Elevated insulin link to increased breast cancer risk

Posted by Neill Abayon

Findings on older women based on women's health initiative study

July 9, 2009 - (BRONX, NY) - Elevated insulin levels in the blood appear to raise the risk of breast cancer in postmenopausal women, according to researchers at Albert Einstein College of Medicine of Yeshiva University. Their findings are published in the online version of the International Journal of Cancer.

Increased breast cancer risk for postmenopausal women has previously been linked to obesity and diabetes. Both conditions involve insulin resistance, which causes increases in circulating levels of insulin. Since insulin is known to promote cell division and enhance breast tumor growth in animal models, the Einstein scientists reasoned that relatively high insulin levels may contribute to breast cancer risk in women.

"Up to now, only a few studies have directly investigated whether insulin levels are associated with breast cancer risk, and those studies have yielded conflicting results," says Geoffrey Kabat, Ph.D., senior epidemiologist in the department of epidemiology and population health at Einstein and the lead author of the paper. "Those other studies were based on just a single baseline measurement of insulin, while our study involved analyzing repeated measurements of insulin taken over several years — which provides a more accurate picture of the possible association between insulin levels and breast cancer risk."

An earlier study linking insulin levels with breast cancer risk was carried out by Einstein researchers and was published in the January 7, 2009 issue of the Journal of the National Cancer Institute.

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Friendly Bacteria Protect Against Type 1 Diabetes

Posted by Neill Abayon

The findings, reported in the journal Nature, support the so-called "hygiene hypothesis" – the theory that a lack of exposure to parasites, bacteria and viruses in the developed world may lead to increased risk of diseases like allergies, asthma, and other disorders of the immune system.

The results also suggest that exposure to some forms of bacteria might actually help prevent onset of Type I diabetes, an autoimmune disease in which the patient's immune system launches an attack on cells in the pancreas that produce insulin.

The root causes of autoimmune disease have been the subject of intensive investigation by scientists around the world.

In the past decade, it has become evident that the environment plays a role in the development of some overly robust immune system responses. For instance, people in less-developed parts of the world have a low rate of allergy, but when they move to developed countries the rate increases dramatically. Scientists have also noted the same phenomenon in their labs.

Non-obese diabetic (NOD) mice develop the disease at different rates after natural breeding, depending upon the environment where they are kept. Previous research has shown that NOD mice exposed to killed (i.e., non-active) strains of tuberculosis or other disease-causing bacteria are protected against the development of Type I diabetes. This suggests that the rapid "innate" immune response that normally protects us from infections can influence the onset of Type 1 diabetes.

Read the full article here.