Assessing the Real Health Benefits of Superfoods
Foods such as kale, blueberries, chia seed and broccoli are often referred to – and labelled in shops – as ‘superfoods.’ It is claimed that these foods’ abundance of nutrients, and particularly antioxidants, can provide almost miraculous health benefits, and protect from a variety of diseases, such as dementia, heart disease, cancer and diabetes.
These claims certainly have an effect on our eating habits. Past research has found that 61% of people have bought a food or drink because it was labelled as a superfood, and we’re buying three times more quinoa, twice as much kale and three times as many almonds as we were five years ago. A recent television study has attempted to determine what the health benefits of superfoods are.
The Science Behind the Claims: Reducing Oxidative Stress
The belief is that the high levels of antioxidants in these superfoods can help to limit a phenomenon called oxidative stress.
Oxidative stress refers to harmful effects of the reactions which occur in our cells as they use oxygen to produce energy. A side effect of these reactions is the production of free radicals – highly reactive molecules which interact with other molecules in cells, causing oxidative damage to proteins, membranes and genes. This damage is involved in the ageing process, and is thought to negatively affect our health in ways which can increase our risks of all sorts of diseases.
The claims made for antioxidant-rich superfoods is that they reduce the numbers of free radicals, and therefore reduce the levels of oxidative stress in our cells, in turn increasing our general health and protecting from disease. However, the veracity of these claims and the actual positive impact of eating these foods is still not entirely clear.
The Blueberry Test
A test carried out for ITV’s Tonight, in conjunction with Newcastle University and PB Bioscience, set out to investigate the benefits of one particularly popular superfood: blueberries.
For the test, five women were asked to eat two bowls of Canadian wild blueberries every day for eight weeks. Finger-prick blood samples were then used to assess the altering levels of oxidative stress in the women’s bodies.
At the end of the eight weeks, the levels of oxidative stress was lower than previous levels for all five women. This is in line with the results of previous research by the same team, in which athletes were asked to eat 250g of wild blueberries a day for 12 weeks. In that study, the athletes saw a reduction in oxidative stress by up to 88%; the general reduction was around 70-80%, and even the lowest reduction was still 33%. This suggests there is at least some truth to the espoused benefits of eating foods with high levels of antioxidants.
The General Benefits of a Healthy, Nutrient-Rich Diet
However, this doesn’t mean that we can necessarily trust everything we read about trendy and expensive superfoods. For example, it would take 13 servings of goji berry juice to get as many antioxidants as are contained in one red apple.
Just like any food, indulging in high quantities of superfoods isn’t necessarily the most healthy way to eat, and instead it is important to maintain a mixed and healthy diet, packed with foods which contain a wide variety of different nutrients, as well as antioxidants. These foods don’t necessarily needs to be too expensive or out of the ordinary.
At the Institute for Functional Medicine conference last year, a group of experts put together by vote a list of foods which they think are especially good for our health. Their suggestions were: avocado, spinach, seaweed, pomegranate, blueberries, broccoli (and all cruciferous vegetables), grass-fed buffalo/beef, wild Alaskan salmon, almonds, coconut oil, olive oil and green tea.