By: Harry G. Preuss MD, MACN, CNS
Professor of Biochemistry, Medicine, Physiology, & Pathology
Georgetown University Medical Center, Washington D.C. 20057
In my last article (#4 Astaxanthin, the Heat’s Off), I described the fortuitous event behind the discovery that the carotenoid (Astaxanthin) could overcome heat stress. To refresh memories, the air conditioning system in the animal quarters failed in the middle of the summer allowing the indoor temperature to reach an exceedingly high level. In three groups, roughly one third survived the heat stress – (a) those consuming only the standard diet containing a high portion of table sugar (control), and (b) those receiving the same diet but containing either the anti hypertensive drug, captopril or (c) a low dose of astaxanthin. In contrast, every rat in the fourth group ingesting high dose astaxanthin (d), survived the high temperature insult. Suffice it to say, the information that astaxanthin at the proper dose could reduce heat stress is very important and remains such, but the original purpose behind the planned study was to assess the ability of astaxanthin to overcome insulin resistance created by ingesting a high sugar intake. A new study had to be carried out to accomplish this particular goal 
Before going into details concerning the second study, let’s return to the basics. What is insulin resistance and why is it so important to determine whether astaxanthin can affect it? To answer the last query, insulin resistance is associated with obesity, diabetes, high blood pressure, inflammation, fatty liver and premature aging – malfunctions generally associated with aging. Obviously, a safe, natural supplement that could overcome would be of immense benefit. In order to arrive at a solution, however, the first query also requires an answer.
With insulin resistance, fat, muscle, and the liver respond very poorly to insulin. The body attempts to address this. Like many hormonal systems, there are complementary reactions to ameliorate any adverse changes in normal balance – in this case, of glucose-insulin. To illustrate this particular point, the relatively poor peripheral response to insulin causing elevation of circulating glucose concentrations is met with increased output of insulin by the pancreas. The overall result is augmented circulating insulin levels purportedly trying to maintain circulating glucose concentrations near baseline. It is important to note that although glucose levels decrease as a result of higher insulin concentrations, both typically remain higher than before the surge. This sequence of events, a rise in glucose followed by a compensatory increase in insulin to compensate may occur over and over again. However, with progression of insulin resistance, elevated circulating insulin concentrations may eventually reach a limit and become less effective. When the inadequate concentration of peripheral insulin becomes severe enough to allow even more significant elevations of circulating glucose concentrations, the entity is called Type 2 diabetes to distinguish it from the originally described Type 1 in which the inadequate production and release of insulin from the initiation of the malady is the primary pathological factor involved .
Accordingly, in the second investigation, it was determined that astaxanthin, indeed, could improve insulin resistance and its various associated malfunctions. Thus, as others have reported, there is the realistic possibility that astaxanthin can prevent, lessen or even overcome aging and many of its manifestations. Astaxanthin can be added to the list of safe, natural insulin sensitizers that include trivalent chromium, maitake mushroom, and bitter melon. The second study determined another important happening from astaxanthin use. Rats constricted in a plastic tube have an immediate rise in blood pressure. If the rodents receive this challenge after consuming astaxanthin, the elevation in blood pressure is significantly less. So, astaxanthin has the ability to overcome another form of stress. I will detail the anti stress abilities of this agent and its importance in the next communication.
Preuss HG, Echard B, Yasmin T, Bagchi D, Perricone NV, Yamashita E: Astaxanthin lowers blood pressure and lessens the activity of the renin-angiotensin system in Zucker Fatty Rats. Journal of Functional Foods 1:13-22, 2009.
Preuss HG, Echard MT, Bagchi D, Perricone NV: Effects of astaxanthin on blood pressure and insulin sensitivity are not directly interdependent. Int J Med Sci 8:126-138, 2011.