Study Review: With some research supporting the benefits of casein protein over whey protein, a new study which compared ingestion of 20g of whey protein isolate versus 20g of micellar casein has once again raised questions as to the ideal protein strategy.
In this study conducted by Burd at el (1) healthy elderly men with an average age of 72 were divided into groups of 7 and performed a single leg resistance exercise followed by consumption of casein or whey respectively. Muscle protein synthesis (MPS) was measured at both rest and up to four hours after the performance of the exercise.
The results showed that MPS was 65% greater in the untrained leg in the group consuming whey (0.040) versus the group consuming micellar casein (0.024).
In the legs which performed resistance exercise, MPS was greater after whey ingestion compared to micellar casein (0.040 vs 0.024).
The study group concluded that whey protein isolate supports greater rates of MPS than micellar casein and that this may be down to the greater leucine and amino acid content of whey.
What does this all mean in light of previous research suggesting casein or a whey/casein mix may be better?
The most important factor is always going to be overall daily protein intake and then how you consume these meals. Where there is a big time lag between meals a dose of whey protein will more rapidly elevate blood amino acid levels and, given its greater BCAA content should lead to greater MPS in the short run. Over the long run, casein’s anti-proteolytic effects which mean it curbs muscle breakdown become more valuable than whey’s protein synthetic effects. What does this all mean for you?
Our advice is to focus on both proteins and, outside of the pre-workout window when whey will be superior due to its faster digestion rate, a mix of both which resembles how they are found in nature should be the best approach. To this end, consider the use of a protein blend to get most of your needs if consuming protein shakes regularly.
Burd NA, Yang Y, Moore DR, Tang JE, Tarnopolsky MA, Phillips SM.: Greater stimulation of myofibrillar protein synthesis with ingestion of whey protein isolate v. micellar casein at rest and after resistance exercise in elderly men.
© 2012, Reggie Johal. All rights reserved.