Cheers!

This is high on health. Your weekly happy message with the freshest and most honest highlights from the health, wellness, and longevity world.

I hope everyone had a great long weekend break! Maybe you could extend it to the week before or after for even more downtime. Though it's not always possible to go completely off-grid, it's still good to have more flexibility, experience a different environment, and engage in activities you normally don't have time for.

I was working remotely from our holiday home this week, but I had to go on a business trip as it was necessary. Life is all about compromises sometimes, and that's perfectly fine.

However, Jeff Bezos had a different perspective on compromise during his recent conversation with Lex Friedman. He says, “The advantage of using compromise as a resolution mechanism is that it requires low energy.” But the problem is that it doesn't lead us to the truth. Jeff says that by compromising, we tend to regress to group thinking and eventually make an average decision. This will only produce average results for an organization. We need to make decisions responsibly and move as fast as possible to make progress. We should commit to the best possible information even if we don't know the truth.

Well, it may have worked for Jeff, but I have heard that being filthy-rich and powerful makes things easier. In my world, I sometimes have to balance my energy, and finding a compromise might be the low-energy solution that fits the bill.

This week, I'd like to delve into heat energy, particularly concerning saunas. Saunas have been receiving much attention lately due to their numerous health benefits. In my competitive sports days, I used to utilize saunas for weight-cutting purposes, although it wasn't a particularly enjoyable experience. Nowadays, I often use saunas for their anti-aging properties and overall health benefits.

I hope you enjoy it.

Take care!

Sauna - bring the heat

My love-hate relationship

I enjoy using the sauna frequently and regularly. In fact, we even built one in our vacation home. Whenever I have the time, I also use saunas in hotels and spas. Something about it makes me feel better; it's very calming and puts me in an almost meditative state where I focus on breathing and tolerate the heat as it rises. I love that.

However, my first experiences with the sauna were not good at all. This is often what it included: a sauna suit, which is as nasty as it looks.

It is used for weight-cutting. It is the opposite of breathable fabric as it keeps all the heat inside and makes you sweat excessively. You may wonder why someone would do this.

Here's a quick explanation: when you need to meet a maximum weight at the weigh-in, you must eliminate all the excess fat and fluids in your body while maintaining your strength. First, you restrict your calorie intake to almost zero. Then, you get all the water out in the last 1-2 days. This is where the sauna and a sauna suit come in. However, I must say that I don't recommend this to anyone as it makes you feel miserable, causes cramps in several muscles, and dries up your mouth to the extent that you can't speak anymore. You learn to hate it.

Through my experiments, I have realized that this practice is unhealthy. However, let's look at the healthy use of the sauna instead.

So, what are the benefits?

Recently, popular media has focused a lot of attention on using saunas. They have been promoted as a "longevity hack" that supposedly benefits cardiovascular health and many other areas. However, these claims require further investigation to determine whether saunas are truly a cure-all for human longevity.

In this edition, I will investigate the various benefits of using saunas, guided by an extensive overview article by Dr. Peter Attia. Also, I will provide practical recommendations for anyone who wishes to use saunas.

Most of the evidence supporting saunas' supposed benefits comes from observational studies carried out in Finland. However, since observational studies can only identify correlations between variables and not causal relationships, we must be cautious in interpreting the results. We cannot be certain that many of the alleged "effects" of sauna use are actually caused by sauna use. Nonetheless, we can estimate the likelihood that they represent cause-and-effect by evaluating correlative data with other relevant literature.

Unveiling the Scientific Insights on Sauna Benefits

Dr. Peter Attia’s team nicely summarizes the top-down message in this chart.

Ranking the benefits of using a sauna based on the magnitude of the effect and certainty of evidence compared to other benefits shows that it is most promising for improving cardiovascular health and preventing dementia. It has also been reported to have a strong effect on improving sleep.

Sauna usage has interrelated benefits on various aspects of our health. Enhanced sports performance is linked to improved circulation and cardiac function, which in turn have a positive impact on cardiovascular health. Reduced stress levels, better sleep, and a healthier cardiovascular system are associated with a lower risk of dementia. Better sleep quality and improved mental health are also associated with reducing pain. The overall consistency of these effects suggests that the evidence in favor of sauna usage is greater than the sum of its parts. However, attempts to isolate a single effect can be complicated due to these interrelated benefits.

