How Does Caffeine Affect You?

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


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

Coffee & Longer Lives

A team here at Stanford studying inflammation in older adults found an interesting correlation between those that regularly drank caffeinated coffee and those with lower levels of chronic inflammation. The study suggests that regular, moderate coffee intake may protect us from age-related inflammation and diseases. The clinical trial looking at markers of inflammation and age-related diseases found that 89 older subjects who regularly consumed caffeine from coffee experienced suppressed disease-related inflammation.

Before grabbing your next cup of joe, there are a few things are team would like you to keep in mind:

1) Coffee can mask grogginess, but you still need regular, sustained sleep! Coffee at any time of the day could disrupt sleep.

2) Too much sugar in your coffee may negate Some health benefits!

3) Be careful not to drink too much! Caffeine levels vary by coffee type.

4) If you don’t like coffee, try tea! We see many nutritional benefits in black and green tea too!

There are lots of factors to consider when discussing the impact of coffee and caffeine on our lifestyles, and we hope to cover a lot of them in the near future! To learn more about how caffeine may affect people differently, check out our post on caffeine and chronotypes.

By: Carly Mae Smith, BS


  1. Expression of specific inflammasome gene modules stratifies older individuals into two extreme clinical and immunological states

Exercise and Mental Health

Suicide is a complex and devastating public health issue that affects millions of people worldwide. Despite advances in mental health treatment and suicide prevention efforts, rates of suicide continue to rise, particularly among vulnerable populations such as those with mental or physical illness. Previous research demonstrated that teens with high sedentary behavior had twice the risk of a suicide attempt vs those with low daily sedentary time. There is growing interest in interventions that may reduce the risk of suicide, including promoting physical activity.

Exercise has been shown to have numerous physical and mental health benefits. But can exercise also help prevent suicidal behaviors? In this systematic review and meta-analysis, researchers explore the potential protective effect of exercise against suicidal ideation, suicide attempts, and death by suicide in people with mental or physical illness. By examining the existing evidence on this topic, we hope to shed light on a promising new avenue for suicide prevention efforts.

The key findings of this systematic review and meta-analysis were that exercise may have a significant protective effect against suicidal behaviors in people with mental or physical illness. The study found that even though people who exercised had thoughts about suicide just as often, the likelihood of acting on those thoughts by attempting to end one’s life was 77% lower among people in exercise interventions compared to control groups. Death by suicide was 36% less likely among exercisers, but this difference did not achieve statistical significance. The randomized controlled trials included in this study were selected through a comprehensive search of multiple databases and were analyzed using established methods for meta-analyses. However, there was a high risk of bias in many studies. Depression was the most common condition in these studies, but people with menopause, breast cancer, sickle cell, and Huntington’s were included in one study each.

Although further research is needed to better understand the mechanisms underlying this effect, and to identify optimal exercise interventions for different populations, these findings suggest that exercise reduces the chance that a person suffering with depression or a medical illness will act on suicidal thoughts. Possible mechanisms include exercise providing relief from distress, improving depression, generating optimism or facilitating social connectedness.

Promoting regular physical activity appears to have important potential as a suicide prevention strategy that could serve us well in an age of growing mental health and suicide crises.

If you are interested in learning more about the connection between lifestyle medicine and mental health, check out a previous post on how physical activity may affect symptoms of depression, anxiety, and psychological distress. Other lifestyle behaviors, such as diet and sleep, may also impact mental health, and this is outlined in detail here.

By: Helena Zhang & Douglas Noordsy, MD


  1. The effect of exercise on suicidal behaviors: A systematic review and meta-analysis of randomized controlled trials

What a 10-Second Balance Test Can (and Can’t) Tell Us About Longevity

A recent study found that standing on one leg for 10 seconds was independently associated with survival and that those unable to perform this test had double the usual risk of premature death. This relationship is an association and not causal – meaning, the test cannot predict when someone will die. It does, however, highlight the importance of monitoring and maintaining balance as we age. Good balance later in life can lower fall risk and help maintain independence, mobility, functional abilities, and overall quality of life.

