Birds convert lactate into fuel to recover from oxygen‑carrying impairment

Scientists have discovered that certain bird species can harness lactate—a compound traditionally viewed as a metabolic waste product—as a vital cellular fuel to accelerate recovery from a state that compromises oxygen delivery. The study, published in *Nature Communications*, shows that when hemoglobin in the blood is oxidized to methemoglobin, its ability to transport oxygen is markedly reduced. In response, the birds’ cells shift to using lactate to sustain energy production and restore normal function.

The research demonstrated that lactate is actively taken up by mitochondria in avian tissues, where it is converted into pyruvate and fed into the citric‑acid cycle. This metabolic flexibility allows the birds to maintain ATP synthesis even when oxygen transport is impaired. The findings suggest that lactate serves not merely as a by‑product of anaerobic metabolism but as a strategic energy reserve that can be mobilized during physiological stress.

These insights broaden the understanding of avian physiology and may inform medical research into conditions involving methemoglobinemia or other oxygen‑delivery disorders. Further studies are needed to determine whether similar lactate‑utilization pathways exist in mammals and how they might be leveraged therapeutically.