It's also important to consider the possibility of a healthy user effect in pro-sauna literature. Many of the most convincing epidemiology studies were conducted in Finland, where sauna use is common among all socioeconomic classes. With a reported 60-90% of Finnish people using a sauna at least once a week, two sources of bias could be present:

1. Individuals who don't use a sauna or use one less frequently may be doing so because they've been advised not to for health reasons,

2. Individuals who use a sauna frequently may be more health-conscious than others, similar to people who exercise more frequently.

If either of these situations is accurate, the benefits associated with sauna use or the lack of benefits associated with less frequent sauna use could be due to other aspects of a healthy lifestyle, such as a better diet or more exercise, rather than the sauna itself.

Sauna use outside Finland is likely a good indicator of healthy individuals. In countries where saunas are less common, those seeking sauna baths are likely to have a higher socioeconomic status and/or be more health-conscious.

Sauna bathing is an important part of Finnish culture and social life. The benefits of a sauna may come from the use of the sauna itself and socialization. Socialization can significantly impact dementia, stress, and depression. A unique experiment would be required to determine whether the benefits of sauna are due to exposure to high temperatures or socialization.

Nonetheless, the evidence supporting the benefits of sauna use is strong enough to conclude that a likely causal relationship exists, especially regarding cardiovascular effects and improvements in exercise recovery.

The following is detailed, I know. I wanted to share this with the curious reader. In case the TL;DR above is ok for you, jump right to the next chapter called “Understanding the Science Behind Sauna Benefits”.

Cardiovascular Health

Several non-randomized prospective cohort studies have reported that frequent use of a sauna can reduce the risk of cardiovascular-related death and other major adverse cardiac events. These studies have corrected for various cardiovascular risk factors and potential confounders such as age, BMI, and blood pressure.

A study conducted in Finland in 2015, involving an exclusively male cohort of 2,315 individuals over a period of 20 years, showed that the risk of sudden cardiac death was reduced by 63% among those who used the sauna 4-7 times per week, compared to those who used it only once a week. The same study also revealed a 48% decrease in fatal coronary heart disease (CHD) and a 50% reduction in all cases of fatal cardiovascular disease (CVD). In 2018, the same research group conducted a follow-up study involving male and female participants, with 1,688 individuals (51.4% female) over 15 years. The results showed that using the sauna 4-7 times per week led to a 64% lower rate of cardiovascular disease-related death compared to using the sauna only once a week.

Using a sauna regularly may help to lower the risk of stroke, according to a 15-year study conducted among Finnish men and women. The study found that individuals who used a sauna 4-7 times a week had a 62% lower chance of experiencing a stroke compared to those who only used it once a week.

According to a study conducted in 2015, increasing the duration of sauna sessions can have a positive impact on cardiovascular health. The study found that individuals who used a sauna for sessions lasting more than 19 minutes had a 52% lower risk of sudden cardiac death, a 36% lower risk of fatal CHD, and a 24% lower risk of other fatal CVD, in comparison to those who used a sauna for sessions lasting less than 11 minutes.

According to research, the protective benefit of sauna on sudden cardiac death, fatal CHD, and fatal CVD may vary based on the frequency of sauna usage. The study found that using a sauna 2-3 times per week resulted in a moderate level of risk between those who use it once a week and those who use it 4-7 times a week. Moreover, the study concluded that the risk of sudden cardiac death, fatal CHD, and fatal CVD all decreased significantly with increasing sauna frequency.

Sauna bathing has been shown to improve cardiovascular health by enhancing the function of the endothelium—the thin layer of cells that lines the interior surface of blood vessels. Specifically, sauna sessions have increased blood vessels' ability to expand and contract while decreasing arterial stiffness. In fact, even one 30-minute sauna session has been found to improve arterial stiffness in men and women at risk of cardiovascular disease.

