Research shows there might be health benefits to eating certain types of dark chocolate. Findings from two studies being presented at the Experimental Biology 2018 annual meeting in San Diego show that consuming dark chocolate that has a high concentration of cacao (minimally 70% cacao, 30% organic cane sugar) 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.
Dr Lee S Berk, associate dean of research affairs, School of Allied Health Professions and a researcher in psycho-neuro-immunology 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."
The flavonoids found in cacao are extremely potent antioxidants and anti-inflammatory agents, with known mechanisms beneficial for brain and cardiovascular health. The following results will be presented in live poster sessions during the Experimental Biology 2018 meeting:
The first pilot feasibility experimental trial examined the impact of 70% 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 signalling pathways involved in T-cell activation, cellular immune response and genes involved in neural signalling and sensory perception – the latter potentially associated with the phenomena of brain hyper-plasticity.
The second study assessed the electroencephalography (EEG) response to consuming 48g 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% cacao enhances neuroplasticity for behavioural and brain health benefits.
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-behaviour relationship with cacao at this high concentration.
Abstract 1
Dark chocolate (70% Cacao) is a major source of flavonoid antioxidants, which appear to support cognitive, endocrine, and cardiovascular health benefits. However, the in vivo effects of cacao on human genome function are unknown. In a pilot feasibility experimental trial, we examined the effects acute and chronic cacao consumption on human gene expression in circulating blood cells.
Purpose: Map the impact of 70% cacao consumption on human immune and dendritic cell gene expression, with focus on pro/anti-inflammatory cytokines.
Methods: This 8-day (d) pilot study enrolled 4 healthy experimental subjects (2 female and 2 male, age 25–50) and one control (female, 28), who were not taking prescribed or OTC medications. Subjects abstained from all other high-antioxidant foods or supplements 48 h prior to and during the study period. After a fasting baseline blood sample, experimental subjects consumed 48 g 70% cacao (Parliament Chocolates, Redlands, CA) over 10 min (antioxidant activity 46,000 μmoles TE/100g). Follow-up blood samples were obtained 2 h later (acute effects) and 1 wk later (chronic effects). During waking hours (14 h/d) experimental subjects consumed 48 g 70% cacao per day (2 pieces/hr; antioxidant activity 3834 μmoles TE/100g). Total RNA was assayed by RNAseq, with data analyzed by linear models to identify differentially expressed genes, followed by bioinformatic analyses of transcription control pathways and cellular origins.
Results: Leukocyte transcriptome profiles showed little systematic change in the initial 2 h of Cacao exposure, although pre-specified bioinformatics analyses indicated small increases in activity of genes regulated by NF-kB and AP1 transcription factors and CD4+ and CD8+ T cells (all, p < .05). By contrast, analyses of change from baseline to 1 wk identified 177 genes showing significant differential expression using a priori-specified False Discovery Rate cut-point of .20 (140 up-regulated, 37 down-regulated), with 116 achieving q < .05. Up-regulated genes were involved in leukocyte activation and motility (e.g., CD40, TICAM2, AZU1, HRAS and RASD2, HSPA1L, FGF22); derived from CD4+ and CD8+ T lymphocytes (p < .001 and .0148, respectively); and showed over-representation of promoter elements for NF-kB, SP-1, MZF-1, and HIF-1 transcription factors (all p < .01) and under-representation of AP-1 (p = .018). Up-regulated transcripts also included genes involved in neural signaling and sensory perception (e.g., OR2J3, OR52A5, OR6C3, OR9I1, NR4A2, and NRXN2).
Conclusion: Cacao consumption up-regulates multiple intracellular signaling pathways involved in T cell activation and cellular immune response. These effects emerged weakly within 2 h but there was greater gene expression by the end of 1 wk intervention. Results are consistent with previous indications that cacao components inhibit MAPK activation but suggest T cell function may be preserved and enhanced via other compensatory molecular pathways. It should be noted that the NF-kB up-regulation source was not from up-regulated monocytes suggesting a role other than cascading inflammation. It is of interest, to note, that genes involved in neural signaling and sensory processes were up-regulated. The functional significance of these effects for immune cells remains to be defined by future expansive research, as do the neurobiological mechanisms involved.
