Janice Bennett and Nathan Livingston
Three major research advances occurred in 2007 in the fields of breast cancer, Alzheimer's disease, and diabetes.
We hear plenty of bad news when it comes to major health threats such as breast cancer, Alzheimer’s disease, and diabetes, but here is some promising research, completed in the past year, which may improve the outlook for these all-too-common conditions.
In 2007 there was good news and bad news on the breast cancer front.
First, the bad news. Researchers at the Kaiser Permanente Center for Health Research in Portland, Oregon, have concluded, after many years of conflicting evidence that increased incidence of breast cancer and the use of hormone replacement therapy, particularly estrogen-progestin treatment, are linked.
Now for the good news. With the decreased use of hormone replacement therapy in menopausal women, starting in 1990 and increasing almost every year since then, breast cancer rates have been dropping in parallel.
Though study after study over the past decade created a tug of war, this year’s research confirmed that, insofar as breast cancer is concerned, hormone therapy definitely increases the risk. Hormone therapy–once touted as being heart healthy and preventing bone-thinning osteoporosis–is now seen as having too many risks to justify its benefits.
See Medscape: pubmedcentral.nih.gov/articlerender.fcgi?artid=1929089, “Recent Trends in Breast Cancer Incidence Rates by Age and Tumor Characteristics Among US Women.”
The other big win of 2007 came from Scotland’s St. Andrews University where researchers developed a compound that appears to stave off the destruction of brain cells in those
suffering from Alzheimer’s disease.
Researchers think that the compound may even reverse some of the effects of the disease’s early stages, improving memory and cognitive ability.
The compound is synthetic but appears to stop an enzyme known as ABAD (amyloid beta alcohol dehydrogenase) from destroying brain cells. Normally, ABAD is a helpful enzyme in brain function, but in Alzheimer’s patients, a protein called amyloid beta binds to it, damaging the brain instead.
St. Andrew’s team of investigators has been able to identify a compound that inhibits ABAD from sticking to amyloid beta in animals with Alzheimer’s. It may be some time before clinical trials can begin, but this research is being touted as the most hopeful and compelling discovery in years in the field of Alzheimer’s study.
See Alzheimer’s Research Trust: alzheimers-research.org.uk and st-andrews.ac.uk/news/Title,14097,en.html.
Researchers from Howard Hughes Medical Institute in the US have found that insulin therapy is not always guaranteed to increase lifespan and decrease disease in animal models with diabetes. Researchers “knocked out” IRS2 genes–insulin-like pathways in the brain–and found that it extended the lives of the test animals.
Researchers were surprised since decades of clinical practice had supported the idea that insulin increases lifespan in those suffering from diabetes–a reasonable connection to make as those with diabetes do not make enough insulin, the hormone that regulates carbohydrate metabolism.
However, the real surprise in the new research revealed that the animals lived longer, although they were overweight and had higher insulin levels once IRS2 was knocked out. Both groups of “IRS2 knockout mice” had other characteristics that marked them as healthier. They seemed, in fact, like much younger mice.
While treating diabetes with insulin has been the usual mode of therapy, to a lesser or greater degree depending on the severity, it now appears–in animal studies, at least–that insulin may actually speed the progression of the disease. Other methods of controlling carbohydrates such as diet and exercise do not appear to impact the IRS2 pathway to the same degree.
In practical terms, what we’ve known all along–diet and exercise are the best prevention and treatment of diabetes and diabetes predisposition–may be all that much more compelling given the results of this new research.
See Harvard Medical School: hhmi.org/news/pdf/white20070719.pdf “New Clue into How Diet and Exercise Enhance Longevity.”