The above findings provide compelling evidence that using a sauna benefits cardiovascular health. The data consistently indicate positive effects of increased sauna use, with the benefits increasing proportionally to the time spent there. Furthermore, using a sauna and regular exercise can improve cardiovascular health outcomes. A study has shown that a combination of exercise and sauna use resulted in better outcomes for cardiovascular disease-related deaths than using a sauna alone.

Dementia

A 2017 study revealed that taking sauna baths frequently may provide cognitive benefits. The study specifically focused on Finnish men and found that those who took sauna baths 4-7 times a week had a 66% lower risk of developing dementia compared to those who used the sauna once a week. Frequent sauna users also had a 65% lower risk of developing Alzheimer's disease.

It is important to understand how sauna use can affect dementia risk in both men and women, as women have a higher lifetime risk of dementia, especially Alzheimer's disease, than men. A study conducted on 13,994 Finnish men and women showed that those who used a sauna 2-3 times per week (9-12 times per month) had a 53% lower risk of developing dementia during the first 20 years of follow-up and an overall risk reduction of 19% over the 39-year study period. The results indicate that sauna use has a positive impact on dementia risk equally in both men and women, as correcting for participants' sex did not alter the association.

All-Cause Mortality

A study conducted in 2015 found that regular use of sauna can significantly reduce the risk of all-cause mortality (ACM). Men who took 4-7 sauna baths per week had a 40% lower risk of ACM than those who took only one bath per week. The risk reduction was dose-dependent, with intermediate risk for those who used the sauna 2-3 times per week. Cardiovascular-related deaths mainly drove the risk reduction. Interestingly, unlike the findings for cardiovascular diseases (CVD), the length of sauna sessions did not affect the risk of ACM.

Athletic Performance

There is compelling evidence suggesting using a sauna can enhance exercise performance as a recovery method. For example, a randomized crossover study conducted on male runners demonstrated that 30 minutes of sauna use after training resulted in a 32% increase in time to exhaustion, a commonly used measure of endurance in runners and bikers. This increase was in comparison to the control recovery condition. Another crossover study revealed that sauna use after training reduces muscle soreness and helps preserve muscle function. Basketball players who used the sauna for recovery reported experiencing less perceived post-workout soreness and a smaller decrease from pre- to post-training in maximal countermovement jump, a test of lower body explosive power, compared to those who engaged in passive recovery.

One possible reason saunas benefit the body is that they increase plasma volume, resulting in better muscle circulation and improved heart function. A study found that the group who used the sauna had a 7.1% increase in plasma volume compared to the control group who did not. Research has shown that this increase in plasma volume occurs mainly within the first day of exposure to heat, but it continues throughout the first week and reaches its peak at around eight days of consistent heat exposure.

According to another study, the increase in plasma volume after sauna use depends on the type of exercise done before using the sauna. People who used saunas after endurance or combined strength and endurance exercises had a higher increase in plasma volume 24 hours later than those who didn't use a sauna. However, this effect wasn't observed in people who used the sauna after strength training alone, which suggests that saunas may be more beneficial for recovery after endurance training. Additionally, the benefits of using a sauna on exercise performance were more noticeable after exercise. For instance, using a sauna 30 minutes before exercise can decrease endurance and strength performance compared to not using a sauna at all.

Mental Health

Saunas are believed to have potential benefits for mental health, but research in this area has been limited. A small study conducted in Japan showed that sauna use may decrease anxiety and improve mood and depressive symptoms. However, it is unclear whether these improvements result from a placebo effect, as there was no control group in the study. Another study conducted on patients with depression showed that hyperthermic baths may lead to a decrease in depression symptoms. However, whether these results would apply to sauna use and whether placebo effects might have played a role is uncertain.

A study conducted in Finland found that regular sauna bathing may have a protective effect against developing psychotic disorders. The study followed men with no history of psychotic disorders for a period of 25 years. Those who used saunas 4-7 times a week had a significantly lower risk of developing psychosis compared to those who used saunas only once a week. However, there was no significant difference in risk reduction between those who used saunas 2-3 times a week and those who used saunas once a week. It is important to note that this study does not establish causality between sauna use and reduced risk of psychosis.

