Department of Nutrition, Harvard TH Chan School of Public Health, Boston, MA, USA.
Department of Neurology, University of Florida, Gainesville, FL, USA.
Am J Clin Nutr. 2021 Jul 1;114(1):154-162. doi: 10.1093/ajcn/nqab087.
Phospholipids are biomarkers of dietary fat intake and metabolism, linked to several cardiometabolic disorders. Few prospective studies have assessed plasma phospholipids in relation to dementia risk and cognitive function.
We aimed to evaluate the association between a decrease in linoleic acid accompanied with an increase in other fatty acids and cognitive function and dementia risk.
We conducted a case-cohort study nested within the Ginkgo Evaluation of Memory Study. We included 1252 participants, 498 of whom who developed dementia during a mean of 5 y of follow-up. We measured 45 individual plasma phospholipids (as a percentage of total plasma phospholipid fatty acids) by GC and related these to Modified Mini-Mental State Examination (3MSE) scores at baseline and neurologist-adjudicated incidence of all-cause dementia and Alzheimer disease (AD), adjusting for sociodemographic and clinical characteristics.
Substitution of 1% of SFAs for 1% of linoleic acid, the predominant polyunsaturated n-6 (ɷ-6) fatty acid, was associated with higher risk of dementia (HR per 1% of SFAs instead of linoleic acid = 1.03; 95% CI: 1.00, 1.07) and a 0.08 point lower 3MSE score at baseline (95% CI: -0.12, -0.03), signifying worse cognitive function. When compared with linoleic acid, we found no associations of total monounsaturated, n-3 polyunsaturated, or trans fatty acids with risk of dementia or AD. However, the substitution of 1% of the marine n-3 PUFA DHA for linoleic acid was associated with lower risk of dementia (HR = 0.86 per 1% of DHA instead of linoleic acid; 95% CI: 0.76, 0.96). These associations were not modified by apolipoprotein E genotype, mild cognitive impairment at baseline, age, or sex.
Specific elements of diet may be associated with late-life dementia, a hypothesis that requires formal testing in randomized controlled trials and that represents a possible preventive intervention.
磷脂是膳食脂肪摄入和代谢的生物标志物，与多种心血管代谢疾病有关。很少有前瞻性研究评估血浆磷脂与痴呆风险和认知功能的关系。
我们旨在评估亚油酸减少伴随其他脂肪酸增加与认知功能和痴呆风险的关系。
我们进行了一项嵌套病例对照研究，该研究纳入了银杏叶评估记忆研究中的 1252 名参与者，其中 498 名参与者在平均 5 年的随访期间发生了痴呆。我们通过 GC 测量了 45 种个体血浆磷脂（占总血浆磷脂脂肪酸的百分比），并将其与基线时改良的简易精神状态检查（3MSE）评分以及所有原因导致的痴呆和阿尔茨海默病（AD）的神经病学家裁定发生率相关联，同时调整了社会人口统计学和临床特征。
用 1%的饱和脂肪酸（SFA）替代 1%的亚油酸（最主要的多不饱和 n-6（ω-6）脂肪酸）与痴呆风险增加相关（每 1%的 SFA 替代亚油酸的 HR = 1.03；95%CI：1.00，1.07），且基线时 3MSE 评分降低 0.08 分（95%CI：-0.12，-0.03），提示认知功能更差。与亚油酸相比，我们未发现总单不饱和、n-3 多不饱和或反式脂肪酸与痴呆或 AD 风险有关。然而，用 1%的海洋 n-3 多不饱和脂肪酸 DHA 替代亚油酸与痴呆风险降低相关（HR = 0.86，每 1%的 DHA 替代亚油酸；95%CI：0.76，0.96）。这些关联不受载脂蛋白 E 基因型、基线时轻度认知障碍、年龄或性别影响。
饮食的特定元素可能与晚年痴呆有关，这一假说需要在随机对照试验中进行正式检验，这也代表了一种可能的预防干预措施。
