136 Beef as a Functional Food for Improving Human Nutrition and Health

Beef is an abundant source of all proteinogenic amino acids (AAs; in both adequate amounts and balanced ratios) and physiologically essential nonproteinogenic AAs (taurine and β-alanine). The content and bioavailabilities of proteinogenic AAs in beef are greater than those in plant-sourced foods. Taurine (a potent anti-oxidant) is essential for the integrity and functions of tissues, including eyes, heart, and skeletal muscle, whereas β-alanine is required for the production of antioxidative and neuromodulatory dipeptides. Furthermore, beef contains a large amount of creatine (essential for energy metabolism in tissues, particularly brain and skeletal muscle), anti-oxidative dipeptides (carnosine and anserine), and 4-hydroxyproline (an anti-inflammatory nutrient that maintains intestinal integrity and inhibits colitis). There are myths that plants provide all nutrients that are available in animal-sourced foods. However, taurine, vitamin B12, creatine, carnosine, and anserine are absent from plants, whereas β-alanine and 4-hydroxyproline are low or negligible in plants. Like other animal-sourced foods, beef plays an important role in the optimum growth of children and the prevention of anemia in humans, as well as maintaining muscle mass, delaying ageing, and mitigating sarcopenia in adults, while meeting the high demands of exercising individuals for high-quality protein. Some epidemiological studies raised concern that the consumption of red meat might increase risks for chronic diseases in humans, including obesity, type 2 diabetes mellitus, cardiovascular disease, kidney disease, and cancers. However, findings from many epidemiological and clinical studies do not support these claims. Beef-derived AAs and other nutrients enhance the metabolism (e.g., nitric-oxide and glutathione syntheses) and the functions of monocytes, macrophages, lymphocytes, and other cells of the immune system, thereby helping the human host to kill pathogenic bacteria, fungi, parasites, and viruses. The latter include severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2 (COVID-19). Therefore, beef is a functional food for optimizing human growth, development, and health.