Today, we cover proposed nutrients/supplements to improve immune resistance.

Immune resistance can be considered as our immune weaponry that protects us by destroying viruses, pathogens and microbes.

Next week, we’ll cover the proposed nutrients/supplements to improve immune tolerance, i.e. our ability to endure and control infection.

In a recent review, Neil Walsh (2019) identified 7 nutrient/supplements and examined their level of benefit in preventing upper respiratory infections (URI) in athletes (not COVID-19):

𝟭) 𝗭𝗶𝗻𝗰:

Potential = Zinc deficiency results in impaired immunity, is required for DNA synthesis and functioning of immune cells.
Supplement Benefit = No support for preventing URI. Regular high dose supplements can decrease immunity and should be avoided. More is not more, just don’t be deficient.

𝟮) 𝗚𝗹𝘂𝘁𝗮𝗺𝗶𝗻𝗲:

Potential = Acts as an energy source for immune cells (lymphocytes) and circulating levels are lower after heavy training.
Supplement Benefit = Supplementing before and after exercise does not alter immune function. There’s some evidence for reduced URI incidence after endurance events through daily supplementation.

𝟯) 𝗖𝗮𝗿𝗯 𝗱𝗿𝗶𝗻𝗸𝘀/𝗴𝗲𝗹𝘀:

Potential = Maintains blood glucose during exercise, lowers stress hormones and counters immune dysfunction.
Supplement Benefit = Limited support that consuming 30-60g carbs/hour during exercise reduces infection risk. Carbs during can dampen stress hormone, but not all changes in immune function.

𝟰) 𝗕𝗼𝘃𝗶𝗻𝗲 𝗖𝗼𝗹𝗼𝘀𝘁𝗿𝘂𝗺:

Potential = Claimed to improve mucosal immunity and improve resistance to infection – contains antibodies, cytokines and growth factors.
Supplement Benefit = Limited support showing a decreased incidence in URI from maintaining mucosal immunity after heavy exercise.

𝟱) β-𝗚𝗹𝘂𝗰𝗮𝗻𝘀:

Potential = Found in cell walls of yeast, fungi, algae and oats: Claimed to stimulate innate immunity.
Supplement Benefit = Effective in mice with the influenza virus, however studies with athletes show no benefit to immunity and mixed results for URI incidence.

𝟲) 𝗘𝗰𝗵𝗶𝗻𝗮𝗰𝗲𝗮:

Mechanism = Herbal extract claimed to enhance immunity through enhancing macrophage function (detecting, engulfing and destroying pathogens).
Supplement Benefit = Meta-analysis shows small reduction in URI incidence but no influence on duration in general population. Unclear findings in athletes – more research needed.

𝟳) 𝗖𝗮𝗳𝗳𝗲𝗶𝗻𝗲:

Mechanism = Immune cells express receptors that caffeine can bind to.
Efficacy = There’s evidence that caffeine can activate lymphocytes and reduce the decline in neutrophil function after exercise. No known evidence for reducing URI in athletes.

Long story short, there’s some nutrients/supplement that may benefit your immune weaponry, but the MOST IMPORTANT THING is to not be deficient in anything in order to maintain immune function. The additional ‘immune boosters’ really don’t do too much in shielding us from infection.

Therefore, we should perhaps place our focus on nutrients/supplement that can improve immune tolerance. Next week I cover; probiotics, vitamin C, D, E, Omega 3’s and polyphenols.