Scientists Identify Protein That May Influence Cravings For Fatty Foods

Why do some people find fatty foods harder to resist? Scientists may have found part of the answer in a protein that helps brain cells produce energy.Researchers from Osaka Metropolitan University in Japan have identified a protein called optic atrophy-1, or OPA1, which appears to influence how much fat mice eat and how quickly they gain weight.

The findings suggest that OPA1 plays an important role in brain cells involved in controlling hunger, appetite and the body's energy balance.

What is OPA1?

OPA1 helps mitochondria, often described as the powerhouses of cells, work properly. The researchers focused on OPA1 in a group of appetite-related brain cells that carry a protein called melanocortin 4 receptor, or MC4R.

These cells are found in the hypothalamus, a part of the brain involved in regulating hunger, food intake and energy use.

To understand the role of OPA1, scientists genetically modified mice so that the protein was missing from these MC4R neurons.

The mice showed a much stronger preference for fatty foods than normal mice. They also gained weight faster and eventually developed obesity. The effect was more noticeable in female mice than in males.

Why does OPA1 matter?

The researchers believe that without enough OPA1, the mitochondria in these appetite-controlling brain cells cannot provide energy as effectively. This may make the neurons less effective at controlling food intake.

The study also found differences between male and female mice when researchers used a drug that activates MC4R to reduce food intake. The treatment worked in males regardless of their OPA1 levels, while its effect was weaker in females lacking OPA1.

The findings could eventually help scientists understand why some people are more likely to overeat or prefer high-fat foods. They may also point towards new approaches to treating obesity.

However, there is an important limitation. The research was carried out only in mice. It is not yet known whether the same OPA1 mechanism controls fatty-food preferences in humans.

Obesity is influenced by many factors, including biology, diet, behaviour and the environment. More research will therefore be needed before scientists can determine whether OPA1 could become a target for future obesity treatments.

The study has been published in the FASEB Journal.