Stanford Lifestyle Sleep Blog - Enhance Your Sleep Habits

Expert Weighs in on Wearable Technology for Sleep: Are They Worth it?

September 14, 2023/in Restorative Sleep /by Maya Shetty

The introduction of wearable technologies has sparked a fascination with personal metrics, particularly when it comes to sleep analysis. Those who have trouble sleeping may think this data could help them sleep however, recent assessments have suggested otherwise.

“These sleep wearables should be used cautiously to avoid misleading conclusions about sleep stages,” says Stanford Lifestyle Medicine sleep expert, Jamie Zeitzer, PhD. “Even if these metrics were accurate, which they aren’t, how much do they matter?”

Dr. Zeitzer says it is crucial to not get too focused on the feedback that wearables provide. “A device’s perception of our sleep quality can greatly influence our own,” says Dr. Zeitzer. “For instance, a device indicating a ‘bad night’s sleep’ can create a perception of fatigue, even if the individual slept soundly. This misperception can lead to feelings of tiredness or even induce insomnia.”

The Importance of REM Sleep

While wearables gather data on all the stages our brain goes through during sleep, one particular sleep stage of interest is rapid-eye movement (REM) sleep due to its positive effects on brain development and learning, regulating emotions and consolidating memories.

During REM sleep, our brain activity is similar to that of being awake and it is during this stage when most of our dreams occur. Research suggests that getting enough REM sleep may help mitigate potentially negative emotional reactions during the day since REM sleep is associated with a reduction in amygdala reactivity—the area of the brain responsible for anxiety, stress, and fear.

On average, REM sleep constitutes about 20 to 25 percent of our total sleep time. This means that getting 7 to 8 hours of sleep would equal around 90 minutes of REM sleep. The REM stage usually starts 90 minutes after you fall asleep, with each of your REM cycles getting longer throughout the night: the first period typically lasts 10 minutes, with the final one lasting up to an hour. Therefore, because REM increases with each cycle, if you do not sleep for long enough, your body may not get enough REM sleep to feel rested the next morning.

“If you need eight hours of sleep, but only sleep for six hours, not only is that a 25 percent reduction in total sleep, that may translate to 60 or 90 percent of lost REM sleep,” says Dr. Zeitzer.

The Importance of Sleep Timing

Rather than looking at a wearable device to determine whether we’ve gotten enough sleep, Dr. Zeitzer suggests checking in with ourselves and assessing our fatigue levels.

“Wearables can be misleading, so a better way to assess whether we’ve gotten enough REM sleep, is to see if there are any functional consequences, such as feeling tired or having reduced mental clarity,” says Dr. Zeitzer.

Instead of focusing on the REM sleep data provided by your wearable, Dr. Zeitzer suggests focusing on sleep timing, i.e. going to bed and waking up at the same time every day. “Quality sleep is highly dependent on consistency in sleep timing,” he says. “Consistent sleep-wake times can keep your circadian rhythm in check, to ensure you get enough quality sleep.”

By Helena Zhang, BS

More Sunlight Exposure May Improve Sleep

August 17, 2023/in Restorative Sleep /by Maya Shetty

What is our circadian rhythm?

Our circadian rhythm is our internal clock, keeping us on track for many of our day-to-day activities. When we go to sleep and when we wake up the following morning are the most common activities that people associate with our circadian rhythm, though there are many more things that it influences (metabolism, mental and physical performance, immunity, etc.). This sleep-wake cycle can be influenced by various stimuli throughout the day, but it is most heavily influenced by changes in light exposure. Light is considered the major “zeitgeber” or stimulus that helps our body to understand when to do certain activities like sleeping and waking. This means when we are exposed to light, especially bright light like sunlight, has a big effect on our sleep-wake pattern.

Sunlight’s effect on circadian rhythm

“Many people today are working remotely or are in offices with little natural light exposure. Many of these same people may tend to struggle with sleeping at night and are unaware of how a few changes to their lifestyle may help them begin to improve their sleep. Finding lifestyle habits to prioritize early morning and daytime sun exposure can help to improve sleep later that night,” says Jamie Zeitzer, PhD, Stanford University Professor and member of the Stanford Lifestyle Medicine sleep team.

