Elizabeth Hurley has taken part in research exploring the benefits of yoga, exercise and mindfulness on those being treated for breast cancer.
The actress, 53, hailed the work as "ground-breaking" during a visit to the laboratory at Brighton and Sussex Medical School, where the team is exploring whether stress reduction techniques can increase the effectiveness of chemotherapy for those with breast cancer.
Hurley, the global ambassador for Estee Lauder's Pink Ribbon breast cancer awareness campaign, had her saliva tested to measure levels of the hormone cortisol, which indicates stress.
Cortisol interacts with almost every cell in the human body, including cancer cells, and doctors believe high levels of the hormone could make chemotherapy less effective.
The research is being carried out by Dame Lesley Fallowfield, Professor of Psycho-oncology at Brighton and Sussex Medical School, in partnership with Dr Melanie Flint, reader in cancer biology at the University of Brighton.
Hurley, whose grandmother died of breast cancer, previously created an Elizabeth Pink lipstick with Estee Lauder, whose sales benefited the Breast Cancer Research Foundation.
The actress said: "Every 19 seconds, somewhere in the world, a woman is diagnosed with breast cancer.
"The work that the team at Brighton and Sussex Medical School is doing is just one example of the extensive ground-breaking research that is being undertaken by the BCRF around the world, with generous support from The Estee Lauder Companies' Breast Cancer Campaign, as part of its mission to create a breast cancer-free world."
Dame Lesley said: "Going through breast cancer treatment can be an extremely challenging and stressful time for patients and their families.
"We want to establish whether stress reducing activities performed on a regular basis could have a positive effect on not only patients' wellbeing, but also on improving the effectiveness of their treatment as we know that cortisol can cause cancer cells to grow and also interfere with treatment.
"Collectively, we are committed to the mission of working towards a breast cancer-free world."
- The Estee Lauder Companies' Breast Cancer Campaign is encouraging the public to use the hashtag #TimeToEndBreastCancer throughout October.