What we consume daily can have a significant implication on how our brain functions and what mental illnesses we may acquire. An unhealthy diet may increase your risk for psychiatric and neurologic conditions such as depression and dementia. Healthy diets may be protective. Here are five dietary items to keep your brain on the right track: Fish oil is loaded with DHA and EPA two polyunsaturated fatty acids (omega 3 fatty acids) that can decrease psychosis and depression. Berries have polyphenols which reduce the oxidative stress of free radicals in the bloodstream and slow cognitive decline. Alcohol, always in moderation (one drink per day for women and two drinks per.