Nutrition Research News
What’s new from the world of nutritional research and how will the latest findings influence the supplements you use? Find out in today’s AllStarHealth.com blog.
Whey and Casein: New Reasons to Use Both
The most-often mentioned advantages of whey or casein protein relate to whey’s fast-absorption and casein’s relatively slow absorption. As consumers, we’re used to thinking of absorption in “faster is better” terms, and that may be true for pain medications or certain types of supplements. But as far as protein goes, it’s much better to have a combination of fast and slow-release proteins; this increases and prolongs the utilization of protein, minimizing the chance that excess amounts will be used for energy instead of maintaining lean body mass. This is one reason why protein blends are becoming the dominant type of protein shake.
A new study has identified another difference between whey and casein. It showed that although both supply protein at different rates, whey and casein have different metabolic effects. Whey protein was found to raise fasting insulin levels, whereas casein protein raised IGF-1 levels. Insulin and IGF-1 are both anabolic (tissue-building) hormones that have broad roles to play in health, so it’s difficult to characterize what the significance of this finding is for protein supplement users. Increased IGF-1 levels may have an an association with increased cancer risk, yet IGF-1 is also a potential breakthrough therapy for ALS. Similarly, the significance of raised fasting insulin levels is a matter of degree and what underlying issues a person may have with insulin and blood sugar levels.
Pre-digested Proteins: Better Absorption, Better Utilization
Speaking of protein, there has always been a lack of consensus about the desirability of different protein types and the rationales for using one type of supplement or the other; whey, casein, milk, egg, pre-digested (hydrolyzed) or not, soy, blends, etc. The differences are many, but include factors like absorption rates and how well the body can actually use the protein to build new body mass. Many customers prefer to buy and use intact (“un-denatured”) proteins under the reasonable assumption that proteins in this natural, chemically un-altered state are absorbed and used most efficiently. Protein powder and shake labels often highlight this feature, too, pointing out that their protein is un-denatured. Also, un-denatured proteins tend to taste best and are easier to work with from a flavoring standpoint.
Pre-digested proteins have always had their supporters, but have also enjoyed a much smaller share of the protein supplement market. They don’t taste as good, that’s one disadvantage. But there are so many new flavor and sweetening ingredients available now that formulators can work around that, and that may be why there’s renewed interest in predigested protein hydrolysates. A new study , for example, made a straightforward comparison of intact casein versus predigested casein and concluded that predigested casein “accelerates protein digestion and absorption from the gut, augments postprandial amino acid availability, and tends to increase the incorporation rate of dietary amino acids into skeletal muscle protein.” This shows that beyond being absorbed better, the predigested casein hydrolysate was also utilized more efficiently.
Zinc and Vitamin A Deficiency: Possible Link to Ear Disease in Children
Many parents have children who suffer from recurrent ear problems which can be very uncomfortable and hard to treat, partly due to the ear’s unique anatomical structure which exposes it to a wide-range of potentially pathogenic organisms from both inside and outside the body. Infections that develop on the surfaces within the ear system are even hard for the body to eradicate, since the body can only “access” the infection from the inside. A pediatric journal just published a review of nutritional factors that relate to the development of ear disease in children. They mention that a deficiency of two specific nutrients – zinc and vitamin A - may play a role in the pathology of ear disease in children. Parents of children with recurrent ear problems may want to consider whether child-appropriate supplementation of zinc and vitamin A would help by – at the very least – ruling out these deficiencies as contributing factors.