwave?
A. So far as cocoa is concerned, you probably don’t need to worry about damaging cacao compounds in your home oven. New extraction techniques include microwave technology (Baharum et al, Tropical Life Sciences Research, Feb. 2016). Presumably, the compounds are not damaged in the process.
Microwaving Pros & Cons:
Microwaving honey inactivates the antimicrobial compounds that bees produce (Bucekova et al, Food Chemistry, Feb. 1, 2018). Cacao polyphenols, however, do not resemble the agents in honey.
Heating food does impact nutrients like Vitamin C and B12. But microwaving food may be less likely to destroy such vitamins than other cooking methods. One study found that the healthful properties of a green smoothie were better preserved through microwave processing than through conventional pasteurization (Castillejo et al, Journal of the Science of Food and Agriculture, online Sep. 8, 2017). As a result, we don’t think that warming your cocoa quickly will have a harmful effect on its nutritional quality.
Why You Should Care About Cocoa Compounds:
Epidemiologists report that people who eat chocolate frequently are less likely to have type 2 diabetes or cognitive decline (Crichton et al, Appetite, Jan. 1, 2017; Crichton, Elias & Alkerwi, Appetite, May 1, 2016). It is not clear, though, whether this is a cause-and-effect relationship. The evidence may still be out on heart health.
Cocoa Compounds Lowered Cholesterol:
Q. I am writing to ask what you might know about CocoaVia. A friend told me she dropped her cholesterol 30 points by taking this natural supplement.
My husband, an internist, said supplements that lower cholesterol may not lower the risk for heart disease. Are there any studies regarding this supplement?
A. Your husband is right that not everything that lowers cholesterol actually prevents heart disease. Despite this, the FDA has approved cholesterol-lowering drugs such as alirocumab (Praluent) on the basis of their ability to lower lipids like LDL cholesterol although they have not yet been shown to reduce heart disease.
Will Cocoa Compounds Help?
There is reason to expect that cocoa compounds will be helpful. A recent review found that cocoa flavanol intake improved insulin sensitivity and blood lipids such as cholesterol, triglycerides and HDL cholesterol (Lin et al, Journal of Nutrition, Nov., 2016).
A thorough review of 20 randomized controlled trials determined that “Flavanol-rich chocolate and cocoa products may have a small but statistically significant effect in lowering blood pressure…” (Ried et al, Cochrane Database of Systematic Reviews, Aug. 15, 2012).
A different review of 19 trials found that type 2 diabetics taking cocoa compounds and mildly hypertensive women taking olive oil lowered their oxidative stress and inflammation (Suen et al, Healthcare, Sep. 14, 2016). All of this is quite promising, but it doesn’t tell us whether cocoa flavanols actually will reduce the risk of heart attacks.
The COSMOS Trial:
There is currently a major study underway to determine whether CocoaVia standardized cocoa flavanols can reduce heart attacks and strokes. It is called COSMOS (COcoa Supplement and Multivitamin Outcomes Study). We will let you know the results when the trial is completed.