April 2018

Natural immune support such as herbal medicines can provide effective solutions to athletes who suffer from recurring colds and flu’s and other immune issues. When most people think of issues for athletes they usually think of musculoskeletal injuries such as sprained ankles, pulled muscles, or knee pain, but a recent study suggested immunity issues cause up to 50% of disruption to training or performance in athletes.

According to research, exercise improves immunity at moderate intensity but impairs immune function at high intensity (and duration) making many endurance and elite athletes more susceptible to respiratory infections. Infection, such as fever and fatigue, can weaken muscles, impair exercise, and predispose athletes to other injuries. For example, fever impairs coordination, muscle strength, and aerobic power while viral illnesses contribute to tissue wasting and muscle breakdown.

Drugs commonly used to treat the symptoms of infectious diseases have variable impacts. Antibiotics can cause diarrhoea and ongoing gut issues, antihistamines can cause sedation, and many ephedrine-containing compounds like Sudafed are prohibited during competition over certain amounts under the Australian (ASADA) and World Drug Agency Association (WADA) guidelines.

To explain this immunity phenomenon perhaps a recap of how the human immune system is set up may be helpful. There are two parts to the immune system, the Innate Immune System and the Adaptive or Acquired Immune System.

Innate Immune System

The innate immune system includes our first line of defence providing physical barriers such as the skin, mucous membranes, nasal hairs, and eyelashes. Functional barriers such as the gastrointestinal tract and defence mechanisms such as secretions, mucus, bile, gastric acid, saliva, tears, and sweat also protect us.

This part of our system also houses our infection-fighting cells such as our natural killer cells and phagocytes which act like Pac-men against microbial invaders, and proteins such as tumour necrosis factor which program cell death and cytokines which play roles in cell-to-cell communication.

The complement system is an additional cascade of proteins that “complements” other aspects of the innate immune system. The innate immune system is always ready to battle with foreign invaders, irrespective of whether they have come into contact with the microbial invader before.

Acquired Immune System

The acquired immune system is a collection of cells called T and B lymphocytes, immunoglobulins produced by the lymphocytes, and cytokines that regulate the immune response. Through a complex pathway of intercellular interaction, immunoglobulins are produced after exposure to a new pathogen, so they can recognise the invader the second time around and have an inbuilt immunological memory and enhance the immune response accordingly.

Gut-Associated Lymphoid Tissue (GALT) is a collection of several types of lymphoid tissue that store immune cells, such as T and B lymphocytes and is our major defence mechanism against pathogens entering the digestive system. Peyer’s patch is a collective of lymphoid cells attached to the gut lining which is the initiation of the immune response when an infection is detected.

Secretory IgA is another substance produced by the acquired immune system produced in all areas where a protective mucosal layer exists such as the digestive, respiratory and urinary tracts to provide front-line defence. It forms the backbone of our immune system because it protects the immunoglobulins from being destroyed and protects the immunoglobulins from invading microbes.

This part of the immune system provides long-lasting protection against anything it has encountered before. When the two systems (innate and acquired) combine, they form an incredible defence against the constant barrage of infectious threats an athlete faces each day.

How does exercise impact on immunity?

So let’s examine how exercise can affect immunity. There is a substantial body of knowledge suggesting moderate exercise of up to 60 minutes at 60% of maximum heart rate improves immune cell counts and salivary IgA concentrations. Studies also show that 61% of new runner’s report fewer upper respiratory tract infections after starting running. However, there is always a flipside to everything and in the case of exercise, the term moderation is wise to observe.

Intense exercise and prolonged exercise greater than 60 minutes may reduce immunity. While there is no doubt hard efforts increase VO2 max, it also forces most athletes to transition from nose breathing to mouth breathing, bypassing the nasal hairs and turbulent flow that protect the lungs from pathogens.

