The Importance of Sleep for Cardiovascular Health

From 1910 to 2010, people in Western countries cut 1.5 hours, on average, from their nightly sleep. As it turns out, we may be cutting years from our lives by doing this.

If you have ever felt more stressed the day after a short night’s sleep, you have experienced the increased activation of the sympathetic nervous system (SNS) that occurs with sleep deprivation. The impacts aren’t just in your head, though. There are actual physiological consequences of lack of sleep. If you checked, your blood pressure may have been higher than normal on that sleep-deprived day. That's because sleeping less than 5 hours a night more than doubles the risk of acute heart attack and causes a similar increase in the risk of diabetes. By impacting both hypertension and diabetes, sleep deprivation increases two major risk factors for cardiovascular disease and, as expected, causes an increase in cardiovascular disease as well.  

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How Important Is Sleep for Cardiovascular Health?

So, there is a link between sleep and cardiovascular health, but how important is it?

A good deal of evidence shows that inadequate sleep is strongly associated with cardiovascular disease as well as intermediate risk factors like inflammation, depression, weight gain, and hypertension. One study showed that people experiencing insomnia and sleeping less than 5 hours a night on average had more than 5x the baseline risk of developing hypertension. Even a few short nights of sleep can significantly increase C-reactive protein (CRP) and IL-6, markers of inflammation, which worsens as short nights accumulate. Napping during the day appears to moderate the inflammatory response.

The sympathetic nervous system (SNS) and Hypothalamic Pituitary Adrenal (HPA) Axis are both activated with chronic sleep disturbance. The increased SNS activity changes gene regulation and causes more pro-inflammatory gene products (IL1B, TNF, and IL6) to be created. Though cortisol, produced by HPA axis activation, is anti-inflammatory, the effects on the SNS create a net pro-inflammatory response on a systemic level. This increased inflammation is a known risk factor for the development of arterial plaques and cardiovascular disease.

How Much Sleep is Enough?

Our need for sleep varies throughout our lifetime and, to a small degree, from person to person. At the beginning of life, the natural pattern is to sleep most of the time. This decreases through childhood and levels out at optimal levels in the 7-9 hours a night range for most adults.

When we look at the relationship between sleep and cardiovascular disease risk in adults, the risks tend to significantly increase with less than 7 hours or more than 9 hours of sleep a night. This relationship is linear, so risk increases similarly for each hour less sleep per night.

Within this range of 7-9 hours a night, there is individual variation in what is ideal. Further refinement in ideal sleep duration will depend primarily on day-to-day feedback. If one regularly needs to use an alarm clock to wake up, feels drowsy during the day, feels unusually mentally foggy or lacking memory, or finds the need to drink more caffeine, these are signs that more sleep is needed.

Functional Medicine Labs to Test for Root Cause of Sleep Disturbances & Cardiovascular Health

Some common labs that can give additional insight into one’s sleep status and it’s accruing impact on cardiovascular health include:

C-Reactive Protein

C-reactive protein is widely known as a marker of inflammation. Inflammation is increased with sleep deprivation and plays a key role in developing arterial plaques and, thus, cardiovascular disease. While it doesn’t specifically prove that inflammation is increased due to poor sleep, a high level in combination may occur as a result of a pattern of insufficient sleep. This test can measure CRP at one point in time. If one has high CRP and known sleep issues, addressing the sleep issues would be an important early step in addressing the root causes of increased inflammation.

Stress and Sleep Hormones

A salivary cortisol and melatonin hormone test can show the daily patterns in hormone levels. Alterations from normal patterns may both be a result of inadequate sleep and contribute to difficulties sleeping.  

Cardiovascular Testing

If sleep and cardiovascular disease are both concerns, advanced testing for cardiovascular disease may be helpful to further assess cardiovascular risk. BostonHeart Diagnostics offers several helpful panels, including a basic lipid panel (LDL, HDL, triglycerides), the HDL Map, and Cholesterol balance tests, which provide additional information on HDL particle size and cholesterol production.

Tryptophan

As a precursor to serotonin, which is involved in the regulation of sleep and is often low in insomnia, levels of the amino acid tryptophan can influence sleep. Reasons that one might have insufficient levels of tryptophan include inadequate or poor quality protein in the diet or poor intestinal absorption. Tryptophan can be tested in the blood plasma as part of an amino acid profile.

BiomeFx

Some evidence shows that the microbiome affects sleep quality. This test gives insight into helpful and pathogenic organisms in the gut microbiome.  

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Functional Medicine Treatment of Sleep Disturbances for Cardiovascular Health

Addressing sleep adequacy may have a significant impact on cardiovascular concerns. In addition to good sleep hygiene, there are numerous functional medicine treatments to consider when addressing a situation where sleep disturbances and cardiovascular concerns are both involved. We will look at some of the most significant options here.

