• Adam Liaw's wine-poached beetroot with mustard cream

Not only is it a tough time of year but the significant increase in the cost of groceries is affecting many a household budget.

As we struggle through the cold and flu season, along with a rising rate of COVID infections, many of us are also facing another challenge: increasing grocery prices.

Then we are also dealing with cold and flu season, along with a rising rate of COVID infections. This presents a conundrum – you want to eat well to support immune function but do not want to have to spend $20 on the latest greens powder for an immune boost.

It will come as music to your ears to hear that some of the best food choices from a health and immune perspective are also relatively cheap, and can cost as little as a couple of dollars at the local supermarket.

Beetroot

Beetroot frequently tops superfood lists thanks to its rich vitamin C content. It's also a natural anti-inflammatory, and its high nitrate content helps to increase blood flow around the body, which can even reduce blood pressure.

With the cost of fresh fruits and vegies so high, you can still get all the nutrients beetroot has to offer via canned or bottled varieties, which you can pick up for as little as $2-3 in your local supermarket.

Add to salads, sandwiches or blend into juices for an easy nutrient-rich addition to your winter diet.

Sardines

They might not be the first type of fish you think of when considering ways to bump up your intake of omega-3s but tinned sardines are extremely rich in important fats and vitamin D, a nutrient that plays a crucial role in the immune system.

Plus, a can of sardines sells for less than $3, making it an extremely cost-effective source of protein.

Enjoy sardines on toast or crackers for a protein and omega-3 hit.

Kale

It is the exceptionally high vitamin K content that supercharges kale to the top of greens superfood lists, and while it is not the sweetest tasting vegetable, it can work well as an addition to soups or smoothies or roasted into vegetable chips.

You can also find kale frozen for as little as $1-2 per packet, which makes it an affordable green to up your vegetable intake and increase your intake of vitamin C when immunity is top of mind.

Kiwi fruit

Forget berries and even citrus fruits when prices are high, because for a dollar or less you can add a kiwi fruit into your diet and get more vitamin C than all these other foods at the same time.

Not only are kiwis extremely rich in fibre, they have almost 100mg of vitamin C or double the daily recommended intake, making them a "must-include" on any immune-boosting meal plan.

Pepitas

There are a handful of key nutrients that play an important role in immune function and zinc is one of them. But it can be challenging to find high amounts of zinc in budget-friendly foods, especially for those who prefer a plant-based diet.

Fortunately pumpkin seeds or pepitas are extremely rich in zinc, and you can pick up pepitas in the baking section of supermarkets for as little as $2 per pack.

Add a tablespoon to your favourite cereal, smoothie or salad for a cost-effective daily serve of zinc.

Plain yoghurt

There are a million different yoghurts out there with protein or aminos or even dessert added but truth is when it comes to yoghurt and our health, natural or plain Greek yoghurt with live cultures are the best bets nutritionally.

It has been shown that fermented milk-based foods help to protect the body against infection and act as an anti-inflammatory helping the immune system to work at its best.

For this reason, a daily serve of plain yoghurt with kiwi fruit and pepitas ticks the box nutritionally on a number of immune superfoods for as little as 30 cents a serve.

Garlic

Garlic has been used to treat bacteria, high blood pressure and infection for thousands of years and it is believed that the organosulfides (naturally occurring chemicals found in garlic and onions), along with vitamin D, help to stimulate the production of the immune cells, macrophages.

Like all foods, fresh is always best, and while garlic is expensive by weight, per serve its cost is extremely low.

As such it makes an excellent daily meal base to stir-fries, vegetables, curries or soups.

Bone broth

It turns out there is some evidence to support the use of chicken soup as a remedy when you're not feeling well.

The specific immune-related benefits derive from the broth within the soup.

Bone broth offers carnosine, an amino acid that helps to slow the movement of infected calls around the body.

This means that you can either utilise leftover bones to make your own broth or find cost-effective options at supermarkets to enjoy or use as a base for your favourite warming soup.

Turmeric and black pepper

Turmeric is well known for its powerful anti-inflammatory effects, thanks to the bioactive molecule curcumin.

While you can find a range of supplements that offer concentrated amounts of curcumin, the key to unlocking much of the potential benefit of curcumin is to consume turmeric with black pepper.

Pepper contains the active molecule piperine, which can significantly increase the absorption of curcumin in the body.

This means that utilising more herbs and spices in your favourite curries and sauces is a smart thing to do, but don't forget the black pepper to maximise any potential immune-related benefits.

Mussels and oysters

All seafood is rich in nutrients and shellfish including oysters, mussels and prawns contain concentrated amounts of essential minerals including iron, zinc and iodine but seafood can also be relatively expensive.

A quick trip to the canned seafood section of the supermarket though will reveal canned mussels and oysters for as little as $2-3 per serve.

Not only are these foods a rich source of quality protein but they will supply a hearty dose of both iron and zinc, nutrients that play key roles in the immune system and nutrients that tend to be low in the diets of Australians, women in particular.

And best of all, herbs, spices and pepper cost just a few cents each.

Susie Burrell is an accredited practising dietitian and nutritionist and holds a master in coaching psychology.