LED is here to support you online whilst our centres are closed. In this 4-part series, Barnaby will be outlining how physical activity and good nutrition can support a healthy immune system whilst providing you with guidance on how to stay active during lockdown and how LED can support you online.
Nutrition & Immunity
Food is essential to life. The food we consume provides our bodies with the energy and the vitamins and minerals we require to grow well, function properly and live healthily. Our nutritional intake has strong influences on our mental wellbeing as well as an even bigger impact on the environment we live in.
Sensible and balanced consumption of a variety of nutrient dense foods is essential for optimal health and well-being. There are a whole range of benefits to consuming such a diet, including:
- Weight management
- Muscle growth and repair
- Sports performance
- Immune System Function
In this blog I will outline how nutrition can help improve immune system function. In the current UK national lockdown there is no better time to focus on simple changes that can improve our immune system.
At this point I want to make it very clear that I am not promoting a magic snake oil that will make you immune from Covid-19. Instead, I want to outline evidence-based research demonstrating how specific nutrients may reduce the risk of infection or severity and duration of symptoms.
If you’d like to contact me for further information, please email me at firstname.lastname@example.org.
Please remember to consult your GP and read our Health Commitment Statement before making significant changes to your diet.
Innate vs. Adaptive immune system
Throughout this blog I may refer to the "Innate" or "Adaptive" immune systems. So before we get going, you may find it useful to read this brief summary of each. If this is a bit beyond what you were expecting, don't worry! You can still read and enjoy this blog. If however you’d like to know more of the science around the immune system, I've linked a handy research paper here.
- Innate Immune System: Also known as the non-specific immune system, this is our bodies 1st defence against pathogens. This immune system doesn’t really care what it kills, it just wants to stop foreign microorganisms from entering the body. This includes physical barriers such as your skin, the mucus lining around major organs and chemical barriers such as stomach acid. Unfortunately, the occasional pathogen makes its way past these defenders so our bodies must mount a targeted attack.
- Adaptive Immune System: Also known as the specific immune system, this immune system minimizes collateral damage but takes time to get started. Cells in the adaptive immune system kill specific pathogens. Once they kill a foreign microbe, they remember this pathogen so they can fight it again, providing you with immunity.
Role in the Body: Carbohydrates fulfil many different roles in our diet, they are primarily our bodies preferred fuel source and can be stored as an energy reserve. Carbohydrates also play an important role in supporting our immune system. I've previously written a blog on Carbohydrates for LED which you can find here.
Role in the Immune System: Diets that do not contain enough carbohydrate, such as low carbohydrate diets like the “ketogenic diet”, have been shown to have detrimental effects on the immune system and increase the risk of infection from URTIs. You may remember from my last blog that URTIs are bacterial or viral infections of the throat, nose etc.
Consuming enough carbohydrate is also crucial for minimizing immune system disturbances that can occur after a single bout of exercise.
Now, this may be contrary to many messages you've heard from the fitness industry or perhaps even from LED before. A lot of the time we suggest to our members that reducing carbohydrate intake in your diet is an effective method for reducing calorie intake and thus weight loss. Whilst this may be true, we shouldn’t completely remove all carbohydrate sources from our diet. Doing so could really hamper the effectiveness of our immune system. Instead, try to find a balance between consuming enough to maintain immune system function without over consuming.
Guidelines: Whilst there aren't specifically guidelines which say "you should eat X grams of carbohydrate a day to prevent immune system dysfunction" I would recommend following your Dietary reference values (DRVs). These guidelines recommend up to 50% of your total calories come from carbohydrate.
Example: An individual who consumes 2,000kcal requires ~250g carbohydrate per day
This should include a portion of starchy foods such as potatoes, bread, rice or pasta with every meal. For more information, click below:
Role in the Body: Vitamin C is an essential micronutrient, meaning we must consume it within our diet for optimal health and wellbeing. It acts as a potent antioxidant helping prevent damage from free radicals. Vitamin C aids the immune system by supporting many cellular functions within both the innate and adaptive immune system.
Role in the Immune System: Vitamin C is a crucial nutrient that supports our immune system. Vitamin C deficiency causes impaired immunity leading to higher susceptibility to infections. Furthermore, our body’s need for vitamin C increases during periods of infection too!
Vitamin C appears to be able to both prevent and treat infections by enhancing various functions of immune cells.
Guidelines: It is so important we consume enough vitamin C in our diet, this is especially true for elderly groups who are more at risk of vitamin C deficiency. Vitamin C can be found in citrus fruits, berries, broccoli and even potatoes. These are all nutrient dense foods that should make up a healthy and balanced diet.
Role in the Body: Vitamin D, technically a hormone, is unique in that it can be produced within the body following exposure to Ultraviolet B rays in sunlight. Vitamin D can also be consumed in the diet via food sources such as oily fish and fortified breads or cereals. The main function of vitamin D is in regulation of blood calcium levels to help maintain healthy bones and teeth.
Role in the Immune System: Vitamin D may also be important in both the innate and adaptive immune systems mentioned above. Research suggests that Vitamin D may help the innate immune system by promoting the elimination of invading bacteria, fungi and viruses.
- In a study of 6,789 British adults Berry et al. discovered the prevalence of respiratory infections were lowest in summer months when vitamin D levels were also highest.
- The “US Third National Health and Nutrition Examination Survey” included 18,883 adults and found that at any time of year, those who had highest levels of vitamin D were less likely to have recently had an URTI compared with those who had lower levels of Vitamin D.
The above research suggests Vitamin D can reduce the risk of respiratory tract infections.
Guidelines: Our body's ability to manufacture vitamine D declines with age, while the risk of osteoporosis or osteoarthritis increases with age too! Given the importance of vitamin D for bone health, the potential benefits for immune function and how difficult it can be to get sufficient sun exposure in lockdown (especially during winter) I would strongly suggest readers consider supplementing vitamin D.
Aim to consume 1,000 – 4,000 IUs per day. Vitamin D supplements are widely accessible and relatively inexpensive. You may be able to find them in your local supermarket or health food shop, such as Holland and Barrett.
Role in the Body: Probiotics are defined as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”. Probiotics can be consumed to alter the gastrointestinal flora (i.e., ratio of good and bad bacteria in your gut). If you have heard of probiotics, you’ve probably heard of the small yogurt drink “yakult”.
Role in the Immune System: Probiotics influence the immune response in the gut and other areas of the body, such as the respiratory tract, by interacting with cells in your intestines. Increasing evidence suggests that probiotics may also improve our immune system.
- Tuchet et al. conducted a 3-week trial in 360 elderly participants. Those who were given probiotics had shorter duration of infections compared to those who did not consume probiotics.
Guidelines: Evidence suggests probiotics may help reduce the duration of symptoms suffered from URTIs as well as other health benefits. Whilst recommendations are currently very limited I think it’s reasonable to suggest readers consider consuming a probiotic yogurt drink each day. Supermarkets often have their own brand alternative to yakult which is cheaper, this can be found in the milk or yogurt section.
How LED can support you
Download our Immunity Support recipe pack for just £2.50 to learn even more about how nutrition can influence your immune system with tasty recipes for you to try too!
Thank you for taking the time to read this email. I hope you now have a better understanding of how nutrition can affect your immune system. If you’d like to contact me for further information, please email me at email@example.com.