Even going outside for 30 minutes can help. In the morning, sunlight helps to tell your circadian clock what time it is. In the afternoon, sunlight helps to make the clock stronger. At any time of day, getting sunlight means that the artificial light to which you are exposed at night will have less of an impact. Whether it is taking the dog out for a morning walk or finding time to bask in the sun over lunch, spending a little more time outdoors during the day can help regulate our internal clock and is the first step in a healthier relationship with sleep. It’s a win-win!

By: Carly Smith, BS, MPH(c)

Sources:

Hoffmann et al. “Aerobic Physical Activity to Improve Memory and Executive Function in Sedentary Adults without Cognitive Impairment: A Systematic Review and Meta-analysis“. Journal of Preventative Medicine Reports. Sep. 2021.

Aerobic & Resistance Exercise Improves Sleep

July 12, 2023/in Movement & Exercise, Restorative Sleep, Student Blogs /by Maya Shetty

Sleep, a fundamental element of human biology, plays a crucial role in various physiological processes. A good night’s sleep is essential for immune function, cognitive performance, emotional well-being, and overall physical health. Exercise is another critical lifestyle factor with tremendous potential to improve your health. Regular physical activity has numerous benefits, from reducing the risk of chronic diseases to improving mental health. However, could exercise improve your sleep?

Impact of Resistance Exercise on Sleep

A 2017 review found that “chronic resistance exercise improves all aspects of sleep, with the greatest benefit for sleep quality” in individuals with sleep problems. In this study, Kovacevic et al. employed a systematic review methodology by conducting an electronic database search of randomized controlled trials. Many studies fit the criteria, but three acute resistance exercise studies, seven chronic resistance exercise studies, and three combined aerobic and resistance exercise studies met the researcher’s inclusion criteria and were analyzed for sleep outcomes. The primary finding from this review was improvements in sleep from chronic exercise; these improvements were “moderate-to-large, and commonly affected overall sleep quality, sleep latency, sleep efficiency, mid-sleep disturbance, and daytime dysfunction”. In comparison, the primary medications prescribed to improve sleep quality had “only small-to-moderate effects on sleep quality” and instead have “adverse effects such as rebound insomnia, depression and anxiety, cognitive impairment, and an increased risk of falls, cancer, and overall mortality” if used in the long-term. Kovacevic et al. call for further research and more data on aerobic exercise but cites an earlier paper that noted how aerobic exercise could improve sleep quality.

Furthermore, their work highlighted how “higher intensity and greater frequency of training offer greater sleep benefits”. More specifically, the chronic resistance exercises studied that had the most benefits included machine-based resistance exercise, circuit training, and resistance bands for an average duration of 14 weeks total with approximately 60 minutes per session. Studies with high exercise intensity as compared to low-to-moderate intensity, and with a frequency of 3 days/week as compared to 1-2 days/week, had a larger beneficial effect on sleep quality.

The review presented another pathway by which exercise could improve sleep; exercise improves levels of anxiety and depression, both of which deeply affect sleep — “notably, exercise has been shown to be an effective treatment for major depression and sleep disturbance is one of the core symptoms of depressive illness” and “the majority of chronic studies included in this review reported significant improvements in neuropsychological outcomes”.

Impact of Aerobic Exercise on Sleep

Additional research has also shown the further benefits of aerobic exercise for people with established sleep disorders. One study showcased how “4 months of aerobic exercise training in a sample of older adults with insomnia significantly improved sleep quality while also reducing daytime sleepiness and depressive symptoms”. Another study found that “12 weeks of moderate-intensity aerobic and resistance exercise resulted in a 25% reduction in OSA [obstructive sleep apnea] severity”. Lastly, studies have even shown that the circadian rhythms disrupted in neurodegenerative disease can be improved with exercise — “exercise has proven to be a low risk and beneficial intervention to improve overall health and sleep disorders in AD [Alzheimer’s disease] and PD [Parkinson’s Disease]”. In particular, “physical activity, even at low intensities, has been reported to improve sleep quality, reduce time to fall asleep, and increase the duration of sleep in the elderly… evidence indicates that exercise increases total sleep time and slow-wave sleep”.