Although saunas have been suggested as a potential option for individuals who have or are at risk for mental health conditions such as depression, anxiety, and psychosis, there is not enough compelling evidence to support the claim that these associations represent effects caused by sauna use. Socialization may be a confounding variable as saunas are often social environments. Alternatively, people who suffer from psychosis may avoid saunas because they prefer to spend less time around others, in which case causality is reversed. Nevertheless, the possibility of sauna use directly improving mental health remains, and it may be worth exploring for individuals who suffer from these conditions in the absence of effective alternative treatments.

Sleep Quality

Research indicates that our body temperature's circadian rhythms can impact the quality of our sleep. As we prepare to sleep, our body temperature declines and continues to do so throughout the night. However, shortly before we wake up, our body temperature increases again. The steeper the slope of our body temperature decline before bed, the faster we fall asleep and sleep better. A hot bath 90 minutes before bed can enhance sleep continuity and increase slow-wave sleep, particularly in older women. These women also reported better sleep quality, including deeper and more restful sleep.

No studies have been conducted yet on how saunas affect sleep. However, it's reasonable to expect that the whole-body heating in a sauna would have a similar effect to that of a hot bath or shower. In fact, a survey study discovered that 83.5% of respondents experienced better sleep after using a sauna.

Pain Management

There are reports that saunas can help reduce different types of pain, such as headaches, back pain, and other chronic pain conditions. In a study that involved people with chronic tension-type headaches, participants were randomly assigned to either a sauna treatment group (using a sauna and receiving advice on managing their headaches) or a control group (receiving advice on headache management only). After eight weeks of treatment, the sauna group reported a decrease in headache pain of 1.27 points (on a 0-11 scale) compared to the control group. However, the study did not find any benefit to headache duration. It is important to note that sauna use was used as a preventative measure rather than as a treatment, as it could potentially increase headache intensity. Therefore, it is crucial to have controlled conditions surrounding sauna use for headaches.

Research has shown that using a dry sauna twice daily for five consecutive days can help reduce lower back pain. This treatment decreased lower back pain by 2 points on the 0-10 verbal numerical rating scale and disability score by 4 points on the 0-50 Oswestry disability index.

There is varying evidence regarding the effectiveness of sauna use in treating certain types of chronic pain. A study conducted on individuals with rheumatoid arthritis and ankylosing spondylitis showed a short-term reduction in pain and stiffness after using a sauna. However, an older study found that sauna use worsened pain symptoms in similar conditions.

Chronic pain can be a severe and persistent condition, and sauna has been considered as a potential treatment option. However, due to the limited effects and conflicting evidence, further research is required before definitive conclusions can be drawn about the impact of saunas on pain-related conditions. Although saunas may offer some minor benefits in pain management in certain cases, other well-established forms of pain management, such as medication, cognitive-behavioral therapy, exercise, etc., are available and may be more effective.

Stress Management

Sauna bathing is often a great way to reduce stress and enhance resilience. Socialization is also a significant factor that motivates people to use saunas. Although there is little concrete evidence to support the benefits of sauna use for stress relief, it does act on many of the phenomena involved in how we experience stress. For instance, the calming effect reported by many people can be explained by the reduction in heart rate and blood pressure that follows a sauna bath. During acute stress, sympathetic nervous system activity increases heart rate and blood pressure; the opposite (a decrease in heart rate and blood pressure) can have a "de-stressing" effect. Reduced stress can benefit various bodily systems, including the cardiovascular and immune systems, and can have a powerful impact on health beyond the conscious perception of a lower-stress state.

Detoxification and Immune Enhancement

There are two commonly discussed benefits of using a sauna - detoxification and improving immune function. Despite this, there is limited scientific evidence to back up these claims.

Many believe that saunas can help remove toxins, particularly heavy metals such as mercury and lead, by encouraging their excretion through sweat. However, it is uncertain whether the additional sweating caused by using a sauna leads to increased excretion of heavy metals or results in a greater volume of sweat with a lower concentration per unit volume. Furthermore, while sweat is an important means of eliminating toxic metals from the body, there is little evidence to suggest that an increase in sweat production would significantly reduce heavy metal levels in the average person's body.

