From the latest "superberry" to the newest health-boosting grain, there are plenty of superfoods that promise to boost your health, but can also leave your bank balance a little worse for wear. Fortunately, not all superfoods have to cost a fortune.

If you want to improve your health while sticking to a budget, check out these seven cheapest superfoods that will leave you feeling great.

1. Oats

With the constant emergence of trendy superfood grains such as spelt, amaranth and quinoa, it is easy to forget about the humble oat. However, oats are not only cheap, versatile and widely available, but they are packed with nutrients such as zinc, iron, calcium and fibre. Oats also have many health benefits, with the ability to reduce risk of heart disease and diabetes, lower cholesterol and blood pressure levels, boost the digestive system and improve heart health.

2. Sweet potato

While sweet potatoes are not as commonly eaten as the regular spud, there are many reasons why they should form a part of your standard diet. Firstly, this healthy root vegetable is packed with minerals and vitamins such as vitamin C, manganese, potassium and iron. Furthermore, it is one of the best natural sources of the antioxidant beta-carotene, which can help lower risk of heart disease and cancer as well as being good for eye health.

3. Sardines

With omega-3 being one of the big buzzwords in healthy eating, salmon has justifiably been hailed as the latest health-boosting superfood. However, for those on a budget, swapping fresh salmon for tinned sardines can deliver the same health benefits for less than half the price. Sardines, like salmon, are packed with omega-3 fatty acids, which are good for your skin, brain and heart. On top of that, sardines are rich in protein, calcium, vitamin D and the ever-elusive vitamin B12.

4. Blackcurrants

For years the healthy eating industry has been all about the acai and goji berry . However, if you can’t afford to shell out on the latest berry du jour, you may be pleased to know that the common blackcurrant is also a superfood in its own right. Research has found that blackcurrants are more nutritious and contain more antioxidants than blueberries, raspberries and strawberries, and they can help ward off a range of diseases including cancer and dementia.

5. Tomatoes

Tomatoes are found in most supermarkets and come at a budget-friendly price, yet they are still one of the best superfoods around. The popular fruit is one of the richest sources of the antioxidant lycopene, which can help lower cholesterol, protect the heart and prevent the risk of diseases such as cancer (particularly of the prostate). Tomatoes can also help prevent blood clots and boost the immune system.

6. Green tea

When it comes to healthy drinks, acai berry juice has received a lot of positive press. However, for the same health benefits at a fraction of the price, green tea is a great alternative. While it may not be quite as exotic, green tea is packed full of antioxidants and has long been renowned for its health-boosting properties. Some of the benefits of green tea include its ability to speed up the metabolism, ward off wrinkles, boost the immune system and protect against cancer.

7. Beetroot

If there was ever a vegetable that truly deserved its place on your vegetable rack, then the beetroot would be it. One of the latest vegetables to be hailed as a ‘superfood’, beetroot juice is packed with antioxidants and has many health benefits including the ability to improve liver function, lower cholesterol, boost stamina for exercise and reduce risk of dementia. This cheap and healthy superfood is also a good source of folate and vitamin C.