ISLAMABAD (Online) Experts say that different types of cooking oils are better for you than others, and a new study suggests that the number of times you reuse cooking oils can also affect your health. Spanish researchers found that people whose kitchens contained any type of oil that had been reused many times over were more likely to have high blood pressure than people whose cooking oils were changed more frequently. People who ate foods cooked with sunflower oil also showed a higher risk of high blood pressure, while consuming more olive oil appeared to protect people from high blood pressure. Based on the findings, study author Dr. Federico Soriguer of the Hospital Civil Plaza in Malaga recommends that people cook with olive oil whenever possible, and discard any oils after using them up to two or three times. Although olive oil is generally considered to be a healthy addition to meals, the findings suggest that repeatedly reusing the oil may invalidate its favorable effects on health, Soriguer says. Many of the study participants consumed the so-called Mediterranean diet, which features liberal use of olive oil and has been linked with numerous health benefits. Soriguer explained that followers of the Mediterranean diet often use an oil bath, or deep fryer, to fry foods. However, when the same pot of oil is repeatedly reheated, the oils begin to degrade, releasing substances known as polymers and polar compounds that can become absorbed by food. To measure the effects of repeated use of cooking oils, Soriguer and his team measured levels of polymers and polar compounds from oil samples taken directly from the kitchens of 538 adults. The more polar compounds and polymers present in oil samples taken from a participants house a sign the oil had been reused repeatedly the more likely it was that participant had high blood pressure. However, people whose blood samples contained a relatively high concentration of fats predominantly found in olive oil were less likely than others to have high blood pressure, Soriguer and his team report in the American Journal of Clinical Nutrition. Olive oil that had been repeatedly reused tended to show a lower concentration of polymers and polar compounds than other types of oil, suggesting that olive oil degrades more slowly than other types, Soriguer explained. He added that although the Mediterranean diet features heavy use of olive oil, its rising cost is inducing some followers to substitute other types of oil, or to use a mixture. Soriguer noted that his findings have induced him to make a personal change. I have removed the fryer out of my house, he revealed. Stress not related to breast cancer risk Stressful life events do not, in general, appear to be associated with the risk of developing breast cancer, according to the results of a new study. However, a modest association was found between breast cancer and the death of a spouse, relative or friend. Breast cancer is the most prevalent cancer in women in Western societies, Dr. Saskia F. A. Duijts and colleagues from Maastricht University, the Netherlands, write. Studies examining the relationship between stressful life events and breast cancer risk have produced conflicting results. In the December 20th issue of the International Journal of Cancer, the researchers published the results of an analysis of several studies that examined the relationship between stressful life events and breast cancer risk. They sought to summarize and quantify this relationship and to explain the inconsistency in previous results. Statistically significant effects were observed for three categories. These included stressful life events, the death of spouse, or the death of relative or friend, which corresponded with a 77 percent, 37 percent and 35 percent increased risk of breast cancer, respectively. The biologic explanation of the overall association and these additional findings might be that stress disturbs various areas of the immune system and that impaired immune system function predisposes to malignant growth, the authors conclude. In contrast to previous studies, clinicians can use these general findings to take an unambiguous and consistent position with regard to women with breast cancer. Bone and intestinal disease may have common cause In studies with mice, scientists have found evidence that osteoporosis-like bone disorders and inflammatory intestinal disorders are both caused by the abnormal regulation of a common protein. Simon R. Carding from the University of Leeds in England and colleagues report their study in the December issue of the journal Immunity. Autoimmune-related bone disease and intestinal inflammation are closely linked with the deregulation and the hyperactivation CD4 T cells, which are involved in the bodys defense system, or immune response, they report. How these T cells are activated and mediate disease is not clear. Mice that were genetically engineered to lack a key regulator of CD4 T cells have overactive T cells and spontaneously develop ulcerative colitis and the loss of bone cells, the scientists explain. Carding and colleagues experiments indicate that this is caused by increased production of a protein called RANKL. We find that the hyperactive CD4 T cells produce too much of this protein, which then contributes to bone breakdown and bowel inflammation, Carding said. Treating mice with osteoprotegerin, a protein that prevents RANKL from binding to its receptor, reversed this bone loss and improved colitis. This study shows that some bone diseases and intestinal problems may share a common cause, Carding told. If similar mechanisms occur in humans, then osteoprotegerin might prove a useful treatment for intestinal disorders such as ulcerative colitis and Crohns disease, he said, which are both often accompanied by bone loss.