Another claimed benefit of using a sauna is improved immune function, but there is no scientific evidence to support this. However, reducing stress levels, as mentioned earlier, could help boost the immune system. Additionally, using a sauna has increased the number of white blood cells, lymphocytes, neutrophils, and basophils, which may indicate an immune system boost. Nevertheless, whether this effect could result in long-term benefits for the immune system is unclear.

Understanding the Science Behind Sauna Benefits

To fully understand the potential benefits of using a sauna, it's important first to understand the process of thermoregulation. This is how the body maintains a stable temperature of around 37±0.5°C, critical for optimal enzyme function. The hypothalamus plays a significant role in maintaining this temperature balance by responding to temperature changes detected by receptors in the skin and internal organs.

The benefits of sauna use can be attributed to a concept called "hormesis," a cellular adaptive response to stressors. A temporary increase in body temperature, similar to what happens during a fever, can be beneficial by creating an environment that is hostile to pathogens while protecting cells. Using a sauna increases body and skin temperature, heart rate, and cardiac output and slightly increases blood pressure, mimicking the physiological changes observed during moderate exercise. This heat stress triggers a cool-down mechanism in the body, releasing various hormones that might be behind the broad benefits of sauna use.

Sauna use causes a surge in hormones such as norepinephrine, beta-endorphins, growth hormone, and prolactin, which contribute to the reported benefits, including changes in heart rate and blood pressure, increased levels of heat shock proteins, and brain-derived neurotrophic factor. These hormones induce a sense of well-being and tissue repair and promote brain health, mental health, and cognitive benefits. Heat shock proteins protect the body's proteins from damage during cellular stress, contributing to the benefits of sauna use, including sports recovery. Brain-derived neurotrophic factors support neuroplasticity and promote neuron survival and growth, which is vital in sauna use's potential mental health and cognitive benefits.

Sauna use - who, what, when, where, and how

As seen above, sauna usage can benefit our health, but it is crucial to consider certain factors to guarantee safety and effectiveness. These factors include

• determining the kind of sauna to use,

• the right temperature and duration for a session,

• the optimal timing,

• and the recommended frequency of sauna use.

Selecting the Right Type of Sauna

There are three primary types of saunas: infrared, steam, and dry, each having different heating mechanisms. While the studies discussed mainly involved dry saunas, benefits were noticed across various heating methods, including infrared and steam saunas, thermal baths, and even exposure to hot weather, provided sufficient heating and duration are maintained. However, infrared and steam saunas require extra caution due to potential inconsistencies in body heating and a quicker rate of overheating, respectively. Older individuals and those with certain health conditions should be vigilant to avoid overheating.

Determining the Appropriate Sauna Temperature

Most studies used dry saunas with temperatures between 80-100°C. It's advisable to stay within this range to ensure safety and effectiveness. For steam saunas, the recommendation falls within 38 to 49°C due to increased body temperature and heart rate, even at lower temperatures. The guidelines for infrared saunas vary based on different factors, so adhering to the manufacturer's recommendations is advisable.

Setting the Ideal Duration for Sauna Sessions

Most studies prescribe a sauna session duration of 15-30 minutes. However, newcomers to sauna use should start with shorter sessions (around 5 minutes) and gradually increase to a maximum of 20-30 minutes to prevent the risk of dehydration. Steam saunas recommend even shorter durations of about 10-20 minutes.

Choosing the Right Timing for Sauna Sessions

The best time for a sauna session depends on your objectives. Schedule your session an hour or two before bedtime to enhance sleep quality. A post-exercise session would be ideal to boost sports performance. Combining a sauna session closely with exercise could offer increased benefits for improving cardiovascular health.

Deciding the Frequency of Sauna Use

Studies indicate that using a sauna four or more times a week yields the most significant benefits. However, too frequent use can elevate dehydration risk and might not be advisable in most cases. Balancing sauna use with other health-supporting practices, especially exercise, is essential to maximize benefits without adverse effects.

A word of caution

Sauna sessions can be beneficial, but knowing the potential side effects and risks is important. Some temporary issues may arise, including dehydration, dizziness, and headaches, which usually subside once you leave the sauna.

