This Section Contains a Selection of Recent Research Articles on the Prevention of Dementia for Instructors Who are Interested in the Scientific Background of the Recommendations Provided in the Saving Your Brain Program.

As you will no doubt notice, there are many different results found by various studies, some positive, some negative, and some ambivalent. This is the scientific process, and it is important to keep an open mind and examine the overall weight of evidence. This website is kept up to date by regular literature searches to assure that it stays up to date.

Research on the Mind Diet and Preventing Dementia:

Berendsen, A.M., Kang, J.H., Feskens, E.J.M. et al. Association of long-term adherence to the mind diet with cognitive function and cognitive decline in American women. J Nutr Health Aging 22, 222–229 (2018). https://doi.org/10.1007/s12603-017-0909-0

Findings: "Greater long-term adherence to the MIND diet was associated with a better verbal memory score (multivariable-adjusted mean differences between extreme MIND quintiles=0.04 (95%CI 0.01-0.07), p-trend=0.006), but not with cognitive decline over 6 years in global cognition, verbal memory or TICS. Long-term adherence to the MIND diet was moderately associated with better verbal memory in later life. Future studies should address this association within populations at greater risk of cognitive decline."

Hosking D, Eramudugolla R, Cherbuin N, Anstey K, MIND not Mediterranean diet related to 12-year incidence of cognitive impairment in an Australian longitudinal cohort study, Alzheimer's & Dementia, Volume 15, Issue 4, 2019, Pages 581-589, https://doi.org/10.1016/j.jalz.2018.12.011. (https://www.sciencedirect.com/science/article/pii/S1552526018336288)

Findings: "In adjusted logistic regression models, MIND diet (OR = 0.47, 95% CI 0.24, 0.91), but not Mediterranean diet, was associated with reduced odds of 12-year cognitive impairment."

Berendsen A, Kang J, H, van de Rest O, Jankovic N, Kampman E, Kiefte-de Jong J, Franco O, Ikram M, A, Pikhart H, Nilsson L, Brenner H, Boffetta P, Rafnsson S, Gustafson D, Kyrozis A, Trichopoulou A, Feskens E, Grodstein F, de Groot L: Association of Adherence to a Healthy Diet with Cognitive Decline in European and American Older Adults: A Meta-Analysis within the CHANCES Consortium. Dement Geriatr Cogn Disord 2017;43:215-227. doi: 10.1159/000464269 (https://www.karger.com/Article/Abstract/464269#)

Findings: "Data from 21,837 participants aged ≥55 years from 3 cohorts... were analyzed. HDI scores were based on intakes of saturated fatty acids, polyunsaturated fatty acids, mono- and disaccharides, protein, cholesterol, fruits and vegetables, and fiber... Using multivariable-adjusted, mixed linear regression, mean differences in annual rates of cognitive decline by HDI quintiles were estimated. A higher HDI score was not related to reduced rates of cognitive decline in European and American older adults."

Research on Exercise and Preventing Dementia:

George, Kurudamannil R, Hemachandra P. Can Healthy Diets, Regular Exercise, and Better Lifestyle Delay the Progression of Dementia in Elderly Individuals? Journal of Alzheimer's Disease, 2019 : S37 – S58. (https://content.iospress.com/articles/journal-of-alzheimers-disease/jad190232)

Findings: "Based on our survey of current literature and findings, we cautiously conclude that healthy diets, regular exercise, and improved lifestyle can delay dementia progression and reduce the risk of AD in elderly individuals and reverse subjects with mild cognitive impairment to a non-demented state."

Halloway S, Schoeny M, Wilbur J, Barnes LL. Interactive Effects of Physical Activity and Cognitive Activity on Cognition in Older Adults Without Mild Cognitive Impairment or Dementia. J Aging Health. 2020 Oct;32(9):1008-1016. doi: 10.1177/0898264319875570. (https://pubmed.ncbi.nlm.nih.gov/31559891/)

Findings: "Results were mixed, with significant physical and cognitive activity interactive effects for working and semantic memory. In models without interactions, higher physical and cognitive activities at Year 1 and less decline in cognitive activity over time were independently associated with better cognition at Year 5."

Michelle Brasure, Priyanka Desai, Heather Davila, et al. Physical Activity Interventions in Preventing Cognitive Decline and Alzheimer-Type Dementia: A Systematic Review. Ann Intern Med.2018;168:30-38. doi:10.7326/M17-1528 (https://www.acpjournals.org/doi/full/10.7326/M17-1528?casa_token=TCFmFlaBGM8AAAAA%3AXhVq6Q4qIpMMT-AiCcyNUBr9sKxys0VByAqg2exps4MY6Buck864jxff33g3_d0s7DMp1j1Fy6NQsRU)

Findings: "Evidence that short-term, single-component physical activity interventions promote cognitive function and prevent cognitive decline or dementia in older adults is largely insufficient. A multidomain intervention showed a delay in cognitive decline (low-strength evidence)."

