Higher energy intake at dinner decreases parasympathetic activity during nighttime sleep in menstruating women: A randomized controlled trial

The Acute Effects of a Fast-Food Meal Versus a Mediterranean Food Meal on the Autonomic Nervous System, Lung Function, and Airway Inflammation: A Randomized Crossover Trial

BACKGROUND/OBJECTIVES

This study aimed to assess the acute effects of two isoenergetic but micronutrient-diverse meals-a Mediterranean-like meal (MdM) and a fast food-like meal (FFM)-on the autonomic nervous system (ANS), lung function, and airway inflammation response.

METHODS

Forty-six participants were enrolled in a randomized crossover clinical trial, consuming two isoenergetic meals: FFM (burger, fries, and sugar-sweetened drink) and MdM (vegetable soup, whole-wheat pasta, salad, olive oil, sardines, fruit, and water). Pupillometry assessed parasympathetic (MaxD, MinD, Con, ACV, MCV) and sympathetic (ADV, T75) nervous system outcomes. Lung function and airway inflammation were measured before and after each meal through spirometry and fractional exhaled nitric oxide (FeNO), respectively.

RESULTS

Mixed-effects model analysis showed that the MdM was associated with a hegemony of parasympathetic responses, with a significant increase of MaxD associated with a faster constriction velocity (ACV and MCV); on the other side, the FFM was associated with changes in the sympathetic response, showing a quicker redilation velocity (a decrease in T75). After adjusting for confounders, the mixed-effects models revealed that the FFM significantly decreased T75. Regarding lung function, a meal negatively impacted FVC (ae = -0.079, p < 0.001) and FEV1 (ae = -0.04, p = 0.017); however, FeNO increased, although after adjusting, no difference between meals was seen.

CONCLUSIONS

Our study showed that the FFM counteracted the parasympathetic activity of a meal, while a meal, irrespective of the type, decreased lung function and increased airway inflammation.

Estimating Sleep Stages Using a Head Acceleration Sensor

Sleep disruption from causes, such as changes in lifestyle, stress from aging, family issues, or life pressures are a growing phenomenon that can lead to serious health problems. As such, sleep disorders need to be identified and addressed early on. In recent years, studies have investigated sleep patterns through body movement information collected by wristwatch-type devices or cameras. However, these methods capture only the individual’s awake and sleep states and lack sufficient information to identify specific sleep stages. The aim of this study was to use a 3-axis accelerometer attached to an individual’s head to capture information that can identify three specific sleep stages: rapid eye movement (REM) sleep, light sleep, and deep sleep. These stages are measured by heart rate features captured by a ballistocardiogram and body movement. The sleep experiment was conducted for two nights among eight healthy adult men. According to the leave-one-out cross-validation results, the F-scores were: awake 76.6%, REM sleep 52.7%, light sleep 78.2%, and deep sleep 67.8%. The accuracy was 74.6% for the four estimates. This proposed measurement system was able to estimate the sleep stages with high accuracy simply by using the acceleration in the individual’s head.

The effect of nocturnal "meat" versus "vegetarian" dinners on sleep quality and daily functioning

INTRODUCTION

Sleep and nutrition are central to an organism's continued physiological existence. Moreover, both of these functions include significant social-behavioral, educational, and cultural elements. This study examined the effects of two types of nocturnal dinners ("vegetarian" versus "meat") on the quality and quantity of sleep, as well as on subjective sleepiness and attention levels the following morning.

MATERIALS AND METHODS

20 healthy subjects (10 men and 10 women) participated in a lab polysomnography study for two non-consecutive nights at the Sleep Institute at Tel-Hai College. They completed questionnaires (Karolinska Sleepiness Scale (KSS) and Brief Symptom Inventory Questionnaire (BSI)), as well as a computerized attention and concentration test (Conner's Continuous Performance Test-III (CPT-III)), on the mornings after each night of polysomnography. On the first night, subjects consumed a vegetarian meal made up of non-animal ingredients (vegetables and vegetable proteins). On the second night, they were given a meat meal composed of carbohydrates, fats, and animal proteins.

RESULTS

No significant differences were measured in the various sleep parameters: efficacy, structure, and quality of sleep. There were also no significant differences found in the behavioral measures examined: subjective sleepiness (KSS), mood (BSI), and attention and concentration abilities (CPT-III).

CONCLUSION

The findings of this study indicate that, contrary to popular belief, consuming a meat dinner may not affect a person's quality of sleep, or their ability to function the morning after, differently than a vegetarian dinner. Future studies should further examine the relationship between sleep and nutrition.

TRIAL REGISTRATION

The clinical trial is registered under the number 0010-18ASMC.

Association between Micronutrients and Heart Rate Variability: A Review of Human Studies

Heart rate variability (HRV) is a measure of the variation between consecutive heartbeats. It provides a marker of the interplay between the parasympathetic and sympathetic nervous systems, and there is an increasing body of evidence confirming an increased HRV is associated with better mental and physical health. HRV may be a useful marker of stress as it represents the ability of the heart to respond to a variety of physiological and environmental stimuli. HRV tends to decrease as we age and is positively associated with physical activity, fitness, and healthier lifestyles. The relation between HRV and micronutrients (vitamins and minerals) has also received some attention in the research literature. In this review, cross-sectional and interventional studies on human populations examining the relation between HRV and micronutrients are appraised. Micronutrients identified and examined in this review include vitamins D, B-12, C, and E; the minerals magnesium, iron, zinc, and coenzyme Q10; and a multivitamin-mineral formula. Due to the paucity of research and significant heterogeneity in studies, definitive conclusions about the effects of these micronutrients on HRV cannot be made at this time. However, there is accumulating evidence suggesting deficiencies in vitamins D and B-12 are associated with reduced HRV, and zinc supplementation during pregnancy can have positive effects on HRV in offspring up until the age of 5 y. To further elucidate the relation between micronutrients and HRV, additional robustly designed and adequately powered studies are required.