VOLUME 2008 issue 13

Compounds in Black Tea Protective Against Diabetes

Amy Cameron, from the University of Dundee (Scotland), and colleagues have discovered that black tea mimics insulin and may help prevent Type 2 diabetes. Specifically, two compounds present in black tea, theaflavins and the arubigins, were found to affect insulin-like signaling of a transcription factor that regulates aging in response to dietary factors. The team is hopeful that their findings lead to the future identification of dietary interventions to treat or defer Type 2 diabetes.
[Amy R. Cameron, Siobhan Anton, Laura Melville, Nicola P. Houston, Saurabh Dayal, Gordon J. McDougall, Derek Stewart, Graham Rena (2008) Black tea polyphenols mimic insulin/insulin-like growth factor-1 signalling to the longevity factor FOXO1a. Aging Cell 7 (1) , 69–77 doi:10.1111/j.1474-9726.2007.00353.x]

Dr Klatz remarks: “In Europe, 19 million people – 4% of the total population – has Type 2 diabetes. The condition affects more than 20 million people, or 7% of the total population, in the United States. Tea is second only to water as the most popular drink around the world. This study offers a unique research pathway to potentially utilize the ubiquity of tea to beneficially impact the onset of diabetes.”

In Older Men, Low Testosterone Levels Correspond to Depression

Osvaldo Almeida, from the University of Western Australia (Perth, Australia), and colleagues studied nearly 4,000 men, ages 71-89 years, for a three-year period. Participants underwent testing for depression and cognitive difficulties, and were surveyed for various physical health conditions. The researchers collected blood samples to test their levels of total and free (unbound) testosterone. The team found that men in the lowers quintile (20%) of free testosterone levels had three-times the odds of having depression (as compared to men in the highest quintile). The team states that: “A randomized controlled trial is required to determine whether … low free testosterone is associated with … depression. If so, older men with depression may benefit from systematic screening … and testosterone supplementation.”
[Almeida OP, Yeap BB, Hankey GJ, Jamrozik K, Flicker L. “Low free testosterone concentration as a potentially treatable cause of depressive symptoms in older men.” Arch Gen Psychiatry. 2008 Mar;65(3):283-9.]

Dr. Goldman observes: “Declining testosterone levels in aging men are suspected to be an underlying cause of many of the symptoms and diseases of aging. Testosterone levels in men decrease gradually over time, a phenomenon sometimes referred to as andropause. This study offers another potential benefit to Testosterone replacement therapy (TRT) in older men.”

Mental Distress May Increase Risk of Stroke

Paul Surtees, from the University of Cambridge (United Kingdom), and colleagues studied more than 20,600 men and women (ages 41 to 80) for an 8 _ year period. They evaluated the participants for major depressive disorder or psychological distress, charting these conditions on a standardized scale; as well as the onset of stroke. The team found that those people who reported the most psychological distress at the start of the study period had a 40% increased risk of stroke, as compared to those who were the least psychologically distressed. They also found that major depression was not found to increase the risk of stroke.
[Surtees PG, Wainwright NW, Luben RN, Wareham NJ, Bingham SA, Khaw KT. Psychological distress, major depressive disorder, and risk of stroke. Neurology. 2008 Mar 4;70(10):788-94.]

Dr. Klatz comments: “Stroke is the third leading cause of death in Europe and the United States, and is a significant cause of long-term disability. This study identifies an important and modifiable risk factor contributing to stroke. The ability to modulate our levels of psychological distress may be an important strategy in stroke prevention.”

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