Does Beta Alanine Reduce Growth Hormone?

Athletes like sprinters may have heard of a supplement called beta alanine. When beta alanine (B alanine) is combined with the amino acid histidine, it forms carnosine. Several studies have investigated whether carnosine can reduce lactic acid levels during exercise.

Anything that might lower lactic acid might, in theory, allow an athlete to recover faster from high intensity exercise as well as last longer during  exercise like marathons.

Bodybuilding and weight lifting also results in considerable lactic acid accumulation inside muscles. Because of this, bodybuilders may also have pondered whether B alanine supplements might help them as well. When it comes to professional bodybuilders and strength athletes, the word of the day might be caution for now if a study published in the Journal of Strength and Conditioning Research holds true.

In essence, researchers gave a carnosine ( and hence beta alanine) drink (derived from chicken breast extract) to 22 healthy young men who were not weight lifters. The average age of the men was 25. A chicken breast extract was chosen to be the “supplement” because previous research found that the B-alanine (and histidine) from this extract can be absorbed into muscle to increase muscle carnosine content. Still other research found that this extract improved aerobic endurance in humans.

The drink contained 2 grams of carnosine and anserine (which also helps buffer lactic acid levels).

Since this study did not use a commercially available B alanine supplement, the results may or may not be the same if using a real beta alanine supplement.

Some of the men received a placebo. Others received the carnosine (Beta alanine) supplement. All subjects performed a seated leg extension and their 1 repetition maximum (RM) were determined. Subjects performed 5 sets of the leg extension, starting at 60% 1 RM. With each subsequent set, the weight was increased 10%. Subjects performed reps to exhaustion on each set. All exercise occurred at the same time of day.

Blood was drawn before supplementation and after supplementation.  Lactic acid, testosterone, growth hormone and cortisol were measured as well epinephrine (adrenalin).

This is basically what the researchers found :

• Epinephrine was lower after supplementation
• Lactic acid levels in response to exercise were lower after  supplementation (they were lower in the placebo group also)
• Subjects did not feel less fatigued with the carnosine supplement
• Growth hormone response to exercise was lower after supplementation
• No significant changes in strength were seen in either group
• No changes in cortisol levels were seen in either group
• No change in testosterone levels were seen in either group

While this study had some issues (such as both groups showing lower lactic acid levels and that nobody felt less fatigued even though lactic acid was reduced) the finding that grabbed my attention the most was that the carnosine  (Beta alanine) supplement appeared to lower growth hormone levels.  The reasons for this are not known.

Some research hints that lactic acid accumulation may in some part be tied to growth hormone release. But if this is true, then why didn’t GH levels go down in the placebo group – who also experienced a reduction in lactic acid levels? Obviously things are more complicated than “lactic acid raises GH levels”.

This study contradicts a previous investigation noting that beta alanine supplements  increased growth hormone levels after squats (6 sets at 70% 1RM). I could not locate many studies specifically looking at how beta alanine (or carnosine) effects growth hormone.

While I have some reservations about this study, for now it might be prudent  for professional bodybuilders who use beta alanine supplements to have their growth hormone levels checked periodically – or avoid B alanine supplements until the results from this study can be replicated.

What do you think?