Consumption of carbohydrates, especially those in its starch form, was found to be vital for the rapid development of human brains for the past million years, according to a study.

The new research, which appeared in The Quarterly Review of Biology, involved the study of a great amount of data focusing on carbohydrate consumption, specifically starch, needed for brain development.

Although proteins from meat can aid in enhancing the growth of human brains, it is cooked starchy meals that may help an individual become smarter.

With more people growing conscious of obesity rates and metabolic illnesses associated with diet, the interest now lies in healthy fad diets, such as the Paleolithic diet, or Paleo diet.

Paleo diet follows the eating habits of cavemen, which means eating meat, vegetables, and foraging for nuts and berries.

However, this type of diet usually overlooked the importance of carbohydrates, which the study believes to be of key importance in brain development.

The research team, led by Karen Hardy from Spain's Catalan Institution for Research and Advanced Studies, based their case on the importance of dietary carbohydrates for brain evolution on certain observations, as reported in EurekAlert.

First, researchers found the brain uses 25 percent of bodily energy and 60 percent of the glucose found in blood. This suggests that low-glucose diet cannot meet the brain's high demand for the simple carbohydrate.

The second observation surrounds on pregnant and lactating mothers. Higher levels of glucose would be needed to sustain pregnancy, and if the mother doesn't have enough glucose stores, it could affect her pregnancy and the baby.

Carbohydrates were also readily available to the cavemen and could be found in tubers, seeds, fruits and nuts. While starches from these food sources were available, the discovery of fire allowed early humans to digest them more easily.

Salivary amylase genes, which play an important role in the digestion of starch, were found to have increased the production of the enzyme that allows easy digestion of carbohydrates.

Hardy explained that the discovery of fire that led to cooking worked together with the presence of the salivary amylase gene, which resulted to the increased supply of pre-formed dietary glucose needed by the brain and the fetus, consequently leading to an increased brain size almost a million years ago up to the present.