Beta-hydroxy-beta-methylbutyrate, or HMB, is a popular bodybuilding supplement that has been shown in scientific studies to positively affect protein balance in the human body. Not surprisingly, those results prompted more intensive research into the supplement and led to some unexpected discoveries. In particular, HMB has been shown to effect your cholesterol levels, an important indicator of cardiovascular health.
Just how does HMB influence your blood lipid profile?
Read on to find out.
What Studies Show About HMB and Cholesterol
Scientists began noticing HMB’s potential effects on cholesterol in 1994 when researchers from Oklahoma State University were examining the methods for improving the quality of feedlot steers. In that study, steers fed HMB over the course of 82 to 147 days showed significantly lower blood cholesterol levels than those NOT fed HMB.
Then, a 2000 literature review by scientists at Iowa State University looked at nine studies to try and determine the safety of HMB use in humans. While the reviewers noted no notable negative side effects, they did observe an overall decrease in cholesterol markers among the HMB users. In particular, HMB led to an average drop in total cholesterol of about 6% and in low-density lipids (LDL), or “bad” cholesterol, by more than 7% when compared to a placebo. What’s more, systolic blood pressure of the HMB users dropped about four points.
After several more years of research, scientists from the University of Illinois undertook an even more ambitious review of available literature in 2008, examining everything about HMB from muscle gain to its use by cancer patients to its effects on blood lipids. While these reviewers found a mixed bag in terms of results related to muscle growth, the general trends pointed to HMB being effective for people in potentially catabolic states, such as those with wasting diseases, new weight trainers, or experienced lifters who kick up their intensity and training poundages.
More significantly for our purposes, the reviewers noted that many studies showed an improvement in total and LDL cholesterol among HMB users when compared to those who received a placebo. They even found this to be the case in studies where placebo groups made progress in both and muscle mass and strength.
The Illinois scientists also proposed some potential mechanisms for HMB’s actions. The prevailing theory is one called the Cholesterol Synthesis Hypothesis which sees HMB as a precursor to HMG-CoA, a coenzyme that is important for the proper formation of cholesterol in muscle cells. This theory hinges on the idea that damaged muscle may lack the ability to create the cholesterol it needs to build and repair cell structures. Easing that shortcoming could be one way that HMB helps to slow down proteolysis, or muscle breakdown.
While this would not fully explain HMB’s ability to lower serum cholesterol levels, there certainly seems to be a strong connection between HMB and cholesterol production.
Can HMB Help You?
If you want to gain muscle while training hard or maintain muscle mass while dieting, available evidence suggests that HMB might help you reach your goals.
On the other hand, if you’re counting on HMB to reduce your blood cholesterol levels, you may need to rethink your approach. While some studies show lowered LDL and total cholesterol for trainees using HMB, the mechanisms and circumstances behind these improvements are not completely understood. At the least, more study is needed before we can anoint HMB as a surefire way to lower your cholesterol.
Whatever your goals and plans, make sure to discuss them with your doctor beforehand, and he can help you figure out if HMB is right, and safe, for you.
For more great workout and nutrition tips checkout the Free Bodybuilding Magazine.