Being a sporty vegetarian, getting enough high quality
protein is important. Most of the plant based protein bars use soy protein as
their protein source demanding me to take a closer look on soy and its health
benefits/risks.
Soy is unique as it is the only plant based protein that
provides all the essential amino acids that the body needs. It contains no
saturated fat or cholesterol, both of which are found in meat. Soy protein is
also a good source of minerals, such as manganese, copper, iron and phosphorus
(1). Soy protein is also considered to be well digestible (2). On the other
hand, soy protein is an allergen and can cause an allergic reaction to some (3).
Nevertheless, now we come to the tricky part. Soy contains
phytoestrogens that some connect to health benefits and some to health dangers.
For example, some studies indicate that phytoestrogens can lower the risk of
breast cancer and some indicate they can increase the risk. Similarly,
phytoestrogens in some studies show to alleviate menopausal symptoms and in
some they have no effect or they make the symptoms worse. It is also said that
25 grams of soy protein a day alongside a healthy diet can help decrease the
risk of heart disease, but then again, soy contains substances that can block
the absorbance of some minerals and inhibit some enzymes to work properly
(2)(3).
So what is one supposed to think then? On one hand, soy
protein is a complete protein that also offers minerals and fiber, on the other
hand, there is a debate whether the substances found in soy are healthy or not.
In addition, it is said that most of the soy consumed in the US is genetically
modified (3). The negative sides of soy protein don’t stop there, but I’m
starting to get the idea.
Intuitively, I would think that the health risks become
tangible when one eats a lot of soy. Therefore I tried to find a number or some
clear limit to tell me how much is too much. Unfortunately, I couldn’t find
anything that could give me a clear picture, only an article saying soy foods
are OK but concentrated soy products are not (4).
Luckily, soy protein is not my only option: beans, lentils,
nuts and dairy all are rich in protein and by mixing and matching I can easily
get enough complete protein in my diet. All in all, when it comes to
choosing to eat or not to eat soy, I would listen to my biology teacher, who once
said: “have everything in moderation, even moderation itself”.
Take care,
Anna-Kaisa
Sources:
(1)
Nutrition Data http://nutritiondata.self.com/facts/legumes-and-legume-products/4389/2
(2)
Livestrong.com http://www.livestrong.com/article/499435-soy-protein-and-digestion/
(3)
Baseline of Health Foundation http://www.jonbarron.org/article/benefits-dangers-soy-products
What about the different "versions" of soy protein that one finds out there? Seitan, tofu, etc., etc. Is one better than the other, or are there any nutritional differences between the different types of soy protein? Or is the only difference in how they are processed?
ReplyDeleteThe way I understand the dangers of soy protein is that one should keep an eye on the consumption of foods that contain specifically soy protein isolate. These foods are typically protein bars, supplements, protein shakes, veggie links and other highly processed foods. Tofu, seitan are not such foods. In fact, seitan is wheat gluten. Check the nutrition labels :)
ReplyDeleteExtremely well voiced article. I especially appreciated the citing of courses so that readers can inform themselves if they want to dig deeper.
ReplyDeleteA Queue: what about whey protein. Many athletes are obsessed with this, however I have heard things negative effects about many brands that are not actually natural whey rather are synthetic which I presume is worse for your body
Thanks for your comment!
ReplyDeleteWhey protein is derived from milk and is a leftover from cheese production. Whey protein is said to be well digestible, but since it comes from milk, it may cause allergic reactions among people who are lactose intolerant or otherwise allergic to milk. It is complete protein and popular among bodybuilders, but there is not a lot of evidence that it really helps you build muscle. Whey does seem to aid recovery from a workout, however.
I didn't find much information about synthetic whey protein, which suggests that it probably is not very common. I imagine that the whey itself is probably the same if it is a cheese byproduct or if it is made synthetically, but there might be other stuff that end up with the whey if it is made synthetically. Natural is better with everything!
Take care,
Anna-Kaisa