Soy Protein Powder – Good or Bad For You?By
I often receive questions from people asking my opinion of various protein powders. One that comes up quite often is about soy and whey protein powder. Here’s the question Steve asked…
“Harry, I’ve heard soy protein powder is bad. How about whey protein powder? Is it good for you? Benefits? And if it is why would it be better for you than the milk it comes from? Thanks, Steve”
Steve, the jury is still out about whether soy protein powder is bad for you. I’ll tell you what the research says, then I’ll tell you a little story that happened to me when I used it.
A recent published study (in the June 2009 issue of Fertility and Sterility) attempted to find out from the published studies (mainly from searches done on Pub Med), whether there was any influence on a man’s bioavailable testosterone concentration as a result of ingesting soy protein powder (that is inherently loaded with isoflavones – phytoestrogens (plant estrogens) that have been theorized to exert estrogen-like effects in men by lowering testosterone concentrations). According to this study, they analyzed 15 placebo-controlled treatment groups, as well as 32 other studies in less rigorously-controlled conditions. Their conclusion was that neither soy foods nor isoflavone supplements alter measures of bioavailable testosterone concentrations in men.
My experience is a little different, albeit unscientific.
It was the last week of my preparation for taking my final photos to send in for the 1998 Body For Life contest (called Physique Transformation Challenge contest back then). I was following a very strict “last week” diet and my bodyfat levels were extremely low. I was also tracking my skin-fold thickness measurements religiously. Well, on recommendation by a famous “guru” at the time, I introduced soy protein powder into the mix approximately 4 days prior to my photo shoot. I did this because he said it could reduce my skin-fold thickness by removing water just underneath the skin. The day after I started this I checked my skin-fold thickness with precise body-fat calipers. I was shocked to discover that ALL of the readings on my body had increased in thickness instead, the exact opposite of what the “guru” said would happen. This means I was somehow now holding water underneath my skin, instead of inside my muscles, where I wanted it to be. Needless to say I almost panicked because I only had 3 more days to go for my final photo shoot.
I immediately stopped taking the soy protein powder and hoped for the best. Thank goodness the following morning my skinfold thickness went down again, which meant I was releasing some of the water that was put there by the soy protein powder, so I reasoned. From that moment forward I have tried to stay as far away from soy protein powder as I could.
The studies showing no adverse affects on testosterone readings not changing with soy protein powder ingestion could be right. But, if you bloat and start holding water as a result of the increased plant estrogens in your system, well, this just won’t work either. You women know exactly what I’m talking about when you bloat up once per month.
So, my recommendation based on my own personal experience with soy protein powder is to NOT take it at all. Plus, I don’t think there is anything “special” in soy protein powder you can’t get somewhere else.
The semi-quick answer to your question (about why whey protein powder would be better for you than milk) is because most whey protein powder products are lactose-free. This is great for those with lactose intolerance. They usually have less than 1% of the original lactose found in unprocessed whey. Just look at the label, if it doesn’t say “lactose-free” then it’s probably not. [There are other good reasons for taking whey too, just keep reading]
Here’s another way to tell if your whey protein powder has lactose in it or not.
Whey ”concentrate” protein powder has the highest amounts of naturally occuring lactose. Whey ”isolate” protein powder has almost none (and is typically over 90% protein by weight).
Whey also has some important and highly beneficial immunological benefits. You get them from what are called, ”biologically active fractions.” Only problem is, these fractions are fragile, i.e., they are easily destroyed by processing (heat and chemicals).
If you’re not lactose intolerant than the least processed whey, or whey concentrate protein powder, is the way to go if you want to preserve these fractions and receive the maximum immune system benefit.
If you’re more interested in muscle building (which everyone should even if you’re not a body builder because more lean muscle on your body increases the potential for fat burning — due to a raised metabolism), you should probably use another form of milk protein either instead of, or in addition to whey protein powder. (casein or milk protein isolates).
So, you now know that whey concentrate protein powder is best for preserving those fractions. However, all whey isolates are not made the same.
Ion-exchange is a popular method that manufacturers use to adjust the pH. Only problem is this is a harsh processing method and results in denaturing the protein found in whey as well as destroying most of the good fractions as well.
Another drawback of ion-exhange processing is it leaves an abnormally high amount of beta-lactoglobulin, which is the one fraction of whey protein in cow’s milk that is not found in human milk, and which has been found to be the most allergenic to humans.
Filtered processing is better as this is a gentle extraction method. Just look for a label that says something like, “triple-filtered” or similar.
Summary: For enhanced immune function take whey concentrate protein powder – if you can tolerate the lactose.
For protein powder supplementation take a filtered whey isolate (even though casein is better for building lean muscle tissue — many recent studies prove this). Or for the best results take a protein powder that combines whey concentrate, whey isolate, and casein (milk isolate).
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