A recent study took a close look at the relationship between lifestyle behaviors and the biomarkers used to determine a diagnosis of Alzheimer's disease. Researchers found that despite having a history of lifelong cognitive stimulation and activity, the biomarkers of disease were still evident.

Christopher M. Gidicsin, from the Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital, Harvard Medical School in Boston led the study, which was published in the journal Neurology. Self-reported cognitive and physical activity histories in 186 older adults were evaluated and compared to brain imaging using Pittsburgh compound B-PET and neuropsychological testing.

What researchers found was that a history of more positive lifestyle behaviors — particularly greater cognitive activity correlated with a greater estimated IQ and education, but not with the biomarkers for Alzheimer's disease, such as amyloid deposits found with imaging.

While the volume of the actual brain deposits may not be modified by a more physical lifestyle, new evidence suggests physical activity may slow the functional decline these deposits cause. Aerobic physical activity causes a release of neurotrophic factors that promote brain health. Stimulation both cognitively and physically may help keep the axonal pathways and connections more healthy, despite the deposits related to Alzheimer's disease.

Quality physical activity can enhance circulatory structures in the brain, as shown by using diffusion tensor imaging (DTI) in combination with the Pittsburgh compound B-PET. DTI is a surrogate marker for the flow of brain signals along connecting nerve pathways.

Research has shown that those with amyloid deposits but an absence of dementia symptoms have better functional flow along nerves than those who have amyloid deposits and symptoms of Alzheimer's disease. High-intensity aerobic exercise has been shown to improve cognitive function in those at risk for Alzheimer's disease symptoms.

Walking at a pace slow enough to allow for conversations was demonstrated to improve cognitive function in a nursing home residents. Other forms of physical activity, such as Tai Chi, are also beneficial in improving cognitive function.

The deposits related to Alzheimer's disease may be inevitable despite physical behaviors, but researchers believe they are modifiable and preventable with behaviors related to diet. There is evidence with imaging technology that the brain structures are influenced by diet.

Therefore, a healthy diet may slow the deposits, and quality exercise may slow the symptoms of what amyloid deposits there are. A lifestyle that includes cognitive activity, physical activity and good nutrition still are considered preventative for the symptoms of Alzheimer's disease.