Researchers from Ohio State University found avocado phytochemicals were able to kill some cancer cells and prevented pre-cancerous cells from developing into actual cancers. Writing in the Seminars in Cancer Biology, lead author Steven D'Ambrosio said avocado should be added to a list of fruits as part of a "cancer prevention diet" and predicts future studies may discover other cancer preventing phytochemicals. While this may be one of the first studies to link avocados to oral anti-cancer potential, a 2005 study by UCLA scientists noted that the fruit may have an ability to inhibit the growth of prostate cancer. The study also adds further weight to the more general role of fruits and vegetables as having a protective effect on cancer. Broccoli, cauliflower, raspberry and pomegranate have all been linked to having a positive effect on various forms of cancer. Oral cancer is a disease with a higher proportion of deaths per number of cases than breast, skin, or cervical cancer, with a mortality rate of about 50 per cent due to late detection, according to British charity the Mouth Cancer Foundation. There are more than 500 varieties of avocados grown worldwide with Hass types - used in the test - being the most readily available at supermarkets nationwide. He said: "Our study focuses on oral cancer, but the findings might have implications for other types of cancer. These are preliminary findings, and more research is needed. "As far as we know, this is the first study of avocados and oral cancer." D'Ambrosio found that phytochemicals extracted from avocados target multiple signaling pathways and increase the amount of reactive oxygen within the cells, leading to cell death in pre-cancerous cell lines. But the phytochemicals did not harm normal cells, he said. Extracts prepared from the fruit using a previously published plant extraction scheme were tested for growth inhibition of the normal, premalignant and malignant human oral cell lines. Among the fractions tested, the chloroform extract was identified as one the more selective growth inhibitors of both the premalignant and malignant human oral epithelial cell lines, the researchers said. "These studies suggest that individual and a combination of phytochemicals from the avocado fruit may offer an advantageous dietary strategy in cancer prevention," said researcher Haiming Ding. Avocados contain antioxidants and phytonutrients, including vitamin C, folate, vitamin E, fibre and unsaturated fats. They are naturally sodium-free, contain no trans fats and are low in saturated fat. D'Ambrosio said: "The future is ripe for identifying fruits and vegetables and individual phytonutrients with cancer preventing activity. "As we identify the molecular mechanisms and targets by which individual phytonutrients prevent cancer, we may be able to improve upon nature by formulating phytonutrient cocktails for specific cancers and individual susceptibility and risk." Source: Seminars in Cancer Biology Chemopreventive characteristics of avocado fruit doi:10.1016/j.semcancer.2007.04.003 Authors: Haiming Ding, Young-Won Chin, Douglas Kinghorn, Steven D'Ambrosio.