According to Corey Rovzar, an expert in balance a postdoctoral fellow at the Stanford Prevention Research Center in the School of Medicine, balance is often overlooked in most people’s exercise regimes and is not regularly included in routine health checks for middle-aged and older adults. This study highlights the importance of monitoring and maintaining balance as you age since balance tends to decline most rapidly beginning in your 60s – and this decline can lead to faulty biomechanics and/or falls. The good news is that you can improve your balance through training! This could be as simple as standing on one leg while you brush your teeth, performing single-leg exercises, or engaging in activities such as tai chi and yoga. Strength training is also important, especially for the lower body, because stronger muscles allow you to have greater stability as you move and to move at an ideal speed. The key to any exercise program is consistency – find something that you enjoy and stick with it!

By: Corey Rovzar, PhD


  1. Successful 10-second one-legged stance performance predicts survival in middle-aged and older individuals

Beneficial Effects of Tea on Longevity

The study analyzed data from 6387 participants and identified three distinct tea consumption trajectories. After a median follow-up of 17.9 years, it was found that high tea consumption was associated with a lower risk of mortality, but this effect was observed only in non-alcohol drinkers. Among current alcohol drinkers, increasing tea consumption was linearly associated with increased mortality. Additionally, the study revealed that alcohol intake masked the protective effect of tea consumption against blood pressure progression.

In conclusion, individuals with a long-term high tea consumption trajectory had a lower risk of all-cause mortality and a slower rate of blood pressure increase. However, the beneficial effects of tea consumption were diminished or even harmful in the presence of alcohol intake.

By: Michael Fredericson, MD


  1. Alcohol intake masked the protective effects of tea consumption against all-cause mortality and blood pressure progression: Findings from CHNS cohort, 1993–2011

Racism and Heart Disease Risk

Our experiences, emotions, and behaviors are interconnected and can profoundly influence one another. While there are times one part of your life can seep into and impact another positively, problems in one area can also have a negative impact if not addressed. One area we aim to highlight is the connection between social relationships and physical health, particularly heart health.

The impact of racism on physical health is a critical area in the healthcare space, and it warrants our attention. In an article published by Boston University, Andrew Thurston sheds light on a groundbreaking study that establishes a strong correlation between experiencing racism and an increased risk of heart disease among Black women.

The study, spearheaded by Dr. Yvette Cozier, an epidemiologist, and professor at the Boston University School of Public Health, analyzed data from the Black Women’s Health Study (BWHS) – an ongoing, long-term research project initiated in 1995. With a cohort of over 59,000 Black women from across the United States, the BWHS has made significant strides in understanding the health disparities faced by this demographic.

To determine the association between racial discrimination and heart disease, the research team employed a detailed questionnaire that assessed participants’ experiences of racism in various contexts, such as work, housing, and public spaces. The questionnaire also considered the frequency and severity of these encounters.

After examining the self-reported data alongside medical records, the researchers found that perceived racism in employment, housing, and interactions with the police was associated with a 26 percent higher risk of coronary heart disease for Black women.

Sheehy, who’s also affiliated with the BU Slone Epidemiology Center, explains, “When we think about how racism impacts our health, it’s a psychosocial stressor… it increases your blood pressure, your level of inflammation—[and] all of these biological mechanisms increase your risk of coronary heart disease”.

The study forces us to examine how the interconnectedness of our lives allows racial discrimination to have far-reaching consequences on one’s health, wellness and lived experience. While the study underscores the importance of providing holistic and culturally aware patient care, further research is needed to elucidate how coping mechanisms can counteract the effects of racism. We must recognize how structural racism within the healthcare system can impact lives, advocate for, and work toward change.


By: Helena Zhang, BS & Michael Fredericson, MD


  1. Study Abstract:
  2. Black Women’s Health Study:

HIIT Exercise May Counteract Heart Disease Progression

As we know, exercise is an essential component of a healthy lifestyle and has many benefits from an evolutionary perspective. However, healthcare professionals have debated the type and intensity of exercise most beneficial for individuals with coronary artery disease.

