Immune Boosting vs Immune Modulation: What Your Body Really Needs

Everyone wants to "boost" their immune system, especially during cold and flu season. But here's the truth: boosting your immune system isn't actually what you want. In fact, research suggests it could cause more harm than good.

The human immune system is miraculous and complex, essential for combating pathogenic microorganisms, preventing infections, and maintaining health. It comprises various layers: physical and biochemical barriers; specialised immune cells for acute responses and immune memory; antibodies that specifically target pathogens; and other factors that address damage caused by external agents or pollutants.

It's no surprise that immune health has become a priority. In 2022, immune system health was rated the most important topic in food, beverage and healthcare products by a FONA survey¹. During the COVID pandemic in 2020, the hashtag "#immunebooster" surged by 46% in just two months². But all this focus on "boosting" may have led us astray.

The idea of boosting your immune system sounds appealing. Who wouldn't want stronger defences against illness? However, this concept is scientifically misleading.

Your immune system isn't meant to be "stronger"; it's meant to be balanced. An overactive immune system doesn't make you any better protected. It can actually attack your own healthy cells (autoimmunity) or overreact to harmless substances (allergies). Think of it like a thermostat: you don't want it stuck on "high heat", you want it to respond appropriately to the temperature.

The focus should be on supporting a balanced immune function rather than simply making it "stronger." If the immune system were to be boosted and react more intensely to everything, this could favour autoimmune reactions or allergies, in which the immune system overreacts to non-harmful stimuli or to healthy body cells. To respond appropriately, your immune system needs to be balanced rather than boosted.

When Symptoms Are Actually a Good Sign

Here's another common misconception: many people believe that getting sick means their immune system is weak. They think that if they could just "boost" their immunity enough, they'd never get sick at all.

In reality, experiencing symptoms like fever, inflammation, or a runny nose is often a sign that your immune system is working as it should. These responses may show your body is actively fighting off threats. You don't necessarily want a "stronger" immune system that never produces symptoms. Instead, you want a balanced one that reacts appropriately when needed³. An overresponse can be as problematic as a weakened response.

Nutrition plays a crucial role in supporting an optimally functioning immune system by providing immune cells with adequate amounts of macro- and micronutrients. When nutrition isn't sufficient, or a micronutrient deficiency is present, supplements can help fill the gap.

Supplementation can be particularly important for more vulnerable groups, including the elderly, people at higher risk of severe infections, or those affected by lifestyle factors such as chronic stress.

Key Nutrients for Immune Function

Vitamin C, vitamin D, and zinc are the micronutrients with the strongest established relationship to immune system function. However, many others also play important roles, including folic acid, vitamin B12, copper, selenium, and more⁴. In fact, various micronutrients hold EFSA-approved claims that they "contribute to the normal function of the immune system."

People managing long-term health challenges may be particularly affected by immune dysfunction and may benefit from supplementation, dietary modifications, and lifestyle changes to support their immune system.

While more large-scale studies are needed, existing research has demonstrated promising results for certain nutrients:

Vitamin C: High-dose supplementation in people with a common cold has been shown in studies to help reduce cold duration and/ severity⁵.

Zinc: Zinc supplementation has been associated with reduced cold duration and/or severity in both children and adults in some publications^6,7.

Elderberry: Research suggests elderberry extract may be a safe option for supporting the body during viral respiratory infections. Studies have indicated it may be associated with lower severity in influenza infections and may help reduce the duration and severity of colds⁸.

The keyword here is support. These nutrients may help your immune system function optimally without overstimulating it. Further standardised, well-characterised clinical trials are still needed to investigate the possible effects of supplementation on infection risk and management, particularly across different populations.

Remember, the goal isn't to boost your immune system; it's to support its natural balance. Here's how:

Lifestyle Foundations

Healthy Sleep: Prioritise quality sleep and good sleep hygiene. Your immune system may perform important repair and maintenance work while you rest.

Balanced Diet: Focus on unprocessed organic foods, healthy fats and oils, and dietary fibre. Eating seasonally and including plenty of nutritious and immune-supporting foods may be beneficial.

Moderate Exercise: Regular, moderate physical activity may support immune function. Overtraining can potentially suppress immunity.

Stress Management: Where possible, manage stress through practices like mindfulness. Chronic stress can significantly impact immune balance.

Targeted Nutritional Support

In accordance with your healthcare professional's guidance, consider targeted supplementation where needed:

• Botanical immunomodulators such as β-glucans, astragalus, and cordyceps

• Adaptogens like rhodiola to help your body manage stress

• Key micronutrients including vitamin C, selenium, zinc, and vitamin D

Infection Prevention Basics

• Regular hand sanitising

• Get recommended vaccines

• Avoid close contact with people who are unwell

• Dress warmly in winter with protection for ears and throat

• Enjoy warm, healthy drinks like lemon or ginger water and herbal teas

¹ mccormickfona.com “Immunity Insights: Immune System Health in the Food & Beverage Space”, January 7, 2022. Accessed December 2025

² Wagner, Darren N., Alessandro R. Marcon, and Timothy Caulfield. "“Immune Boosting” in the time of COVID: selling immunity on Instagram." Allergy, Asthma & Clinical Immunology 16.1 (2020): 76.

³https://www.cedars-sinai.org/blog/boosting-your-immune-system.html accessed December 2025

⁴ Gombart, Adrian F., Adeline Pierre, and Silvia Maggini. "A review of micronutrients and the immune system–working in harmony to reduce the risk of infection." Nutrients 12.1 (2020): 236.

⁵ Hemilä, Harri, and Elizabeth Chalker. "Vitamin C reduces the severity of common colds: a meta-analysis." BMC Public Health 23.1 (2023): 2468.

⁶ Wang, Min Xian, Shwe Sin Win, and Junxiong Pang. "Zinc supplementation reduces common cold duration among healthy adults: a systematic review of randomized controlled trials with micronutrients supplementation." The American journal of tropical medicine and hygiene 103.1 (2020): 86.

⁷ Vakili, Rahim, et al. "Effects of zinc supplementation in occurrence and duration of common cold in school aged children during cold season: a double-blind placebo-controlled trial." (2009): 376-380.

8 Tiralongo, Evelin, Shirley S. Wee, and Rodney A. Lea. "Elderberry supplementation reduces cold duration and symptoms in air-travellers: A randomized, double-blind placebo-controlled clinical trial." Nutrients 8.4 (2016): 182.