The FIFA World Cup will take off in Qatar 20 November 2022 and Ghanaians can not wait to see the Black Stars in action. I am continuing with my regular posts on the health benefits of cocoa. The month of September is dedicated to the health benefits of cocoa on exercise capacity and muscle function. I came across this paper by Fraga et al., titled “Regular consumption of a flavanol-rich chocolate can improve oxidation stress in young soccer players” and published in Clinical & Developmental Immunology, March 2005; 12(1): 11–17). The consumption of a diet rich in flavonoids has been associated with a reduced risk for vascular disease. Cocoa is a rich dietary source of flavonoids. The antioxidant actions of the cocoa flavanols inhibit the rate of oxidation of low density lipoprotein (LDL), plasma and liposome. Following consumption of flavanol-rich cocoa there is an increase in the body’s antioxidant defense system. In the study referred to twenty-eight healthy, free-living, non-smoking young male adults with no history of heart disease or haemostatic disorders were active soccer players. All of the subjects played in at least one 90-min-match per week. The intervention group of fourteen active soccer players received per person flavanol-rich cocoa product on daily basis with 168mg of flavanols per day for fourteen days. The control group of fourteen active soccer players received per person per day a very low flavanol containing cocoa product (5mg flavanol content). for fourteen days. The flavanol-rich cocoa group (intervention group) outcome favourably influenced several variables associated with cardiovascular health and antioxidant capacity of the body.
Flavanol-rich cocoa improves endothelial function in humans, modulate nitric oxide synthesis and/or bioavailability in and around the vascular bed. Consumption of flavanol-rich cocoa decreases blood pressure, total-cholesterol and LDL-cholesterol blood levels. With respect to oxidative stress, plasma malondialdehyde levels were lower after 14 days of consumption of flavanol-rich cocoa. Antioxidants can exert their functions by i prevention of formation of reactive oxygen species (ROS) and reactive nitrogen species (RNS-1st line defence, ii scavenging/ removing active ROS/RNS before they cause molecular damage-2nd line defence, iii repairing damage caused bu ROS/RNS-3rd line defence or iv) upregulating antioxidant transcription and translation.
When excessive amounts of ROS/RNS are produced and the body’s antioxidant defence system cannot sufficiently eliminate ROS/RNS, the large amounts of ROS/RNS result in oxidative stress. Oxidative stress refers to the imbalance between oxidants/ free radicals and antioxidants in favour of the oxidants. Large amounts of ROS/RNS will interact with cellular proteins (protein oxidation), lipids (lipid peroxidation) and DNA (oxidative DNA damage), leading to cellular damage and even cell death. Oxidative stress is involved in many pathologies including neurodegenerative diseases (such as Parkinson’s disease, Alzheimer’s disease), cardiovascular disease, cancer, chronic fatigue syndrome and diabetes. Oxidative stress is also elicited during exhaustive exercise. Flavanol-rich cocoa reduces muscle damage, by counteracting the excess of free radicals produced during exhaustive exercise. Flavanol-rich cocoa increases flow-mediated dilatation (FMD) and endothelial function in humans by increasing endothelial nitric oxide (NO) synthesis and NO availability. This enhances blood flow and oxygen (O2) and nutrient delivery to the active muscles, thereby improving exercise tolerance and exercise recovery. In 2013, the European Commission approved for the first time a health claim for flavanol-rich cocoa powder and dark chocolate (with minimum 70% cocoa solids), stating that “daily intake of 200 mg cocoa flavanols (CF) contributes to normal blood circulation by helping to maintain the elasticity of the blood vessels” (EFSA 2012). This amount could be provided by 2.5 g of high CF powder or 10 g of high CF dark chocolate. After intake, CF appear in plasma after 30-60 minutes (min), with epicatechin appearing in a larger concentration than catechin. This increase takes place in a dose-dependent way. The peak concentration is obtained 2 hours post-ingestion and CF are still detectable after 8 hours.
Cocoa flavanol (CF) can cross the blood-brain barrier (BBB) to enter the brain and exert beneficial effects on several cognitive domains including working memory, executive function and attention, after both acute and chronic CF intake. CF affects sports performance because of their i ability to improve cognitive function, ii ability to promote NO production and availability, and iii antioxidant capacities. CF intake enhances sport performance by boosting cognitive function since it has been shown that CF intake can improve executive function (decision making) and motor control- two important factors influencing sports
performance. CF has proven beneficial effects of CF on vascular function via modulation of nitric oxide (NO). The enhanced vascular function and increased oxygen (O2) and nutrient tissue delivery can lead to improved exercise performance. Nitric oxide (NO) is involved in mitochondrial biogenesis and efficiency. While NO production and availability are upregulated through repeated exposure to shear stress during regular exercise training, increasing NO availability by NO-related supplements, such as CF, can support or enhance exercise performance.
There is another related application of CF consumption in sports. When athletes train or compete at high altitude, the decreased arterial pressure of O2 (PaO2) and arterial saturation of O2 (SaO2) compromise tissue oxygen (O2) delivery. This places an extra burden on physical and cognitive performance. Since brain function and brain integrity are dependent on continuous oxygen (O2) supply, brain desaturation may result in impaired cognitive function in hypoxia. During exercise in hypoxic conditions, exercise and hypoxemia both lead to cerebral vasodilation, but when hyperventilation occurs, the induced hypocapnia can lead to cerebral vasoconstriction. As a result of the opposing vasodilation and vasoconstriction, similar blood velocities at (sub)maximal exercise have been observed in the middle cerebral artery in normoxia and acute hypoxia. Since hypoxia does not only impair O2 delivery to brain tissue, but also to muscle tissue, the decreased O2 supply to and impaired oxidative energy production in the exercising muscle negatively affects exercise performance. Furthermore, hypoxia-induced reductions in cerebral oxygenation may favour central fatigue, i.e. the failure of the central nervous system to excite
the motor neurons adequately, hence impairing exercise performance in hypoxic conditions. Hypoxia also results in increased levels of oxidative stress. Thus CF, a notable antioxidant can reduce oxidative stress and also increase cerebral blood flow (CBF) and cerebral oxygenation. With these reasons it should be a must that athletes especially those representing the nation at the World Cup in Qatar 2022 be encouraged to regularly consume flavanol-rich cocoa.
BY DR. EDWARD O. AMPORFUL
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