Winter Wellness: "Can Eating Right Keep Me from Getting Sick?"

Victoria Biddick, NZ Associate Registered Nutritionist

The advice below is general advice, for any specific tailored advice relevant to any health conditions please talk to your health professional

As temperatures drop and the cold and flu season settles in, you may be wondering whether your diet can help protect you from seasonal illnesses. In this article, we explore how nutrition influences immunity, whether smart food choices can keep you healthier this winter, and the truth behind common immunity myths.

Can Food Really Boost Immunity?

With the growing interest in immune health, many people seek ways to enhance their body's defenses. However, one of the biggest misconceptions is the idea that a single food or supplement can "boost" immunity instantly. This belief can sometimes overshadow the importance of an overall balanced diet.

A balanced diet is rich in essential vitamins, minerals, and antioxidants plays a key role in supporting the immune system. Nutrients like vitamin C, vitamin D, zinc, and probiotics contribute to immune function, helping the body fight infections more effectively. While food supports immunity, no single ingredient can provide complete protection from illness.

What is our Immune System?

Our immune system is the body’s defense mechanism against infection from germs, including bacteria, viruses, and other foreign substances. It is a complex network that consists of organs, tissues, cells, and molecules all working together to protect our health (1).

Diet and Immune Function

Our immune system is influenced by multiple factors, some like age and genetics, are beyond our control. However, lifestyle choices can play a significant role in maintaining a strong immune system (1).

Key lifestyle behaviours that support immunity include:

· Eating a diverse range of nutrient-rich foods

· Staying physically active

· Getting enough sleep

· Managing stress and limiting alcohol intake

· Avoiding smoking

A well-functioning immune system requires a variety of essential micronutrients in adequate amounts. Some of the key immune-supporting vitamins include A, B6, folate, B12, C, D, and E, alongside important trace minerals such as copper, iron, selenium, and zinc. These nutrients work collectively to enhance immune function, contributing to the body's ability to defend itself against illness (1).

Additionally, several vitamins and minerals particularly A, C, and E, along with zinc and selenium possess antioxidant and anti-inflammatory properties that further support immune health. Phytonutrients, found in all fruits and vegetables, also play a vital role in protecting cells and reinforcing the body’s natural defenses (1). For more information on vitamins and food sources read this Vitamins - NZ Nutrition Foundation

Protein and Immune System

Protein also plays an important role in supporting immune function. It provides the building blocks for immune cells, antibodies, and enzymes that help defend the body against infections. Good sources of immune-supporting protein include lean meats, fish, eggs, dairy, legumes, nuts, and seeds (3)

What about Pre and Probiotics and Immune Function?

The gut microbiome is a diverse ecosystem of bacteria and microorganisms living in our gut and plays an important role in immune health. A well-balanced microbiome supports the body's ability to fight infections and maintain overall well-being (1).

Some people take probiotic supplements, which contain live bacteria, or prebiotics, which are food components that nourish beneficial gut bacteria. Research into the potential benefits of pre, and probiotics is ongoing. However, we do know that eating a diet rich in fibre-packed plant foods (such as fruits, vegetables, nuts, legumes, and wholegrains) can naturally promote a strong microbiome. Probiotics can also be consumed naturally through foods like yoghurt, sauerkraut, kimchi, and other fermented products (1).

Do I Need to Take Dietary Supplements to Support my Immune System?

While supplements can help fill nutritional gaps, they cannot replace the benefits of whole foods (1).

Research into the effects of specific nutrients on immunity has produced mixed findings. Some studies suggest that vitamin C and zinc supplements may slightly reduce the duration or severity of the common cold (2). However, excessive intake of vitamin C (over 1,000mg per day) can cause digestive discomfort.

Some people may struggle to get enough nutrients through diet alone, such as during pregnancy or with conditions that impact nutrient absorption such as Crohn’s and Coeliac disease. In these cases, healthcare professionals such as GP’s, nutritionists and dieticians can recommend appropriate supplements to prevent deficiencies and support overall well-being (3).

If you are taking a supplement you need to be aware that there can also be risks. For example, when taking fat soluble vitamins such as A and D they can build up to toxic levels in the body, so don’t exceed recommended daily allowance (listed on the bottle) and consider food sources of these vitamins in your diet as they contribute to daily allowances too (3).

Eating Right can Help with Winter Wellness!

While there’s no magic ingredient that instantly "boosts" immunity, nourishing your body with the right nutrients can strengthen your immunity and support overall wellbeing. Supplements can help fill gaps when needed, but they’re no substitute for wholefoods. Beyond diet, factors like regular exercise, adequate sleep, and stress management also influence immunity

If you're unsure whether you're getting the nutrients your body needs, a nutritionist can offer expert advice, tailoring your diet to support your unique requirements and immune health. Email victoria@vbnutrion.nz if you’d like some nutrition support for your winter wellness.

References

1. Calder, P. C. (2020). Nutrition, immunity and COVID-19. *BMJ Nutrition, Prevention & Health*. https://doi.org/10.1136/bmjnph-2020-000085

2. Hemilä, H., & Chalker, E. (2013). Vitamin C for preventing and treating the common cold. The Cochrane database of systematic reviews, 2013(1), CD000980. https://doi.org/10.1002/14651858.CD000980.pub4

3. Whitney,E.,Rolfes,S.,Crowe,T.,Walsh.,A(2019).Understanding Nutrition.(4th Australia and New Zealand ed.).Cengage Learning.

4. HealthEd. (2020). Behind the hype: Food and immune function (NPA268). Retrieved from HealthEd

Victoria Biddick is available at Halswell Rd Clinic on Thursdays. To book an appointment, call 03 3224506 or go to VICTORIA BIDDICK NUTRITION.