Dr. Emily Chew, director of the Division of Epidemiology and Clinical Applications at the National Eye Institute in Bethesda, Maryland, claims that people who strictly follow the Mediterranean diet had a 45-50% reduction in the risk of having an impaired cognitive function.

The Mediterranean diet is mainly composed of vegetables, fish, whole grain, and olive oil. Two new studies assert the fact that people who are cognitive deficit can boost their brain function with the help of this diet.

Dr. Richard Isaacson, the director of the Alzheimer's Prevention Clinic at NewYork-Presbyterian's Weill Cornell Medicine Center, says the new evidence continues to validate the saying that 'you are what you eat,' especially about brain health.

Strict compliance to the diet was described as eating fish twice a week, while also regularly consuming fruits, vegetables, legumes, whole grains, nuts, and olive oil. Adhering to the diet also meant reducing the consumption of red meat and alcohol.

Chew added that cognitive decline increased as the levels of compliance with the diet dropped. According to her, people who displayed the highest adherence to the diet had better brain protection, thus exhibiting improved cognition, than those in the second tier, who then had more protection than those in the last tier.

Help Your Brain; Eat Some Fish

Although compliance with the Mediterranian diet seemed to lower the risk for cognitive decline in general, it did not, however, give evidence to slow down cognitive decline for people with the Apolipoprotein E gene. It is the most common gene associated with late-onset Alzheimer's disease.

Although, when the study focused on the levels of fish consumption, a slower pattern in cognitive decline was apparent in patients who ate fish twice a week, despite having the gene.

"In this study, while the Mediterranean diet overall decreased risk, the strongest factor to really move the needle was regular fish consumption," said Isaacson, who is also a trustee of the McKnight Brain Research Foundation.

Isaacson adds that the findings from the long-term study mirrored the results of their own clinical research in the Alzheimer's Prevention Clinic. In the study, people who made dietary and other lifestyle changes showed cognitive improvements in 18 months. He says that future studies regarding the matter will help explain how long it takes a person to see a positive shift in cognition after making dietary changes.

Get Started on the Mediterranean Diet

For those of you who are curious about how to start the Mediterranean diet, here's how you do it. Experts claim that it's better if you ease your way into it by replacing one thing at a time.

For instance, replace commercial grains with whole grains by choosing whole wheat bread instead of regular flour bread. You can also start by swapping white rice with brown rice. Cook your meals based on beans, vegetables, and whole grain.

Meat consumption is not encouraged in the diet, but if you have to, do so in small amounts. Cheese and yoghurt should be eaten daily to weekly in moderate portions, while chicken and eggs can occasionally be prepared.

If fish is the king, olive oil is the queen in the Mediterranean diet, experts say. Avoid coconut and palm oil because they are plant-based. Researchers say that those oils are high in saturated fats that will raise bad cholesterol.