Nutrition Considerations for Better Quality Sleep

Though it may not be the first thing that comes to mind when we think of sleep, overall dietary patterns do affect the quality of our sleep. In a way that creates a cycle, our sleep also influences dietary choices, with poor sleep often leading to less healthy food choices. Paying attention to both aspects of this cycle can help shift it such that good food is feeding good sleep and good sleep is feeding healthy eating habits. This has significant promise for overall health improvement. In this review, the Mediterranean-style diet was associated with the best sleep of those examined. As an additional benefit, the Mediterranean diet can also lower inflammation and improve heart health.

Another review found several specific nutrient associations with sleep. These include improved quality of sleep from the consumption of the amino acid tryptophan and decreased quality of sleep from depletion of tryptophan. This is due to the ability of tryptophan to cross the blood brain barrier and be converted into serotonin and melatonin, which enhances sleep naturally. Foods such as cherries that are naturally high in melatonin and serotonin are also associated with improved sleep. Consuming fiber and plant phytonutrients also have shown benefit on sleep quality. There are also consistent findings that sleep is improved if a high carbohydrate meal is consumed 3-4 hours before bedtime, likely due to an effect on insulin, which results in more melatonin production.

While having an alcoholic drink in the evening to unwind from the day is extremely common and is perceived to help with falling asleep, heavier use of alcohol is associated with decreased REM sleep. If heavy use becomes a lifestyle pattern, it often interferes with getting good quality sleep. Patterns of sleep disruption from alcohol abuse may take several years of sobriety to return fully to normal.  

Supplements and Herbs for Better Quality Sleep, Reduced Stress and Inflammation and Cardiovascular Health

There are many supplements that integrative practitioners use to help improve sleep quality. Here are several of the top supplements that support a healthy stress response, lower inflammation and protect cardiovascular health:

Tryptophan for Sleep

Tryptophan is an essential amino acid needed to make serotonin, which is involved in regulating sleep and is a precursor for melatonin, which prepares the brain for sleep. As an essential amino acid, we can only get tryptophan from diet or supplementation. A 2022 review article found that supplementing with tryptophan at doses over 1 gram daily (1-5 grams) can help improve sleep quality.  

Melatonin for Sleep

A significant body of evidence indicates that melatonin supplementation improves subjective and objective measures of quality of sleep. Supplements are commonly taken from 1-10 mg, though there is generally no reason to start above 1 mg. The dose can be increased from there if needed.

Prebiotics, Postbiotics and Probiotics for Sleep

There is some evidence that prebiotics, postbiotics and probiotics may impact neuroactive and immune modifying compounds made in the gut in such a way as to improve sleep quality. Prebiotics are non-digestible food components that serve as food for helpful microorganisms. These are naturally found in many high fiber whole plant foods and may also be taken as a supplement. Postbiotics are products gut microbes produce, including some B vitamins, butyric acid and antimicrobial peptides. They can be individually supplemented or found in fermented foods. Probiotics are gut microbes such as lactobacillus, that are taken as a supplement. All should be started at a low dose and increased gradually to avoid sudden upsets of the gut ecology and potential associated symptoms.

Passionflower (Passiflora incarnata) for Stress and Sleep

Passionflower is a great herb for managing stress, especially if the stress is creating anxiety or having a negative impact on sleep.

Passionflower is commonly taken in a number of different forms. The leaves may be used to make a tea, which has a mild and pleasant taste and can be a nice ritual before bed. Tinctures are readily available, absorb quickly, and are easy to transport and take at any time throughout the day if doses are desired at times other than before bed. Tinctures may be dosed at 2-4 ml up to 4 times daily.

Hawthorn (Crataegus) for Heart Health and Inflammation

Hawthorn (Crataegus) has been used for centuries for the treatment of heart-related conditions. It may be a useful part of a heart-healthy protocol by helping with blood pressure, improving lipid status, improving exercise capacity and antioxidant status and reducing inflammation.

Hawthorne berry is often taken in capsules at doses ranging from 300 to 1000 mg three times daily. It also makes a pleasant-tasting tea that may be easier for some to incorporate as a habit. Tea dosing should be around 1 tsp of leaves and flowers in a cup of hot water three times daily. Liquid extracts, tinctures, and solid extracts are also good options for dosing, especially if there are doubts about the digestion of capsules or one needs to be able to carry it easily during travel. Tinctures are typically dosed at 1-2 ml three times daily.  

Red Ginseng (Panax ginseng) for Sleep, Resilience and Hypertension

Various kinds of ginseng have been used for at least 2000 years in Asian cultures. It is an herb that is often used to increase resilience to stress. Studies show that it can help improve sleep and reduce high blood pressure.

While very safe at standard doses, it should be noted that more is not better with ginseng. Too high of doses over too long a period of time have been known for millennia to cause ginseng abuse syndrome (GAS).” The symptoms of ginseng abuse syndrome are hypertension, rashes, anxiety, insomnia, and morning diarrhea. These are clearly counter-productive to the goals of improving sleep, reducing inflammation and stress and improving long term cardiovascular health.

