This is my last update from Experimental Biology 2007 - a meeting too vast to cover all, but here are some last snippets getting news coverage:* Dr. Martha Payne reported as part of the American Society for Nutritionthat elderly men and women who consumed higher levels of calcium and vitamin D are significantly more likely to have greater volumes of brain lesions, regions of damage that can increase risk of cognitive impairment, dementia, depression and stroke.
Dr. Payne and her co-investigators from Duke and the University of North Carolina examined magnetic resonance imaging (MRI) scans from 232 men and women (79 men, 153 women) between the ages of 60 and 86 (average age 71). All the subjects had at least some brain lesions of varying sizes, including the extremely miniscule ones often seen in even healthy older persons, but those who reported consuming more calcium and vitamin D were markedly more likely to have higher total volume of brain lesions as measured across numerous MRI scans.
“At this point,” says Dr. Payne, “we do not know if high calcium and vitamin D intake are involved with the causation of brain lesions, but the study provides support to the growing number of researchers who are concerned about the effects of too much calcium, particularly among older adults, given the current emphasis on promoting high intakes of calcium and vitamin D.”
* By giving ordinary adult mice a drug - a synthetic designed to mimic fat - Salk Institute scientist Dr. Ronald M. Evans is now able to chemically switch on PPAR-d, the master regulator that controls the ability of cells to burn fat. Even when the mice are not active, turning on the chemical switch activates the same fat-burning process that occurs during exercise. The resulting shift in energy balance (calories in, calories burned) makes the mice resistant to weight gain on a high fat diet.
The hope is that such metabolic trickery will lead to a new approach to new treatment and prevention of human metabolic syndrome. Sometimes called syndrome X, this consists of obesity and the often dire health consequences of obesity: high blood pressure, high levels of fat in the blood, heart disease, and resistance to insulin and diabetes. Dr. Evan’s presentation was part of the scientific program of the American Society for Biochemistry and Molecular Biology.
* Being obese increases the risk of breast cancer in post-menopausal women, shortens the time between return of the disease and lowers overall survival rates. Researchers now report evidence on how leptin, a hormone found in fat cells, significantly influences breast cancer development and progression in mice. This new understanding, says Dr. Sebastiano Ando, establishes a new mechanism for the link between obesity and breast cancer and suggests new targets for drugs that could intervene in that mechanism.
Dr. Ando’s presentation was part of the scientific program of the American Society of Investigative Pathology.
Dr. Ando’s presentation was part of the scientific program of the American Society of Investigative Pathology.
* Recent findings that the widely-used herbal supplement Saint John’s wort could dramatically affect the absorption and metabolism of many prescription and non-prescription drugs raised concerns that other popular herbal supplements might cause similar changes, thus significantly altering drugs’ therapeutic or toxic effects. What, for example, about ginseng and ginkgo biloba, two of the most widely used herbal supplements in this and other countries?
Speaking at Experimental Biology 2007 in Washington, DC, Dr. Gregory Reed reported a study that found daily use of ginseng or ginkgo biloba supplements at the recommended doses, or the combination of both supplements, are unlikely to alter the pharmacokinetics - by which drugs are absorbed, distributed, metabolized, and eliminated by the body - of the majority of prescription or over-the counter drugs. Dr. Reed’s presentation was part of the scientific program of the American Society for Pharmacology and Experimental Therapeutics.
Speaking at Experimental Biology 2007 in Washington, DC, Dr. Gregory Reed reported a study that found daily use of ginseng or ginkgo biloba supplements at the recommended doses, or the combination of both supplements, are unlikely to alter the pharmacokinetics - by which drugs are absorbed, distributed, metabolized, and eliminated by the body - of the majority of prescription or over-the counter drugs. Dr. Reed’s presentation was part of the scientific program of the American Society for Pharmacology and Experimental Therapeutics.
