We are often bombarded with headlines about ‘superfoods’ - but what are they, and are there benefits to including them in our diets?
There is actually no definition of a superfood and no way of testing whether a food is 'super' or not. The term is sometimes used in the media to describe a food that is rich in a particular nutrient or other bioactive substance.
Marketing superfoods is illegal in Europe unless there is substantiated research to support the view that they make a difference to a particular medical condition.
You may be interested to know about why some foods have been given this label, so keep reading for a few examples of foods that have been described as having extra properties, particularly when it comes to cancer prevention or health. It may help you decide whether it is worthwhile choosing such foods.
Fruits such as blueberries and pomegranates
Fruits provide an excellent source of vitamins and minerals as well as substances called ‘phytochemicals’. Phytochemicals are the substances in plants that are responsible for the colour, flavour or smell of the plant or fruit.
It is important to remember that, in most dietary studies, these substances have usually been extracted from the plant and then examined in the laboratory setting rather than seeing how they work in humans. That’s why it is really hard to find big studies conducted with humans and with brilliant evidence.
Research suggests that some of these substances may have a particular action in the laboratory, for example, antioxidant properties or be able to influence cell growth.
In real life, we eat fruit and vegetables rather than the individual substances contained within them, and we know from many studies that the best diet is one that is plant-based and includes moderate amounts of animal protein foods.
Including a wide variety of fruits and vegetables is the best way of getting the range of vitamins, minerals, dietary fibre and other phytochemicals.
Perhaps think of ways to increase the variety of vegetables and fruit in your diet rather than feeling you need to choose those that appear to be fashionable (these can sometimes be expensive too). Consider ways of increasing the variety you eat to maximise the range of nutrients that fruit and vegetables provide.
Green tea can be a delicious refreshing drink but does it have special properties? It contains substances called polyphenols which in laboratory studies have been shown to interfere with the way cells multiply causing them to die.
The polyphenols act as antioxidants but whether they actually influence the risk of cancer remains to be seen.
Green tea can affect the absorption of nutrients such as iron and can interact with some medications, so it is always advisable to check with your pharmacist before taking large amounts of any alternative or complementary substances.
Cocoa contains flavanols, a type of polyphenol and therefore similar to the substances described in other food items such as tea, coffee, fruit and vegetables. Reports on the potential health benefits of dark chocolate, which include heart health, the immune system and cancer, are generally focused on the effects of high amounts of flavanols.
Often these are given as capsules, drinks or occasionally as chocolate which is known to contain high amounts of flavanols.
There have been some interesting findings relating to heart health, but it usually not possible to know how much of these products are actually present in chocolate.
Dark chocolate has higher amounts of cocoa solids but the amount of flavanols is usually not provided on the label. Chocolate (even dark chocolate) is high in energy, fat and sugar, and therefore is one of those foods to be enjoyed in moderation.
Turmeric is a root that has been used as a spice for many years. It contains substances called curcuminoids.
In the laboratory, these substances reduce inflammation and have been demonstrated to increase the activity of substances that reduce DNA damage. Animal studies have shown that turmeric has protective effects against some types of cancer including those of the colon, stomach and skin.
Some studies in people at high risk of colon cancer have failed to demonstrate any effectiveness of curcumin when compared to a placebo. There are a number of studies underway to determine the safety of taking curcumin and whether it has any health benefits.
Studies on curcumin generally use concentrated supplements rather than the quantities of turmeric that would be consumed in a normal diet. The amounts that are used are often approximately 10 – 20 times the amount that would be consumed in the average Indian diet.
Turmeric is a great spice to add flavour and colour to your food, but at the moment the jury is out on what effect it may have on health and whether it is possible to eat the amounts that are being tested in research.
How do you know if any article is reliable?
- Look at where it is written – is it from a reliable source or is it just someone’s opinion on social media?
- Does the article say whether research has been done in the laboratory? Has it been tested on humans or animals?
- If what you hear about a food sounds too good to be true... it usually is.
This does not mean there isn’t any value in including these foods in your diet, but take the hype with a pinch of salt.