Korean Red Ginseng can be taken in a variety of herbal forms. Due to concern about GAS, it is ideal to take for up to 3 months at a time, then take a break. A typical dose is 200 mg to 3 g daily for 12 week intervals.

Red Yeast Rice for Lowering Cholesterol

In cases where diet and lifestyle alone are not adequate to attain healthy cholesterol levels, those with concerns around sleep and cardiovascular illness who do not respond well to traditional statins may want to consider Red Yeast Rice as an alternative. It is a naturally derived product that has long been used in Chinese Medicine. The active component, monacolin K, is chemically identical to lovastatin but is used at a much lower effective dose. It is important to ensure that any product used has been made with good manufacturing processes to ensure consistency of dosing and purity from contaminants.

Dosing for Red Yeast Rice is often one 600 mg capsule twice daily. This can be increased up to four 600 mg capsules daily if needed.

Lifestyle Changes For Better Quality Sleep, Lower Stress, Less Inflammation and Cardiovascular Health

Numerous lifestyle practices and complementary therapies may help improve the balance of the autonomic nervous system and, thus, both sleep quality and cardiovascular and metabolic health. Some of the most effective ones include:

Sleep in a Dark Environment

Even one night of sleep in a moderately bright environment stimulates the sympathetic nervous system and has negative impacts on heart and metabolic health. When setting up a sleeping space, keeping it dark should be a key consideration.

Yoga

Yoga is popular for its relaxing effects. Given the relationship between the autonomic nervous system, stress and sleep, practicing yoga has been evaluated for the potential benefit on sleep quality. A recent review found that yoga practice can be effective in improving the quality of sleep in women in a direct relationship to the time spent practicing.

Music with Naps

As many as 60% of people sometimes use music to help with sleep. Studies have shown that both subjective and objective aspects of sleep are improved by listening to music before a nap.

Acupuncture

Acupuncture is commonly used to treat insomnia. A recent study found that it does improve both subjective and objective measures of quality of sleep, including the number of times one awakens during the night and total sleep duration. A minimum of 12 sessions is recommended for full therapeutic effect.

Aromatherapy

Our sense of smell is a potent feeder of information about the environment to the brain. Pleasant scents may help create an enjoyable bedtime routine and associations, and, it turns out, aromatherapy, the use of essential oils for their scents, also appears to benefit sleep quality, even more so when combined with relaxing massage. Lavender and rose are two of the most commonly used essential oils for sleep.

Grounding

The Earth has its own electromagnetic field, and grounding our bodies to the Earth has repeatedly been associated with reports of better sleep. Studies are showing improved sleep quality and reduced stress and cortisol levels with the implementation of grounding during sleep. This can be as simple as walking barefoot on the ground a few times a day, ideally in the presence of moisture. Grounding mattress pads are available to provide a connection to ground during sleep.

Exercise

Many of us turn to exercise for fun and to release stress. It is also one of the most effective ways to improve sleep and cardiovascular health. Most studied is aerobic exercise, like walking, dancing, biking or running, but it appears that resistance exercise, like lifting weights, also positively impacts sleep quality. There is no question that regular moderate-intensity aerobic exercise has very positive effects on cardiovascular health. The benefit doesn’t necessarily extend to the far extremes. There has been an observed trend toward increased cardiovascular illnesses with the amount of training involved in regularly participating in endurance events. The sweet spot may be around 2.5-5 hours a week of moderate to vigorous exercise, with fewer benefits potentially beginning around 10 hours a week, though this is likely to vary by individual.

Avoid Exposure to Tobacco Smoke

For both sleep and cardiovascular health, avoiding smoking, exposure to others smoking, and even third-hand exposure to spaces and clothes where the residue of tobacco smoke lingers (for up to 30 years) is helpful. A 2021 study showed that third-hand smoke exposure decreases melatonin levels in humans. This would have implications on sleep quality. In addition, secondhand smoke increases the risk of coronary heart disease by as much as 25 to 30%, and smoke residue also appears to increase the risk of heart disease.

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Summary

About 30% of us are not regularly getting enough good quality sleep. If you find yourself among that group, what would it look like to ditch the routine of dragging yourself out of bed and stumbling to the coffee maker every morning? What if you could wake naturally, feeling refreshed?

The benefits are not just in the short term but have real impacts on blood pressure and long-term cardiovascular health. Sometimes it is just a matter of really taking a close look at the structures and habits that would make getting enough sleep as natural as brushing the teeth. Although that may seem like just another thing to do in a sleep-deprived state, the long-term payoff and sustainability due to improving daily functioning make it worth prioritizing.

To the degree that inadequate sleep is partially due to difficulties falling or staying asleep despite taking the time and implementing good sleep hygiene measures, a root cause medicine approach can identify several potential contributing factors that can then be addressed. Additional tools, like yoga and aromatherapy can become a part of a whole-person nighttime habit.