Authors
Lee Berk, Kristin Bruhjell, Warren Peters, Peter Bastian, Evertt Lohman, Gurinder Bains, Jesusa Arevalo, Steve Cole
Abstract 2
Cacao or dark chocolate is a major source of flavonoids. Flavonoids are extremely potent antioxidants and anti-inflammatory agents, with known mechanisms beneficial for cardiovascular health. However, the correlates of neuroelectric activity that initiate the mechanisms of cacao’s effects on brain neurocognition, synchronization, memory, recall, mood and behavior are not well known. Studies have shown that absorbed cacao flavonoids penetrate and accumulate in brain hippocampal regions involved in learning and memory. However, neurological initiation and modulatory control from acute and chronic exposure of cacao flavanoids (via consumption) on intensity of kinetic response of brain frequency and specifically beneficial gamma frequency (25–40 Hz), has not been studied.
Purpose: Therefore, the purpose of this study was to assess 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 0–40 Hz; specifically beneficial gamma frequency (25–40 Hz).
Methods: Dark chocolate bars, made from Tanzania organic cocoa beans consisting 70% cacao and 30% organic cane sugar, were used in this study (Parliament Chocolate, Redlands, CA). EEG wave bandwidth activity was recorded from 9 cerebral cortical scalp locations F3, Fz, F4, C3, Cz, C4, P3, Pz, and P4 using the EEG B-Alert 10X System™ (Advanced Brain Monitoring, Carlsbad, CA). Each of 5 healthy subjects, age 22–40, consumed 48 g of the dark chocolate after the baseline EEG acquisition. At an acute period of time (30 mins) and chronic period of time (120 mins) EEG was recorded for two mins. From each of the 5 subjects and summated for the respective time points. Power Spectral Density uV2 (PSD) were Z-scored for the two time points using the reference pretest resting EEG baseline..
Results: Z-scores were graphed for both acute and chronic time periods across 0–40 Hz (Fig. 1). The most significant outcome observed showed PSD γBA was quantitatively greatest of all frequencies in the study (p<0.01). In Fig, 2, using “heatmaps”, we show qualitative responses for extent and intensity (PSD) of the cacao on the cerebral cortical brain for: baseline (Task 1 – after 8 hr n.p.o., and no cacao) for both acute and chronic time periods (Task 2 – 30 mins post consumption and Task 3 – 120 mins post consumption, respectively). The acute time period (Task 2) clearly shows the entire cerebral cortical region is modulated to varying degrees of PSD increase in γBA, with the largest increase in regions C4/P4/PZ/P3, while the chronic time period (Task 3) shows the frontal left side returning towards baseline, but still has residual γBA in C4/P4/Pz regions.
Conclusion: This study provides quantitative and qualitative evidence that EEG γBA is enhanced by consumption of 48 g 70% cacao and shows a significant acute effect at 30 mins post consumption to all cerebral cortical regions, and a residual γBA PSD response at 120 mins., primarily to brain EEG regions C4/P4/Pz. We suggest that 48 g 70% cacao consumption with a concentration of antioxidant activity of 52,000 umoles TE/100 g, is associated with subsequent γBA increase in the cerebral cortical brain. We suggest that this superfood of 70% cacao (organic cocoa beans from Tanzannia) enhances neuroplasticity for behavioral and brain health benefits. Further research is in progress to elaborate the mechanisms that may be involved in the cause/effect brain-behavior relationship.
Authors
Lee Berk, Josh Miller, Kristin Bruhjell, Sayali Dhuri, Krisha Patel, Everett Lohman, Gurinder Bains, Ryan Berk
[link url="https://news.llu.edu/for-journalists/press-releases/new-studies-show-dark-chocolate-consumption-reduces-stress-and-inflammation-while-improving-memory-immunity-and-mood"]Lorna Linda University Adventist Health Sciences Centre material[/link]
[link url="https://www.fasebj.org/doi/10.1096/fasebj.2018.32.1_supplement.755.1"]Experimental Biology 2018 meeting/The FASEB Journal abstract 1[/link]
[link url="https://www.fasebj.org/doi/10.1096/fasebj.2018.32.1_supplement.878.10"]Experimental Biology 2018 meeting/The FASEB Journal abstract 2[/link]