[MUSIC] In Chinese Medicine, Qi is regarded as the primary force for supporting all live activities. Qi is not merely the air breathed into the lungs for oxygenating red blood cells, which then deliver oxygen to various tissues of the body, it is essentially the driving force for all body functions. According to the Yin-Yang theory in Chinese Medicine, the interaction between Yin and Yang results in the generation of Qi. In essence, the formation of Normal Qi, or "Zheng Qi" in Chinese, can be described as follows: The lung inhales atmospheric air which then descends into the body and forms the Clean air. Grain Qi, which is derived from the Spleen by transforming ingested food and water, combines with the Clean air to form the Pectoral Qi. Although inherited Primordial Qi is stored in the Kidney, it can be mobilized to combine and interact with Pectoral Qi to generate Normal Qi, or simply called "Qi". Qi is comprised of 2 functional components, namely Defensive Qi, responsible for the events against microorganism invasion, and Nutritive Qi, responsible for providing nutrients to cells and tissues. To enable its functional role, Qi circulates throughout the body through the Meridian. As such, the uninterrupted flow of Qi to various parts of the body is essential for good health with optimal body functioning. By analogy with farming, if one irrigates growing crops with sufficient water and fertilizers, the result will be healthy growing crops. Let's now look into the biochemistry of Qi. Qi can also be viewed as a manifestation of function. At the cellular level, a give function is usually supported by chemical processes, which are fueled by energy in the form of ATP in the cell. In other words, ATP, which is generated from mitochondria, the powerhouse of the cell, can be regarded as the biochemical unit of Qi. Bioenergy (ATP) is generated from the biochemical oxidation of fuel molecules. In essence, foodstuffs, including carbohydrates, lipids and proteins are ingested. Following digestion, molecules such as glucose, fatty acids and amino acids are oxidatively degraded via glycolysis and Kreb's cycle, and ATP is generated from mitochondrial electrons transport and oxidative phosphorylation. The mitochondria can therefore be regarded as the cellular origin of Qi. During the course of the electron transfer in mitochondria, due to the leakage of the electrons, reactive oxygen species (ROS) are unavoidably generated as by-products of energy metabolism. These chemically reactive ROS can cause oxidative damage to cellular components and biomolecules, particularly in mitochondria. This is analogous to the release of waste emissions from a power plant that can pollute the atmosphere. If ROS are not effectively neutralized by cellular antioxidant defense systems, mitochondria and other cellular components can be damaged, resulting in cellular dysfunction or cell death. Given the far-reaching damage produced by ROS, antioxidant supplementation has become popular in preventive health with the goal of scavenging ROS and thereby preventing diseases, including those associated with aging.