The Diet Therapist
WHAT EXACTLY IS A
ARE THESE FUNCTIONAL FOODS WITH BENEFITS OR IS THE TERM JUST A MARKETING PHRASE?
What does the term 'superfood' actually mean?
Posted by The Diet Therapist, 24th February 2017
Most people are now familiar with the term “superfood” thanks to its increasing prevalence in the media, on food packaging, in cafes, and within cookery books. Often the word is used in conjunction with health promises – to help you live longer, lose weight or look younger. But what does it actually mean? What is a “Superfood?”…
The term “Superfoods” does not actually have a precise scientific or legal definition but it commonly used to loosely refer to foods that are thought to be particularly nutrient-dense. You can even find an entry in the Oxford English Dictionary where a superfood is defined as:
“A nutrient-rich food considered to be especially beneficial for health and well-being.”
So…what exactly makes them so “super?”
“Superfoods” are really a sub-set of what are termed “functional foods.” The British Nutrition Foundation defines functional foods as those that “deliver additional or enhanced benefits over and above their nutritional value”. Some of these are classified by virtue of one specific functional ingredient - for example probiotic containing yoghurts or plant sterol rich spreads – or because they are fortified with a nutrient that would not naturally be present in that food, e.g. folic acid enriched bread.
Often the word “superfood” is used in relation to fruits and vegetables that are especially rich in phytochemicals (plant-derived chemicals), which might be antioxidant micronutrients (e.g. Vitamin C) or other classes of plant “bioactives” such as phytosterols or polyphenols.
In nutrition terms, plant “bioactives” literally means compounds in plant foods that are known or thought to have an effect on a tissue or cell. Usually when you read about these, these effects are linked to a suggestion of a positive or potentially beneficial effect on overall health, e.g. anthocyanins (polyphenols) in pomegranate, lignans (phytoestrogens) in flaxseed, or specific fatty acids (phytosterols) in nuts and vegetable oils. Bioactive compounds can also be found in animal products, such as the fatty acids found in milk and fish, and are sometimes produced synthetically in a lab.
These compounds are different from other nutrients you read about (macronutrients – fats, carbs and protein, and micronutrients e.g. vitamins and minerals) as they are not thought to be essential for your body to sustain life and often, other nutrients have similar functions to these bioactive compounds, e.g. antioxidant activity.
So basically, superfoods are foods found to contain high levels of antioxidants or other compounds – some of which have been associated with potential health benefits.
Should we all be eating “superfoods?”
One of the accusations levelled against the use of the term “superfood” is that it is often a very useful marketing term for up-selling products and used as justification by food manufacturers and retailers for a higher price point. A couple of years ago, when the term was used it was mostly associated with exotic, nutrient-dense foods which were frequently imported and came with an associated narrative of their cultural consumption or medicinal use in other parts of the globe. For example, goji and acai berries, coconut oil, maca, lucuma, Spirulina, chlorella, raw cacao, goldenberries, and chia seeds. But more recently, nutritionists and dieticians have pointed out that by virtue of their nutritional content and the functional benefits of some of the health-promoting compounds present, some of our more traditionally recognisable supermarket foods like broccoli, green tea, berries, salmon, kale, garlic, pomegranate and pumpkin seeds can also be termed “superfoods.”
This is really confusing…so, what makes a particular food count as a “superfood?”
Companies selling superfoods tend to orientate their marketing narrative around the nutritional benefits of their products and this has language has now infiltrated healthy eating blogs, healthy recipe books and social media. Yet often, there is a real lack of broader context when you read claims such as “acai has more anti-oxidants than any other food on the planet and are loaded with omega-3 fatty acids.”
This actually came up on one of the top 5 websites that appeared when I typed in “acai berries AND nutrition AND health benefits” into Google. I’m pretty sure that the former claim is not true (although Acai does have a high ORAC value which is a measure of antioxidant activity), and the second is false. It’s actually really hard to find the nutrient composition of acai berries, but a 2006 study in the Journal of Agricultural and Food Chemistry by Schauss et al., found that oleic acid (omega-9) comprised 56.2%, palmitic acid (a saturated fatty acid found in butter, cheese and dairy) made up 24.1% and linoleic acid (omega -6) 12.5%. The amount of omega-3 fatty acids contributed less than 0.1% of the fatty acid composition.
Acai berries have lots of nutritional benefits and are high in antioxidants as well as other micronutrients and some plant sterols. But my point is that it is easy to find misinformation about lots of “superfoods” that gets repeated and creates a mythical status around these foods that just isn’t true. For the record, I do believe that acai has lots of nutritional benefits, and I love it when it’s blended into smoothies and topped with granola and nut butter.
I just happen to also believe that the antioxidants in kidney beans, courgettes, apples, blueberries, aubergines and a whole host of other foods are just as important for overall health and equally “valid” as sources of nutritious and bioactive compounds.
Why is one more “super” than the other just because it contains higher levels of a certain antioxidant?
The complex bit: Phytochemical Synergy…
Another thing to remember is the importance of what is called pharmacodynamics and phytochemical “synergy”. This is the idea that the “whole is greater than the sum of the parts” with specific foods. The researchers looking at the antioxidant compounds of the acai berry (above) noted that the high overall antioxidant capacity (ORAC value) which has been noted frequently was believed to be due to the main antioxidant phytochemicals (anthocyanins and flavonoid compounds) present in the fruit.
Yet the researchers estimated that only 10% of the antioxidant capacity was down to the contribution of these compounds…suggesting that “compounds that have yet to be identified are the major antioxidants in acai berries.”
This has been shown to be the case for lots of foods; the total antioxidant capacity is often not related to the amount of one micronutrient (e.g. Vitamin C) that is present. Lots of different compounds present in wholegrains, fruits, vegetables, beans, and fatty fish work together to exert effects at a biochemical level. And we don’t yet know how this works exactly, or even (as with acai) what some of these compounds are.
The Bottom Line:
I have no issue at all with people eating more foods that are high in antioxidants and other phytochemicals and bioactive compounds. I love many of the foods touted as “superfoods” (especially blueberries, maca, chia and chocolate) and I quite like a wholefood-based powder to give an extra dose of nutrients/antioxidants when I’m feeling particularly stressed or really tired. My issue is that focusing on the nutritional benefits of particular foods and labelling these as “super” can mislead people to think:
These are “super” high in antioxidants and healthful nutrients and eating lots of these rather than a broad range of other healthy foods is “better.”
That other foods are somehow nutritionally inferior.
The reality is that eating a diverse range of foods, particularly beans, wholegrains, fruits and vegetables and fatty fish provides you with lots of different nutrients that are beneficial for health. You don’t need to spend tons of money on “superfoods” to increase the nutrient-density of your diet or to up your intake of antioxidants through a range of different foods.