Obesity cure possible after discovery of fat ‘switch’
*Babies of overweight, diabetic mothers have increased risk of lung problems
Scientists have discovered the precise brain mechanism that causes the body to hold onto fat, raising hopes of a cure for obesity.For the first time, lab trials have explained how the brain’s ability to sense insulin in the body, levels of which are raised after a meal, is coordinated with expending or conserving energy.
Researchers at Monash University in Australia have described the findings as “very exciting”, and said they highlight targets for potential fat-inhibiting medicines for people who cannot help putting on weight.
Fat in the human body is stored in specialised cells called adipocytes, which can change from white, when in storage mode, to brown, when expending energy, and back again. In healthy people, the mechanism responds to high levels of insulin in the blood by “browning” the fat, and to low levels, such as after a fast, by keeping the fat white.
For obese people, the “switch” stays on all the time, the researchers said.”What our studies have shown is that there is a fundamental mechanism at play that normally ensures that energy expenditure is matched with energy intake,” said Dr Garron Dodd, first author on the study, which is published in the journal Cell Metabolism.
Meanwhile, babies born to women who are overweight, obese or have diabetes during their pregnancy have less mature lungs than babies of normal weight pregnancies. That is according to research done in a sheep model of pregnancy, published in The Journal of Physiology.
Previous research has shown that women who are overweight, obese or suffer diabetes during pregnancy have an increased risk of giving birth to a baby that experiences lung problems both at birth and later during infancy and childhood.
The team of researchers at the University of South Australia found that the offspring at risk had more immature lungs compared to offspring of mothers with normal weight. Lungs produce a substance called surfactant that serves two purposes: it keeps the airway surfaces from sticking together, and also fights bacteria and viruses. Immature lungs produce less surfactant meaning that the lungs cannot perform their normal functions.
The researchers either fed the pregnant sheep a normal diet or a diet that provided 55 per cent more energy, simulating an over-nutrition and obesity model. This diet was fed during the last trimester of pregnancy, which is when the most critical stage of lung development happens. They looked at the lungs of the lambs before birth and one month after birth to evaluate the growth of the lung and to check if there were a normal number of cells that make surfactant.
They found that there was less surfactant production and fewer cells producing it in the offspring from mothers in the over-nutrition model.One month after birth, the amount of surfactant had normalised in this model, so the long-term effect on lung maturation of being overweight, obese, or diabetic during pregnancy is unclear.