Two new studies present promising findings for early detection of and intervention for Alzheimer’s disease.
Alzheimer’s disease is an incurable neurodegenerative disease characterized by progressive cognitive decline. In 2017, about 6 million Americans were living with the disease, according to research published in the journal Alzheimer’s & Dementia.
Currently, the disease is diagnosed through PET scans of the brain or testing of cerebrospinal fluid.
New technologies, however, might change how Alzheimer’s is diagnosed. A January 2018 study published in Nature indicates positive findings for a potential blood test.
Alzheimer’s is characterized by the buildup of amyloid-β proteins in the brain. These plaque deposits are toxic to nerve cells.
The study demonstrates that a blood test measuring the presence of amyloid-β precursor proteins, along with a few other related proteins and their composites, was accurate at predicting Alzheimer’s disease.
The researchers tested for these biomarkers in people with Alzheimer’s, mild cognitive impairment and normal cognitive status. Comparing the blood test results with PET scans, they found that the test was about 90 percent accurate.
This development, the authors suggest, poses “cost-benefit and scalability advantages over current techniques, potentially enabling broader clinical access and efficient population screening.”
They write that a significant use of this technology could lie in early diagnosis. Because the disease is progressive, they suggest that early, experimental intervention holds the most promise for altering its course. Currently there are no treatments for Alzheimer’s.
However, another new study, a January 2018 research review published in the Journal of the American Geriatrics Society, has determined that exercise has a small positive effect on cognitive function. Aerobic exercise in particular was found to boost participants’ cognitive abilities.
The researchers analyzed the findings of 19 studies that measured cognitive function pre- and post-exercise intervention. All studies reviewed had a non-exercise control group. Almost all participants in the studies had mild cognitive impairment (64 percent) or Alzheimer’s disease (35 percent). The researchers found that:
Comparing differences in cognitive function between control and exercise groups, the authors found a small positive effect for the experimental group.
The authors write, “Our overall finding was that moderate-intensity exercise training performed approximately 3 days per week for approximately 45 minutes per session resulted in modestly better cognitive function than in controls.”
Looking more specifically at cognitive function before and after different forms of exercise intervention, the researchers found that those who participated in aerobic exercise in particular had “clinically meaningful improvements in cognitive function.”
Combined exercise (aerobic and resistance training) did not have a significant effect on cognitive abilities.
The researchers conclude, “Our meta-analysis is the first to suggest that aerobic exercise may be more effective than other types of exercise in preserving the cognitive health of older adults at risk of or who have AD [Alzheimer’s disease.]”