Trading car keys in for a bike helmet may lower the risk of dementia and Alzheimer’s disease, a new study finds.Researchers say biking on a regular basis may even help increase the size of a brain region that’s important to memory.They analyzed data from nearly 480,000 people who reported on the types of transportation they used most often. During about 13 years of follow-up, more than 8,800 participants developed dementia and nearly 4,000 developed Alzheimer’s.But participants who biked or included biking with other forms of travel like walking, driving or public transportation had 19% lower odds of dementia and 22% lower odds of Alzheimer’s, according to the results.The benefits appeared to extend mostly to people without a genetic risk for Alzheimer’s.The authors say MRI brain scans revealed another interesting trend related to active transportation. “The cycling and mixed-cycling mode was significantly associated with a higher hippocampal volume.”The hippocampus plays a critical role in memory formation and learning.The study also suggests driving may be more cognitively beneficial than public transportation.Source: JAMA Network OpenAuthor Affiliations: Huazhong University of Science and Technology, The University of Sydney .Sign up for our weekly HealthDay newsletter