A recent study published in the European Journal of Preventive Cardiology sheds new light on this issue by examining the effects of high-intensity interval training on coronary atheromatous plaques. After selecting patients with stable coronary artery disease who had undergone percutaneous coronary intervention (PCI), patients were randomly assigned to follow high-intensity interval training or current preventive guidelines. The atheroma volume of patients was measured at baseline and after 12 months.

The results indicate that high-intensity interval training can counteract atherosclerotic coronary disease progression by reducing atheroma volume in residual coronary atheromatous plaques following percutaneous coronary intervention (PCI).

The evidence of how high-intensity interval training can effectively reduce atherosclerotic coronary disease progression and improve cardiovascular health has significant implications. First, the possibility of HIIT as an effective way to mitigate atherosclerotic coronary disease progression introduces the idea of incorporating HIIT into patient rehabilitation programs. Moreover, adding HIIT into their lifestyle may improve their quality of life.

Healthcare providers may consider incorporating HIIT into rehabilitation programs for patients with coronary artery disease, and anyone hoping to optimize their heart health may create personal lifestyle goals and add HIIT to their routine.

By: Helena Zhang, BS & Michael Fredericson, MD



Box Breathing: A Calming Technique

The Research Behind Box Breathing

Picture this: you’ve just encountered a stress-inducing event, such as a disapproving email or a tense phone conversation. Almost immediately, you begin to worry, your heart rate quickens, and your breaths become more rapid.

A study published on in Cell Reports Medicine by Yilmaz Balban et al. revealed that participants in controlled breathing groups – box breathing, mindful meditation, and cyclic sighing – experienced notable improvements in problem-solving, peacefulness, and positive thoughts.

On average, those in the controlled breathing groups reported a daily uplift in positive affect of 1.91 points on the Positive and Negative Affect Schedule scale, compared to 1.22 points for the mindfulness meditation group – an increase of roughly one-third.

The Technique

Box breathing consists of a series of four breaths, ideally inhaling and exhaling through the nose. Inhale deeply for 3-10 seconds, then exhale for the same duration. Be sure not to hold your breath when your lungs are empty!

To determine the optimal inhale and exhale duration, take a deep breath, filling your lungs to capacity, and then time how long it takes to empty your lungs as slowly as possible.

If it takes 0-20 seconds, your inhales, exhales, and breath holds should last 3-4 seconds.

If it takes 25-45 seconds, your inhales, exhales, and breath holds should last 5-6 seconds.

If it takes 50-75 seconds, your inhales, exhales, and breath holds should last 8-10 seconds.


The next time you face a stressful situation, remember to take control and simply breathe.

By: Helena Zhang, BS & Bruce Feldstein, MD


Mg Magnesium

Proper Magnesium Intake May Improve Exercise Performance and Healthy Functioning Throughout Life

Mg Magnesium


Whether you’re a regular at the gym or interested in supplement talk, you may have been recommended to increase your magnesium intake. Are you getting enough? Why does is matter? There are many benefits of having a healthy amount of magnesium in our diets since it is believed to be involved in muscle relaxation, regular neural firing, energy production, and other systems throughout the body that keep you performing and feeling well. One specific phenomenon popular in research right now is the potential ability of enhanced magnesium intake to reduce the occurrence of muscle cramps. This is of interest to both the exercise science and sleep communities since cramping can disrupt either activity significantly. So, how much magnesium should you be getting regularly anyways? National intake recommendations vary by age, sex, and events of pregnancy, but tend to range between 310 and 420 mg daily for most adult individuals. For the most efficient absorption and usage by the body, it is also recommended that magnesium intake be balanced with Vitamin D and calcium. We have put together a quick reference for different foods that are pretty rich in magnesium content to make reaching this goal easier, but visit the National Institute of Health’s page for more.

Mg Magnesium

By: Marily Oppezzo, PhD & Carly Smith, BS


What Exactly Does Quality Sleep Mean?

What Exactly Does Quality Sleep Mean?

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, MDHelena Zhang, BS