Could coffee polyphenols improve sleep and energy metabolism in obese people?

Chlorogenic acids – the most abundant polyphenols in coffee – may help people fall asleep and boost fat burning during sleep, suggests a new study from Japan.

Five days of dietary supplementation with beverages formulated with 600 mg of chlorogenic acids results in an average 50% increase in the breakdown of stored fat (958 kJ/16 h), compared to a control beverage (639 kJ/16 h), report scientists from the University of Tsukuba and Kao Corporation.

The beverages with chlorogenic acids (CGA) was also associated with a reduction in the time to fall asleep (sleep latency) but had no effect on others measures of sleep, such as REM sleep or waking up during the night, according to findings published in the British Journal of Nutrition.

“The effect of CGA in stimulating fat oxidation during sleep was manifested without an adverse effect on sleep architecture, which is in contrast with the effects of sympathomimetics such as capsaicin, catechins and caffeine,” wrote the researchers.

Study details

The Japanese scientists recruited nine healthy people to participate in their double-blind, placebo-controlled, cross-over intervention study. Participants were assigned to consume a beverage containing 0 or 600 mg of CGA for five days. On the last day their sleep was assessed in a metabolic chamber. The test beverage contained 0 or 600 mg of chlorogenic acids, which consisted of caffeoylquinic acids (CQA, 68%), feruloylquinic acids (FQA, 14%) and dicaffeoylquinic acids (diCQA, 19%).

The results indicated that after CGA consumption the average time to fall asleep was 9 minutes, compared to an average time of 16 minutes following the control beverage. No other sleep effects were recorded.

The CGA beverage was also associated with an increase in fat oxidation but no effects on energy expenditure were recorded. Further analysis revealed that CGA consumption was enhancing parasympathetic activity, the so-called rest and digest system.

“The function of the autonomic nervous system was also affected by ingestion of CGA through up-regulation of parasympathetic nervous system activity and a decrease in heart rate,” wrote the researchers. “An increase in parasympathetic nervous system activity may explain the antihypertensive effects of CGA, for which several mechanisms have been proposed: reduction of free radical production, scavenging free radicals, stimulation of NO production and inhibition of angiotensin-converting enzyme.

“Ingestion of CGA increased parasympathetic activity during sleep, and the causal relation to its effects on sleep and fat oxidation remains to be evaluated. To generalize the present findings, an experiment with a larger sample size of obese and/or aged subjects should be performed,” they concluded.

Source: British Journal of Nutrition

Published online ahead of print, doi: 10.1017/S0007114517000587

“Effects of subacute ingestion of chlorogenic acids on sleep architecture and energy metabolism through activity of the autonomic nervous system: a randomised, placebo-controlled, double-blinded cross-over trial”

Authors: I. Park et al.