A new study, based on data of over a million women, has found link between high cholesterol and breast cancer risk.

Researchers said that the study is still preliminary, but could explain why obese women with high levels of cholesterol are more likely to be diagnosed with breast cancer. The study could also strengthen the idea that cholesterol-lowering drugs such as statins could cut breast cancer risk.

Previous research has shown that high-fat diet is linked with an increased breast cancer risk. A recent study by the Duke Cancer Institute found that a break-down product of cholesterol acts like the hormone estrogen, increasing breast cancer risk.

The present study was based on data from one million women in the Algorithm for Comorbidities, Associations, Length of stay and Mortality (ACALM) clinical database. The women were from the U.K. and had participated in the study between 2000 and 2013.

For the study, researchers looked at information from 664,159 women, of whom 22938 had hyperlipidaemia - medical term for too many lipids or fat in the body. In the study, 9312 had breast cancer and around 530 women with hyperlipidaemia had developed breast cancer.

Researchers used statistical analysis to see whether high cholesterol levels increased breast cancer risk. They found that being diagnosed with hyperlipidaemia raised breast cancer risk by 1.64 times.

"We found that women with high cholesterol had a significantly greater chance of developing breast cancer. This was an observational study so we can't conclude that high cholesterol causes breast cancer but the strength of this association warrants further investigation," said Dr Rahul Potluri, lead author of the study, according to a news release.

"A prospective study that monitors the risk of breast cancer in women with and without high cholesterol is needed to confirm what we observed. If the connection between high cholesterol and breast cancer is validated, the next step would be to see if lowering cholesterol with statins can reduce the risk of developing cancer," he added.

The study will be presented at the Frontiers in CardioVascular Biology (FCVB) 2014 in Barcelona, Spain.