Inhaling larger volumes of colder and drier air thickens the mucous and disrupts the mucociliary elevator which is like our own inbuilt elevator designed specially to clear mucus from the respiratory tract. Hence why many athletes find they need to do a fair bit of “hoiking” to clear the phlegm during hard efforts in cooler months, especially when coupled with the ingestion of proinflammatory and mucous-producing foods such as dairy, coffee and bananas.

As more foreign particles are deposited in the lower airways, the ability to clear them is diminished, and airway inflammation results. Studies show our natural killer cells and secretory IgA fall after intense or prolonged exercise. The key members of our acquired immune system are also affected by neutrophils and B cell function declining.

With repetitive hard and long sessions that most endurance athletes over the marathon, ultra-marathon, ironman, triathlon or cycling do on a regular basis, hormones such as cortisol, prolactin, adrenaline, and growth hormone are constantly elevated and these also impair cellular immunity.

While most upper respiratory infections start off as viral infections, athletes who develop symptoms that are ongoing may also have a secondary bacterial infection.

What can be done about an underperforming immune system?

Few athletes stop training because they get a few annoying sniffles. When on a mission, athletes should always seek out a solution to overcome or manage the issue.

At this point, it may be wise to seek help from a healthcare practitioner. Natural medicine has plenty to offer in regards to boosting the soldiers of the immune system. Most people are aware of the immune cell turbo boost vitamin C, and zinc provide but what about nature’s little wonders?

Natural remedies such as garlic and horseradish, Andrographis, Echinacea, Cat’s claw and Astragalus can increase immune cell count and function, and anti-microbial herbs like Thyme, Garlic, Thuja, St John’s Wart or Pelargonium have antiviral and antibacterial properties.

Maintaining digestive system integrity and gut health through quality probiotics will also help support GALT and sIGA in the adaptive immune system. Herbal adaptogens also assist with improving immunity integrity and resilience to future invasions. As with any treatment, these options are not going to be a magic bullet, but they can certainly reduce the severity of the infection, reduce recovery time and get you back to what you love doing. We always suggest athletes listen to their bodies and if needed modify training loads and convalesce to some extent.

Many studies use incorrect dosage ranges and timeframes for herbal medicines, so the evidence may be unclear and confusing to the untrained eye. However, when used in the correct dosage ranges, herbal medicines are viable options for athletes with few side effects. Research shows that seeking treatment quickly can reduce the impact respiratory illness may have on athletic performance.

About the Author: Kate Smyth is a Sports naturopath, nutritionist and female-centric running coach. She is the founder of the Athlete Sanctuary- a holistic healthcare clinic for athletes of all levels and sporting codes. Kate has a thirst for knowledge with two bachelor’s and a master’s degree under her belt. She has been involved in sports for many decades and competed for Australia in the Commonwealth Games and Olympic Games marathons with a personal best time of 2 hours 28 minutes. For more information visit www.https://https://athletesanctuary.com.au/wp-content/uploads/2023/03/normatec-3-lower-body-system-thumb_720x-1.webp.com.au/wp-content/uploads/2020/05/Seed-Cycle-Blends-scaled-1.jpg.com.au

Iodine and thyroid hormones are essential to sports performance and yet many athletes are iodine deficient.

Thyroid hormones perform many key functions in the human body including regulation of body temperature, metabolism and play an important role in how an athlete creates and uses energy. Thyroid hormones bind to receptors on each cell’s membrane surface and inside the cell at the mitochondria where energy is made. Binding activates the cell’s energy and metabolic functions.

Iodine is a key trace mineral stored primarily in the thyroid gland. The thyroid gland produces the key thyroid hormones thyroxine (T4) and triiodothyronine (T3), using iodine and other key nutrients such as selenium and tyrosine. To further convert thyroid hormones into activated forms the body can use, sufficient levels of magnesium, iron, selenium, vitamin C and zinc are also required.

