Hens Give Clues on Preventing Ovarian Cancer Deaths
Dale ‘‘Buck’’ Hales, physiology department chair at Southern Illinois University Carbondale, works with Romana Nowak, University of Illinois animal science professor. Researchers at Southern Illinois University School of Medicine in Carbondale are trying to determine how flaxseed helps prevent deaths from ovarian cancer in chickens.
Turns out chickens and women have a lot in common, physiology department chair Dale "Buck" Hales has discovered.
Hales began searching more than 10 years ago for an animal model to study the link between inflammation and ovarian cancer in women. He focused on the 2-year-old hen, which he found has ovulated about the same number of times as a woman who has reached menopause, when ovarian cancer manifests.
Hales is interested in the "incessant ovulation theory" of ovarian cancer. Each time a woman ovulates, the surface of the ovary is ruptured, which is followed by a healing response. The theory is that this continual cycle of tear and repair creates a cancer-causing environment.
"Ovulation is an inflammatory event," Hales said.
The theory is supported by the fact that half of all egg-laying hens — which ovulate nearly every day — develop ovarian cancer after four years. And women who ovulate less — because of pregnancy, breast-feeding or using birth control pills — also have been found to have a lower incidence of ovarian cancer.
For four years, Hales and his research team studied hundreds of chickens past their prime who would've otherwise ended up as Campbell's Soup.
"We began to systematically validate the use of the hen as a model for studying ovarian cancer," Hales said. "By all criteria, it really looks like the human disease."
Hales' next idea came in the grocery aisle, after seeing a box of eggs rich in omega-3 fatty acids. Chickens fed flaxseed — the richest vegetable source of the anti-inflammatory fatty acids — can produce the eggs because the acids accumulate in their ovaries.
Hales began to study whether a flaxseed-rich diet affected cancer rates in chickens. He found that flaxseed-fed hens were likely to be leaner and live longer. They were just as likely to get ovarian cancer, but they were much less likely to die from it.
"By doing dietary intervention with flaxseed, you are able to actually significantly decrease the severity of the disease," Hales said.
Bolstered by the data, Hales recently won a $1.8 million federal grant to further study what components of flaxseed cause the health benefits, and in what amounts. The anti-oxidant, lignan, is also in flaxseed.
In the course of research, Hales said he is also discovering molecular changes that occur early in ovarian cancer that could lead to blood or ultrasound tests to improve early detection in women.
Ovarian cancer, known as the 'silent killer," is usually not discovered until its later stages when it's nearly untreatable. If detected early, however, survival rates are 95 percent.
"I anticipate we will really make some landmark observations," Hales said.