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Objective: To determine changes in the incidence of dementia between 1988 and 2015., Methods: This analysis was performed in aggregated data from individuals >65 years of age in 7 population-based cohort studies in the United States and Europe from the Alzheimer Cohort Consortium. First, we calculated age- and sex-specific incidence rates for all-cause dementia, and then defined nonoverlapping 5-year epochs within each study to determine trends in incidence. Estimates of change per 10-year interval were pooled and results are presented combined and stratified by sex., Results: Of 49,202 individuals, 4,253 (8.6%) developed dementia. The incidence rate of dementia increased with age, similarly for women and men, ranging from about 4 per 1,000 person-years in individuals aged 65-69 years to 65 per 1,000 person-years for those aged 85-89 years. The incidence rate of dementia declined by 13% per calendar decade (95% confidence interval [CI], 7%-19%), consistently across studies, and somewhat more pronouncedly in men than in women (24% [95% CI 14%-32%] vs 8% [0%-15%])., Conclusion: The incidence rate of dementia in Europe and North America has declined by 13% per decade over the past 25 years, consistently across studies. Incidence is similar for men and women, although declines were somewhat more profound in men. These observations call for sustained efforts to finding the causes for this decline, as well as determining their validity in geographically and ethnically diverse populations., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Background: We aimed to investigate prospective associations of circulating or adipose tissue odd-chain fatty acids 15:0 and 17:0 and trans-palmitoleic acid, t16:1n-7, as potential biomarkers of dairy fat intake, with incident type 2 diabetes (T2D)., Methods and Findings: Sixteen prospective cohorts from 12 countries (7 from the United States, 7 from Europe, 1 from Australia, 1 from Taiwan) performed new harmonised individual-level analysis for the prospective associations according to a standardised plan. In total, 63,682 participants with a broad range of baseline ages and BMIs and 15,180 incident cases of T2D over the average of 9 years of follow-up were evaluated. Study-specific results were pooled using inverse-variance-weighted meta-analysis. Prespecified interactions by age, sex, BMI, and race/ethnicity were explored in each cohort and were meta-analysed. Potential heterogeneity by cohort-specific characteristics (regions, lipid compartments used for fatty acid assays) was assessed with metaregression. After adjustment for potential confounders, including measures of adiposity (BMI, waist circumference) and lipogenesis (levels of palmitate, triglycerides), higher levels of 15:0, 17:0, and t16:1n-7 were associated with lower incidence of T2D. In the most adjusted model, the hazard ratio (95% CI) for incident T2D per cohort-specific 10th to 90th percentile range of 15:0 was 0.80 (0.73-0.87); of 17:0, 0.65 (0.59-0.72); of t16:1n7, 0.82 (0.70-0.96); and of their sum, 0.71 (0.63-0.79). In exploratory analyses, similar associations for 15:0, 17:0, and the sum of all three fatty acids were present in both genders but stronger in women than in men (pinteraction < 0.001). Whereas studying associations with biomarkers has several advantages, as limitations, the biomarkers do not distinguish between different food sources of dairy fat (e.g., cheese, yogurt, milk), and residual confounding by unmeasured or imprecisely measured confounders may exist., Conclusions: In a large meta-analysis that pooled the findings from 16 prospective cohort studies, higher levels of 15:0, 17:0, and t16:1n-7 were associated with a lower risk of T2D., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: JHYW and RM report research support from Unilever for other projects of the FORCE on other fatty acid biomarkers. RM reports personal fees from the World Bank and Bunge outside the submitted work. IAB reported involvement in a research project partly funded by Unilever. JMG and JdG received funding from Unilever for epidemiological studies of dietary and circulating fatty acids and cardiometabolic disease and for research on assessment of fatty acids. LCdG reported receiving ad hoc consulting fees from the Life Sciences Research Organization. CH reported receiving fees for a conference from Novartis. NGF is an invited member (unpaid) of ILSI-Europe Qualitative Fat Intake Task Force Expert Group on update on health effects of different saturated fats. DM reports research funding from the NIH and the Gates Foundation; personal fees from GOED, DSM, Nutrition Impact, Pollock Communications, Bunge, Indigo Agriculture, Amarin, Acasti Pharma, and America’s Test Kitchen; scientific advisory board, Omada Health, Elysium Health, and DayTwo; and chapter royalties from UpToDate; all outside the submitted work. Patents US8889739 and US9987243 to Tufts University (unlicensed), listing DM as a co-inventor, for use of trans-palmitoleic acid to prevent and treat insulin resistance, type 2 diabetes, and related conditions, as well as reduce metabolic risk factors. SSSM reported receiving an international award and unrestricted grants for meta-analysis work on dairy foods and cardiometabolic diseases from Global and Dutch Dairy Associations. Other authors do not have any conflict of interest to declare. The lead author affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.

Objectives: To study the subtle changes in instrumental activities of daily living (IADLs) over the 10 years preceding the clinical diagnosis of dementia., Design: Prospective cohort designed in 1988 to study cerebral and functional aging., Setting: Community-based study in southwestern France., Participants: The sample included 104 incident cases of dementia at the 10-year follow-up (T10) and 882 subjects free of dementia at the same visit, all forming part of the PAQUID Study., Measurements: Restriction in four IADLs was studied (telephone, transportation, medication, and finances) 2, 5, 7, and 10 years before the T10 visit., Results: The future dementia cases had greater IADL restrictions 10 years before the clinical diagnosis of dementia and more-rapid functional deterioration over time. Controlled for age, sex, and education, subjects restricted in at least two IADLs at baseline had a higher risk of dementia 10 years later (odds ratio (OR)=2.59, 95% confidence interval (CI)=1.24-5.38). In finances, difficulty at baseline was a predictor of dementia 10 years later (OR=2.15, 95% CI=1.13-4.08)., Conclusion: This study is the first to show that, 10 years before the clinical diagnosis of dementia, subjects who later developed dementia performed worse in complex activities of daily living, which may constitute an early marker of the disease. In practice, restriction in IADLs may be a simple and useful tool for screening subjects at risk of developing dementia in the long term.

Alzheimer's disease and related disorders (dementia) are a major public health problem due to the number of cases in the general population, the projections for the future, and the consequences of these diseases. We can estimate that about 850 000 cases of dementia were present in France in 2005 and this number will increase to 1,200,000 in 2020 and 2,100,000 in 2040 if the incidence and the duration of the disease did not change. The development of prevention is therefore necessary. Four ways of prevention are credible. The most important is the treatment of vascular risk factors and particularly hypertension. Other ways are nutritional factors, stimulating leisure activities and depression.