Superfoods: Nutrition Superstars or Merely Super Marketing?
Stacy Kennedy, MPH, RD, CSO, LDN
Senior Clinical Nutritionist
Dana-Farber Cancer Institute
It’s hard to go grocery shopping lately without being tempted to supercharge your health with superfoods. Globally, reports show a 36% increase in the number of foods and beverages featuring “superfood” on their labels, with the US consuming more than any other country. Popular examples include goji and acai berries, green tea, chia, flax and hemp seeds, teff, sprouts, pomegranate, cacao, maca, Kombucha and spirulina/chlorella/algae. Superfoods expected to hit the mainstream American marketplace in 2018 include watermelon seeds, chaga mushrooms, tiger nuts and maqui berries.
The bad news: no one really knows exactly what a superfood is. While the E.U. clamped down on the unsubstantiated use of the term “superfood” in 2007, food marketers in the U.S can currently use the term without getting approval from the USDA and FDA, which regulate nutrition labelling and health claims. While words like “organic,” “all-natural” and “gluten-free” must meet specific criteria for health claims and labeling, “superfood” has thus far gotten a pass.
That lack of regulation has proven to be a goldmine for marketers, who are happy to keep adding new and exotic food types to the rapidly-expanding category. But it’s problematic for those looking to improve their health – especially people looking to prevent, fight, or recover from cancer, who are particularly susceptible to overblown nutritional claims.
Many foods of the foods below, commonly marketed under the “superfood” banner, have shown some indications of beneficial results during in vitro or animal trials, but haven’t been proven to work in human clinical trials:
- Goji Berries
Contain fiber, Vitamin C, Vitamin A and iron.
Unproven claim: preliminary in vitro studies looking at breast and liver cancer cells suggest goji berries may help the body kill cancer cells.
- Chaga Mushroom
Contains Inonotus obliquus, used in Russian traditional medicine, said to have antioxidant and antimicrobial properties. High in oxalates, toxic in high doses.
Unproven claim: Inhibits cancer progression.
- Chia Seeds
Contain some fiber, omega-3 healthy fats, calcium, magnesium, iron, zinc, niacin and protein.
Unproven claim: Extracts from chia seeds can help cancer patients hold up better during treatment.
Comes from Africa and Asia and contains antioxidants, flavonoids, phenolic acids and isothiocyanates.
Unproven claim: It may have potential to slow the growth of breast cancer and neuroblastoma cells, and positively impact glucose metabolism and fats in the liver.
- Tiger nuts & Watermelon seeds
Currently rising fad foods without much research to back up claims that range from aphrodisiac powers to cancer prevention.
What we do know: a balanced diet plentiful in plant-based foods, such as fruits, vegetables and whole grains, along with healthy fats, and lean proteins like fish, peas and lentils, animal and soy proteins, in combination with regular physical activity, can help reduce the risk for developing certain cancers and can help promote survivorship. And though “superfoods” may not be especially effective in preventing or curing cancer, most of them can be a part of a well- balanced diet. Just make sure you take their purveyors’ claims with a healthy grain of salt.