A lot of athletes, with CrossFit and others, supplement their protein intake with protein powders (such as whey) or by eating more meat. Some from the old school swear by drinking a lot of milk, which some will deride as not being Paleo. So what’s best? It turns out that for weight loss, whey is better at reducing appetite and food intake than red meat, soy protein or milk (Huang et al. 2008), and produces less of an insulin response. Whey contains a protein/hormone called relaxin. One of the things relaxin does is inhibit secretion of insulin. This is not necessarily a good thing. Inhibiting insulin may result in sugars remaining in the blood stream, and doing damage, longer than they would have if insulin was getting it out of there. Relaxin is also believed to increase sperm motility . . . might be good if yours are sluggish and you want kids. Not good if you are emotionally drained and exhausted by the kids you already have . . . and inhibit collagen synthesis (not good for weight lifters, but good for pregnant women getting ready to give birth). Just speculation at this point as to whether or not eating a lot of whey would do any these things though.
For bone strength, skim milk powder seems to produce better results than a combination of whey protein and calcium. It sounds like there may be more to skim milk powder, and probably milk in general, that helps with growth and strength. Oh, this would not be growth hormone because growth hormone will be found in milk fat. The skim stuff is pretty safe. Cow’s milk contains lactoferrin, which has recently been shown to increase production of angiogenic factors (these aid development of blood vessels and capillaries) in bone tissue (Nakajima et al. 2011). Since lactoferrin is a whey protein it is likely that whey supplements (as long they have not been heat treated) would provide similar benefits.
Here it is in plain English: Whey protein and skim milk seem to be OK. There is a lot of research that shows both may have a lot of benefits. A lot of commercial products contain artificial sweeteners. Natural plain whey protein is available too but does not dissolve well. So far the best whey-based protein powder we’ve tried is Primal Fuel, which you can order through this site if you feel like it. No artificial sweeteners.
In a nutshell: There is evidence that whey protein:
- is a good source of protein
- will suppress appetite
- is good for bone health
- may help reduce insulin levels
- is low in some hormones and chemicals and so forth.
- more research is needed to find out if the hormones that are in whey have an effect on people.
Fried A, Manske SL, Eller LK, Lorincz C, Reimer RA, & Zernicke RF (2012). Skim milk powder enhances trabecular bone architecture compared with casein or whey in diet-induced obese rats. Nutrition (Burbank, Los Angeles County, Calif.), 28 (3), 331-5 PMID: 22119485
S, Egert S, & Heer M (2011). Effects of whey protein supplements on
metabolism: evidence from human intervention studies. Current opinion in clinical nutrition and metabolic care, 14 (6), 569-80 PMID: 21912246