“Up to 50% of the cases of Alzheimer’s disease may be the result of diet and lifestyle. This means that we have a real opportunity to lower the burden of dementias in the Canadian population through improving diet, exercise, and lifestyle.” Dr. Carol Greenwood
“Whether we like it or not, our couch potato lifestyles are unhealthy for our brains,” says Dr. Carol Greenwood.
While it’s common knowledge that eating the right combination of foods can support healthy aging, it’s less well known that sedentary lifestyle and poor diet each contribute to increasing the risk of dementia. And the combination of both is worse than either alone, Greenwood explains.
The silver lining is that individuals who shift their pattern of eating can protect their brain health and prevent memory loss.
Of course, there is a science to this. Working with a team across Canada within the Canadian Consortium on Neurodegeneration in Aging (CCNA), Greenwood and her colleagues are answering the following questions:
1) Are there combinations of diet and other lifestyle characteristics that best support cognition in older adults?
2) Can brain blood flow and cognitive function (which are pre-existing dementia risk factors) be improved in older adults through diet and physical activity?
3) Is the combination of diet and exercise more effective than increasing physical activity alone?
Greenwood’s team is set to launch a clinical trial exploring the effects of diet and exercise on the brain’s structure and its cognitive performance. The study will include older adults who have subjective cognitive decline (i.e. self-reported perception of memory or cognition problems) and vascular risk factors.
These groups have been targeted because they are at high risk for both Alzheimer’s disease, vascular dementias and their combination, but are still performing cognitively within a normal range. Greenwood explains that individuals within these groups can also experience lifestyle-associated risk factors (including obesity, central adiposity, hypertension, hypercholesterolemia, insulin resistance and type 2 diabetes) which can each be managed through better lifestyle choices. Simply put, early diet and lifestyle interventions may be most effective within these groups.
Knowing that diet has a direct impact on cognitive function and that there aren’t many evidence-informed tools out there to help people shift their pattern of eating, the team has prepared resources and toolkits to support dietary change in study participants, as well as the broader public. This included developing a brain health food guide and a brochure that explain the food pyramid their research supports. Following its development, the team carried out focus groups to pilot test these resources and then adapted them based on feedback. The completed food guide is available here (Brain Health Food Guide, Greenwood 2016). Brochures can be requested for your clinic by clicking here.
You’ll notice that the top of the pyramid shows foods to limit, including red meats, pre-packaged food, and sweets. Further down are the foods to include, such as fish, nuts, fruits and vegetables, including berries and raw leafy greens.
According to Greenwood’s colleague, Dr. Matthew Parrott, “this eating plan is based on research that identified dietary patterns that can help lower the risk of developing Alzheimer’s disease by 36% and pre-dementia by 27%. Studies show that adults aged 50+ – who shifted to similar eating plans for four years – did not experience any memory loss.”
In addition to the long-term gains, adults who were on a similar diet for only four months were given speed reading and writing tests. Their test results showed they performed as if they were 9 years younger, according to Parrott. It is important to note that this eating plan is beneficial for more than brain health. “The same combination of healthy ingredients can help reduce the risk of heart disease, diabetes, and some types of cancer,” Parrott adds.
Cognitive Resilience Through Meaningful Activity
The team has also shown that older adults, who remain socially engaged and have worked in mentally-stimulating roles for long periods of time, may be spared from the adverse effects of a Western diet on age-related cognitive decline. This conclusion was based on Parrott’s recent study that measured the effects of a traditional “Western” diet (e.g. red and processed meats, white bread, potatoes, pre-packaged food and sweets) alongside the occupational complexity, level of education, and social engagement of 351 independently living older adults.
The researchers concluded that a Western diet is associated with more cognitive decline in older adults. However, those who followed this diet, and also had a mentally stimulating lifestyle – particularly higher educational attainment, complex work and ongoing social engagement – were protected from cognitive decline. These findings are consistent with fellow CCNA researcher, Dr. Sylvie Belleville’s work on building cognitive resilience through engaging activity.
“We all know the old adage that an apple a day keeps the doctor away. However, it can also keep dementia away, especially if we skip to the grocery store,” Greenwood says with a smile.
To learn more about Dr. Carol Greenwood and her team’s work within the CCNA, view this mini-video of her colleague, Dr. Guylaine Ferland by clicking here.