Research on Cognitive Activity and Preventing Dementia:

Gidicsin C, Maye J, Locascio J, Pepin J, Philiossaint M, J. Becker A, Younger A, Dekhtyar M, Schultz A, Amariglio R, Marshall G, Rentz D, Hedden T, Sperling R, Johnson K, Cognitive activity relates to cognitive performance but not to Alzheimer disease biomarkers, Neurology Jul 2015, 85 (1) 48-55; DOI: 10.1212/WNL.0000000000001704 (https://n.neurology.org/content/85/1/48.short)

Finding: "We conclude that a history of lifelong cognitive activity may support better cognitive performance by a mechanism that is independent of brain β-amyloid burden, brain glucose metabolism, or hippocampal volume."

Sajeev G, Weuve J, Jackson JW, et al. Late-life Cognitive Activity and Dementia: A Systematic Review and Bias Analysis. Epidemiology. 2016;27(5):732-742. doi:10.1097/EDE.0000000000000513 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5460628/)

Findings: "We reviewed 12 studies involving 13,939 participants and 1,663 dementia cases, of which 565 were specifically evaluated as AD. Most studies found associations between late-life cognitive activity and lower AD and/or all-cause dementia incidence. Differences in cognitive activity operationalization across studies precluded meta-analysis of effect estimates. Our bias analysis indicated that the observed inverse associations are probably robust to unmeasured confounding, and likely only partially explained by reverse causation."

Jenna Najar, Svante Östling, Pia Gudmundsson, Valter Sundh, Lena Johansson, Silke Kern, Xinxin Guo, Tore Hällström, Ingmar Skoog, Cognitive and physical activity and dementia A 44-year longitudinal population study of women, Neurology, 2019, 92 (12) e1322-e1330; DOI: 10.1212/WNL.0000000000007021 (https://n.neurology.org/content/92/12/e1322.abstract)

Finding: "We found that cognitive activity in midlife was associated with a reduced risk of total dementia (hazard ratio [HR] 0.66; 95% confidence interval [CI] 0.49–0.89) and Alzheimer disease (HR 0.54; 95% CI 0.36–0.82) during follow-up. Physical activity in midlife was associated with a reduced risk of mixed dementia (HR 0.43; 95% CI 0.22–0.86) and dementia with cerebrovascular disease (HR 0.47; 95% CI 0.28–0.78). The results were similar after excluding those who developed dementia before 1990 (n = 21), except that physical activity was then also associated with reduced risk of total dementia (HR 0.67; 95% CI 0.46–0.99). Our findings suggests that midlife cognitive and physical activities are independently associated with reduced risk of dementia and dementia subtypes. The results indicate that these midlife activities may have a role in preserving cognitive health in old age."

Research on Vitamins and Preventing Dementia:

B12:

Hooshmand B, Refsum H, Smith AD, et al. Association of Methionine to Homocysteine Status With Brain Magnetic Resonance Imaging Measures and Risk of Dementia. JAMA Psychiatry. 2019;76(11):1198–1205. doi:10.1001/jamapsychiatry.2019.1694 (https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2738056)

Findings: "The methionine to homocysteine ratio was higher in individuals who consumed vitamin supplements (median, 1.9; interquartile range [IQR], 1.5–2.6) compared with those who did not (median, 1.8; IQR, 1.3–2.3; P < .001) and increased per each quartile increase of vitamin B12 or folate. In the multiadjusted model, an elevated baseline serum total homocysteine level was associated with an increased risk of dementia and AD during 6 years: for the highest homocysteine quartile compared with the lowest, the hazard ratios (HRs) were 1.60 (95% CI, 1.01-2.55) for dementia and 2.33 (95% CI, 1.26-4.30) for AD. In contrast, elevated concentrations of methionine were associated with a decreased risk of dementia (HR, 0.54; 95% CI, 0.36-0.81) for the highest quartile compared with the lowest. Higher values of the methionine to homocysteine ratio were significantly associated with lower risk of dementia and AD: for the fourth methionine-homocysteine quartile compared with the first quartile, the HR was 0.44 (95% CI, 0.27-0.71) for incident dementia and 0.43 (95% CI, 0.23-0.80) for AD... The methionine to homocysteine status was associated with dementia development and structural brain changes during the 6-year study period, suggesting that a higher methionine to homocysteine ratio may be important in reducing the rate of brain atrophy and decreasing the risk of dementia in older adults."

