Cholesterol: the forgotten anabolic for building muscle?

Cholesterol is a small, fat-like molecule that supposedly clogs your arteries and slowly kills you. But is cholesterol really to be avoided? Or is it actually our muscles' best friend?

Cholesterol and bodybuilding:

Riechman et al. (2007) found that cholesterol can be GOOD for your MUSCLES. In their study, 49 seniors completed a 12-week strength training program as well as a nutritional program. Retrospective analysis of participants' food diaries revealed a linear dose-response relationship between dietary cholesterol intake and increase in lean body mass (supporting DXA scan). The more cholesterol they consumed, the more muscle the subjects gained. This relationship was maintained when protein and fat intake were controlled. See the diagram below.

Lee et al. (2011) compared high (~ 800 mg / d) and low cholesterol (<200 mg / d) diets in healthy young adults. The high cholesterol diet group had nearly 3 times the myofibrillary protein synthesis rate 22 hours after intense resistance training than the low cholesterol diet group. Myofibrillar protein synthesis is a measure of muscle growth, specifically how quickly your muscles create new protein. These results therefore again suggest that a high cholesterol diet is beneficial for muscle growth.

Van Vliet et al. (2017) also found that whole eggs stimulated myofibrillar protein synthesis more than the same amount of protein from egg whites. The yolk is very high in cholesterol, so knowing that cholesterol stimulates the synthesis of myofibrillar proteins, it is likely that it is the cholesterol in whole eggs that makes it an excellent food for building muscle.

Most of the other research on the relationship between cholesterol and muscle growth has yet to be published. Below is a summary of the data we currently have.

• In a similar design to the first study by Riechman et al., Riechman and Gasier (2007) again found beneficial effects of high cholesterol intake for muscle growth and strength development, although the effects were were more modest than in their previous study and it is not clear whether protein intake was controlled or not.
• Riechman et al. (2008) performed another replication study and found a dose-response relationship between cholesterol intake and strength development, but not lean body mass. Again, it is not known if protein intake has been controlled.
• In another replication study, Iglay et al. (2009) found no relationship between cholesterol intake and muscle growth or strength development. However, they also did not find an effect between 0.9 and 1.2 g / kg / d of protein, suggesting that their study was statistically insufficient to examine the subject properly.

Research on statins also suggests a beneficial role for cholesterol in your muscles. Statins are a type of medicine used in the treatment of various cardiovascular problems. The purpose of statins is to lower your cholesterol level, but one of their common side effects is myopathy. Treatment with statins can reduce muscle strength and functionality, induce inflammation of the muscles (myositis) and even complete death of muscle fibers (rhabdomyolysis).

Low cholesterol intake may also be the reason why lacto-ovo-vegetarian diets tend to result in less muscle growth than omnivorous diets in bodybuilders, even with the same protein intake. The cholesterol content of plant lipids is about 100 times lower than that of lipids from animals. However, many other factors, such as the quality of protein, could also explain the lower muscle mass of vegetarians.

Overall, the available research suggests that a diet high in cholesterol is good for muscle growth and the development of strength.

• The mainstream media demonizes cholesterol because of its alleged effects on your arteries. If you have based your perception of cholesterol on this extremely biased bias, you may be surprised to find that cholesterol has several potential mechanisms of action that actually allow it to increase muscle growth.
  • Cholesterol increases the viscosity of the cell membrane, which can influence its stability. This can positively influence the extent to which muscle cells are damaged during exercise, and the extent of the inflammatory response.
  • Cholesterol appears to play a role in the muscle repair process by controlling inflammation. Muscle damage creates inflammation, which leads to the recruitment of immune cells to aid in the recovery process.
  • Cholesterol is essential for the formation of lipid rafts. Lipid rafts assemble components of signaling pathways and enhance signaling between pathways that play important roles in muscle hypertrophy, such as growth factors IGF-I and mTOR. Depleted cholesterol can lead to poor sorting of proteins, which reduces signal transduction. The activation of mTOR corresponds to the observed increase in myofibrillar protein synthesis after consumption of cholesterol.

Simply put, cholesterol can help your muscle cells resist damage and may improve their ability to repair themselves after your workouts, which is crucial for muscle growth. Cholesterol can also indirectly improve your weight training progress. It is the precursor of anabolic hormones and thus is crucial for their production.

However, just having high serum cholesterol or eating a ton of dietary cholesterol does not, by itself, necessarily lead to increased testosterone or leaner body mass gain. The limiting factor in the production of anabolic hormones is often the transport of cholesterol to the mitochondria, where its renewal takes place, not necessarily the amount of cholesterol available in the bloodstream. Thus, increasing dietary cholesterol intake did not lead to an increase in testosterone levels in all studies .

