Eating for Immunity: How to support your immune system this winter

27 May 2019

Colds and flus are an unfortunate part of the winter months. The best way to prevent them is with thorough and frequent handwashing and a flu vaccine. While even the best diet can’t stop you getting ill entirely, poor nutrition over the winter months can make you more susceptible to illness and infection and inhibit your recovery. A few small dietary improvements over the winter months can improve immune function to reduce the number of colds we get and recover more quickly.

Fruits and vegetables
Fruits and vegetables are natural immune boosters that are full in antioxidants, vitamins and minerals to strengthen the immune system. They also contain fibre which is not only important for your bowel, but also your gut microbiota which play a role in your immunity. Before you reach for a multivitamin to keep you going, make sure you’re getting enough fruit and vegetables every day.

Vitamin C
Vitamin C is known to boost the immune system and make colds milder and shorter. This common vitamin is found in most fruit and vegetables, especially kiwi fruit, cabbage, beans, broccoli, capsicum and sweet potatoes. The recommended dietary intake to avoid deficiency is just 45mg (which you can get from eating one orange or half a capsicum). However, Studies have shown that high dose supplements, such as 1,000mg a day, to be effective at improving cold and flu symptoms*.

Zinc increases the production of white blood cells which work to destroy invading bacteria and therefore can assist in fighting infection. The current daily recommendations for zinc is  8mg for women and 14mg for men. This is available through diet by eating plenty of fish, oysters, poultry, eggs, milk, unprocessed grains, and wholegrain cereals.

Probiotics + Probiotics
A large proportion of your immune system is located in your gut. Probiotics are healthy bacteria that live within your gut and help to keep the digestive system free from nasty bacteria which can lead to illness and infection. Plain pot-set yoghurt, kefir, kimchi and sauerkraut are good source of probiotics and contain live cultures such as Lactobacillus Bulgaricus. It is just as important to take care of your existing gut bacteria by eating plenty of plant foods high in dietary fibre and limiting unhealthy processed foods. It is unclear if probiotic supplements are effective for treating cold and flu, so invest in fruits, vegetables, natural yoghurt and wholegrains instead. 

Extreme Diets
Research has shown that very low-kilojoule or very high-kilojoule diets can decrease our immune function. Avoid drastic dietary changes like fad diets, detoxes or missing meals. Falling off the healthy eating wagon and suddenly eating more unhealthy foods isn’t a good idea either. This could be true for people who eat very well and exercise throughout the week and then overindulge in treat meals and alcohol on the weekends. Chose healthy meals often and eat regularly to keep your immune system happy and healthy.

* Talk to your GP or pharmacist before taking any supplements, even if it is bought over the counter.