We all strive for better sleep even if we do not have a known sleep disorder, and it could be within our grasp through a novel route. Exercising for an hour three times a week at high intensity with machine-based resistance exercise, circuit training, or resistance bands can improve your sleep quality and decrease issues in the day. Even once a week at a lesser intensity for 40 minutes showed beneficial effects! Sleep and exercise are significant pillars in lifestyle medicine, and it is fascinating how one affects the other. Rather than relying on medications that can have adverse effects, research suggest exercise is a natural way we can improve our sleep. While further research is needed, recognizing the interconnectedness of exercise and sleep as critical components of a healthy lifestyle is crucial.

By: Keshav Saigal, BS(c)

Sources:

Kline, Christopher E. “The bidirectional relationship between exercise and sleep: Implications for exercise adherence and sleep improvement.” American Journal of Lifestyle Medicine. 2014 August
Kline, Christopher E et al. “The effect of exercise training on obstructive sleep apnea and sleep quality: a randomized controlled trial.” Sleep. 2011 December
Kovacevic, Ana et al. “The effect of resistance exercise on sleep: A systematic review of randomized controlled trials.” Sleep Medicine Reviews. 2018 June
Memon, Adeel A et al. “Effects of exercise on sleep in neurodegenerative disease.” Neurobiology of Disease. 2020 July
Reid, Kathryn J et al. “Aerobic exercise improves self-reported sleep and quality of life in older adults with insomnia.” Sleep Medicine. 2010 October
Yang, Pei-Yu et al. “Exercise training improves sleep quality in middle-aged and older adults with sleep problems: a systematic review.” Journal of physiotherapy. 2012 September

How Does Caffeine Affect You?

May 31, 2023/in Healthful Nutrition, Restorative Sleep /by Maya Shetty

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

No Content Available

Sources:

Modeling caffeine concentrations with the Stanford Caffeine Questionnaire: preliminary evidence for an interaction of chronotype with the effects of caffeine on sleep

Can Lifestyle Reverse Your Biological Age?

April 26, 2023/in Cognitive Enhancement, Healthful Nutrition, Movement & Exercise, Restorative Sleep, Social Engagement, Stress Management /by Maya Shetty

By: Ben Maines, MD candidate

We all know that eating right, sleeping well, and minimizing stress are good for our health, but what if they could turn back the clock on biological aging? A small but groundbreaking 2020 study found that an 8-week prescription of a healthful diet, stress reduction breathing practices, and exercise decreased participants’ epigenetic age by a little over three years relative to a control group. Sounds too good to be true, doesn’t it? And what do we mean by epigenetic age? We’ll answer those questions and more, but first, a primer in epigenetics. Epigenetics describes reversible molecular modifications made to DNA. At the cutting edge of our modern understanding of medicine and cellular biology, epigenetics facilitates variation between genetically identical cells like your neurons and muscle cells. In the case of twins, for example, you can think of the DNA as the blueprint shared by twins, while epigenetics is the footnotes — instructions that dictate how the blueprint is interpreted and applied. Think of it as the mechanism that bridges nurture and nature, fine-tuning your genetics in response to your environment and lifestyle. At the molecular level, that tuning involves the addition or removal of small molecules like methyl groups to DNA and its packaging. Some molecules make the genes to which they are attached more accessible to the machinery that will translate them, essentially turning those genes on, while others do just the opposite. Evolutionarily, these changes facilitate rapid adaptation to an ever-changing environment. An individual’s experience of famine, for example, can epigenetically tune their metabolism and growth for energy conservation. These epigenetic changes may also be seen in their descendants for several generations to come. The exciting news is that tuning isn’t permanent, which is where lifestyle medicine comes in. Many of the epigenetic phenomena that we understand are related to metabolism and stress responses. Though evolutionarily conserved, these epigenetic changes can be maladaptive in the modern context. A traumatic childhood experience, for example, can trigger epigenetic modifications that not only alter an individual’s stress response to cause chronic stress, but are also heritable to their offspring. This enhanced stress response may have protected an early human in the savannah from repeating risky behaviors, but in our more predictable modern world, chronic stress more often contributes to poor mental health and diseases like cardiovascular disease and high blood pressure. Thinking back to epigenetic age, it seems rational then that if we know the patterns of epigenetic modifications associated with failing health and the diseases of aging, we can use them as a surrogate measure of healthfulness. Though we don’t yet fully understand its nuances, molecularly determined epigenetic age is a better predictor of an individual’s health and longevity than chronological age, presenting an exciting frontier for understanding and modifying health and longevity through lifestyle medicine and targeted therapeutics. For example, a team led by scientists here at Stanford and at the Buck Institute for Research on Aging used deep learning to identify key molecules of systemic inflammation such as CXCL9 that correlate closely with morbidity, cardiovascular degradation, frailty, and other signs of biological aging. As we age, this increasing chronic, systemic inflammation is likely driven by epigenetic changes, raising the tantalizing possibility that it could also be reversed.

