Chocolate: The Good, The Bad, and The Ugly

Frances Meredith, MD

For many Valentine’s Day brings with it thoughts of chocolate. February is both American Heart Month and National Chocolate Lovers Month, a brilliant combination as the nutrients within chocolate can help to improve heart health. Let’s dig into the good, the bad, and the ugly of chocolate.

Dark chocolate is rich in polyphenols, specifically flavonoids, the substances that have a wide range of health benefits. These include lowering blood pressure, improving the function of our vascular endothelium (the inner walls of our arteries), protecting skin against sun damage, improving blood flow to the brain, and reducing the risk of cardiovascular damage. Dark chocolate has also been proven to help with mood. These benefits come from chocolate’s ability to promote production of the vasodilator Nitric Oxide as well as the anandamide within, a cannabinoid compound (like CBD) that binds to receptors in the brain to alter mood and brain activity. In addition, methylxanthine compounds, such as theobromine and caffeine, are powerful antioxidants. Remember that these are stimulants as well and should be kept far from your bedtime.

As milk chocolate has a much higher sugar content and lower flavonoid content, dark chocolate, at least 70%, is the best choice.  Know that white chocolate has no flavonoids, and hot chocolate mixes have very low amounts. As even dark chocolate has sugar, limiting daily intake to 1 oz of at least 70% dark chocolate is the best choice.

There is however, a DARK side to chocolate: heavy metals. Lead and cadmium have been known for many years to be elevated in chocolate. Consumer reports has recently reported their results of batch metals testing of multiple brands of chocolate. They have confirmed levels of metals in many brands of chocolate that exceed California Proposition 65 standards, specifically for lead and cadmium. These metals are associated with multiple health issues in both children and adults. The risk is highest for young children and pregnant women as metals have a negative effect on brain development and IQ. However, even outside this patient population, accumulation of metals in the body can cause a wide range of health conditions including kidney damage, elevated blood pressure, immune and hormonal disruption, and central nervous system dysfunction.

Now why would metals be in our chocolate? For cadmium, the cacao plant absorbs the metals from the soil and levels accumulate in the beans. Lead, however, gets in after harvesting, with levels rising as the beans dry and are processed. Highest levels are found on the outside of the bean, consistent with environmental contamination.

So…. should we give up chocolate? My vote is a resounding NO! The “Yum” and “Aaaaah” response to chocolate are undeniable, and the health benefits are substantial and backed by science. The Consumer Reports study gives us guidance as to which brands of dark chocolate are lowest in metals. See the report for details where one bar each from Mast, Tatza, and Valrhona, and two bars from Ghirardelli have relative low levels of both cadmium and lead

From the Functional Medicine perspective, food is medicine. But the devil is in the details where purity, dose and timing make it medicine or poison. Choose your brand wisely, be moderate in your amount, and time your chocolate well away from your bedtime. And most of all: ENJOY!

Your partner in health,
Frances T Meredith, MD