How Does Caffeine Affect You?

/in /by

It is difficult to predict how and for how long caffeine affects our bodies. Research suggests that caffeine affects everyone differently and our relationship with it could change as we age. A study examining the relationship between chronotype and the effects of caffeine on sleep in Stanford students found early birds had a strong correlation between daytime caffeine use and waking during sleep. Night owls’ sleep seemed to not be affected by their daytime caffeine intake. People in between seemed to experience minor effects. However, this study was exclusive to Stanford students, who are generally a more sleep-deprived population. It is unclear the degree to which this affected the results but is likely a significant confounding variable.

One of our sleep experts, Dr. Jaime Zeitzer, PhD, says , “There is massive variability in how people metabolize caffeine and in many, even a single cup of coffee with breakfast can interfere with sleep. Being aware of how your caffeine consumption personally impacts your sleep is incredibly important.”

By: Carly Mae Smith, BS

Sources:

  1. Modeling caffeine concentrations with the Stanford Caffeine Questionnaire: preliminary evidence for an interaction of chronotype with the effects of caffeine on sleep
What Exactly Does Quality Sleep Mean?

What Exactly Does Quality Sleep Mean?

/in , /by

What Exactly Does Quality Sleep Mean?

Many understand that nutrition and physical activity are important for maintaining good health. However, the significance of sleep is often overlooked, even though it is vital for our heart and overall health.

A new study presented at the American College of Cardiology’s Annual Scientific Session emphasizes the importance of good sleep for heart health, overall well-being, and life expectancy. With data from 172,321 participants, the study examines the impact of poor sleep quality.

The researchers defined quality sleep relative to insomnia: 1) ideal sleep duration of seven to eight hours a night; 2) difficulty falling asleep no more than two times a week; 3) trouble staying asleep no more than two times a week; 4) not using any sleep medication; and 5) feeling well rested after waking up at least five days a week.

The results showed that individuals with all five favorable sleep factors were 30% less likely to die for any reason, 21% less likely to die from cardiovascular disease, 19% less likely to die from cancer, and 40% less likely to die from other causes. Moreover, among men and women with all five quality sleep measures, life expectancy was 4.7 years greater for men and 2.4 years greater for women, compared to those with none or only one favorable sleep factor.

While further research is needed to explore the reasons for the observed sex differences, Frank Qian urges, “even from a young age, if people can develop these good sleep habits of getting enough sleep, making sure they are sleeping without too many distractions and have good sleep hygiene overall, it can greatly benefit their overall long-term health.”

Sleep quality can mean many different things. According to Stanford Lifestyle Medicine expert, Dr. Jamie M. Zeitzer, who is also Co-Director at the Stanford Center for Sleep and Circadian Sciences, a newer conceptualization is the RU-SATED model developed by Pittsburgh’s Dr. Daniel Buysse. RU-SATED incorporates six conceptual sleep areas: sleep regularity, subjective satisfaction, daytime alertness, timing, sleep efficiency, and sleep duration. Instead of dichotomizing sleep into “good” and “pathological”, Zeitzer explains that the RU-SATED model allows for us to understand sleep as a continuum.

Like many health behaviors, sleeping well is cumulative over time. Whether you already me the sleep factors mentinoed, or are working towards healthier sleep habits, it is time we prioritize and understand the role of quality sleep for a longer and healthier life with quality sleep.

By: Jamie Zeitzer, MD & Helena Zhang, BS

Sources:

  1. https://www.acc.org/About-ACC/Press-Releases/2023/02/22/21/35/Getting-Good-Sleep-Could-Add-Years-to-Your-Life
Insufficient Sleep and Vaccine Response

Insufficient Sleep and Vaccine Response

/in , /by

Insufficient Sleep and Vaccine Response

Sleep and all that happens in the world of sleep have significant effects on our mind, body, and health. However, in the whirlwind of modern existence, we often cut corners on sleep.

In a recent study, researchers studied the profound impact of sleep on the effectiveness of vaccines. Understanding that vaccination is a critical strategy for controlling the pandemic of COVID-19, the researchers looked at how sleep, as a behavioral intervention, can boost vaccine response.

The researchers first screened and selected studies for their meta-analysis. They then found a consistent pattern: insufficient sleep duration of <6h, for 7 days around inoculation is significantly associated with a weakened antibody response to vaccination. Vaccines in the study included hepatitis A, hepatitis B, influenza A H1N1 and H3H2, and the effect size was positive, indicating that short sleep is associated with a lower level of antibodies or reduced protection status. These findings underscore the critical role that sleep plays in the choreography of our immune system.

Furthermore, the researchers explored how variations in sex hormone levels can affect the association. In the study “Acute sleep deprivation has no lasting effects on the human antibody titer response following a novel influenza A H1N1 virus vaccination” by Benedict et al., 2012, the association between short sleep periods and a decrease in antibody response was significantly significant. However, the association between insufficient sleep duration and weakened response to vaccination did not reach significance for women. Moreover, through forest plots of multiple studies, the effect size for men was determined to be 0.93 [0.54, 1.33]. On the other hand, the effect size for women is smaller, at 0.42 [-0.49, 1.32].

While the study calls for further research on the disparity between sex in the impact of sleep on our immune response – large-scale, well-controlled studies are urgently needed to define the window of time around vaccination when optimizing sleep duration is the most beneficial. In addition, the question remains, “how much sleep is enough sleep?”. While the National Sleep Foundation recommends 7 to 9 h of sleep for healthy adults and 7 to 8 h for adults over 65, the exact sleep duration for effective antibody response needs further study.

Overall, the study highlights the importance of adequate sleep for optimal vaccine effectiveness as we face ongoing concerns over Covid and new threats of flu strains. Moreover, sleep profoundly impacts our overall health, and habits must be prioritized for better health outcomes.

 

By: Helena Zhang, BS

Journal References:

  1. Spiegel, K., et al. (2023) A meta-analysis of the associations between insufficient sleep duration and antibody response to vaccination. Current Biology. doi.org/10.1016/j.cub.2023.02.017.
Healthy Lifestyle Habits Have Positive Effects on Mental Health

Healthy Lifestyle Habits Have Positive Effects on Mental Health

/in , , , /by

This review article clearly highlights the importance of healthy lifestyle choices on mental health. Whole plant based diet and daily exercise have remarkable effects on our mood. In many studies, the effect has been described as equivalent to taking antidepressant medications. In addition, good sleep, daily gratitude, positive thoughts about the future, and being of service to others has also been shown to have lasting positive effects on our mental health.

By: Sarita Khemani, MD, Head, Lifestyle Medicine Stress Pillar

Journal Reference:

  1. Morton DP. Combining Lifestyle Medicine and Positive Psychology to Improve Mental Health and Emotional Well-being. Am J Lifestyle Med. 2018 Apr 18;12(5):370-374. doi: 10.1177/1559827618766482. PMID: 30283261; PMCID: PMC6146362.