I am still on the health benefits of flavanol-rich cocoa consumption on exercise capacity. This time it is on exercise at high altitudes. I am also certain that my good friends within the country’s Tourism sector (GTA) will be interested in this piece. The same goes for partners at the Ghana Investment Promotion Centre (GIPC), Ghana Export Promotion Authority (GEPA), the Ghana Free Zones Authority (GFZA), and the Trade and Industry Ministry (MOTI). A key thrust of the Ghana Cocoa Board’s agenda on value addition is promoting cocoa consumption in Ghana and beyond especially with the advent of the African Continental Free Trade Area (AfCFTA) of which Ghana is the host of the Secretariat.
I will be using materials from a study by Decroix et al. One-week cocoa flavanol intake increases prefrontal cortex oxygenation at rest and during moderate-intensity exercise in normoxia and hypoxia. J Appl Physiol125: 8–18, 2018.
The prefrontal cortex (PFC) is a brain region that is crucial for decision-making, planning, and attention. PFC oxygenation is a mediating factor of performance decisions during endurance performance. Normoxia is the condition of having a normal levels of oxygen in tissue or blood. Hypoxia is an absence of enough oxygen in the tissues to sustain bodily functions.
Several sports such as skiing, mountaineering, and some-times cycling and running involve exercise at high altitude. The lower barometric pressure at high altitude reduces the partial pressure of inspired oxygen, which results in reductions of oxygen delivery to the active muscles and the brain and elicits the formation of reactive oxygen species (ROS).This leads to a faster development of peripheral and central fatigue, resulting in decreased exercise performance . Therefore, enhancing oxygen (O2) delivery by improving blood flow at high altitude will improve tolerance to physical exercise and better recovery from exercise.
One of the key molecules regulating blood flow is nitric oxide (NO). NO is endogenously produced by the conversion of arginine into citrulline by endothelial NO synthase (eNOS),in the presence of O2. This portion is actually a feedback readers of my posts on health benefits of cocoa as regards exercise capacity during the month of September 2022. Nitric oxide (NO) exerts its vasodilatory function via stimulating guanylate cyclase and relaxing smooth muscle cells. Endothelial NO synthase (eNOS)-dependent NO production can be limited in conditions of low O2 availability and high levels of oxidative stress. Furthermore, oxidative stress decreases NO availability by increased NO degradation through the reaction of NO with superoxide, the precursor of most other ROS, to form peroxynitrite. Both exercise and hypoxia independently elicit the formation of ROS. Excessive ROS leads to oxidative modification and damage of DNA, RNA, proteins, and lipids.
During exercise, especially at altitude, the excessive ROS formation can lead to impaired muscle contractile and mitochondrial function, resulting in faster development of exercise-induced muscle fatigue and a decreased NO availability. It has been reasoned that modulating NO metabolism by nutritional interventions should influence physiological responses to exercise and exercise performance in both normoxia and hypoxia. The intake of flavanol-rich cocoa with strong antioxidant capacity, enhanced NO-mediated vasodilatation and flow-mediated dilatation should therefore be routinely be made available to persons embarking on trips to high altitude areas or even to persons already living in such areas and o engaged in exercises. This study is particularly useful because several studies on the effects of flavanol-rich cocoa in relation to vasodilation, flow-mediated dilatation, and antioxidant properties have been conducted at sea level.
The study investigators reasoned that the intake of flavanol-rich cocoa will be a very useful nutritional strategy and even more efficient in countering hypoxia, where oxygen (O2) delivery is reduced and where there is an enhanced ROS formation.
The study objectives investigated the effects of a 7-day intake of flavanol-rich cocoa on I/ selected plasma markers of NO availability and oxidative stress, ii/ muscle and cerebral oxygenation in response to an acute exercise bout in normoxia (sea level) and normobaric hypoxia (simulated altitude of 3,000 m, 14.3% O2), and iii/ its implications for exercise performance. The intake of flavanol-rich cocoa should increases NO availability, decreases oxidative stress, and increases cerebral and muscular oxygenation during exercise in normoxia and hypoxia and in turn enhances exercise performance. The important findings of this study among others are that, 1-wk flavanol-rich cocoa intake can increase prefrontal cortex oxygenation, decrease oxidative stress after different types and durations of exercise in humans at both sea level and high altitude. Even though at high altitude, the magnitude of exercise-induced oxidative stress is elevated compared with at sea level, the study showed that intake of flavanol-rich reduces oxidative stress and its broader untoward effects. The reduced oxidative stress at high altitude after the intake of flavanol-rich cocoa also protects against muscle damage and promotes better exercise recovery after exercise. Consistent with previous research, the exercise-induced drops in tissue oxygenation were larger in hypoxia than in normoxia during moderate-intensity exercise. Flavanol-rich cocoa beneficially impacted cerebral oxygenation during rest and during moderate-intensity exercise in hypoxia. The novel study showed that the intake of flavanol-rich cocoa inhibited oxidative stress during exhaustive exercise in hypoxia. Therefore cocoa flavanols (CF) show beneficial effects on endothelial function at rest, as well as on prefrontal oxygenation at rest and during moderate-intensity exercise. The study outcome is relevant for athletes exposed to
altitude, and for hypoxemic patients who suffer from a reduced blood oxygenation, and patients suffering from chronic diseases involving increased levels of oxidative stress.
The Ghana Cocoa Board is exploring opportunities within AFCFTA for our local processors. All conversations at various levels in the country are to add value to the cocoa before export. In a related work Kenya and Ethiopia and South Africa had been identified as part of strategic countries for cocoa consumption within AFCFTA. I am therefore elated by findings of this study since Kenya and Ethiopia are notable high altitude countries. The study outcomes provide additional areas to pitch increased cocoa consumption within AFCFTA by our local cocoa processors.
BY DR. EDWARD O. AMPORFUL