Certain individuals should avoid saunas entirely, such as those with uncontrolled cardiovascular diseases like angina or those who have recently had a heart attack. This is because sauna use can cause substantial increases in blood pressure, heart rate, and cardiac output, which can be dangerous for these individuals. Those with controlled cardiovascular diseases should consult with a healthcare provider before using a sauna. In many cases, sauna use could potentially be safe and even beneficial for them.

People with compromised ability to regulate body temperature due to age or underlying health conditions should also exercise caution, as they are more susceptible to overheating. Pregnant or nursing women should abstain from sauna use, as elevated body temperatures during pregnancy can lead to complications and birth defects. Nursing women are at a higher risk of overheating due to a naturally warmer baseline body temperature during breastfeeding.

Individuals who are dehydrated or have a tendency to become easily dehydrated should avoid saunas, as sweating induced by sauna use can worsen dehydration, potentially leading to severe kidney and brain damage or even death.

Despite these potential risks, sauna use is generally considered safe and tolerable within the recommended guidelines, even for individuals who may not be in optimal health.

What’s left to say

Sauna bathing has been shown to have health benefits. The evidence suggests that if the protocols used in robust studies match those used in sauna use, sauna use is likely to be beneficial. The evidence is solid about cardiovascular health, which is the primary cause of death worldwide. However, the magnitude of the effect may be lower than indicated by the evidence due to healthy user bias and the social benefits that are part of the studies.

It is important to consider the opportunity cost of sauna use. While you can spend 30 minutes daily in the sauna, you may neglect other healthy behaviors like exercise. Therefore, it is essential to prioritize exercise, sleep, and nutrition as the foundation of healthy habits before considering other behaviors like sauna use.

As I mentioned before, I try to use the sauna frequently. But I see this as an addition rather than an essential to my healthy habits.

I would love to get your thoughts and comments!

Futon Tokyo

I recently wrote on LinkedIn about my decision to switch to a tatami and a futon mattress for sleeping due to my experimentation and desire for minimalism. I researched extensively and ordered my new bedding from Futon Tokyo in Japan.

After using it for several weeks, I can confidently say that I love everything about it. Admittedly, it was a bit of a gamble, but the ordering and delivery process was straightforward. The local shop in Tokyo produced the mattress according to my specifications; everything is handmade with top-notch Japanese craftsmanship.

The sleeping experience itself is incredible. It's less soft and cushy than traditional Western mattresses, but I enjoy sleeping closer to the ground and the harder floor experience.

I highly recommend this business if you're considering making the switch or trying it out for yourself.

I have a soft spot for fiction and novels, especially those with deep and complex characters and narratives that weave through life's many complexities. These stories resonate strongly with our personal struggles, serving not only as an escape but also as a powerful reflection of the crazy journey of human experiences.

One such narrative that has deeply resonated with me is "Looking for Alaska" by John Green. It is a touching exploration into the vibrant yet sometimes harsh journey of youth, encapsulating themes of love, friendship, and the inevitable loss. We venture into this world with Miles Halter, a teenager with a keen interest in the famous last words. As he steps into a new phase at a boarding school, he encounters the vibrant and mysterious Alaska Young. This starts a journey filled with adventures and a whirlwind of budding emotions.

However, life's not all sunshine and rainbows, a reality that Miles and his friends are thrown into, forcing them to navigate the complex puzzle of growing up and the hard process of healing. In this beautiful narrative, John Green paints a vivid picture of the turbulent yet profound journey of adolescence, leaving readers engrossed in a story that not only moves the heart but also incites deep contemplation on the intricate fabric of human connections and the essence of life itself.

A quote from the book that profoundly resonates with me is "The only way out of the labyrinth of suffering is to forgive." In our ever-complex world, this sentiment often emerges as a beacon of truth, a necessary path to tread to maintain sanity and forge ahead, a testament to the nuanced understanding and forgiveness that is sometimes required to navigate the labyrinth of our own lives.

DISCLAIMER: None of this (such as text, graphics, images, and other materials) is medical or health advice. This newsletter is strictly for informational, educational, and entertaining purposes only. While I’m a medical doctor and a dentist by training, I’m not your doctor. The content is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read on high on health! Please be careful and do your research.