How can we use lifestyle medicine to modify our epigenetic fate?

So far, the main clinical epigenetic therapies that have seen success are small molecules that reduce DNA methylation to treat cancer. These molecules function by pushing the reset button on many of the accumulated epigenetic changes that allow the cancer cells’ runaway growth. What if we could do the same to the changes that predict ageing, chronic inflammation, and disease? For now, it seems that our therapeutic tools are too blunt, lacking the precision to target the maladaptive and disease-associated epigenetic changes. So, for now, our best tool for harnessing our epigenetic destiny is our lifestyle. Let’s take a deeper dive into what that looks like at the cutting edge of each of our Stanford Lifestyle Medicine Pillars.

Epigenetics & Physical Activity

Daily exercise has long been associated with health benefits from reduced incidence of cardiovascular disease and improved cancer prognosis to slower cognitive decline. The CDC recommends getting at least 150 minutes of moderate-intensity aerobic activity and 2 strengthening workouts a week for optimal health benefits. There is now evidence that exercise also broadly improves the capacity of your cells to alter their methylation patterns. Exercise leads to higher levels of the protein superoxide dismutase, which works through a series of receptors and pathways in the liver to alter the methylation of key metabolism genes and enhance metabolic function. These pathways affect health in a myriad of ways including improving glucose tolerance to reduce the risk of diabetes. Though some of those epigenetic changes are maintained from parents to children, many are re-programmed during critical developmental periods in-utero, allowing maternal exercise during pregnancy to have profound impacts on offspring health later in life. Lifestyle, it seems, is preventive care that begins even before we’re born. The systemic epigenetic changes induced by physical activity were seen in a recent study by Washington State University that analyzed differences between physical activity and epigenetics in identical twins. Researchers found that twins who exercised for 150 minutes a week or more had more epigenetic markers related to lower risk of metabolic syndrome than twins who exercised less.

Epigenetics & Nutrition

According to recent research, what you eat, and perhaps more unexpectedly, what your parents ate, seems to affect our health through epigenetics in two interesting ways. First, by the availability of small molecules that participate in and modulate the biochemical reactions that add and remove epigenetic tags. For example, plant-forward diets tend to be high in epigenetic substrates like folate, a precursor of the methyl groups added to DNA; cofactors that facilitate that reaction like vitamins A and C; and polyphenolic compounds like curcumin (found in turmeric) that modulate DNA Methyltransferase, the protein that initiates the reaction. Leading theories suggest that by maintaining abundant nutrients involved in epigenetic processes, the body’s response to stress and ever-changing metabolic supply and demand can be efficiently fine-tuned. Diseases like diabetes arise in part because of maladaptive or improper metabolic tuning. A second way that nutrition impacts epigenetics seems to be mediated by metabolic stressors and nutrient sensing. Our cells work along the spectrum between two main modes; when nutrients are limited, pathways turn on that favor maintenance, and clearing and recycling debris, to enhance cellular function and efficiency. Abundant nutrients, on the other hand, downregulate the efficiency pathways and promote storage and more reckless use of resources. With time, famine or feast can become encoded as heritable epigenetic changes, contributing to the increased risk of obesity, diabetes, and several other health conditions in the offspring of parents with poor diet and nutritional profile.

Epigenetics & Sleep

Sleep, namely the lack thereof, has been associated with everything from heart disease and stroke to metabolic disruption. Its greatest impact, though, is on the brain. Interestingly, susceptibility to sleep deprivation is a highly genetic phenomenon. Some people can barely function without 8 hours of sleep, while for others, 6 is more than enough. This suggests a significant role for epigenetics. Cognitive functions like learning and memory rely on neural plasticity, which requires fine-tuned epigenetic adjustments to the gene expression patterns of individual neurons. This process requires sleep, and even single sleep disruption events can impair them, especially in the hippocampus, one of our primary memory and learning centers. More chronic sleep deprivation can alter mood, exacerbate psychiatric disorders, and increase the risk of neurodegeneration as in Alzheimer’s. Most of the epigenetic changes seen with sleep deprivation modify genes involved in metabolism, circadian rhythm, and synaptic plasticity and signaling. For example, night shift workers have altered expression of the genes CLOCK and Dlg4, a master regulator of our body’s internal clock, and a protein implicated in autism that scaffolds synaptic signaling respectively.

