Pigments found in berries offer a new insight into the mechanisms behind cancer.
There is little more pleasing to the eye than a freshly plucked berry. Part of this beauty is thanks to their pigments, or anthocyanins.
Anthocyanins are a type of flavonoid. Much of the work looking at their antioxidant action has, to date, been carried out in the laboratory rather than in animals.
Because of this, there is some debate about whether anthocyanins are easily absorbed in the body. After all, there is a substantial difference between introducing a compound to a cell in a petri dish and eating it.
Also, with over 500 different types of anthocyanin, it will take a great deal of work to unravel all possible interactions in the body.
Despite these concerns, there is growing evidence that anthocyanins may help to protect against some human diseases, such as cardiovascular disease and type 2 diabetes. However, results are mixed in human studies.
Others have investigated whether or not they might also help in the fight against cancer, and while some laboratory and animal studies have offered hope, observational studies in humans have not been so encouraging.
In short, there is a lot to learn about anthocyanins and how they impact human health.
Anthocyanins and their influence
Currently, there is little known about how anthocyanins may interact with and influence molecular pathways in the body. This is where today's study comes in.
Recently, a team of researchers from the School of Pharmacy at the University of Eastern Finland teamed up with the National Institute on Aging in the United States.
They looked specifically at anthocyanins' effects on an enzyme implicated in cancer and aging: sirtuin 6 (SIRT6). Their findings were published in the journal Scientific Reports.
Sirtuins regulate the expression of genes involved in a number of cellular signaling pathways. As we age, sirtuin — like much of the rest of us — stops working as well, which can contribute to a variety of ills.
Of this family of enzymes, SIRT6 is lesser known, but it is thought to be important in the metabolism of glucose. It has garnered a fair amount of interest from pharmacologists, as the authors explain:
"Because SIRT6 has been implicated in longevity, metabolism, DNA-repair, and inflammatory response reduction, it is an interesting target in inflammatory and metabolic diseases as well as in cancer."
Berries, cancer genes, and the future
The researchers, led by Dr. Minna Rahnasto-Rilla, found that one type of anthocyanin, known as cyanidin, could be of particular interest.
Found in wild bilberry, raspberry, and cranberry, cyanidin was shown to increase production of SIRT6 in cells by an impressive 55-fold. Similarly, it increased expression of the enzyme in colorectal cancer cells.
Interestingly, cyanidin decreased expression of the cancer genes Twist1 and GLUT1, and it also increased expression of the FOXO3 gene, which is a tumor suppressor.
In other words, this compound appeared to reduce the activity of cancer-causing genes and boost the activity of cancer-stopping genes.
As mentioned previously, there is some debate around whether any anthocyanins we consume survive our alimentary canal and enter our cells, but regardless of this, the findings are useful.
The more we understand about how chemicals interact with cancer cells and the pathways that they use to survive, the better equipped we will be to fight the disease. Drugs that regulate the SIRT6 pathway may, one day, be useful in the battle against cancer.
So, eating berries each day may or may not improve your health and increase your lifespan. We will have to patiently wait for scientists to untangle the increasingly complex web that anthocyanins weave.