1. Eat 2 Brazil nuts everyday.  In New Zealand, we have low selenium intake, due to low levels in our soil. Two Brazil nuts provide over 100% of your selenium requirements, which helps with immune function. However, don't be tempted to down a whole handful - Brazil nuts are such a potent source of selenium that too many can be harmful.

2. Enjoy vitamin C foods, rather than taking supplements, since there are so many other benefits of fruit and veg that science hasn't figured out yet. When scientists think that they know why a certain fruit or veg is beneficial, they often try to test it in a supplements, but most of the time the supplement doesn’t show that benefit, and sometimes even shows harm.

Foods that are high in vitamin C include citrus fruits, kiwifruit, capsicum, and even kumara.

3. Prioritise immune-boosting superhero foods, which are those that are high in zinc and beta-carotene.

Zinc warriors include oysters, mussels, steak, chicken, whole grains, and dairy.

Beta-carotene crusaders include carrots, capsicum, pumpkin and kumara (think orange foods), broccoli and spinach.

4. Sip on a steamy cup of green tea. Green tea might help you fight off viruses and colds. Plus it’s super important to stay hydrated in the winter, so this is a good choice.

Photo by Benjamin Balázs, Flickr