Thursday 22nd September 2011
You are what you eat
I recently came across an interesting article about microRNA making it from your food into your blood stream and having direct impact on your own genetic function on nature.com.
Abstract from the article...
Our previous studies have demonstrated that stable microRNAs (miRNAs) in mammalian serum and plasma are actively secreted from tissues and cells and can serve as a novel class of biomarkers for diseases, and act as signaling molecules in intercellular communication. Here, we report the surprising finding that exogenous plant miRNAs are present in the sera and tissues of various animals and that these exogenous plant miRNAs are primarily acquired orally, through food intake. MIR168a is abundant in rice and is one of the most highly enriched exogenous plant miRNAs in the sera of Chinese subjects. Functional studies in vitro and in vivo demonstrated that MIR168a could bind to the human/mouse low-density lipoprotein receptor adapter protein 1 (LDLRAP1) mRNA, inhibit LDLRAP1 expression in liver, and consequently decrease LDL removal from mouse plasma. These findings demonstrate that exogenous plant miRNAs in food can regulate the expression of target genes in mammals.
The article shows that microRNA from rice can make it from food, through the bowel, into the blood stream, then on to the liver where it interferes with the production of a protein called LDLRAP1. This protein is part of a complex series of events which when inhibited result in the hosts cholesterol levels rising. The interference occurs when the rice microRNA binds with some of the hosts own messenger RNA stopping it from being translated in a ribosome.
In short, eating rice causes the hosts cholesterol levels to rise because something in the rice stops the cholesterol from being managed by the body's natural processes.
Taking a step back from the mechanics of the process for a moment... it would seam that in effect what is happening here (for better or worse) is the free inter-mingling of biochemical processes between plants and animals. Some fundamental part of the life process of a rice plant is not only making it into a new host but it is providing evolutionary pressure to that host because it is directly participating in the hosts own fundamental process of living.
It seems, you really are what you eat after all... in the truest sense of the words, at least in some very small (though apparently not insignificant) ways.
