Dietary Myths – Are ‘superfoods’ really all that they claim to be?

‘Superfood’ is such a nutritional buzzword right now but what does it really mean? And do these foods really live up their hype? The word ‘superfood’ isn’t actually a nutritional term used by dieticians or nutritional scientists, but rather just a marketing term. According to Cancer Research UK (a well reputed research and awareness charity) states that ‘superfood’ is truly just a marketing tool with little scientific basis often promoting health-benefits due to an unusually high concentration of anti-oxidants, vitamins, or other nutrients.

In 2007 the European Union made the marketing of products as ‘superfoods’ prohibited unless they had specific, credible, scientific research to back up their medicinal claims. The problem with that particular restriction is that ‘superfoods’, or more specifically polyphenols (the actually anti-oxidant and anti-inflammatory parts of the food) are commonly tested on cells directly. Quite often this yields positive results, but in reality that is not how the polyphenols are exposed to our cells; they have to make it through our digestive system first and across the gut membrane. Thankfully, some incredibly smart people have found a way to mimic this using something they coin as the Caco-2 Method. Basically what they did is grow a single layer of cells in a lab that takes on the characteristics and functions of the wall of the small intestine (where most of our nutrients are taken up and absorbed into the blood stream for transport throughout the body). Pretty neat, huh?

Let’s take a look at the ‘superfood’ that started it all: Blueberries are native to North America and even grow (albeit tiny) in the far north regions of Canada in the summer. As with all berries, their surface area is larger than that of other fruits, so it is best to buy organic because of this increased area to absorb pesticides. Yes, I realize how expensive organic berries are, but it’s for good reason. That being said, I don’t pay $10 for a half pint of blueberries at the grocery store. It’s all about timing and finding the right farmer’s market. Out of fresh berry season, frozen blueberries are the next best thing. Actually, in some places it might even be better than fresh because of the long journey the berries have to make to get to the grocery store shelf. When they are flash frozen all of the nutrients stick around, rather than disappearing on their trip from the field to the shelf. Regardless, do blueberries live up the marketing claim as being a ‘superfood’?

Surprisingly, yes. Blueberries contain all kinds of phytochemicals that cross the gut membrane and actually work as anti-oxidants to fight free radicals. Cell turnover is a normal physiologic process, but sometimes things don’t go as planned and a cell comes out a little wonky. The scientific term for this wonky cell is a free radical. Free radical cells have been proven to be linked to cancer. Anti-oxidants, such as the ones found in blueberries, help denature the free radial cell and allow the body to absorb it. Sounds pretty super to me! Sorry, was that lame?

The other great thing about blueberries is that they are chock full of fibre which is great for all kinds of digestive cancers, specifically colon cancer. Fibre is the key player here, though, not the blueberry anti-oxidant phytochemical. Actually, the anti-oxidants of blueberries don’t really have a strong effect of cancers of the gut. The fibre content does, though, just not the anti-oxidants.
This dietary fibre also does good things for maintaining a healthy weight, which in turn lowers your risk of cancer and health problems in general. The fibre increases the feeling of fullness as well as helps ‘smooth the way’ for other, heavier foods.
What’s the issue, then? Blueberries and their anti-oxidants sound pretty awesome, no? The problem is that most of the research studies work directly with the components of the blueberry and how they interact with cancer cells. In general, the studies don’t take into account how much our body actually absorbs of these chemicals. Several studies show an increased level of anti-oxidants in the blood stream in those people who eat blueberries on a regular basis, but the evidence is a little weak on the level required to actually help in free radical destruction. Overall, though, the research is positive, and more is coming . One thing is for sure: this is not the last that we’ll hear about this super-berry.

References:
Adams, L.S., et al., Blueberry phytochemicals inhibit growth and metastatic potential of MDA-MB-231 breast cancer cells through modulation of the phosphatidylinositol 3-kinase pathway. Cancer research, 2010. 70(9): p 3594-605.
Seeram, N.P., et al., Blackberry, black raspberry, blueberry, cranberry, red raspberry, and strawberry extracts inhibit growth and stimulate apoptosis of human cancer cells in vitro. Journal of Agricultural and food chemistry, 2006. 54(25): p. 9329-39.
Simmen, F.A., et al., Lack of efficacy of blueberry in nutritional prevention of azoxymethane-initiated cancers of rat small intestine and colon. BMC gastroenterology, 2009: p67.
Kingston University, London, England. Dr. Lucy Jones, Deputy Dean of the University’s Faculty of Science, Engineering and Computing. October 2012.
United States Cancer Institute, Dr. Lucy Jones, Dr. Elizabeth Opara, 1980. The Caco-2 Method.

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