Overview
- The paper by Brand‑Miller and colleagues, published in Science on Thursday, models an 'obligatory glucose demand' for brain and other tissues across six evolutionary stages to test whether available carbohydrates could meet those needs.
- Their outputs indicate the earliest hominins may have obtained as much as about 66 percent of energy from sweet foods and that sugars contributed roughly 20 to 25 percent of energy across four million years of hominin evolution.
- The authors draw on tooth damage, isotope data, primate diet studies, genetics and physiology to support the model but note key inputs are assumptions and independent experts say those uncertainties limit precision.
- The analysis places much brain expansion before widespread control of fire, which means natural sugars from fruit, honey and underground plants would have been primary glucose sources until cooked starches became significant later.
- The team disclosed funding from the Powerful Plants UKRI Horizon Europe Guarantee Fund and author ties to carbohydrate research, and they argue the findings help explain human sweet preference, pregnancy and childhood glucose needs while prompting further tests of the model.