Chocolate Lovers – Read On!

New research from Loma Linda University indicates that there are possible health benefits to eating certain types of dark chocolate. The studies were recently presented at the 2018 Experimental Biology meeting in San Diego; they showed that consuming dark chocolate that has a high concentration of cacao (minimally 70% cacao) has positive effects on stress levels, inflammation, mood, memory and immunity. While it is well known that cacao is a major source of flavonoids, this is the first time the effect has been studied in human subjects to determine how it can support cognitive, endocrine and cardiovascular health.  (Flavonoids are a diverse group plant chemicals found in fruits and vegetables. Along with carotenoids, they are responsible for the vivid colors in these foods. Flavonoids are antioxidants with anti-inflammatory and immune system benefits.)

Lee S. Berk, DrPH, associate dean of research affairs, School of Allied Health Professions and a researcher in psychoneuroimmunology and food science from Loma Linda University, served as principal investigator on both studies. "For years, we have looked at the influence of dark chocolate on neurological functions from the standpoint of sugar content -- the more sugar, the happier we are," Berk said. "This is the first time that we have looked at the impact of large amounts of cacao in doses as small as a regular-sized chocolate bar in humans over short or long periods of time, and are encouraged by the findings. These studies show us that the higher the concentration of cacao, the more positive the impact on cognition, memory, mood, immunity and other beneficial effects."  

Here are the results presented during the Experimental Biology meeting:

Dark Chocolate (70% Cacao) Affects Human Gene Expression: Cacao Regulates Cellular Immune Response, Neural Signaling, and Sensory Perception

This pilot feasibility experimental trial examined the impact of 70 percent cacao chocolate consumption on human immune and dendritic cell gene expression, with focus on pro- and anti-inflammatory cytokines. Study findings show cacao consumption up-regulates multiple intracellular signaling pathways involved in T-cell activation, cellular immune response and genes involved in neural signaling and sensory perception -- the latter potentially associated with the phenomena of brain hyperplasticity.  (Greenwood’s explanation - Neuroplasticity is the brain's innate ability to adapt to training and learn new skills - from foreign languages to math, and, for an athlete, physical movement and strength. By stimulating the motor cortex during athletic training, the brain enters into a state of heightened plasticity known as "hyperplasticity," during which the brain adapts to training most effectively.)

Dark Chocolate (70% Organic Cacao) Increases Acute and Chronic EEG Power Spectral Density (μv2) Response of Gamma Frequency (25-40Hz) for Brain Health: Enhancement of Neuroplasticity, Neural Synchrony, Cognitive Processing, Learning, Memory, Recall, and Mindfulness Meditation

This study assessed the electroencephalography (EEG) response to consuming 48 g of dark chocolate (70% cacao) after an acute period of time (30 mins) and after a chronic period of time (120 mins), on modulating brain frequencies 0-40Hz, specifically beneficial gamma frequency (25-40Hz). Findings show that this superfood of 70 percent cacao enhances neuroplasticity for behavioral and brain health benefits.

(Greenwood – Many chocolate bars with 70% cacao contain about 48g in half a bar. Read the label carefully.  An Endangered Species bar with 72% cacao has 43g, 210 calories and 12 g of sugar in half a bar. Lily’s 70% cacao bars are sweetened with stevia – available at some specialty stores and on the internet. )

Berk said the studies require further investigation, specifically to determine the significance of these effects for immune cells and the brain in larger study populations. Further research is in progress to elaborate on the mechanisms that may be involved in the cause-and-effect brain-behavior relationship with cacao at this high concentration.

Take home message from these studies – while chocolate is a delicious treat with valuable properties for health, it often comes with too much added sugar.  If you eat part of a 70% cacao bar regularly, avoid other sources of sugar and satisfy your sweet cravings with multicolored fruits.   If you have an elevated blood sugar, go for the Lily’s brand and follow the dietary advice of your health care provider.

Sadja Greenwood, MD. MPH   back issues on this blog

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