Funding for diet and breast cancer link

An expert in cancer control and detection at The Ohio State University Comprehensive Cancer Center (OSUCCC) has received a second grant from The Breast Cancer Research Foundation (BCRF) to continue her study into the relationship between diet and breast cancer prevention.

Dr Electra Paskett, associate director for population sciences at the OSUCCC and holder of the Marion N. Rowley Designated Chair in Cancer Research at Ohio State, said her grant of $250,000 will support one of the first studies at the OSUCCC to be conducted under the auspices of the new Breast Cancer Prevention Through Nutrition Programme. The study will compare a low-fat with a low-sugar diet to see if either is able to reduce a woman's chances of developing breast cancer.

"We know that women recognise the relationship between nutrition and health, but they are being bombarded with misleading information that comes from the promotion of fads and quick fix-it schemes rather than findings of scientific fact,"​ said Paskett.

Last year, Paskett received a similar award to study soy and tomatoes as dietary factors that may inhibit breast cancer.

The new study will enroll 140 pre-menopausal women who will be randomised to either a low-fat or a low-sugar diet for one year. Participants in both categories will be encouraged to exercise and will be monitored for changes in a number of key biomarkers that may be linked to the development of breast cancer.

Some studies suggest a link between a high-fat diet and breast cancer. Laboratory tests have shown that animals placed on high-fat diets develop breast tumours at a higher rate than those on low-fat diets. "But we don't really know exactly what factors are at work in that relationship,"​ said Paskett. "That's one of the things we want to find out."​

Paskett explained that women on high-fat diets who have mutations in two genes called GSTM1 and GSTT1 may not be able to detoxify certain metabolic byproducts called reactive free radicals. Some scientists believe that when free radicals build up in the body, they can lead to cancer. She added that changes in the metabolism of GSTM1 and GSTT1 - as well as other chemicals in the women's blood and urine - may turn out to be good biomarkers to help them understand the impact of nutrition as a preventive approach.

Generally, there has been less attention to sugar as a possible carcinogen or promoter of cancer cell growth, but Paskett said there is evidence suggesting it may be problematic. Some studies show that sugar provides cancer cells with more energy, or may contribute to a phenomenon known as the IGF cascade.

IGF is an acronym for insulin growth factor, a hormone that stimulates the growth of cancerous cells. Paskett said data indicating a positive relationship between IGF-1 levels and breast cancer risk appears to be strongest in pre-menopausal women.

Obesity alone may be a risk factor for developing breast cancer, said Paskett, adding that restricting calories, weight-loss and exercise can all help decrease the level of circulating IGF.

Potential study participants need to be at least 30 years old, pre-menopausal, consuming a diet of at least 30 per cent fat and have a body mass index between 25-34. They must also be deemed at high risk for developing breast cancer, measured by having a first-degree relative with breast cancer diagnosed pre-menopausally, or two or more first-degree relatives diagnosed with breast cancer at any age.

Women in both arms of the study will be given ways to increase their exercise activity to 30 minutes five times a week, and will be given regular feedback on their adherence to diet and exercise and their relative risk of developing breast cancer.

The Breast Cancer Research Foundation awarded the research grant at its seventh annual awards luncheon in New York this week.