On Wine, Sunburn, and the Tendency of Headlines to Mislead…

by Katie Pratt

If you’ve been reading “Mind the Gap” for a while now, you are probably aware of the fact that I am a fair-skinned lass from England. You will therefore understand my excitement when I saw the headline “Wine consumption can help prevent sunburn”. Not only am I fond of a corked cocktail every now and then, but I burn in the sun like an over-achieving moth in a flame.

Unfortunately, further scientific sleuthing lead me to the conclusion that perhaps that enticing headline was better suited for coverage in Sensational Science Headlines than newspapers. Shocking, I know.

A recent article in the Journal of Agricultural and Food Chemistry illustrated that certain antioxidant compounds in grapes could protect human skin cells from developing UV-induced cellular damage. The specific molecules, procyanidin oligomers and gallate esters (a.k.a. polyphenols), were able to soak up reactive oxygen species within cells and thus prevent DNA damage. Regrettably, I can’t really use these data to rationalize drinking vast quantities of vino on the beach. As the researchers point out, in order for polyphenols to protect against sun damage they’d have to be applied directly to the skin.

So you're saying I should have gone with the merlot?...

But all is not lost! Marta Cascante, senior author on the sun-damage study, has a new report out this month in The Journal of Nutrition. This time her team looked into the protective effects of grape antioxidant dietary fiber (GADF) on the gut lining of mice. Diet has long been known to affect the development of colorectal cancers; particularly, a diet rich in fruits and vegetable is thought to reduce one’s risk of developing this disease. While the effect is often attributed to the fibrous nature of plants, fruits and vegetables are also rich in antioxidants such as polyphenols.

In order to study the effects of GADF, the researchers supplemented the normal diet of a group of mice. They were given GADF (equivalent to the amount of dietary fiber that humans are recommended to consume) for two weeks and then their intestines were removed and used for gene expression profiling. Several genes associated with tumorigenesis, including a number of genes from the Ras family of oncogenes, were down-regulated in the mice who received GADF supplements compared to their deprived counterparts. In addition, expression of the tumor suppressor gene NBL1 was increased after GADF treatment. These data therefore imply that GADF could in fact exert a protective effect against cancer in a healthy colon.

Outstanding bouquet: The '07 Cabernet by Coppertone is not to be missed.

So we can rationalize that second glass of Pinot after all!?

Sadly, there remains a caveat. The mice were given their GADF through “gastric gavage”, aka a feeding tube inserted through the mouth and into the stomach. Not a method of ingestion I would voluntarily engage in. And it’s not clear to me that these polyphenols survive the winemaking process. Even if they do, it’s the piggybacking onto dietary fiber that allows them to be slowly released as they pass through the gut.

Sigh. I guess I’ll just have a beer then.

Katie Pratt is a graduate student in Molecular Biology at Brown University. She has a passion for science communication, and in an attempt to bring hardcore biology and medicine to everyone, she blogs jargon-free at www.katiephd.com. Follow her escapades in the lab and online on Twitter.

Be the first one to mind the gap by filling in the blank as a comment and get your name in the blog along with a sweet new BenchFly mug!

UPDATE: Congratulations to Catherine Leigh Allen – winner of this week’s Mind the Gap!

About the winner: Catherine Leigh Allen, PhD, is a postdoctoral associate in Andrew Gulick’s lab at Hauptman-Woodward Medical Research Institute. She just graduated from Duke University (Dewey McCafferty’s lab, Department of Chemistry) leaving the South and her dance family (Ninth Street Dance and Blank Slate Dance Company) behind to move to Buffalo, NY.

About the prize: In addition to fame and glory beyond their wildest dreams, winners receive our new hot-off-the-presses large (15 oz) BenchFly mug to help quench their unending thirst for scientific knowledge… or coffee.