A Closer Look at Cognitive Health

Previous research on a large British cohort of people born in 1946 discovered that those who emigrated from the UK, on average, had a 5 point higher IQ compared to those who stayed in the UK, according to senior author Dr. Esme Fuller-Thomson, professor at University of Toronto’s Factor-Inwentash Faculty of Social Work (FIFSW). The current study limited subjects whose native language was English in order to evaluate the link between immigrant status and verbal fluency, regardless of bilingualism.Older research shows that a lower incidence of delayed onset dementia was seen in those who are bilingual. Other studies showing an advantage in those whom are bilingual have not accounted for immigration status. According to Fuller-Thomson, immigrants whose native tongue is English had higher verbal fluency scores than those born in Canada. A “healthy immigrant effect” may explain the “bilingualism advantage”.Not surprising, younger subjects had better cognitive functioning scores than older participants, which is similar to other studies according to co-author Dr. Hongmei Tong, assistant professor of Social Work at MacEwan University in Edmonton.Cognitive reserve factors including educational level is seen as protective and may modify the link between cognitive decline and advanced age. Older subjects (aged 75 to 85) with a high school diploma had verbal fluency scores similar to those that were 10 years younger without a high school degree, according to co-author Dr. Vanessa Taler, associate professor of psychology, University of Ottawa.Cognitive status and verbal fluency scores were also negatively affected by chronic conditions including stage 2 hypertension, obesity and body fat. Obesity is associated with inflammation and insulin resistance, which are both associated with cognitive decline, according to co-author Dr. Karen Kobayashi, professor in the Department of Sociology and a research fellow at the Institute on Aging & Lifelong Health at the University of Victoria.Data from 8,574 anglophone subjects aged 45 to 85, of which 1126 were immigrants that had arrived in Canada at least 20 years ago was analyzed from the Canadian Longitudinal Study on Aging. Participants all lived in the community and were dementia-free. The Controlled Oral Word Association test and the Animal Fluency Test were the verbal fluency tests used.This research suggests some benefit to developing policies and health care practices to improve nutritional status and diet quality, address obesity and high blood pressure in midlife and elderly individuals to improve modifiable risk factors for those with lower verbal fluency scores.While higher levels of education in baby boomers and those born after may reduce age-related cognitive decline, the following changes in diet and lifestyle may help as well.

• Control blood pressure. Follow a DASH style eating pattern with plenty of fruits, vegetables, whole grains, low-fat dairy products, nuts/seeds and legumes.
• Add fruits and vegetables to all meals including breakfast. Add peppers, onions or zucchini to eggs or chopped apples, sliced berries or other fruit to oatmeal and yogurt.
• Include legumes and lentils in your diet in place of meat. Add them to salads, soup, grain bowls and other dishes.
• Lose unwanted weight. Reduce intake of calorie-dense foods and beverages such as regular soft drinks, sweetened tea and sports drinks, alcohol, high calorie desserts and other non-nutritious food.
• Manage blood sugar. Diabetes is a risk factor for cognitive decline. Manage your blood sugar through a nutritious high fiber diet, reduced red meat consumption, regular exercise and medication (if needed).
• Stay active. Studies show the regular physical activity reduces the risk of dementia.

By Lisa Andrews, MEd, RD, LDReferences:

1. Fuller-Thomson, E, Saab, Z., Davison, KM., Lin, S, Taler, K, Kobayashi, K, Tong, H. (2020). Nutrition, immigration and health determinants are linked to verbal fluency among Anglophone adults in the Canadian Longitudinal Study on Aging (CLSA). Journal of Nutrition Health and Aging 24(6):672-680.
2. Karssemeijer EGA, Aaronson JA, Bossers WJ, Smits T, Olde Rikkert MGM, Kessels RPC. Positive effects of combined cognitive and physical exercise training on cognitive function in older adults with mild cognitive impairment or dementia: A meta-analysis. Ageing Res Rev. 2017 Nov;40:75-83.