Key hallmarks of iodine deficiency and low thyroid function in athletes include:

Fatigue and low stamina can really cause havoc to an athlete’s training and racing season
Lethargy, muscle aches, cramps, pains and weakness
Low basal body temperature (temperature first thing in the morning)
Intolerance to cold weather
Cold hands and feet
Slow brain function, poor memory and “foggy” brain
Constipation
Joint pain
Thin, brittle hair or hair loss
Dry flaky skin
Menstrual disorders and fertility problems
Weight gain and slower metabolic rate

Iodine is primarily lost through sweat, although some are also excreted in the urine. Some studies suggest athletes may lose more iodine through sweat in an hour of vigorous exercise than through their entire daily urine output. High levels of sweating during exercise can deplete iodine levels and result in dehydration and poor performance.

The recommended iodine intake is 150ug/ day but some studies show on average athletes may lose nearly 50% of this requirement in sweat alone. Athletes living in more humid conditions (even without exercise) can lose a greater amount of sweat than those living in cooler environments.

Athletes performing at high intensity for prolonged periods of time, particularly in a humid environment, have a significantly increased risk of becoming iodine deficient if they don’t pay special attention to replacing this important nutrient.

What else can impact iodine and thyroid function?

It is important to keep in mind there are lots of things that impact the thyroid gland.

Chronic physical or emotional stress and high cortisol will result in elevations of another thyroid hormone called reverse T3 (rT3). Pesky rT3 inhibits our active thyroid hormone T3.

Heavy metals and chemicals, a low carbohydrate diet and fasting and selenium deficiency can also reduce T3 levels. There are many chemicals and metals in our environment known as “endocrine disruptors” that inhibit healthy thyroid function. Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are common in our environment containments (in soil and food grown in that soil including meat, electronics, electrical cables, paints, plastics, furniture ) which can disrupt thyroid hormone signalling at the receptor level.

Perchlorate found in food and water inhibits the thyroid’s ability to absorb iodine from the bloodstream while long-term consumption of fluoridated drinking water is associated with hypothyroidism (low thyroid function).

Dioxins, BPA (found in cling wrap, drinking bottles and plastics) or bisphenols in tinned foods and plastic containers and plastic wraps, are also endocrine disruptors.

Non-stick cookware, fragrances, detergents, cosmetics and skincare, foods exposed to pesticides and herbicides, flame retardant material, new carpets, furniture and clothing may also be sources of endocrine disruptors.

When a female athlete has excess oestrogen, it may reduce the efficiency of thyroid hormone by 25%. Female athletes with high testosterone levels or insulin resistance may also have reduced thyroid efficiency due to a reduction in the globulin that carries thyroid hormone around the body (thyroid binding globulin) which means not enough thyroid hormone can circulate. But the hormone dance doesn’t stop there.

Low thyroid function due to low iodine or other nutrients can also cause receptor sensitivity issues with other female hormones such as progesterone causing PMS symptoms, irregular periods and fertility issues.

Cortisol up-regulates estrogen and high oestrogen also up-regulates cortisol which increases the binding of T4 up to 3 times, resulting in lower thyroid hormone activity, lowered metabolism and weight gain.

As thyroid hormones influence the tight junctions in the stomach and small intestine, athletes with low iodine and thyroid can also suffer from digestive complaints such as gas, bloating, diarrhoea or constipation and digestive infections.

Approximately 20% of our thyroid hormone T4 is converted to T3 in the gut by bacteria. So if digestion is disrupted and inflammation exists, the conversion will be impacted. Thyroid hormones also influence the tight junctions in the stomach and intestine that prevent large undigested molecules from passing into our bloodstream. Hence why thyroid abnormalities are also associated with leaky gut, food intolerances, constipation, reflux, heartburn, and dysbiosis (gut microbiome imbalance).

