Research presented at the most recent International Conference on Alzheimer's Disease suggests that lifestyle (exercise, diet and alcohol intake) has the strongest and most direct influence on preventing and/or delaying mental decline. In terms of exercise, just 20 to 30 minutes of activity per day can help protect your brain. Over 3,831 participants were studied. The most sedentary adults had the lowest level of cognitive functioning, whereas the most active adults had the highest level of cognitive functioning. As for diet, "our results suggest that including whole grains, vegetables, lowfat diary foods and nuts in one's diet may offer benefits for cognition late in life." And lastly, moderate alcohol intake of just one or two drinks per day may reduce the risk of dementia. Light drinkers are less likely to develop alzheimer's than teetotalers.