Timothy Kwok, Yuanyuan Wu, Jenny Lee, Ruby Lee, Cho Yiu Yung, Grace Choi, Vivian Lee, John Harrison, Linda Lam, Vincent Mok, A randomized placebo-controlled trial of using B vitamins to prevent cognitive decline in older mild cognitive impairment patients, Clinical Nutrition,Volume 39, Issue 8,2020, Pages 2399-2405, https://doi.org/10.1016/j.clnu.2019.11.005. (https://www.sciencedirect.com/science/article/pii/S0261561419331322)

Findings: "Vitamin B12 and folic acid supplementation did not reduce cognitive decline in older people with MCI and elevated serum homocysteine, though the cognitive decline over two years in placebo group was small. The supplement led to a significant reduction in depressive symptoms at month 12, though this effect was not sustained. Aspirin use had a negative interaction effect on cognitive functioning with B supplements."

Vitamin D:

Littlejohns, Thomas J et al. “Vitamin D and the risk of dementia and Alzheimer disease.” Neurology vol. 83,10 (2014): 920-8. doi:10.1212/WNL.0000000000000755 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4153851/)

Findings: "Our results confirm that vitamin D deficiency is associated with a substantially increased risk of all-cause dementia and Alzheimer disease. This adds to the ongoing debate about the role of vitamin D in nonskeletal conditions."

Feart C, Helmer C, Merle B, Herrmann F, Annweiler F, Dartigues J, Delcourt C, Samieri C,Associations of lower vitamin D concentrations with cognitive decline and long-term risk of dementia and Alzheimer's disease in older adults, Alzheimer's & Dementia, Volume 13, Issue 11, 2017, Pages 1207-1216, https://doi.org/10.1016/j.jalz.2017.03.003 (https://www.sciencedirect.com/science/article/pii/S1552526017301383)

Findings: "This large prospective study of French older adults suggests that maintaining adequate vitamin D status in older age could contribute to slow down cognitive decline and to delay or prevent the onset of dementia, especially of AD etiology."

Vitamin E and Selenium:

Kryscio R, Abner E, Caban-Holt A, et al. Association of Antioxidant Supplement Use and Dementia in the Prevention of Alzheimer’s Disease by Vitamin E and Selenium Trial (PREADViSE). JAMA Neurol. 2017;74(5):567–573. doi:10.1001/jamaneurol.2016.5778 (https://jamanetwork.com/journals/jamaneurology/article-abstract/2612477?casa_token=HnWE3UHHc5cAAAAA:OogAo-lYc8PaoRhQXlucusX9_G-jMPbNIxi65rdazSRCIs5hRM_q6z-x8NchoYLKxqMOReccyqc)

Findings: "The Prevention of Alzheimer’s Disease by Vitamin E and Selenium trial initially enrolled 7540 elderly men who were exposed to the supplements for an average of 5.4 years; a subset of 3786 men agreed to be observed for up to 6 additional years. Dementia incidence (4.4%) did not differ among the 4 study arms."

Prevention of Dementia with Adequate Sleep:

Spira A, Chen-Edinboro L, Wu M, Yaffe K. Impact of sleep on the risk of cognitive decline and dementia. Curr Opin Psychiatry. 2014;27(6):478-483. doi:10.1097/YCO.0000000000000106 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4323377/)

Findings: "Findings indicate that poor sleep is a risk factor for cognitive decline and AD. Although mechanisms underlying these associations are not yet clear, healthy sleep appears to play an important role in maintaining brain health with age, and may play a key role in AD prevention."

Larsson S, and Wolk A, ‘The Role of Lifestyle Factors and Sleep Duration for Late-Onset Dementia: A Cohort Study’. 1 Jan. 2018 : 579 – 586. (https://content.iospress.com/articles/journal-of-alzheimers-disease/jad180529)

Findings: "During a mean follow-up of 12.6 years, dementia was diagnosed among 3,755 participants (mean age at diagnosis 83.2±5.1 years). There were no associations of an overall healthy diet (defined by a modified Dietary Approaches to Stop Hypertension Diet score or a Mediterranean diet score), alcohol and coffee consumption, or physical activity with dementia incidence. Compared with never smokers, dementia risk was increased in former and current smokers (hazard ratio [95% confidence interval] = 1.13 [1.04–1.23] and 1.10 [1.00–1.21], respectively). Extended time of sleep (>9 h per night) was associated with an increased risk of dementia. However, this association appeared to be related to a reverse causation effect since the association did not remain after exclusion of cases diagnosed within the first five or ten years of follow-up. This study found no evidence that major lifestyle factors, aside from smoking, or sleep duration influence the risk of dementia."