Generally, it is thought that any food items containing chocolate are unconsidered unhealthy as many of those are associated with snacks that are high in calories, fat, and sugar. While excessive consumption of chocolate may be unhealthy, it is typically associated with generic brands and products that contain lower-quality cocoa which is used to make chocolate. High cocoa content – usually found in dark chocolate (1) – can elicit several health benefits when consumed in moderation. This is because dark chocolate can be a rich source of antioxidants that can have a positive impact on one’s health such as improving blood flow and lowering blood ad enhancing brain function. There are extensive research findings to support these claims and this article aims to examine the evidence in detail.
To better comprehend the positive impacts that dark chocolate has on one’s health, one must understand antioxidants. These are substances that prevent or slow down the process of oxidation – which is a chemical reaction that produces harmful molecules known as free radicals which can compromise bodily cells (2). This damage to the body has been linked to cancer and different neurological diseases like Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, multiple sclerosis, depression, and memory loss (3-7). Dark chocolate may protect against free radicals given that it is a powerful source of antioxidants such as polyphenols, flavanols, and catechins (8). Even compared to fruits that are known to have large amounts of antioxidants like blueberries, dark chocolate and cocoa were shown to have stronger antioxidant activity and larger amounts of polyphenols, and flavanols (9). Taken together, the antioxidants in dark chocolate can help to protect the body's cells and tissues from damage to promote overall health.
Healthy blood flow is normally indicated by the delivery of oxygen, nutrients, and other essential substances to the body’s cells and the removal of waste products (10). This process is essential to produce energy in the body to fuel daily activities and ensure its proper functioning (11). Comparatively, high blood pressure (also known as hypertension) has been associated with an increased risk of serious diseases and cardiovascular events like stroke, heart attack, heart disease, and irregular heartbeat (12). However, flavonoids – which is an antioxidant that can be found in dark chocolate (1) – have been shown to have benefits for blood-related functions. Flavonoids can have a positive effect on the lining of our blood vessels through the endothelium - a single layer of cells that line the inside of our blood vessels (13). Specifically, flavonoids stimulate the endothelium to produce a molecule called nitric oxide which has the effect of relaxing arteries to make blood flow more smoothly (14-15). This helps decrease resistance to blood flow in arteries which results in lowered blood pressure. One academic review that assessed studies regarding the effects of cocoa and dark chocolate on blood flow and lower blood pressure had favourable findings. The review showed that consumption of cocoa and rich chocolates can be beneficial for cardiovascular health by reducing blood pressure, improving endothelial function, and lowering the risk of adverse cardiovascular events (16). Despite these favourable results, more research is needed to determine the appropriate amount and method of producing cocoa to produce health benefits. It must also be noted that dark chocolate does not replace a healthy lifestyle and should be integrated with a good diet and regular exercise. To summarize, dark chocolate with cocoa that is high in flavonoids can be beneficial for blood-related functions.
Dark chocolate has also been shown to improve brain function. These functions generally reflect cognitive processes like perception, attention, memory, language processing, problem-solving, decision-making, reasoning, and creativity that are required for daily functioning (17). In one study, dark chocolate consumption for 30 days in younger adults led to an increase in blood flow to the brain, improved performance on tests of attention, and greater levels of theobromine – a compound that is involved in cellular processes that are essential for cognitive processes (18-23). This effect may be partly explained by the presence of flavonoids which increases blood flow. More precisely, greater blood flow to the brain has been associated with greater cognitive functioning (24), and this effect may be due to the flavonoids in dark chocolate. Older adults with mild cognitive impairment – which is a condition that is reflected by a person’s cognition not being as good as it should be for their age and can progress to dementia (25-26) – are also shown to benefit from consuming dark chocolate by helping maintain their cognitive function (27). In summary, the flavonoids from dark chocolate may have advantages to brain function by increasing blood flow to the brain and eliciting compounds that are important for cognition.
In conclusion, dark chocolate when consumed in moderation can be beneficial for one’s overall health. This may be likely attributed to the antioxidants that are prevalent in cocoa which can combat free radicals. One of the antioxidants discussed, specifically flavonoids, can have positive effects on blood flow that may be advantageous for cardiovascular health and brain functioning. On top of tasting great, consuming dark chocolate may provide great nutritional benefits.
References
Katz DL, Doughty K, Ali A. Cocoa and chocolate in human health and disease. Antioxidants & Redox Signaling. 2011;15(10):2779–811.
Salehi B, Martorell M, Arbiser J, Sureda A, Martins N, Maurya P, et al. Antioxidants: Positive or negative actors? Biomolecules. 2018;8(4):124.
Pizzino G, Irrera N, Cucinotta M, Pallio G, Mannino F, Arcoraci V, et al. Oxidative stress: Harms and benefits for human health. Oxidative Medicine and Cellular Longevity. 2017;2017:1–13.
