I've noticed that protein has been such a popular topic in the nutrition world today. Protein is so important to our health and often either gets overlooked, or becomes TOO much a part of our daily dish. I thought I would write this post to share my thoughts on protein as a dietitian, as well as shed some light on the research for, and against, a high protein consumption.
Recently, I came across an article entitled "High-Protein, reduced-carbohydrate weight-loss diets promote metabolite profiles likely to be detrimental to colonic health." Here is the link if anyone is interested:
Russell, Wendy R., et al. "High-protein, reduced-carbohydrate weight-loss diets promote metabolite profiles likely to be detrimental to colonic health." The American journal of clinical nutrition 93.5 (2011): 1062-1072.
These types of articles rub me the wrong way because they automatically take one side without considering other possibilities. I won't go into too much of the scientific detail, but the researchers compared a "weight-maintenance" diet of 85g protein with a "high protein, moderate carbohydrate" diet with 139g protein, and a "high protein low carbohydrate" diet with 137g protein and only 22g carbohydrate daily. They found that the diet with the highest protein and lowest carbohydrate level showed a decrease of colonic protein metabolites (also known as the short chain fatty acid butyrate)...leading to the conclusion that a high intake of protein may cause colon cancer. However, they found that if the diet still contains adequate amounts of fiber, the benefits of the fiber could counteract the possible negative side-effects of the high protein diet. With only 22g carbs a day, I highly doubt that diet contained enough fiber! Lastly, the researchers concluded that even though this relationship exists, there could be other factors leading to an increased risk of colon cancer, such as the fact that all of these experiments were done on obese people, as well as the fact that these findings depend on age, gender, and other lifestyle factors.
To me, these findings don't necessarily mean that we should all cut out protein and eat carbs all day long. I think protein is essential to health, well-being, energy, clear skin, good hair, and muscle strength. I believe that it all comes down to the quality of the foods we eat, including our protein quality. The quality of the foods we eat helps us maintain a healthy weight, which IN TURN decreases our chances of colon cancer, as well as many other chronic lifestyle diseases such as diabetes and heart disease. Stabilizing your weight to a healthy place while eating quality, real foods, and decreasing processed carbohydrates and sugars, leads to optimal health. Protein is definitely a part of that equation in my opinion. I would also like to note that a diet of 22 g of carbohydrates is just too low for a healthy body function. I don't believe we need as many carbohydrates as we are told to eat, but I also think that 22g of carbohydrates is a bit extreme. Going too low prevents you from even eating a good amount of vegetables, which provide vitamins, minerals, and fiber, as well as contribute to overall health. However, an adequate and moderate consumption of carbohydrates (100-200g depending on goals and activity level) can be reached by vegetables, fruits, and starchy vegetables (think sweet potatoes, squash, pumpkin, etc) without having to turn to breads, cereals, and other processed carbohydrate choices. Real food always wins! :)
Anyways, back to protein! At about the same time I came across the colon cancer article, I came across this article as well from Today's Dietitian Magazine:
http://www.todaysdietitian.com/newarchives/060114p22.shtml
This article is about athletes and protein intake. The article suggests that the amount of protein we have been recommending throughout the years (0.8 g protein/kg body weight for the average person) may actually not be enough for some people, including athletes. The author, a PhD RD, suggests that protein needs should be increased to 1.2-1.7g protein/kg body weight based on the activity level and age of the person in question. I fully agree with this! This article even goes on to address concerns of the high-protein diet, and that no data fully establishes a connection between a high protein intake and impaired kidney function in HEALTHY individuals that consume protein. Again, we must remember who we are comparing. In the first article, the experiment was done on obese people with multiple other health problems other than a colon cancer risk. In Today's Dietitian magazine, the author is reviewing studies that have been done on healthy, athletic people. Context is crucial.
Where does that leave us? As cliche, and perhaps disappointing as it sounds, I think it all boils down to balance. We can't completely cut out protein, but we always can't make it 80% of our diet. In fact, our bodies and brains won't let us. Protein has built in mechanisms to keep us full. Think about it; have you ever binged on chicken, or felt an uncontrollable need for 4, 5, or even 6 chicken breasts? I didn't think so. But, how easy it is to have 4, 5 or 6 dinner rolls before even touching your actual meal? Yes, been there, done that! That's why I love having protein with every meal. It's like a built in regulator for how much food I will consume and ensures that I will really stop eating when I am full. Protein is satisfying and filling, and should be a part of a healthy diet! However, please don't eat 4 chicken breasts in one sitting unless you are 300 lbs of pure muscle. You probably wouldn't want to anyway.
Lastly, what kind of protein do I recommend? Well, first of all, animal protein is the most bioavailable protein there is. So I recommend sources such as chicken, eggs, turkey, fish, grass-fed beef*, lamb, pork, etc. But I am also a realist and know that, at times, animal sources of meat may seem overwhelming, especially when consumed multiple days in a row. This is why other sources such as beans and lentils can be used as well. However, I recommend that animal proteins be given priority because they are more nutrient rich and satiating! And, as always, let's not forget what the majority of our plate should consist of...VEGETABLES! As long as your plate is full of those leafy greens, bright oranges, or deep reds, your protein options can vary.
I hope this review was helpful to those out there who are protein confused and will help you gage if you need to increase the quality and quantity of the protein you consume! I always recommend people trying things for themselves. Nutrition research is important, but it is also flawed as it has to do with so many factors other than solely what food is consumed during a certain period of time. And on that note, I am off to prepare my lunch for tomorrow! Green bean stew with leftover Armenian sausage patties...YUM! (Both recipes can be found on the blog with some searching!) Have a great night folks!
*I encourage grass-fed beef because it has more nutrition and is much better for us. Grass-fed meat is rich in vitamins and micronutrients, omega-3 fatty acids, and even antioxidants. So, my opinion is that grass fed is best. But I certainly can't control the source each and every time I have red meat, especially when eating out. The point is to do your best, don't stress yourself out, and enjoy your food and good health!
Daley, Cynthia A., et al. "A review of fatty acid profiles and antioxidant content in grass-fed and grain-fed beef." Nutrition journal 9.1 (2010): 10.
