If you are anything like me, then
you really enjoy your carbs and a meal without them often doesn’t suffice. Unfortunately, too much carbohydrate intake
can be damaging to the heart, which we know struggles to repair itself.
Researchers at Vanderbilt and the University of Alabama studied the acute
affects of carbohydrate overload by giving individuals a shake containing
264kcal. The subjects were asked to follow a standard diet in order to decrease
the amount of variables that could affect the components of the heart before
participating in the study. After the subjects ingested the shake, their blood
levels were monitored for significant changes. The acute load of carbohydrates altered
the heart’s production of atrial natriuretic peptide by a 25% reduction. ANP is
important in getting rid of excess salt and reducing blood pressure. The
research continued in order to try and mimic the results in mice. It appeared
that a reduced ANP level was due to an increase in glucose, which caused the
cells to produce more of the miR-425 molecule. This molecule regularly would
inhibit the synthesize of ANP, therefore an increase in this molecule caused a
decrease in circulating ANP. With less ANP being produced, the body is more
likely to have an increase in sodium retention and an increase in blood
pressure.
Over time, an increase in blood
pressure can be detrimental to our heart and blood vessels. In order for the
heart to properly function we need adequate blood pressure, peripheral
resistance, and blood flow through the
vessels to our tissues. The blood
pressure is the amount of force exerted on the wall of a blood vessel that
drives the blood to move from pressure gradient of higher to lower areas. In
order to have sufficient blood flow to reach all of our tissues we need a
pressure gradient and resistance of blood vessels. If blood pressure increase,
but resistance stays the same, the blood flow will speed up. The same
relationship is true for when blood pressure decreases. If the blood pressure
gets too high, the heart is working at a very intensive rate to pump the blood,
which can eventually lead to congestive heart failure. An increased blood pressure can also exert
enough force on the vessel walls that will eventually damage the smooth muscle
and result in a decrease in elasticity. Without proper elasticity, the vessels will
struggle to vasoconstrict and vasolidate to compensate for homeostatic
imbalances.
Vanderbilt University Medical Center. (2016, March 29). Study explores carb-loading's effect on the
heart. ScienceDaily. Retrieved November 27, 2017 from
www.sciencedaily.com/releases/2016/03/160329153403.htm
This is a very interesting finding, and similar to you, I love carbs! While reading your post I was thinking about why it is recommended to "carbo-load" before a big workout? Will an intake of a lot of carbs here and there greatly affect the body's blood pressure or is it just when someone continually consumes a lot of carbs? I was also thinking that maybe it is advised to consume many carbs before a workout in order to increase the blood pressure in your body which will give that individual more energy/adrenaline with more blood pumping through the body?
ReplyDeleteGood point Morgan, I do believe this study is looking at the effects on the heart when the carbohydrates are not directly used for fuel, but rather consumed in excess while not exercising. However, it would be interesting to find a study that compares the different situations, one being the carb-loading and working out after, and another being carb-loading and remaining inactive.
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ReplyDeleteI find this interesting in terms of starvation. It seems like the body would do well with more carbohydrates and thus could rely on breaking down fatty acids less in the result of starvation as a result of this. On another note, I'm having a bit of a hard time understanding the exact significance of this study. They gave the subjects one carbo-loaded shake and basically assessed them over a 6 hour period. I wish this study mentioned the break down of actual carbohydrates in this "264kcal shake". If it's "acutely high" it seems like people might not regularly take in that many carbs at one time. I wish the study emphasized more the effect of eating carbs over time and not just in one high carb shake a day.
ReplyDeleteI agree with you, I wish the study gave more long term information instead of just giving us the acute results. However, I think the point is that if ANP is being affected directly after carb-loading then the long term affects would be even greater. As for starvation, having a large amount of carbs in your body most definitely would be beneficial, allowing your body more fuel for a longer period of time. I could be wrong, but I assume that the effects on the heart from carbs would be totally different in a starving situation because there would not be an increase in blood glucose since these molecules would be used up by the body. Therefore, there would not be the signal from the glucose to the cells to produce more of the miR-425 molecule and the synthesis of ANP would not be inhibited.
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