During the month of November I highlighted some important topics in digestive health and performance in The Full Potential Newsletter; this is a summary of those emails:
One of the most important aspects of sports performance is proper nutrition; fuelling your exercising muscles to improve recovery, maximize performance, and reach your full potential. What is often overlooked is how your gastrointestinal system is functioning, are you absorbing all of those vital nutrients?
Week 1: The Microbiota and Performance.
No matter what you call it: the microbiota, gut flora, or good bacteria, it is extremely important when it comes to digesting, absorbing and using the nutrients you consume. Over the past decade or so, these good bacteria have been receiving a lot of attention both in the media and in the research realm. The question is, do they have any role in performance?
The research says "yes". There is a wide range of ways the microbiota can effect your performance:
First, the gut flora plays a role in inflammation. A more diverse microbiota is associated with lower inflammatory markers (1). Furthermore, constant physical and mental stress (similar to what athletes experience) can lead to increased stress hormone release which can increase these inflammatory markers. This inflammation can cause damage to the endothelial lining in our guts, leading to hyper-permeability, AKA "leaking gut" (2). As noted above, a healthy microbiota may help mitigate some of these inflammatory results, leading to greater gut health which results in better nutrient absorption.
Second, a healthy gut flora may lead to less upper respiratory tract infections (the common cold) (3). In this study they looked at the effect that probiotics had on elite athletes. They found that those taking probiotics trained longer per week throughout cold and flu season and had fewer incidence of the common cold.
Third, decreases in muscle recovery time were noted in those taking probiotics (4).
Fourth, the link between brain function and gut bacteria is becoming more mainstream (5, 6). This link has important implications for athletes; your ability to focus plays a large role in competition and training.
Week 2: Food Sensitivities and Performance
Be it gluten, dairy, eggs, or corn, food sensitivities and intolerance are a hot topic in health circles, but is there any benefit to elimination certain foods? How might certain foods be affecting your performance?
To be clear, food sensitivities are NOT allergies; although the terms are often used interchangeably they are quite different. In short, an allergy is an immune mediated response that can be as severe as throat swelling and could require an EpiPen. A food sensitivity is more like your digestive system not handling a food as well as it could. This does not mean that a sensitivity isn't negatively effecting your performance.
Athletes are especially susceptible to digestive issues since they put themselves through constant physical and mental stress leading to a diversion of blood away from the GI tract to the lungs, the heart, and exercising muscles. This diversion of blood may lead to a decrease in your digestive system's ability to break down and absorb foods. The decrease in function may be more noticeable with certain foods resulting in decreased mental and physical performance.
Should you eliminate foods from you diet? I can't recommend this without good reason. Especially for an athlete, the more high quality foods you have at your disposal, the better. However, if you suffer from GI distress, headaches or decreased mental function, going through a systematic food elimination and reintroduction may be warranted.
Be warned, following an elimination diet can lead to issues of its own, such as: nutrient deficiencies and calorie restriction. Seeking guidance with a trained professional is key to maintain performance while determining what foods may be causing issues.
Week 3 - The Digestive System and the Immune System - A Unique Relationship
We all know the importance of the GI tract and nutrient absorption, but more and more information is being uncovered on the multitude of roles the GI system plays in our bodies. One of these roles is the effect that the GI system has on our immune system.
The immune system is constantly being developed as we go about our lives; we get exposed to bacteria and viruses and we have responses to these pathogens, often times without even developing symptoms. The GI tract is one of the first places our bodies encounter external pathogens (1) and we know our immune system interacts with the "external" environment through our GI tract, so it would make sense that a healthy GI system would lead to a better immune system. What does the research say?
Researchers have been working on the effect of the microbiota for over a century. We know that the interplay between our immune system and microbiota is largely responsible for the maturation of our immune systems (2). This maturation begins at birth and continues throughout the lifespan, with new antibodies being produced as we encounter different pathogens.
Furthermore, the mucous layer that covers the inside of our digestive tract provides a layer of protection from pathogens, houses the good bacteria, and provides a medium for our immune system and pathogens to "meet" (3). This mucous layer can be disturbed, and lead to GI distress (diarrhea, bloating, constipation, etc). Maintaining this mucous layer is paramount to keeping your digestive system working optimally.
So, what does all of this mean for your performance? Athletes put themselves through physical and mental stress on a daily basis, which may decrease immunity leading to a greater risk of infections (especially the common cold). Maximizing the immune system on a long term basis is the best option to prevent illness, decrease duration of illnesses, and get back to performing and feeling your best. A good place to start optimizing your immune system is where it all begins, in your gut.
Week 4: Melatonin and GI System
Melatonin in a key player in our circadian rhythm (sleep-wake cycle): it helps us fall asleep and is highest in the middle of the night. It is released from a small gland in the brain called the pineal gland in response to visual low-light exposure. In the most simple sense, the interplay between melatonin and cortisol determine when we sleep and when we wake, but it does have effects elsewhere.
The hormone Melatonin was discovered in 1917, was first found in an animal pineal gland in 1958 and was found in the human digestive tract in 1974. So since the 1970's we have known melatonin to be present in the digestive tract, but we still don't know the full role it plays in digestion.
We do know:
- There is much more melatonin present in the gut VS the pineal gland (400 times more!)
- Gut production of melatonin is not dependant on light exposure
- Gut levels are no dependant on pineal gland production (the gut makes its own)
- There are many melatonin receptors throughout the GI tract responsible for a lot of different important digestive functions
We also know Melatonin:
- Has an effect on gut motility (how digesting food moves through your intestines),
- Decreases fluid excretion into the intestines (reducing diarrhea),
- Increases various immune molecules and,
- Decreases inflammation in the gut (1).
How do you optimize it? Dietary source of the amino acid L-tryptophan (melatonin's precursor) can increase gut levels. So eat a wide range of protein sources including: red meat, fish, poultry, eggs, and yogurt.
So what does this mean for performance? The level of melatonin in our digestive tract is important for the optimal functioning of this important system. The better this system is functioning the more nutrients will be absorbed, helping you get closer to your full potential.
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