Objective To examine the associations between dietary intake and tissue biomarkers of alpha linolenic acid (ALA) and risk of mortality from all causes, cardiovascular disease (CVD), and cancer. Design Systematic review and meta-analysis of prospective cohort studies. Data sources PubMed, Scopus, ISI Web of Science, and Google Scholar to 30 April 2021. Study selection Prospective cohort studies that reported the risk estimates for death from all causes, CVD, and cancer. Data synthesis Summary relative risks and 95% confidence intervals were calculated for the highest versus lowest categories of ALA intake using random effects and fixed effects models. Linear and non-linear dose-response analyses were conducted to assess the dose-response associations between ALA intake and mortality. Results 41 articles from prospective cohort studies were included in this systematic review and meta-analysis, totalling 1 197 564 participants. During follow-up ranging from two to 32 years, 198 113 deaths from all causes, 62 773 from CVD, and 65 954 from cancer were recorded. High intake of ALA compared with low intake was significantly associated with a lower risk of deaths from all causes (pooled relative risk 0.90, 95% confidence interval 0.83 to 0.97, I2=77.8%, 15 studies), CVD (0.92, 0.86 to 0.99, I2=48.2%, n=16), and coronary heart disease (CHD) (0.89, 0.81 to 0.97, I2=5.6%, n=9), and a slightly higher risk of cancer mortality (1.06, 1.02 to 1.11, I2=3.8%, n=10). In the dose-response analysis, a 1 g/day increase in ALA intake (equivalent to one tablespoon of canola oil or 0.5 ounces of walnut) was associated with a 5% lower risk of all cause (0.95, 0.91 to 0.99, I2=76.2%, n=12) and CVD mortality (0.95, 0.91 to 0.98, I2=30.7%, n=14). The pooled relative risks for the highest compared with lowest tissue levels of ALA indicated a significant inverse association with all cause mortality (0.95, 0.90 to 0.99, I2=8.2%, n=26). Also, based on the dose-response analysis, each 1 standard deviation increment in blood concentrations of ALA was associated with a lower risk of CHD mortality (0.92, 0.86 to 0.98, I2=37.1%, n=14). Conclusions The findings show that dietary ALA intake is associated with a reduced risk of mortality from all causes, CVD, and CHD, and a slightly higher risk of cancer mortality, whereas higher blood levels of ALA are associated with a reduced risk of all cause and CHD mortality only. Systematic review registration PROSPERO CRD42021229487. No additional data available.

中文翻译：

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膳食摄入量和α亚麻酸生物标志物以及全因死亡率、心血管死亡率和癌症死亡率的风险：队列研究的系统评价和剂量反应荟萃分析


目的 研究膳食摄入量和 α 亚麻酸 (ALA) 组织生物标志物与全因死亡风险、心血管疾病 (CVD) 和癌症之间的关联。设计前瞻性队列研究的系统回顾和荟萃分析。数据来源 PubMed、Scopus、ISI Web of Science 和 Google Scholar 截至 2021 年 4 月 30 日。 研究选择 前瞻性队列研究，报告了全因死亡、CVD 和癌症的风险估计。数据合成 使用随机效应和固定效应模型计算 ALA 摄入量最高类别与最低类别的相对风险和 95% 置信区间摘要。进行线性和非线性剂量反应分析以评估 ALA 摄入量与死亡率之间的剂量反应关联。结果 本次系统评价和荟萃分析纳入了 41 篇前瞻性队列研究文章，总计 1 197 564 名参与者。在两年至 32 年的随访期间，记录了 198 113 人死于各种原因，62 773 人死于 CVD，65 954 人死于癌症。与低摄入量相比，高摄入 ALA 与较低的全因死亡风险显着相关（汇总相对风险 0.90，95% 置信区间 0.83 至 0.97，I2=77.8%，15 项研究）、CVD（0.92、0.86 至 0.99） ，I2=48.2%，n=16) 和冠心病 (CHD)（0.89、0.81 至 0.97，I2=5.6%，n=9），以及癌症死亡风险稍高（1.06、1.02 至 1.11， I2=3.8%，n=10)。在剂量反应分析中，每天增加 1 克 ALA 摄入量（相当于一汤匙菜籽油或 0.5 盎司核桃）与全因风险降低 5% 相关（0.95、0.91 至 0.99，I2= 76.2%，n=12）和 CVD 死亡率（0.95、0.91 至 0.98，I2=30.7%，n=14）。 与最低 ALA 组织水平相比，汇总相对风险表明与全因死亡率呈显着负相关（0.95、0.90 至 0.99，I2=8.2%，n=26）。此外，根据剂量反应分析，ALA 血液浓度每增加 1 个标准差，CHD 死亡率风险就会降低（0.92、0.86 至 0.98，I2=37.1%，n=14）。结论 研究结果表明，饮食中 ALA 摄入量与降低全因、CVD 和 CHD 死亡风险以及略高的癌症死亡风险相关，而较高的血液 ALA 水平与降低全因和冠心病死亡风险相关。仅冠心病死亡率。系统审评注册PROSPERO CRD42021229487。没有其他可用数据。