Many of us in the developed world are either taking
care about what we eat or are feeling guilty about not doing enough in that
direction. Our annual checkups mean that we have to wait on our low-density
lipid numbers (“bad Cholesterol”) with the same trepidation that we waited for
our math test results in high school.
On days that our self-control is winning, we munch
through our brown rice and green veggies and feel that we’re doing our bit. But
all may not be as well as we think. Chen-Yu Zhang and his team at Nanjing U
have turned up some surprising and unsettling data (1,2).
As we chomp through our veggies, our digestive
system processes them and we end up with lots of short lengths of plant RNA
floating around in our system. Zhang and his team checked on 31 healthy
subjects and identified 40 different brands of these micro-RNAs floating
around.
So far so good, but here is the interesting result.
They showed that these micro RNAs from the plants can bind to our messenger
RNAs and modify their effectiveness in gene expression. They focused on one in
particular, the microRNA known as MIR168a, which is found in greens such as
cabbage and broccoli, and showed that it can bind to about 50 of our genes.
One in particular caught their eye and that is the LDLRAP1,
which we have in our liver, and which MIR168a binds to and inhibits its ability
to keep our bad cholesterol low. It’s unsettling to hear that eating our greens
may screw up our LDL numbers.
More importantly, it throws open the whole area of
how our food may be interacting with our body control systems. Clearly, there
is a lot of mileage in research into the effects of diet on our health in terms
of cell control mechanisms.
- L. Zhang et al, Cell Research advance online publication 20 September 2011; doi: 10.1038/cr.2011.158
- http://the-scientist.com/2011/09/20/plant-rnas-found-in-mammals/
