Maternal consumption of omega-6 and omega-3 fatty acids is essential for fetal brain development. Maintaining the proper balance of these two fatty acids is critical, but the typical Western diet is high in omega-6s and low in omega-3s. Findings from a new study in mice suggest that a high omega-6 to omega-3 fatty acid ratio of intake during pregnancy alters dopamine signaling, contributing to overeating in offspring.

Dopamine is a neurotransmitter best known for its role in motor activity, motivation, and pleasure control. When exposed to a rewarding stimulus, the brain responds by increasing dopamine release to motivate behavior. Neurons that release dopamine are activated when a reward is expected.

The authors of the study fed female mice either regular mouse chow or chow that was high in omega-6 fatty acids and low in omega-3s. The mice began eating their respective diets before mating and then throughout pregnancy and lactation. After the offspring were weaned, they ate the same diets as their mothers.

The authors measured how much of a sucrose-containing solution (three solutions containing 3, 10, or 30 percent sucrose) the mice consumed after being water-deprived or when allowed to consume freely. Then they examined whether the mice preferred only sucrose-containing solutions or a high-fat diet after being food deprived. Finally, they administered a dopamine-inhibiting drug to the mice to determine if dopamine signaling influenced the mice’s eating behaviors.

The mice that had been fed the high omega-6/low omega-3 diet consumed far more sucrose solution whether they were water-deprived or allowed to consume freely, compared to the mice fed the regular diet. The high omega-6/low omega-3 mice also consumed higher quantities of sucrose solution or high-fat foods after being food-deprived. Administration of the dopamine inhibitor reduced the animals' intake, however.

These findings suggest that mice that are fed a diet with a high omega-6 to omega-3 ratio from conception through early life develop a stronger preference for highly palatable foods, many of which can contribute to obesity and other chronic health conditions. Foods high in omega-3 fatty acids include salmon and their roe, shellfish, walnuts, and flaxseed. For a fun, tasty way to eat salmon roe, check out this episode in which Dr. Rhonda Patrick shares her recipe for salmon roe stacks.

• Link to full study.

• Learn more about salmon roe and the fatty acids they contain in this overview article.