连续三周的生酮饮食与高碳水化合物、低脂肪饮食相比，在健康个体中对认知功能、睡眠和情绪没有影响：一项随机、交叉、对照试验。

Three consecutive weeks of nutritional ketosis has no effect on cognitive function, sleep, and mood compared with a high-carbohydrate, low-fat diet in healthy individuals: a randomized, crossover, controlled trial.

机构信息

Brain Function Research Group.

Movement Physiology Research Laboratory, School of Physiology, Faculty of Health Sciences, University of the Witwaters and rand, Johannesburg, South Africa.

出版信息

Am J Clin Nutr. 2019 Aug 1;110(2):349-357. doi: 10.1093/ajcn/nqz073.

DOI:10.1093/ajcn/nqz073

PMID:31098615

Abstract

BACKGROUND

The high-fat ketogenic diet (KD) has become an increasingly popular diet not only in overweight/obese populations, or those with clinical conditions, but also in healthy non-overweight populations.

OBJECTIVE

Because there are concerns about the association between high-fat diets and cognitive decline, this study aimed to determine the effects of a KD compared with an isocaloric high-carbohydrate, low-fat (HCLF) diet on cognitive function, sleep, and mood in healthy, normal-weight individuals.

METHODS

Eleven healthy, normal-weight participants (mean age: 30 ± 9 y) completed this randomized, controlled, crossover study. Participants followed 2 isocaloric diets-an HCLF diet (55% carbohydrate, 20% fat, and 25% protein) and a KD (15% carbohydrate, 60% fat, and 25% protein)-in a randomized order for a minimum of 3 wk, with a 1-wk washout period between diets. Measures of β-hydroxybutyrate confirmed that all participants were in a state of nutritional ketosis during post-KD assessments (baseline: 0.2 ± 0.2 mmol/L; KD: 1.0 ± 0.5 mmol/L; washout: 0.2 ± 0.1 mmol/L; and HCLF: 0.3 ± 0.2 mmol/L). Cognitive function was assessed using a validated, psychological computer-based test battery before and after each diet. Subjective measures of mood and sleep were also monitored throughout the study using validated scales.

RESULTS

Three weeks of sustained nutritional ketosis, compared with the HCLF diet, had no effect on speed and accuracy responses in tasks designed to measure vigilance (speed: P = 0.39, Cohen's d = 0.26; accuracy: P = 0.99, Cohen's d = 0.04), visual learning and memory (speed: P = 0.99, Cohen's d = 0.04; accuracy: P = 0.99, Cohen's d = 0.03), working memory (speed: P = 0.62, Cohen's d = 0.26; accuracy: P = 0.98, Cohen's d = 0.07), and executive function (speed: P = 0.60, Cohen's d = 0.31; accuracy: P = 0.90, Cohen's d = 0.19). Likewise, mood, sleep quality, and morning vigilance did not differ (P > 0.05) between the dietary interventions.

CONCLUSION

The results of our randomized, crossover, controlled study suggest that 3 wk of sustained nutritional ketosis had no effect on cognitive performance, mood, or subjective sleep quality in a sample of healthy individuals. This trial was registered in the Pan African Clinical Trial Registry as PACTR201707002406306.

摘要

背景

高脂肪生酮饮食（KD）不仅在超重/肥胖人群或有临床病症的人群中，而且在健康的非超重人群中也越来越受欢迎。

目的

由于人们担心高脂肪饮食与认知能力下降之间存在关联，本研究旨在确定 KD 与等热量高碳水化合物、低脂肪（HCLF）饮食相比，对健康、正常体重个体的认知功能、睡眠和情绪的影响。

方法

11 名健康、正常体重的参与者（平均年龄：30±9 岁）完成了这项随机、对照、交叉研究。参与者按照随机顺序至少连续 3 周遵循两种等热量饮食——HCLF 饮食（55%碳水化合物、20%脂肪和 25%蛋白质）和 KD（15%碳水化合物、60%脂肪和 25%蛋白质），两种饮食之间有 1 周的洗脱期。β-羟基丁酸的测量结果证实，所有参与者在 KD 后的评估中均处于营养性酮症状态（基线：0.2±0.2 mmol/L；KD：1.0±0.5 mmol/L；洗脱期：0.2±0.1 mmol/L；HCLF：0.3±0.2 mmol/L）。在每种饮食前后，使用经过验证的、基于心理的计算机测试套件评估认知功能。使用经过验证的量表在整个研究过程中监测情绪和睡眠的主观测量结果。

结果

与 HCLF 饮食相比，3 周的持续营养性酮症对旨在测量警觉性的任务中的速度和准确性反应没有影响（速度：P=0.39，Cohen's d=0.26；准确性：P=0.99，Cohen's d=0.04）、视觉学习和记忆（速度：P=0.99，Cohen's d=0.04；准确性：P=0.99，Cohen's d=0.03）、工作记忆（速度：P=0.62，Cohen's d=0.26；准确性：P=0.98，Cohen's d=0.07）和执行功能（速度：P=0.60，Cohen's d=0.31；准确性：P=0.90，Cohen's d=0.19）。同样，饮食干预之间的情绪、睡眠质量和早晨警觉性也没有差异（P>0.05）。