Brown Fat Helps Clear TriglyceridesWednesday, January 26, 2011
Regular readers may recall that recently brown adipose tissue, long thought to be only present in new born infants, is also present in varying amounts in human adults.
Furthermore, variations in the amount of brown adipose tissue, which is primarily a heat-generating organ, can contribute to substantial variations in daily total energy expenditure between individuals.
To produce heat, brown adipose tissue directly burns fatty acids derived from circulating triglycerides.
Now Alexander Bartelt and colleagues from the University of Hamburg-Eppendorf, Germany, in a paper just published in Nature Medicine, demonstrate that this property of brown adipose tissue can significantly contribute to clearance of triglycerides from the blood stream.
In their studies, the researchers stimulated activity of brown adipose tissue in mice by exposing the animals to low temperatures. Cold exposure drastically increased clearance of triglycerides via increased uptake into brown adipose tissue and corrected increased lipid levels in insulin resistant mice.
Given that elevated plasma triglyceride concentrations, especially in diabetic dyslipidemia, is an important risk factor for cardiovascular disease, activation of brown adipose tissue may be a novel therapeutic approach to reduce elevated triglyceride concentrations.
Of course, increasing brown adipose tissue would perhaps also help burn excess calories, thereby reducing the risk of obesity.
Unfortunately, the best known way to increase brown adipose tissue activity is to increase sympathetic nervous activity, a side effect of which may be an increase in heart rate and blood pressure.
On the other hand, short burst of cold exposure may suffice to stimulate brown adipose tissue activity, without persistent effects on sympathetic activity. Whether such cold exposure can indeed improve triglycerides levels and help burn extra calories in humans remains to be seen.
Thankfully, with our winters here in Edmonton, I am in the right place to get plenty of cold exposure for free.
Bartelt A, Bruns OT, Reimer R, Hohenberg H, Ittrich H, Peldschus K, Kaul MG, Tromsdorf UI, Weller H, Waurisch C, Eychmüller A, Gordts PL, Rinninger F, Bruegelmann K, Freund B, Nielsen P, Merkel M, & Heeren J (2011). Brown adipose tissue activity controls triglyceride clearance. Nature medicine PMID: 21258337
Monday, September 5, 2011
There’s a bodybuilding supplement that came out in early 2010 by PES called Alpha-T2. The active ingredient was methyl-synephrine but, later, got changed to higenamine. From around the internet, I didn’t read any complaints on methyl-synephrine, but I think PES did that for marketing reasons due to the FDA’s intent on banning the ephedra/synephrine family. Higenamine is probably more potent but has a short 2hr (or less) half-life in the bloodstream, so you have to do your cardio workout as soon as you take it. Methyl-synephrine and higenamine are beta-3 adrenergic receptor agonists with little to no activity on beta-1 and beta-2 which deal with the heart and lungs respectively. Messing with beta-1 and beta-2 is what got ephedra/ephedrine banned and synephrine under current scrutiny. There are four known beta adrenergic receptors in the human body. OxyELITE Pro is another supplement that contains the active ingredient rauwolscine (which is a stereoisomer of yohimbe/yohimbine). Rauwolscine is an alpha-2 adrenergic receptor antagonist with little to no activity on alpha-1. It’s the messing with alpha-1 that is cause of criticism/scrutiny on yohimbe/yohimbine. Combine higenamine with rauwolscine, and you get a temporary metabolic pathway for a few hours to activate brown fat cells without standing in the snow. You still need a clean diet and cardio exercise regimen to shrink your white fat cells, though. ;P