Olive oil and colon cancer
Spanish researchers suggest that including olive oil in your diet may also offer benefits in terms of colon cancer prevention. Their study results showed that rats fed diet supplemented with olive oil had a lower risk of colon.
Breast cancer risk reduction
Good quality extra-virgin olive oil contains health-relevant chemicals, 'phytochemicals', that can trigger cancer cell death.
New research published in the open access journal BMC Cancer sheds more light on the suspected association between olive oil-rich Mediterranean diets and reductions in breast cancer risk.
Javier Menendez from the Catalan Institute of Oncology and Antonio Segura-Carretero from the University of Granada in Spain led a team of researchers who set out to investigate which parts of olive oil were most active against cancer. Menendez said, "Our findings reveal for the first time that all the major complex phenols present in extra-virgin olive oil drastically suppress overexpression of the cancer gene HER2 in human breast cancer cells".
Extra-virgin olive oil is the oil that results from pressing olives without the use of heat or chemical treatments. It contains phytochemicals that are otherwise lost in the refining process. Menendez and colleagues separated the oil into fractions and tested these against breast cancer cells in lab experiments. All the fractions containing the major extra-virgin phytochemical polyphenols (lignans and secoiridoids) were found to effectively inhibit HER2.
Although these findings provide new insights on the mechanisms by which good quality oil, i.e. polyphenol-rich extra-virgin olive oil, might contribute to a lowering of breast cancer risk in a HER2-dependent manner, extreme caution must be applied when applying the lab results to the human situation. As the authors point out, "The active phytochemicals (i.e. lignans and secoiridoids) exhibited tumoricidal effects against cultured breast cancer cells at concentrations that are unlikely to be achieved in real life by consuming olive oil".
Nevertheless, and according to the authors, "These findings, together with the fact that that humans have safely been ingesting significant amounts of lignans and secoiridoids as long as they have been consuming olives and extra-virgin oil, strongly suggest that these polyphenols might provide an excellent and safe platform for the design of new anti breast-cancer drugs".
Lowering cancer risk
27/12/06 By Mark Reynolds
Four teaspoons of olive oil a day can help prevent cancer, scientists revealed yesterday. The oil, found in Mediterranean diets, cuts levels of substances in the blood which can trigger the disease. Just a small amount of the oil every day helps protect against cell damage which can lead to tumours developing.
The research may help explain why many cancer rates are higher in northern Europe than in the south, where olive oil is a major part of the cuisine. Researchers also suggest that combining a wider Mediterranean diet rich in fruit, vegetables and pasta with the use of olive oil provides an even greater chance of cutting the risk of cancer as well as fighting Alzheimer's, obesity and heart disease.
People in Mediterranean countries such as Spain and Italy live longer than those in other European countries, while rates of breast, colon, ovarian and prostate cancer are much lower. Dr Henrik Poulsen, who led the research, said: "Every piece of evidence so far points to olive oil being a healthy food." Daily Express doctor Rosemary Leonard, a GP, said: "The Mediterranean diet is very good for you." Dr Poulsen and his team at Copenhagen University Hospital studied a large group of healthy men aged 20 to 60 from five European countries. The scientists then added olive oil to their diet over a period of two weeks. At the end of the study, they measured levels of 8oxodG a substance in urine which indicates oxidative damage to cells.
Oxidative damage is where the balance of a cell is disrupted, exposing it to substances that result in the accumulation of free-radicals particles known to cause cancer. Men who consumed just 25ml of olive oil a day showed a 13 per cent drop in 8oxodG. Significantly, men from northern Europe had higher levels of 8oxodG to start with supporting the theory that a Mediterranean diet cuts the risk of cancer. Dr Poulsen said: "Our findings must be confirmed, but these data provide evidence that olive oil consumption explains the difference in cancer incidence between north and southern Europe. Determining the health benefits of any particular food is challenging because it involves relatively large numbers of people over significant periods of time. We overcame these challenges by measuring how olive oil affected the oxidation of our genes, which is closely linked to development of disease."
Dr Poulsen stressed that for the greatest cancer-reducing effects, adiet must also be rich in fruits, vegetables, whole grains and fish ; and that olive oil was no substitute for calorie control and regular exercise. However, his findings indicate for the first time how olive oil may be part of the reason that cancers such as breast, colon, ovarian and prostate are less common in Mediterranean countries. They also support existing theories that we should try to replace saturated fats, found in meat and butter, with vegetable fats, particularly olive oil. Olive oil is known to contain compounds called phenols which are believed to act as powerful antioxidants. But these did not seem to account for the drop in DNA oxidative damage found by Dr Poulsen's team.
The men in the study were given three different olive oils virgin, common and refined with varying levels of phenols. Oxidative damage declined in all cases regardless of the phenol content. Dr Anthea Martin, of Cancer Research UK, gave the findings a cautious welcome, adding: "More long-term research is needed to confirm these effects.
"We do know that a healthy, balanced diet, including plenty of vegetables and fruit and limited amounts of red and processed meat, can help reduce the risk of cancer." Mediterranean-style eating has long been associated with a healthy and long life. Research has also shown that those who eat lots of fruit, vegetables, whole grains and fish, and drink a moderate amount of red wine, are 68 per cent less likely to suffer Alzheimer's than those who do not.