Thyroid hormones also influence the foundation of our immune system in the stomach called Gut Associated Lymphoid Tissue (GALT). GALT is made up of several types of lymphoid tissue that store immune cells, such as T and B lymphocytes. The majority of infectious agents invading the human body gain access through the gut and GALT protects us against these pathogens. Therefore, an athlete can be more susceptible to infections if thyroid hormones are low or iodine deficiency exists. n

Other nutrients have an impact on iodine and thyroid function. Many athletes suffer from anaemia or low iron and believe their fatigue and poor performance may just be iron related. The situation is a double-edged sword as iron deficiency impairs thyroid hormone synthesis and low thyroid function impairs gastric secretions which reduce iron absorption from food.

Another tricky synergy exists between zinc, copper and thyroid function. Zinc is required for T4 and T3 production and therefore zinc deficiency may lead to low gastric secretions and low iron. Zinc and copper also antagonise each other so low zinc may lead to high copper. Excess copper slows thyroid function and depletes zinc.

Iodine concentration in foods is variable depending on soil concentrations and the amount of fertilizer used with farming methods. Therefore, our food iodine content also varies greatly in grains, meats and vegetables. Although the daily recommended iodine intake is 150ug, it can still be tricky even when eating iodine food sources due to such variability.

Metabolic acidosis is a condition when the body’s pH is too acidic (pH of 7.35 or lower). This may occur in athletes from prolonged exercise at high intensity leading to lactic acid build-up. Chronic metabolic acidosis may decrease T4 and T3 and increase TSH concentrations and may lead to subclinical hypothyroid states.

Tracking athletes’ basal (morning) body temperature can assist with identifying issues with thyroid function. Anything less than 36.4c suggests your thyroid may need some attention.
Athletes should not rely on blood tests to confirm thyroid function status. Under activity of the thyroid gland results in low basal temperatures and symptoms of low thyroid function are not detectable by the standard laboratory tests-thyroid stimulating hormone (TSH), T4 and T3.
Athletes should consume sufficient sources of iodine on a regular basis. Good food sources include seafood (wild sea fish contain more iodine than freshwater fish), kelp and other seaweeds (wakame, Kombu, Nori), kelp noodles, Sushi are a rich source of iodine. Other reasonable sources include milk and yogurt, navy beans, eggs, cranberries, strawberries and some meats.
Since 2009 all packaged bread has added iodine in Australia although freshly baked bread may not disclose the amount added. Iodized salt is also available but keep in mind too much salt is not great for blood pressure and even sea salt and Himalayan salt contains 90% sodium chloride which is not desirable as chloride inhibits iodine absorption.
Be mindful of high intake of goitrogenic vegetables. The cabbage family including cabbage, kale, broccoli, cauliflower, Brussels sprouts, radishes, turnips, watercress, spinach contain isothiocyanates (goitrogens) which may block the uptake and utilisation of iodine in the thyroid gland. Cooking these vegetables reduces the goitrogens and the likelihood of their impact.
Although controversial, some evidence suggests soy supplements such as soy protein powders should be avoided if you have been diagnosed with low thyroid function as they may also reduce the genetic expression of the enzymes needed to produce thyroid hormones.
Get your vitamin D levels checked. Vitamin D deficiency is common in Australia and in athletes with low body fat this issue can be even more prevalent as Vitamin D is stored in fat cells. Vitamin D is associated with hypothyroidism and thyroid autoimmune conditions while studies show serum vitamin D > 125 is associated with a 30% reduced risk of hypothyroidism.
Get your hormones, cortisol, iron, zinc, copper and iodine levels checked.
Improve your gastric acid secretions by consuming bitter foods (endive, rocket, radicchio, chicory, dark chocolate) on a regular basis or sip lemon in water or apple cider vinegar before meals.
Reduce your exposure to endocrine disruptors by drinking filtered water, installing filters on shower heads, choosing natural water sources to swim in rather than chlorinated pools, eating pesticide-free or ideally organic foods, choosing organic personal care products, cosmetics and detergents, avoiding storage of food in plastics and instead use wax wraps and choose low emitting products when renovating or building your home.

If you suspect you may be suffering from iodine deficiency or reduced thyroid function, consider making an appointment with the Athlete Sanctuary to help navigate your recovery process.

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