Meat and Nicotinamide:A Causal Role in Human Evolution, History, and Demographics

Hunting for meat was a critical step in all animal and human evolution. A key brain-trophic element in meat is vitamin B 3 /nicotinamide. The supply of meat and nicotinamide steadily increased from the Cambrian origin of animal predators ratcheting ever larger brains. This culminated in the 3-million-year evolution of Homo sapiens and our overall demographic success. We view human evolution, recent history, and agricultural and demographic transitions in the light of meat and nicotinamide intake. A biochemical and immunological switch is highlighted that affects fertility in the ‘de novo’ tryptophan-to-kynurenine-nicotinamide ‘immune tolerance’ pathway. Longevity relates to nicotinamide adenine dinucleotide consumer pathways. High meat intake correlates with moderate fertility, high intelligence, good health, and longevity with consequent population stability, whereas low meat/high cereal intake (short of starvation) correlates with high fertility, disease, and population booms and busts. Too high a meat intake and fertility falls below replacement levels. Reducing variances in meat consumption might help stabilise population growth and improve human capital

Effects of early amino acid administration on leucine and glucose kinetics in premature infants

We previously showed that, in prematurely born infants, an anabolic state without metabolic acidosis can be achieved upon intravenous amino acid (AA) administration in the immediate postnatal phase, despite a low energy intake. We hypothesized that the anabolic state resulted from an increased protein synthesis and not a decreased proteolysis. Furthermore, we hypothesized that the energy needed for the higher protein synthesis rate would be derived from an increased glucose oxidation. To test our hypotheses, 32 ventilated premature infants ( <1500 g) received intravenously either solely glucose or glucose and 2.4 g AA/kg/d immediately postnatally. On postnatal d 2, each group received primed continuous infusions of either [1-13C]leucine or [U-13C6]glucose. 13CO2 enrichments in expiratory air and plasma [1-13C]alpha-KICA (as an intracellular leucine precursor) and [U-13C6]glucose enrichments were measured by mass spectrometry techniques. The AA administration resulted in an increased incorporation of leucine into body protein and a higher leucine oxidation rate, whereas leucine release from proteolysis was not affected. Glucose oxidation rate did not increase upon AA administration. In conclusion, the anabolic state resulting from AA administration in the immediate postnatal period resulted from increased protein synthesis and not decreased proteolysis. The energy needed for the additional protein synthesis was not derived from an increased glucose oxidatio