Not that I am biased or anything (which I totally am), but in my opinion birds are amazing animals. Besides the whole being able to fly thing, did you know that birds naturally have really high blood sugar? In fact, their blood sugar levels are 1.5-2 times higher than mammals of comparable body size. A mammal that maintains similar levels would develop diabetes (Braun and Sweazea, 2008). Birds are also really long-lived. For example, the maximum recorded longevity of a mouse weighing 20 grams is 4 years. Compare that to a 22 gram canary that lives up to 24 years! One reason for their extraordinary long-lives may be that they are able to protect their tissues from high blood sugar somehow (Holmes et al., 2001).
There are many proteins circulating in your blood. One of the most abundant proteins is albumin. When blood sugar concentrations remain high, glucose can bind to the free amino groups on proteins like albumin, thereby forming “glycated albumin”. At first this is not a major problem as the initial reaction is reversible. However, the glycated albumin can rearrange to form advanced glycation end products (AGEs) which are irreversible once formed. Because of their irreversible nature, AGEs are bad…really bad. AGEs are considered to be a major contributor to the development of diabetic complications and aging. This whole process was actually reviewed in the Journal of Young Investigators: The Undergraduate Research Journal (check it out!).
As if birds were not already one of the coolest vertebrates, researchers have looked at protein glycation in birds and have found that levels are much lower than in mammals (Holmes et al., 2001). Moreover a recent study showed that birds do not even have the receptor for AGEs (RAGE; Sessa et al., 2014) making them more resistant to potential damage from what little AGEs they do make.
What do you think is the coolest thing about birds? Comment below!
Braun EJ, Sweazea KL. (2008) Glucose Regulation in Birds. Comparative Biochemistry and Physiology B – Biochemistry and Molecular Biology. 151(1): 1-9.
Hatfield J. (2005) Review: Advanced Glycation End-products (AGEs) in Hyperglycemia Patients. Journal of Young Investigators. October. http://www.jyi.org/issue/review-advanced-glycation-end-products-ages-in-hyperglycemic-patients/
Holmes DJ, Flückiger R, Austad SN. (2001) Comparative Biology of Aging in Birds: An Update. Experimental Gerontology. 36(4-6): 869-883.
Sessa L, Gatti E, Zeni F, Antonelli A, Catucci A, Koch M, Pompilio G, Fritz G, Raucci A, Bianchi ME. (2014) The Receptor for Advanced Glycation End-products (RAGE) Is Only Present in Mammals, and Belongs to a Family of Cell Adhesion Molecules (CAMs). PLoS ONE. 9(1): e86903.
Karen Sweazea was awarded a PhD in physiological sciences in 2005 from The University of Arizona, Tucson, where she studied sugar and fatty acid utilization in birds. She completed her postdoctoral studies in vascular physiology at The University of New Mexico, Albuquerque, where she developed a model of vascular complications caused by poor nutrition.
Sweazea’s current research focus is on understanding how being overweight, obesity, sugars, and fats, contribute to the development of insulin resistance and impaired vascular reactivity from lower vertebrates to humans. This includes studies designed to explore potential dietary supplements that may regulate blood pressure through decreasing oxidative stress and inflammation.