oes long term use of dietary supplements such as whey protein or BCAA cause any harm? - A tricky question that has often haunted our minds. The answer for which is never a straight forward “Yes” or “No”. The reason here is very simple - all dietary supplements in the market are created with a specific purpose and they do not always have the same effect in every individual. Hence, there is no conclusive answer to this question. However, it is always said that the intake of the protein supplements above the recommended dietary allowance will always cause adverse effects. So, do you think that intake of protein supplements within the recommended allowance will not cause adverse effects? Come, let us understand clearly to have no more doubts lingering in our minds.

 As a layman, it becomes important for us to actually understand protein supplements properly. We know what the daily recommended dose is and what is type of supplements that we should take in. The DRI (Dietary Reference Intake) is 0.8 grams of protein per kilogram of body weight. So, you can make your own calculations based on this. I would like to inform you that this reference is for those who have a sedentary lifestyle and for those who have an active lifestyle (professional athletes to sports and fitness enthusiasts), the DRI is between 1.6-2.2 grams of protein per kilogram of body weight.

Now that we have understood the daily requirement needed for an individual, it is time to look at some pointers.

• Protein is naturally available in many food items that we most often consume. One should, therefore, consume protein supplements taking into consideration the amount of natural protein intake, exceeding which can cause adverse effects.
• Some protein dietary supplements contain artificial sweeteners that may taste good while consuming, and on the flip-side may put you at high risk for diabetes and obesity. Therefore, reading through the labels thoroughly will help.
• People who are lactose intolerant must choose the protein supplement that is void of any lactose ingredient, such as soy protein or pea protein.
• Heavy metals, such as lead, cadmium and mercury, bisphenol-A (BPA, which is used to make plastic), pesticides, or other adulterants with link to cancer and other health conditions are known to be certain ingredients in certain protein supplements. This report was published by CleanLabel Project, an independent non-profit organization. It is therefore advised to read through the labels carefully.

There has been a good amount of research devoted to finding any adverse effects that are a result of prolonged use of protein supplements. Let us see what the adverse effects could be.

• Over-use of protein supplements can cause damage to kidneys and the liver. The reason is simple. Consumption of protein supplements that are above the prescribed levels for a day, can cause your body to over-work, which could result in damage.
• A high protein diet releases a large amount of acid in body fluids. The kidneys respond to this dietary acid challenge with net acid excretion, and, concurrently, the skeleton supplies buffer by active desorption of bone resulting in excessive calcium loss^[1]. So, bone density lowers, increasing the risk of bone-related disorders, and Calcium Homeostasis. This again is for those who exceed the daily intake limit of protein per person.

Consumption of protein supplements alone cannot cause any harmful effects unless there is an excessive intake of natural proteins combined with the supplements. In most cases, the adverse effects are seen in those who do not follow a proper dietary regime and fitness schedule. Also, a sudden change in the dietary pattern can cause discomfort to an individual, and therefore it is suggested that one consult a doctor/physician/fitness expert before starting any diet or fitness regime. Please do not be a self-prescribed doctor. 

https://www.ncbi.nlm.nih.gov/pubmed/9614169