Online exclusive
As well as Jennifer Bowden’s columns in the NZ Listener and here at listener.co.nz, subscribers can access her fortnightly “Myth busters” column, in which she explores myths around food and nutrition. This week, she reveals the truth about so-called super foods.
Move over kale smoothies and turmeric lattes – we’re about to dive into the nutrient-packed, antioxidant-laden world of superfoods. It’s natural to seek foods that enhance our health and satisfy our hunger. So, what qualifies a food as a superfood? Spoiler alert: superfoods are regular foods with better PR teams.
Superfoods are nutrient-dense foods, rich in essential nutrients, such as essential amino acids or fatty acids, or bioactive compounds like antioxidants, that purportedly offer health benefits such as reducing our chronic disease risk, boosting immunity or improving overall health. Examples include kale, quinoa, chia seeds, flaxseeds and berries, probiotic yoghurts and salmon.
However, while the term superfood is widely used on social media and in marketing materials, no scientific consensus exists on the definition of a superfood, noted a 2022 review in Critical Reviews in Food Science and Nutrition. Moreover, the term “superfood” is not regulated under the Food Standards Australia New Zealand, explains Jenny Bishop, acting deputy director-general of New Zealand Food Safety.
“If this statement is made, whether on the food label or in marketing, it must not misrepresent the product under the Food Act 2014 and it must be truthful and not misleading under the Fair Trading Act 1986.” Thus, marketers cannot claim their food is a “superfood” with health effects it does not possess.
Case in point: acai berries. They peaked in popularity around 2010 with claims that acai berries were a superfood that boosted weight loss, had numerous health benefits and had a high antioxidant content.
However, in 2013, the US Federal Trade Commission fined online marketers of acai products millions of dollars for their misleading claims about acai berries and weight loss because there is no evidence they promote weight loss. Moreover, weight loss is not a proxy for good health – but that’s a topic for another day.
While a few trials suggest acai berries may help lower cholesterol and manage blood sugar, similar or more significant benefits are seen with other berries. For example, a 2022 review in Food & Function found blueberries may improve blood pressure and cholesterol levels. Acai berries do not uniquely deserve a “superfood” crown, as almost all edible berries are highly nutritious and beneficial to our health.
Moreover, while it’s common to base superfood claims on high antioxidant levels, this is misleading because high antioxidant levels do not automatically translate into biological effects, explains Dr Carolyn Lister, principal scientist & science team leader - food & health information at the New Zealand Institute for Plant and Food Research.
Lister explains that antioxidants have different absorption rates and biological effects in the human body. In other words, claims about high antioxidant levels do not guarantee a health benefit.
Affirming that point, an Australian study published in PeerJ found differences in the nutritional composition and antioxidant properties of superfood seeds: flax, chia, sunflower and hemp, did not directly correlate with the improved health of cells in their lab-based studies. Nutritional factors in the seeds, besides antioxidants, seemingly affected the health of cells.
Similarly, a 2018 review found inconsistent links between superfood intake and changes in blood pressure, cholesterol levels and blood glucose levels of study participants. Those inconsistencies might be caused by how researchers ran the clinical trials, or they may affirm that foods claiming to be “superfoods” have inconsistent health effects.
Life would be easy if we gained super nutrition and health by eating one or two “superfoods”. But the reality is that superfoods are just representatives of nutritious food groups.
You’ll likely crack the superfood code if you eat a predominantly plant-based diet daily, containing plenty of fruit, vegetables, legumes, nuts, olive oil, wholegrains, a moderate fish and poultry intake, dairy products and some lean meats.
Explains Lister, “No one food is “super”, and there is nothing we could live on alone. Each food contributes a different array of nutrients and phytochemicals. It is the combination of foods that we eat that is important to get the diversity of health-promoting compounds we need.”
