1. Exercise your brain. Brain games and certain puzzles and brainteasers help create new associations between different parts of the brain, which keeps it sharp. Other exercises that challenge the brain are things like doing normal activities with your non-dominant hand like brushing your teeth or combing your hair.   
2. Vary activities. Most of us here are already physically active, which is extremely important for brain health, but consider challenging your body – and brain – in a variety of ways from time to time. Mix up exercise routines, do something you haven’t done in a while whether it’s hiking or tossing a ball around. This variety is as healthy for your brain as it is your body.      
3. Eat brain food. We all know that a good, clean diet will improve all areas of our health, but there are many studies and an increasing amount of evidence that certain foods slow mental decline. Topping the list of brain-boosting food is any food high in Omega 3 fatty acids DHA and EPA, which has been linked to a lower risk of dementia and improved focus and memory And you were just taking your fish oil to keep your joints from hurting.    
4. Try new things outside of the gym.Take up a language, an instrument, memorize poetry. Asking your brain to do some new tricks keeps it active and able to learn. 
5. Volunteer. Research shows that this can lower your stress levels and increase mental functioning. Volunteering adds to a person’s well-being and overall health. Not only does it feel good, but it promotes brain health by raising self esteem.      
6. Socialize. We are social animals and according to a recent study published in the Journal of Health and Social Behavior, we need a variety of brain stimulation, including social activity, to keep our minds sharp. This is especially true later in life, when aging takes its toll on memory and other complex neurological processes. In the study, older adults who were less socially active than those who were socially active had both cognitive and physical limitations.