Halliwell B. Role of free radicals in the neurodegenerative diseases. Drugs & Aging. 2001;18(9):685–716.
Singh RP, Sharad S, Kapur S. Free Radicals and Oxidative Stress in Neurodegenerative Diseases: Relevance of Dietary Antioxidants. The Journal, Indian Academy of Clinical Medicine . 2004;5(3):218–25.
Christen Y. Oxidative stress and alzheimer disease. The American Journal of Clinical Nutrition. 2000;71(2):621S–629S.
Allan Butterfield D. Amyloid β-peptide (1-42)-induced oxidative stress and neurotoxicity: Implications for neurodegeneration in alzheimer's disease brain. A Review. Free Radical Research. 2002;36(12):1307–13.
Zugravu C, Otelea MR. Dark chocolate: To eat or not to eat? A Review. Journal of AOAC International. 2019;102(5):1388–96.
Crozier SJ, Preston AG, Hurst JW, Payne MJ, Mann J, Hainly L, et al. Cacao seeds are a "Super fruit": A comparative analysis of various fruit powders and products. Chemistry Central Journal. 2011;5(1).
Institute for Quality and Efficiency in Health Care (IQWiG). How does the blood circulatory system work? 2019. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279250/
Rhodes CE, Denault D, Varacallo M. Physiology, Oxygen Transport. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2022. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538336/
Gabb G. What is hypertension? Australian Prescriber. 2020;43(4):108–9.
Félétou M. Part 1: Multiple Functions of the Endothelial Cells—Focus on Endothelium-Derived Vasoactive Mediators. In: The Endothelium [Internet]. San Rafael, CA: Morgan & Claypool Life Sciences; 2011. Available from: https://www.ncbi.nlm.nih.gov/books/NBK57149/
Bondonno CP, Croft KD, Ward N, Considine MJ, Hodgson JM. Dietary flavonoids and nitrate: Effects on nitric oxide and vascular function. Nutrition Reviews. 2015;73(4):216–35.
Ahmad A, Dempsey S, Daneva Z, Azam M, Li N, Li P-L, et al. Role of nitric oxide in the cardiovascular and Renal Systems. International Journal of Molecular Sciences. 2018;19(9):2605.
Ludovici V, Barthelmes J, Nägele MP, Enseleit F, Ferri C, Flammer AJ, et al. Cocoa, blood pressure, and vascular function. Frontiers in Nutrition. 2017;4.
Ispas D, Borman WC. Personnel selection, psychology of. International Encyclopedia of the Social & Behavioral Sciences. 2015;:936–40.
Sumiyoshi E, Matsuzaki K, Sugimoto N, Tanabe Y, Hara T, Katakura M, et al. Sub-chronic consumption of dark chocolate enhances cognitive function and releases nerve growth factors: A parallel-group Randomized Trial. Nutrients. 2019;11(11):2800.
Sugimoto N, Miwa S, Hitomi Y, Nakamura H, Tsuchiya H, Yachie A. Theobromine, the primary methylxanthine found in Theobroma cacao, prevents malignant glioblastoma proliferation by negatively regulating phosphodiesterase-4, extracellular signal-regulated kinase, Akt/mammalian target of rapamycin kinase, and nuclear factor-kappa B. Nutrition and Cancer. 2014;66(3):419–23.
Yoneda M, Sugimoto N, Katakura M, Matsuzaki K, Tanigami H, Yachie A, et al. Theobromine up-regulates cerebral brain-derived neurotrophic factor and facilitates motor learning in mice. The Journal of Nutritional Biochemistry. 2017;39:110–6.
Kandel ER. The Molecular Biology of Memory: Camp, PKA, Cre, CREB-1, CREB-2, and CPEB. Molecular Brain. 2012;5(1):14.
Lee D. Global and local missions of Camp Signaling in neural plasticity, learning, and memory. Frontiers in Pharmacology. 2015;6.
Li Y-F, Cheng Y-F, Huang Y, Conti M, Wilson SP, O'Donnell JM, et al. Phosphodiesterase-4D knock-out and RNA interference-mediated knock-down enhance memory and increase hippocampal neurogenesis via increased camp signaling. Journal of Neuroscience. 2011;31(1):172–83.
Leeuwis AE, Smith LA, Melbourne A, Hughes AD, Richards M, Prins ND, et al. Cerebral blood flow and cognitive functioning in a community-based, multi-ethnic cohort: The sabre study. Frontiers in Aging Neuroscience. 2018;10.
Anderson ND. State of the science on mild cognitive impairment (MCI). CNS Spectrums. 2019;24(1):78–87.
Emmady PD, Schoo C, Tadi P. Major Neurocognitive Disorder (Dementia). In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2022. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557444
Calabrò RS, De Cola MC, Gervasi G, Portaro S, Naro A, Accorinti M, et al. The efficacy of cocoa polyphenols in the treatment of mild cognitive impairment: A retrospective study. Medicina. 2019;55(5):156.