We need to eat in order to stay alive. If we don’t eat, our bodies run out of fuel and a variety of negative symptoms begin to arise. Immune function shuts down, bodily functions take a hit and our mental abilities drop.
In the case of complete dietary restriction, the effects on immunity are fairly easy to understand and comprehend. But what about more mild deficiencies? How about deficiencies of single nutrients? Can just small changes in our dietary choices have a significant impact on our health and well being?
Luckily, the research in this area is detailed and abundant. The majority of which, concludes that deficiencies of single nutrients (even at moderate stages) are associated with a weakened immune response and a higher risk of infection . While on the other hand, excessive intake of some nutrients has also been shown to weaken the immune response as well .
Thus, in order to maintain good health we must have an adequate understanding of what our bodies need for optimal functioning. And this is becomes especially important in today’s world where a large portion of the available food is lacking in many essential nutrients .
This section will attempt to go over some of the most important factors of nutrition that influence our immune systems.
The Effect of Nutritional Deficiencies on Immunity
Immunity consists of a number of various components that work together to protect the body. Malnutrition and nutrient deficiencies can weaken these defense systems. This allows microbes to invade and may cause clinical infection leading to further weakening of the immune system. And this can create a downward spiral which can be difficult to stop.
When it comes to immunity, various nutritional deficiencies have been shown to have a long list of negative effects. The inter-relation between each single micronutrient is quite complex, so it may not be worthwhile to try to isolate each one’s specific function.
- Impaired cell mediated immunity
- Reduced number of circulating T-Cells
- Decreased lymphocyte stimulation response
- Altered production of cytokines
- Lower secretory IgA antibody response on mucosal surfaces
- Decreased antibody affinity
- Phagocyte dysfunction
Additionally, an excessive intake of specific nutrients has also been shown to have negative effects on immune function . This makes nutrition more of a balancing act than a race. And without proper balance we become weaker and less likely to perform to our full potential.
But if the list above is no where near complete, what’s the point of it? Well, it’s purpose is to simply underline the fact that a balanced diet is crucial for healthy immune function.
The importance of nutrition during pregnancy
Immune system alterations caused by nutritional deficiencies that exist during pregnancy may have a significant chance to carry over to the children .
Most Common Nutritional Deficiencies
Though there is a huge number of possible nutritional deficiencies, some are more likely to occur than others. Accordingly, it makes sense to quickly review some of the most common ones known to date.
Here is a list of common micronutrient deficiencies in the United States (the percentages represent estimated number of individuals not meeting requirements) :
- Vitamin D (70%) – essential for normal absorption of calcium and immune modulation
- Vitamin E (60%) – provides protection against free radical damage
- Magnesium (45%) – important component of various bodily processes
- Calcium (38%) – required for a variety of metabolic functions and bone health
- Vitamin A (34%) – helps maintain the integrity of epithelial tissues (surface linings of eye, intestinal tracts, etc.)
- Vitamin C (25%) – assists a large number of biological functions
This means that a significant portion of the population is lacking in some essential micronutrients. And this may, in part, explain the rise in various health problems and degenerative disease in the last several decades.
Viewing each nutrient by itself is unlikely to provide any real benefit. Evaluating dietary habits that lead to these sort of deficiencies may prove much more useful in the long term.
How beneficial is supplementation?
Supplementation has shown to be the most effective in high risk population or specific cases. Uneducated supplementation and/or superfood consumption may carry a high risk of side effects. Obtaining adequate nutrients from diet appears to be the best method of obtaining the right mix of nutrients our bodies need for adequate immunity.
Macronutrient Balance Must Also Be Considered
Additionally, we must also consider the balance of macronutrients (protein, fat and carbohydrates) as it appears that a proper balance and quantity is essential for stable immune functioning.
Some key findings relevant for macronutrients include:
- The relative amounts of each macronutrient can steer the overall direction of our immune system 
- Large amount of dietary fats can negatively affect the immune response 
- Balance of omega 3 to omega 6 fatty acids has a strong impact on the immunity and inflammation 
Once again, this list is also nowhere near complete. It is just included to show that what we eat directly affects our body’s abilities to defend itself.
Ending Remarks on Nutrition and Immunity
In the end, our bodies are extremely complex systems and the research on nutrition and immunity is constantly evolving. What may be considered as fact today could be proven completely wrong tomorrow. Instead of focusing on the details it may be more beneficial to shift our focus on eating a balanced diet that best fits our lifestyle.
This section discussed the important relationship between nutrition and immune function. Key points included:
- Deficiencies or excessive intakes of single nutrients have been associated with a weakened immune response and a higher risk of infection
- A weakened immune system increase the chance of infection and infection can lead to further progression of nutritional deficiencies, creating a downward spiral
- The most prominent micronutrient deficiencies in the USA include Vitamin D, Vitamin E, Magenisium, Calcium, Vitamin A and Vitamin C
- Isolating specific nutrients and their individuals effects can get quite complex, focusing on a well balanced diet is likely produce the most benefit
- Macronutrient balance has also been shown to produce significant effects on the immune response and their availability must also be considered