How
red wine prevents cancer
Alcohol use is a major risk factor for head and neck cancer.
But an article published in the November issue of the journal Advances in Experimental Medicine and Biology shows that the chemical resveratrol found in grape skins and in red wine may prevent cancer as well.
But an article published in the November issue of the journal Advances in Experimental Medicine and Biology shows that the chemical resveratrol found in grape skins and in red wine may prevent cancer as well.
"Alcohol bombards your genes. Your body has ways to repair this damage, but with enough alcohol eventually some damage isn't fixed. That's why excessive alcohol use is a factor in head and neck cancer. Now, resveratrol challenges these cells -- the ones with unrepaired DNA damage are killed, so they can't go on to cause cancer. Alcohol damages cells and resveratrol kills damaged cells," says Robert Sclafani, PhD, investigator at the University of Colorado Cancer Center and professor of biochemistry and molecular genetics at the CU School of Medicine.
Some of what we know about the ability of alcohol to cause
cancer comes from the study of another disease, namely Fanconi anemia, a rare
genetic disorder that affects about 1 in every 350,000 babies.
DNA naturally
accumulates tangles called "cross links" and healthy genes can repair
and disentangle cross-linked DNA. In Fanconi anemia, people are born without
the ability to repair DNA cross links and so DNA damage accumulates.
Accordingly, patients with Fanconi anemia are at greatly increased risk of
developing cancers including leukemias and also head and neck cancer.
"We learn a lot from genetic disorders because you can put
a finger on a gene and say, hey, we know what that does!" says Sclafani,
who has presented at and regularly attends the annual meeting of the Fanconi
Anemia Research Foundation.
In fact, it turns out that a genetic accelerator of cancer in
Fanconi anemia is the same as the cancer-causing mechanism of alcohol. In both
cases, the cause is partially metabolized alcohol. The body metabolizes alcohol
by converting it first to acetyl aldehyde and then the body uses aldehyde
dehydrogenase (ALDH) to further convert it to acetic acid, which is excreted.
The partially processed state of alcohol, acetyl aldehyde, is a carcinogen and
produces "cross links" in DNA.
Because Fanconi anemia patients cannot repair the DNA damage
produced by acetyl aldehyde, they are at even higher risk for cancer if they
also lack ALDH.
"With enough alcohol, the body can get behind and end up
with a backlog of acetyl aldehyde," Sclafani says. "Increased
exposure to alcohol, loss of the ALDH gene that helps the body process alcohol,
and loss of the ability to repair DNA cross links all result in increased
cancer risk."
With hard alcohol that's the end of the story: increased risk
for head and neck cancer due to increased production of acetyl aldehyde.
"But when you look at epidemiological studies of head and
neck cancer, alcohol is a factor, but by alcohol source, the lowest cancer
incidence is in people who drank red wine," Sclafani says. "In red
wine, there's something that's blocking the cancer-causing effect of
alcohol."
The recent article points to resveratrol as Sclafani's
"something."
Sclafani describes the effects of resveratrol in terms of
probability: "The more you drink, the more you accumulate DNA damage, and
the more chance that one or more cells will accumulate the specific type of DNA
damage that can cause cancer. Now, resveratrol takes out the cells with the
most damage -- the cells that have the highest probability of being able to
cause cancer."
According to Sclafani, the resveratrol in red wine (and other
chemopreventive chemicals found in grape seed extract) isn't a magic bullet
that can completely undo the cancer-causing effects of alcohol, but by killing
the most dangerous cells it may decrease the probability that alcohol use will
cause cancer.
"Because alcohol-related head and neck cancer has a high
rate of recurrence, after a cancer has been treated once, you've still got a
very high-risk population," Sclafani says.
Ongoing clinical trials are testing the ability of resveratrol
to prevent colon and liver cancer. Dr. Sclafani and his colleague Dr. Rajesh
Agarwal plan to test resveratrol in the prevention and possibly treatment of
head and neck and other cancer types.
Story Source:
The above story is based on materials provided by University of Colorado Denver.
The original article was written by Garth Sundem. Note: Materials may
be edited for content and length.
Journal Reference:
Sangeeta Shrotriya, Rajesh Agarwal, Robert A. Sclafani. A
Perspective on Chemoprevention by Resveratrol in Head and Neck Squamous Cell
Carcinoma. Advances in Experimental Medicine and Biology, December
2014 DOI:10.1007/978-3-319-09614-8_19
Cite This Page:
University of Colorado Denver. "How red wine prevents
cancer." Science Daily,
3 December 2014. <www.sciencedaily.com/releases/2014/12/141203161134.htm>.