A handful of walnuts three times a week is enough to boost attention and brain growth in secondary school kids, according to a new study of students in Spain. The nuts contain a type of omega-3 oil that is particularly beneficial to growing brains.

Scientists who studied 700 kids aged 11-16 found the cognitive development and psychological maturation increased in those who ate the nuts regularly.

They also found a big difference in those diagnosed with ADHD wherein the walnut-munchers were much more able to concentrate in class than before and were less hyperactive.

Students from 12 different schools in Barcelona were randomly divided into two groups. A control group, which received no intervention of any kind and the experimental group, which received packages containing 30 grams of walnut kernels that they were told to consume every day for a period of six months.

The research team from the Barcelona Institute for Global Health, the Institut d’Investigació Sanitària Pere Virgili (IISPV), and the Hospital del Mar Medical Research Institute, found the benefits even in those who only ate them 100 times in the 182 days.

Walnuts are rich in alpha-linolenic fatty acid (ALA), a type of omega-3 that plays a fundamental role in brain development – especially at this life stage when kids’ bodies are changing a lot as they grow.

“Adolescence is a time of great biological changes,” said Principal investigator Dr. Jordi Julvez from the IISPV.

“Hormonal transformation occurs, which in turn is responsible for stimulating the synaptic growth of the frontal lobe – the part of our brain that enables neuropsychological maturation i.e. more complex emotional and cognitive functions.

“Neurons that are well nourished with these type of fatty acids will be able to grow and form new, stronger synapses.”

They also found an increase in functions relating to fluid intelligence, which is less influenced by learning and is inherent in each person’s biology.

While there have been previous studies on the effect of nuts on our health, the impact of their consumption at such a critical stage for cognitive development as adolescence has never been examined.

Ariadna Pinar, a doctoral student from IISPV and first author of the study published in the journal eClinicalMedicine, said their findings demonstrate that following a healthy diet is as important as maintaining these habits over time.

“Adolescence is a period of great brain development and complex behaviour that requires a significant amount of energy and nutrients.

“If boys and girls heed these recommendations and actually eat a handful of walnuts a day, or at least three times a week, they would notice many substantial improvements in cognitive abilities and it would help them face the challenges of adolescence and entering adulthood.”