Sapodilla's Role In Promoting Better Sleep

When you wake up in the morning and feel a little tired, maybe you have a headache and are finding it hard to focus at work or school, it is usually your body trying to tell you that you need more sleep. Sleep is a function without which we simply could not exist, throughout the animal kingdom there is little available evidence to support the idea that specific organisms can live without sleeping. However, there are certain animals such as jellyfish and several other aquatic creatures that go long periods without sleep and exhibit an altered sleep state compared with humans and other animals. 

We are recommended to sleep at least between 7 and 9 hours a night and there are many ways we can support this essential function. Having a regular sleep schedule and suitable mattress and bedding are just some of the ways to enhance both the quality and duration of sleep. Foods and drinks are also known to provide sleep-enriching benefits. Many people are known to enjoy a cup of chamomile tea before going to bed while nuts and tart cherries are said to produce similar results. In this article, we will examine the sapodilla fruit and how it can help to promote a better night's sleep.

What is sleep?

Sleep is described as a state of rest in which there is reduced physical activity and changes in brain wave activity, awareness, and responsiveness to external stimuli. You may notice around the same time each day you begin to feel sleepy and ready for bed, this is not just by chance but due to a sleep-wakefulness cycle governed by circadian rhythm. Circadian rhythms are cycles that run approximately every twenty-four hours, generated by an internal clock known as the suprachiasmatic nucleus which resides in the brain and can be modulated by several compounds. Sleep is divided into two states, non-rapid eye movement (NREM) and rapid eye movement (REM) sleep². These two sleep states occur cyclically and provide distinct benefits to the body.

Brain waves captured during the two sleep stages give an insight into the differences between REM and NREM sleep. REM more closely resembles the waking brain and is associated with vivid dreams, rapid eye movements and complete loss of muscle tone, while during NREM the brain exhibits slower brain waves and reduced response to external stimuli.

Why is sleep so important?

Good quality sleep for the required amount of time is associated with many health benefits. Sleep is believed to play a role in preventing obesity, reflected by its ability to adjust appetites (Sutanto). Additionally, sleep can also:³,⁴

• Balance hormones
• Boost immune system
• Aid memory consolidation
• Improve mood
• Aid learning
• Clear metabolic waste products
• Conserve energy

Sapodilla

As previously mentioned, some foods and drinks are believed to support good sleep and by looking at its nutritional content the sapodilla could be one of them. The sapodilla fruit, also known as Manilkara zapota is native to Central America and the Caribbean, but in more recent years has been introduced to parts of Asia. Its unique flavour is creamy and a cross between a pear and a pineapple. It is brimming with amino acids, minerals, and fibre, which are highly beneficial to our health. 

Potassium

Potassium (denoted by the symbol K on the periodic table) is not naturally occurring and is brought into the body by the food we eat. Potassium is an essential nutrient used in the body for maintaining cellular function, certain tissues rely on the presence and balance of potassium in the body more than others, nerve and muscle being just two examples.⁵

Poor sleep has been documented in patients with known dysregulated potassium levels. Hypokalemia is a condition in which patients have lower-than-normal levels of potassium in their blood and has been linked to reduced sleep quality and increased daytime fatigue.⁶

Abnormal potassium levels have also been linked to:

• Sleep-related hallucinations
• Nightmares

Research has shown that potassium supplementation can benefit sleep by helping improve sleep quality and reducing the amount of time spent in bed trying to fall asleep.⁷ Transportation of potassium has been observed to affect circadian rhythm, with different levels of potassium shortening or lengthening cycles.⁸ Potassium’s capacity to regulate circadian rhythm may be the mechanism by which it can impact sleep quality.

Many people are reported to have a potassium deficiency, not always to dangerous degrees, but it is something we could benefit from adding more to in our diet and the sapodilla fruit provides a good source of this mineral. Please take into consideration the fact that excessive potassium in the body can be harmful, and it is best to stick to recommended daily consumption.

Tryptophan

Tryptophan is an amino acid that the body uses to produce proteins including serotonin, melatonin, and niacin. This amino acid is not synthesised by the body, so we rely on our supply from the food we eat. Animal proteins provide a good source of tryptophan, one of the best-known is turkey, but it can also be found across other food groups including nuts, seeds, and vegetables. 

Related to the red mamey, which is regarded as one of the richest sources of tryptophan, the sapodilla fruit doesn’t quite provide as much tryptophan as its relative but it can still provide you with its benefits. 

Tryptophan is transported to the brain, following consumption, and is converted into a neurotransmitter known as 5-Hydroxytryptamine or 5-HT.⁹ You may actually be familiar with 5-HT, more commonly known as serotonin, a neurotransmitter, a “happy chemical” that can boost our mood and emotions and also facilitate the sleep cycle. 

The direct role serotonin has on our sleep cycle has not yet been established, but what we do know is that serotonin is converted to melatonin in the brain¹⁰. Melatonin is a hormone produced by the pineal gland in the brain at night and induces sleepiness in accordance with the light and dark. 

Melatonin has been found to¹¹:

• Synchronise circadian rhythms
• Increase sleep duration
• Improve sleep quality
• Reduce time taken to fall asleep

Glycine

Sapodilla fruits are abundant in another amino acid, glycine, which has been promoted as a therapeutic option for people struggling to obtain good quality sufficient sleep¹². This has been linked to its ability to lower core body temperature which naturally falls during the sleep phase of the day helping to reach a deep sleep quicker. 

Fiber

The sapodilla is a great source of fiber, which has proven to reduce the incidence of insomnia and through its restoration of the gut barrier may encourage sleep cytokines and serotonin production^13,14. 

Adding sapodilla to your diet

If you live in an area where you have access to this delicious tropical fruit, it is worth giving it a try. There are many ways it can be enjoyed such as on its own or as part of a fruit salad, many people also enjoy having sapodilla in smoothie form. It is important to remember that due to its high sugar content, moderate consumption is advised. If you are pregnant or have a medical condition such as diabetes seek professional advice before introducing it into your lifestyle.

Summary

Sleep is a fundamental function key to our survival as a species and as living organisms as a whole. During this period of rest, can: physically recover from rigorous daily activities and sports, form memories, absorb learning, soothe our mood and mind from the stressors of the day, and regulate hormones and cardiovascular health. Given its importance when we experience a lack of sleep it can have a great impact on our health, affecting our quality of life as a whole. Various teas and concoctions have been used in traditional medicine and throughout history to support sleep health but more recently there has been a move to pharmacological agents and supplementation with biosynthetic tryptophan and glycine. Due to the possible risk of unpleasant side effects, it is still preferable to naturally incorporate these sleep-inducing compounds into your diet. Breaking down the nutritional components of the sapodilla fruit, we can see it can provide a source of sleep-inducing substances amongst other health benefits. In addition to the amino acids and potassium aforementioned in this article, the sapodilla fruit is abundant in many other vitamins and minerals and will make a delightful addition to your fruit bowl if it is readily available to you.