- There is no reason to restrict protein intake in healthy individuals to protect the kidney. Proteins help maintain a nitrogen balance in the body and help the kidneys to function more, helping flush out the toxins from the body.
- There is no evidence that the increased calcium is lost in urine is from bone, and the overall net calcium balance is either unaffected or actually improved by a high protein diet.
- Having a higher protein : carb ratio typically helps in maintaining better glucose homeostasis, increasing insulin sensitivity and controlling glucose in normal people and those suffering from type II diabetes.
- A high protein diet helps maintain lean muscles, promotes weight loss, muscle maintenance and appetite suppression.
The science behind eating a protein-rich diet is quite ambiguous. All the textbook knowledge about protein consumption, talk about how protein-rich diets can be harmful to your health—from cardiovascular diseases to renal failure to bone resorption.
In our body, protein, and its basic unit, amino acids are known as the building blocks of the body, as they are responsible for the building of new tissues—muscles, skin, organs, and tendons. It plays a crucial role in forming several hormones, enzymes, and brain chemicals. Proteins also help in the transportation of important molecules, act as antibodies, a great source of energy by yielding calories, and helps maintain the acid-base balance of the body. Thus, protein plays a very important role in the anabolic (building new tissues) process that takes place inside your body.
So, the question is that, are the myths that revolve around high protein diet intake backed up with enough scientific proofs?
High protein intake : Functioning of Kidneys
Did you know that out of the three macronutrients that our body requires—Carbohydrates, Fats, and Proteins, only proteins contain nitrogen? A protein-rich diet means a higher amount of nitrogen accumulation in the body, and a high nitrogen level in the body leads to strain on the kidneys. A person who has suffered renal failure in the past should definitely refrain from consuming a protein-rich diet. A high protein diet being bad for kidneys, is true for this set of a population who suffer from a pre-disposed kidney issues. In a healthy individual, high protein consumption makes the kidneys work harder, as they flush out the by-products of protein from the body, but this definitely doesn’t lead to renal failure. A study was conducted by the International Society of Sports Nutrition in which they analysed the data about the connection between protein consumption and renal failure, it concluded, “It is clear that protein restriction does not prevent the decline in renal function with age, and, in fact, is the major cause of that decline. A better way to prevent the decline would be to increase protein intake. There is no reason to restrict protein intake in healthy individuals to protect the kidney.”
To understand this better an understanding of protein metabolism in accordance with renal function is crucial. The functional unit of every molecule of protein, the amino acid is deaminated in the liver. Deamination is the process of removal of nitrogen from the amino acids, which results in the formation of ammonia. The liver releases ammonia (NH3) and due to the presence of carbon dioxide (CO2) in the body, urea is formed. Through the bloodstream, this urea travels to the kidneys. The kidneys filter out the blood and remove urea from the body in the form of urine. Our kidneys are capable of dealing with a higher nitrogen intake. This is known as a positive nitrogen balance, which means that the body is synthesising more protein than it degrades and where the nitrogen intake exceeds excretion. On the other hand, a negative nitrogen balance is when the body degrades more nitrogen than protein synthesis and when the body excretes more Nitrogen than produced.
High protein intake : Effect on Bones
According to theories, a high protein diet might be a possible reason for increasing cases of osteoporosis. These claims have not only been floating online, but certified by certain reputable nutrition science textbooks. The science applied behind this theory is that eating a protein-rich diet causes calcium excretion, which might lead to an increase in the acid load of the body.
A study published in The Journal of Clinical Endocrinology & Metabolism in 2004, stated that an increase in protein consumption does not hold any evidence of an increase in bone calcium excretion, but has had a positive influence in the elderly. In fact, a high protein diet increases the production of bone health-promoting hormones, Insulin-like growth factor 1. Dairy products that we consume daily are responsible for the maximum source of calcium in our bodies. Along with being a great source of calcium, dairy products are loaded with vitamin D. Vitamin D makes calcium more bioavailable, which means it helps the body to absorb calcium easily.
According to Dr. Layne Norton, “Thus, while increasing protein may increase calcium excretion, there is no evidence that the increased calcium is lost in urine is from bone, and the overall net calcium balance is either unaffected or actually improved by a high protein diet.”
High protein intake : Increased risk of Diabetes
While hitting the gym, all of us are asked to increase protein intake. The major cause of this is when the body breaks down fat, proteins help in muscle building and maintaining the skin elasticity, aiding in weight loss. Recent studies done on the consumption of macronutrients indicates having a higher protein : carb ratio typically helps in maintaining better glucose homeostasis, increasing insulin sensitivity and controlling glucose in normal people and those suffering from type II diabetes.
High protein intake : Increased risk of Cancer
Along with all the daily life factors that we are exposed to, consumption of a protein-rich diet is also considered as a leading cause of cancer. In a recent study published by Cell Metabolism in 2014 titled “Low Protein Intake Is Associated with a Major Reduction in IGF-1, Cancer and Overall Mortality in the 65 and younger but Not Older People”. This study was an epidemiological one and the conclusions were made through experiments on rodents, primarily. Epidemiological studies are done to initiate further studies and do not account for scientific claims. The study had a lot of limitations and drawbacks.
It is safe to say that a protein-rich diet is not only safe for consumption but it also helps in the prevention/treatment of diabetes, obesity, and heart diseases. So, the next time when someone misleads you by saying that your protein-rich diet is doing more harm than good, back up your nutritional choices with some scientific facts!
- 5 Dangerous Myths About Protein – Science Driven Nutrition. Science Driven Nutrition. (2020). Retrieved 28 September 2020, from http://sciencedrivennutrition.com/myths-about-protein/
- Norton, A. (2020). Myths Surrounding High Protein Diet Safety | Biolayne. Biolayne. Retrieved 28 September 2020, from https://www.biolayne.com/articles/nutrition/myths-surrounding-high-protein-diet-safety/
- High Protein Diets and Kidney Function. Lookgreatnaked.com. (2020). Retrieved 28 September 2020, from http://www.lookgreatnaked.com/blog/high-protein-diets-and-kidney-function/
- Carbone, J., & Pasiakos, S. (2020). Dietary Protein and Muscle Mass: Translating Science to Application and Health Benefit. Retrieved 28 September 2020, from. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566799/
- Campos-Nonato, I., Hernandez, L., & Barquera, S. (2020). Effect of a High-Protein Diet versus Standard-Protein Diet on Weight Loss and Biomarkers of Metabolic Syndrome: A Randomized Clinical Trial. Retrieved 28 September 2020, from. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5644969/
- Antonio, J., Ellerbroek, A., Silver, T., Vargas, L., Tamayo, A., Buehn, R., & Peacock, C. (2020). A High Protein Diet Has No Harmful Effects: A One-Year Crossover Study in Resistance-Trained Males. Retrieved 28 September 2020, from. https://www.hindawi.com/journals/jnme/2016/9104792/