However, we have indirect evidence from the saturated fat literature that shows that a typical high cholesterol diet increases testosterone production. Saturated fat is a building block of cholesterol, which in turn is used for the production of testosterone.

A low intake of saturated fat is associated with a reduced production of testosterone. For example, men switching from a 40% fat diet with a high saturated fat intake to a 25% fat diet with a low saturated fat intake experience decreased levels of total and free testosterone; going back to their diet boosted their testosterone levels (see graph below if you are interested in the details). Several other studies have also shown that diets low in saturated fat reduced levels of circulating testosterone .

In fact, in the first study on the effect of cholesterol on lean mass, the authors also found a significant correlation between saturated fat intake and lean mass growth.. Many high cholesterol diets are also high in saturated fat, so not too surprisingly, but it leaves open the possibility that cholesterol is in fact irrelevant and instead is fat. saturated. To find out, the Bayesian research team reached out to Dr. Riechman, the principal investigator of the above cholesterol study. He confirmed that he and his colleagues monitored total fat intake (as well as total protein and energy intake) in their cholesterol analysis, which strongly suggests that cholesterol plays an independent role in muscle growth.

The cholesterol conspiracy theory

Before everyone starts eating 10 eggs a day, it's important to note that the research can also seem a bit suspicious: only 1 in 3 studies on the relationship between cholesterol and muscle growth have been published, although the research was already carried out several years ago. And most of the published research mentioned above was done by the same principal investigator, Dr Riechman, who received research grants totaling around $ 2.7 million (from what we could find) from sources such than the US Poultry & Egg Association.

However, it is a simple reality that scientific research is expensive, so people willing to invest a lot of money in it often have something to gain. People like Bret Contreras and Menno Henselmans who pay out of pocket for their scientific research are very rare. The scientific industry is set up so that the integrity of researchers prevents conflicts of interest of sponsors from misleading the public. And it works most of the time. Nutrition research funded by the food industry does not have very different results from research with other funding. In addition, Dr. Riechman has also received funding from the American Heart Association and the United States military. Not to mention the fact that it would be pretty darn far-fetched to pour millions of dollars and risk your career and reputation to promote - among all the things you could sell - cholesterol, specifically for - of every possible market. - people interested in muscle growth. Let us remember that cast iron lovers represent only a tiny part of the population. And we folks interested in the contributions of scientific research, even more.

Ok, so let's take off the foil helmets and assume there isn't a major conspiracy theory going on. Well in any case not concerning cholesterol… This leaves the question of knowing if…

Isn't cholesterol bad for your heart?

Nope. The mainstream media portrayal of the health effects of cholesterol is about as valid as the claim by most Olympic athletes that it is natural. This is telling you. The media will have you believe that all the cholesterol you eat will eventually clog your arteries, but the reality is that for most people, the amount of cholesterol you eat in your diet doesn't even influence the amount of cholesterol in your blood. . Cholesterol is so important to the body that it is highly regulated. If your diet is low in cholesterol, your intestines will increase their absorption to compensate for the problem. If that's not enough, your body will even make its own cholesterol.

However, some people, around 20%, have a genetic variation that causes them to absorb or synthesize so much cholesterol that their diet does influence their blood cholesterol level. However, even among these hyper-responders, a diet high in cholesterol generally does not negatively influence the cholesterol profile. If total blood cholesterol increases during a high-cholesterol diet, the “good” HDL cholesterol and the “bad” LDL cholesterol generally increase by the same amount .

A review article on the effects of cholesterol on cardiovascular health concluded: " Epidemiological data do not support a link between dietary cholesterol consumption and cardiovascular disease ".

A study on egg consumption came to the following conclusion “ Evidence suggests that a diet containing more eggs than recommended (at least in some countries) can be safely consumed as part of a diet. healthy diet both for the general population and for those at high risk of cardiovascular disease, those with established coronary artery disease and those with type 2 diabetes mellitus ”.

Take-away messages

• Available research indicates that a high cholesterol diet may be beneficial for muscle growth and strength development by increasing muscle cell integrity and signaling for muscle growth. The beneficial daily cholesterol intake appears to be at least 7.2 mg dietary cholesterol per kg of lean body mass, and more than 400 mg per day in humans.
• Because your body automatically regulates your blood cholesterol levels, high cholesterol intake usually does not increase your serum cholesterol levels. Even in hyper-responders, consuming cholesterol generally does not change the ratio of “good” HDL cholesterol to “bad” LDL cholesterol, and does not cause heart problems.

Here is the amount of cholesterol in various foods according to the USDA.

Since only foods of animal origin contain significant amounts of bioavailable cholesterol, vegans should probably consider compensating for their low cholesterol intake by consuming more (saturated) fat so that their body can produce enough of its own cholesterol. .

Related research and references:

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1. Bayesian France training / MennoHenselmans.com