The latest ‘superfoods’ to hit the scene, these exotic berries and seeds are a marketer’s dream. But are they what they claim to be? Dietitian Kate Marsh finds out.
Goji berries, also called Chinese wolfberries, have long been used in traditional Chinese medicine. In Australia, they are available as a dried fruit, which looks similar to red sultanas, or as a red juice. Marketers claim a long list of health benefits, such as promoting longevity, improving metabolism, treating impotence, preventing cancer and cleansing the blood.
A number of studies have shown that they display antioxidant properties, and a study published earlier this year in the journal Nutrition Research found that daily consumption of 120ml of goji juice was able to improve antioxidant markers in healthy adults. However, at around $50 per kilogram for the dried fruit or $40 per litre for the juice, they don’t come cheap. There is also some evidence that goji berries may interact with the medication warfarin – increasing the risk of bleeding. Generally, it is a good idea to check with your doctor before trying goji berries.
Goji berries do appear to be a rich source of antioxidants, but whether they are significantly better than other antioxidant-rich foods (and can thus justify their hefty price) remains to be seen.
Marketers claim this dried blue-green algae extract is a ‘superfood’ with more nutrients than any other plant, grain or herb. Allegedly, it has three times more protein than meat, 10 times more calcium than milk and is a plant source of vitamin B12 (usually found in animal foods).
Sounds impressive! However, a typical serving size of spirulina is only around 3g, providing less than 2g protein and around 4mg calcium (when adults need around 50–60g protein and 1000mg of calcium per day). And the B12 found in spirulina is inactive, so it’s of no use to the body and can even interfere with the absorption of the active form of this vitamin.
Spirulina doesn’t contain any special nutrients, and while it may be a rich nutrient source gram-for-gram, it won’t contribute greatly to your nutrient intake in the quantities recommended.
Açaí berries are the fruit of a palm native to Central and South America. In Australia, they are available as a juice made from fresh or dried pulp. While studies have shown that the juice does exhibit some antioxidant activity, a 2006 Brazilian study found that the berries had less antioxidant activity than a number of other fruit, including mango, strawberries, and grapes, but more than guava, passionfruit and pineapple.
A 2008 US study compared the antioxidant activity of a variety of juices and found that açaí berry juice had more antioxidant activity than orange or apple juice and similar levels to black cherry and cranberry juice, but less than red wine, pomegranate, blueberry and grape juices.
At around $60 per litre, açaí juice seems to be an expensive means of obtaining antioxidants that could easily be obtained from other fruits or juices.
Like other seeds, chia (which look like tiny black or white sesame seeds), are a rich source of healthy fats, especially omega-3 fats, which are mainly found in seafood. Also high in fibre (around 37 per cent), chia may help lower cholesterol and control blood glucose and insulin levels. If that isn’t enough, chia seeds also contain a rich mix of vitamins and minerals, including iron, calcium, magnesium and potassium. A 10g serve (about 1 dessertspoon) provides a useful amount of iron and calcium and it supplies more than the adult RDI of the plant-based omega-3 fats alpha-linolenic acid.
So are they worth their often expensive price tag? Some would argue that flaxseeds contain similarly beneficial nutrients, but chia seeds don’t need to be ground for these nutrients to be absorbed – so yes.
This is one ‘miracle’ food that lives up to the hype. Flaxseeds offer similar benefits for less money, but they need to be ground up for us to properly absorb their nutrients. So, chia gets a tick for convenience.