Chang Woock Lee, B.A.
Cholesterol is perhaps the most notorious biological molecule of all. To many people, cholesterol is simply a synonym for heart attack, stroke, or cardiovascular disease because excessive blood cholesterol and lipid contributes to development of plaque build-up in the arteries and can eventually narrow and clog the blood vessels. Thus, cholesterol has become a nemesis to be overcome and destroyed. People try to eliminate cholesterol from their diet, and the media constantly emphasizes the importance of limiting cholesterol intake in lowering blood cholesterol levels.
However, there are important things about cholesterol that few people realize. Cholesterol is an essential component of all cell membranes - a precursor to steroid hormones, bile acids, and vitamin D - and thus vital for life. Without a proper amount of cholesterol, you simply cannot survive. Moreover, dietary cholesterol does not necessarily increase blood cholesterol and can even make you stronger and more muscular.
It’s OK to eat cholesterol
While there is clear evidence suggesting that high blood cholesterol is associated with cardiovascular risk/diseases, there are no convincing data supporting the idea that dietary cholesterol intake alone increases blood cholesterol and the risk of cardiovascular disease. Recent studies revealed that significant individual difference exists in response to high cholesterol consumption and that dietary cholesterol does not increase cardiovascular risk in healthy people. Genetic factors are thought to play a major role in the different individual responses to dietary cholesterol but physical activity is certainly an important determinant.
Exercise can independently lower blood cholesterol levels and/or cardiovascular risk. For example, an animal study found that treadmill exercise with moderate intensity may prevent or delay coronary heart diseases because the lumens of exercised monkeys’ arteries were significantly larger than those of sedentary animals even though their blood
cholesterol levels were similar to each other. Many other studies also suggest that muscle contractions during exercise can enhance cholesterol metabolism/usage and can significantly lower blood cholesterol in circulation.
Cholesterol can be good for you
A recent study examined the effects of dietary cholesterol and resistance training in healthy 60-69 year old people for 12 weeks. The results showed that high cholesterol consumption induced more muscle and strength gains with no association between dietary cholesterol and cardiovascular risk factors. Since cholesterol is an essential component of cell membranes and resistance training generally results in muscle enlargement, it is possible that the increased cholesterol consumption contributed to building bigger muscle cells, as more cholesterol is needed for the enlarging cell membranes.
The balance between consumption (input) and expenditure (output) is what determines the total body level of cholesterol. Even if you eat more cholesterol, you will be fine if you use it by doing exercise. So, enjoy your favorite 3-egg omelet without guilt. Just don’t forget to exercise. As long as you remain physically active, eating cholesterol is not bad for you. Moreover, if you lift some weights, well, it may make you bigger and stronger!
References
- Riechman SE, Andrews RD, MacLean DA, and Sheather S. Statins and Dietary and Serum Cholesterol Are Associated With Increased Lean Mass Following Resistance Training. J Gerontol Medical Sciences. 2007;62A:1164-71. http://biomedgerontology.oxfordjournals.org/content/62/10/1164.full.pdf+html
- Riechman SE, Lee CW, Chikani G, Chen VCW, and Lee TV. Cholesterol and Skeletal Muscle Health. World Rev Nutr Diet. 2009;100:71-79. http://www.karger.com/Article/FullText/235713
- Huffines Institute Text Article by Chang Woock Lee titled "The Chicken or The Egg?"