|Have not found any research on athletic performance and goat milk.
A lot of athletes, with CrossFit and others, supplement their protein intake with protein powders (such as whey) or by eating more meat and some from the old school swear by drinking a lot of milk. 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, not good if you are emotionally drained and exhausted by the kids you already have . . . and inhibit collagen synthesis. This is 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 whey protein and calcium combined. 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 may both offer a lot of benefits. If you are trying to follow a Paleo-style diet (aka Paleolithic Diet), whey may be a good option, since milk is on the “no” list. Some people will tell you whey is not Paleo, but from a scientific perspective that really doesn’t matter. A lot of commercial products contain artificial sweeteners. Natural plain whey protein is available too but does not dissolve well.
In a nutshell: There is evidence that whey protein:
1. is a good source of protein
2. will suppress appetite
3. is good for bone health
4. may reduce insulin levels
5. is low in some hormones and chemicals and so forth.
6. more research is needed to find out if the hormones that are in whey have an effect on people.
Graf 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
Nakajima K, Kanno Y, Nakamura M, Gao XD, Kawamura A, Itoh F, & Ishisaki A (2011). Bovine milk lactoferrin induces synthesis of the angiogenic factors VEGF and FGF2 in osteoblasts via the p44/p42 MAP kinase pathway. Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine, 24 (5), 847-56 PMID: 21404021
Yamamoto, H., Arai, T., Tasaka, R., Mori, Y., Iguchi, K., Unno, K., & Hoshino, M. (2009). Inhibitory Effect of Relaxin-3 on Insulin Secretion in Isolated Pancreas and Insulinoma JOURNAL OF HEALTH SCIENCE, 55 (1), 132-137 DOI: 10.1248/jhs.55.132
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