I’m just getting old, that’s all…

Drawing the link between aging and cognitive health

The Canadian population is aging, and overall, people are living longer. In 2011, the first wave of baby boomers turns 65 years old. This group will contribute to a doubling of the Canadian population over 65 years of age by 2025 and to a tripling in the number of centenarians by 2031.

HBI Researchers Dr. Eric Smith and Dr. Mark Poulin will be participating in a free and interactive science café on June 23 at 5:30 pm at Bottlescrew Bill’s Old English Pub to discuss the link between aging and cognitive health.

Identifying Risk Factors for Vascular Dementia

Dr. Eric Smith joined the HBI in 2008 after more than five years as a clinical researcher at Harvard Medical School. Smith is interested in understanding ‘silent cerebral infarctions’ - or silent strokes - caused by blood clots that block the small blood vessels feeding the brain. Many of us suffer numerous silent strokes as we age without even knowing it; something neuroscientists believe contributes to signs of aging, such as impaired memory and mobility.

By adapting clinical imaging tools, including functional magnetic resonance imaging (fMRI) and transcranial Doppler ultrasound, Smith wants to develop a diagnostic technique to measure silent strokes and help identify those most at risk of clinical stroke or advanced cognitive decline before it’s too late.

“Once we can identify who is most at risk [of silent strokes], we can try to intervene to improve blood vessel health and stroke outcomes” he says.

Smith will be building on the success of fellow HBI brain imaging experts Richard Frayne and Brad Goodyear and fellow stroke researchers Marc Poulin and Andrew Demchuk as he continues his search for new ways of determining the health of our blood vessels. Ultimately Smith and his colleagues aim to ease the burden of stroke and cognitive decline in our community.

Understanding how exercise can improve brain function in older adults

As we age, our bodies face increased levels of oxidative stress, which is an imbalance in the body between pro-oxidant (damaging free-radicals) and antioxidant (protective) chemicals, with the balance tipped towards the free-radicals. Oxidative stress is involved in many diseases such as hypertension (high blood pressure) – a leading cause of cardiovascular and cerebrovascular diseases, such as stroke.

Dr. Marc Poulin, a member of the HBI’s Cerebral Blood Flow Regulation foundational research program, recently had his work published in Hypertension, the top-ranked journal in the field of hypertension, for his work uncovering the beneficial effects of aerobic exercise in decreasing oxidative stress in postmenopausal women.

“The results of the study suggest that after menopause, fitness levels and regular physical activity mediate against oxidative stress, while also reducing blood pressure and improving the brain’s vascular responses,” explains Dr. Vincent Pialoux, a former AHFMR postdoctoral fellow in Poulin’s lab and now an Assistant Professor at the Université Claude Bernard in Lyon, France. “This may help reduce the risks of stroke,” says Poulin. “But we need to conduct and intervention study to understand the direct relationships between exercise, oxidative stress and blood pressure, before we can generalize these results to the greater population”.

The unanswered questions from this earlier work led to Poulin setting up a long-term study to look at the effects of regular exercise on brain blood flow and its role in preventing cognitive decline in Canada’s aging population. “We know that working out is good for our brains, but what we don’t know what key mechanisms are at play in this process.”

Poulin successfully secured funding from the Canadian Institutes of Health Research (CIHR) to initiate this critical study.

“The expectations aren’t just about living longer – but about living well,” he says. “Our goal is to establish a strong scientific basis to explain how exercise improves cognition and brain function in older adults. The implications are huge given age-related diseases, such as vascular dementia, Alzheimer’s and stroke.”

This HBI Science Café will be held June 23 at 5:30 p.m. at Bottlescrew Bill’s Pub in Calgary. For more information and to RSVP, email ydurnin [at] ucalgary [dot] ca

Posted June 1, 2010