Sweet-toothed smoker is less strong
A diet that's high in sugar, but also smoking, dodgy insulin metabolism and a sedentary lifestyle all reduce muscle strength. Japanese researchers at Tohoku University come to this conclusion from their study in which they measured the effects of this kind of lifestyle via the skin of men aged between 37 and 56. Advanced glycation end products spell bad news for athletes in the long term.
When immune cells break down and clear up sick cells, sugared proteins are released; their technical name is advanced glycation end products [AGEs]. Cells have receptors for these proteins. One of these – RAGE – is shown here. When the receptors notice AGEs, cells start up inflammatory processes. If there are indeed inflammatory processes taking place in the body, then this is positive. But this is not the case if the AGEs are produced as the result of an unhealthy lifestyle.
AGEs are present in our food. Meat that's burned at the edges is an important source. AGEs are also formed in the body, especially if you smoke, become dehydrated or have a raised glucose level. The body can remove AGEs, but does so slowly. The older you are, the more the AGEs accumulate in your body.
AGEs and strength
The Japanese wanted to know whether AGEs reduce muscle strength, so they measured the concentration of AGEs in the skin. The more AGEs they found, the less strength the men were able to develop when they did exercises with handgrips.
The older the men, the more AGEs the Japanese found. Smoking also increased the amount of AGEs, and it looks like a high blood sugar level, diabetes and sedentary lifestyle are also causes of higher levels of advanced glycation end products.
What's also a bit strange is that high physical activity also raises the amount of AGEs. This may be because men with a lower educational level are more likely to do physical work. And people with less education often have a less healthy lifestyle than people with more education.
The relationships that the researchers found were not strong. But if other studies confirm this research, then strength athletes are likely to derive long-term benefits from a lifestyle that minimises AGEs. Animal studies have shown that advanced glycation end products accumulated mainly in the fast muscle fibres. [Pathobiology. 2009; 76(5): 227-34.]
As people age they lose muscle strength. A theory is that the accumulation of AGEs in the muscle tissue has something to do with this. [J Appl Physiol. 2007 Dec; 103(6): 2068-76.] [Eur J Appl Physiol. 2010 Jan; 108(1): 191-5.]
Looks like a couple more points for the low-carb and paleo movement.
Eur J Appl Physiol. 2011 Jul;111(7):1545-52.