Epigenetics & Stress

Technically, stress is any stimulus that disrupts our body’s homeostasis, whether running from a predator in our evolutionary past, experiencing a traumatic life event, or persistent psychological distress. The hypothalamus-pituitary-adrenal (HPA) axis, then, is the stress response control center, a system that connects our brain to our hormone-secreting glands that release systemic stress signals like cortisol, adrenaline, and pro-inflammatory molecules. These signals go on to modulate all our body’s systems, from metabolism and neuronal activity to immune function, and are themselves epigenetically tuned. Typically, our bodies overcome the stressor and return to homeostasis, but traumatic and chronic stress can lead to compounding epigenetic changes that dysregulate our immune, metabolic, neuronal, cardiovascular, and other systems. For example, traumatic childhood experiences trigger epigenetic changes in immune cells like macrophage, increasing pro-inflammatory reactivity and hormonal dysregulation, which may underlie the plethora of adverse health outcomes associated with childhood trauma. Much like the epigenetics of nutrition and exercise, parental stress can be passed on to children both through inherited epigenetic patterns, and through stress hormones circulated from the mother to the developing fetus. On the bright side, positive life experiences, social relationships, and mindfulness practices like meditation and breathing exercises all work to short-circuit these maladaptive stress responses and associated epigenetic changes. For example, one mindfulness-based intervention in breast cancer patients resulted in a reduction of greater than 50% in the epigenetically controlled levels of 91 pro-inflammatory hormones and molecules compared to control patients, an effect that persisted 12 months later.

Epigenetics & Social Engagement

Our capacity to form complex social bonds is evolutionarily foundational to survival, so it’s no wonder that relationships, too, are intimately tied to epigenetics. On one hand, the epigenetic changes associated with chronic and traumatic stress are implicated in impaired capacity for developing and maintaining social bonds. On the other hand, Strong social relationships are important for mitigating stress and its deleterious epigenetic effects, and are one of the strongest predictors of health, happiness, and longevity. Though this is one of the more complex and least understood areas of epigenetics, it’s hard to overstate its role. For instance, mutations in MeCP2, a gene that helps interpret epigenetic methylation patterns, results in the profound cognitive and social dysfunction known as Rhett syndrome.

Epigenetics & Cognitive Enhancement

As it turns out, synaptic plasticity, the phenomenon underlying higher cognitive functions like memory and learning, is largely governed by epigenetic mechanisms. In a highly simplified sense, the strength of patterns and combinations of synaptic firing are enhanced by repeated stimulation, and conversely tuned down in the absence of activity. This is accomplished by epigenetic changes that modulate the sensitivity of neurons to subsequent stimulation. Carrying that principle one step farther, research indicates that enhanced synaptic activity is also essential in synaptic and axonal regeneration after damage such as in the brain of a stroke patient. In animal models, for example, exposure to stimulatory physical and social environments after a brain injury or in disease states such as Parkinson’s leads to increased synaptic activity, which triggers epigenetic changes that promote regenerative healing. Given this observation, it is speculated that similar mechanisms underlie the positive effects of exposure to nature and socially stimulating environments on cognitive and neurological recovery after a brain injury or in diseases like Alzheimer’s. Further, it is plausible that the epigenetic benefits of physical fitness, a varied, plant-based diet, sleep, and relationships translate to beneficial effects on cognitive performance in both health and recovery. For example, the Mediterranean Diet is associated with slowed brain aging and improved cognitive functioning, whereas the Western Diet has been implicated in accelerating natural brain aging processes.

What is Quality Sleep?

April 21, 2023/in Restorative Sleep /by Maya Shetty

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

No Content Available

Sources:

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

Insufficient Sleep Impairs Vaccine Response

March 27, 2023/in Restorative Sleep /by Maya Shetty

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

No Content Available

Journal References:

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

November 4, 2022/in Movement & Exercise, Restorative Sleep, Stress Management /by Maya Shetty

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:

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.