Are high protein diets harmful to the kidneys?

To add to the mounting research on protein diets and kidney health, another study was performed.  For an introduction to the whole discussion, I recommend reading Chris Kresser's post on protein and kidney health and this post over at Precision Nutrition on protein diets in relation to those with diabetes and hypertension.  This most recent study by Jose Antonio's research group observed 14 males athletes for a year and had them do a randomized cross-over trial, where they would eat normal protein or high protein for 6 months and track blood markers such as cholesterol, kidney filtration rates, and more.  

Before we go on,  I think it's important to first understand what is a high protein diet.  The baseline level for most nutrition societies is 0.8 grams per kg of body-weight.  This study used between 2.5 and 3.3 grams of protein per kg of body-weight, which is 3-4x the baseline recommendation.  It's important to always be calculating protein in this manner as it is more accurate than saying "people ate 15-35% of calories from protein" because people have different body-weights.  It should also be noted that the amount of protein the athletes were eating in the normal phase would still be considered high by many people in the nutrition field.  

The participants tracked their food 3x per week using the MyFitnessPal App on their phones and most of the additional protein was supplied by whey protein powder.  Five blood test were sampled and analyzed pre/during/post the high protein intervention.  Body composition was taken using the oh-so-sexy BodPod.  Results showed no significant changes in kidney, liver, or blood markers nor did body composition change. 

Now this study is far from perfect and has many limitations: Sample size, gender, age, not controlling for training volume, self-reporting, etc. But to me, it adds more skepticism to the idea that protein is inherently damaging to our kidneys.  Do you want to know what damages your kidneys?  High blood pressure and diabetes!!!  Don't get those!  

New Berberine Research

Just read through this paper by Chinese researchers.  Along with another paper on berberine's mechanism of action in diabetes.  

Non-Alcoholic Fatty Liver Disease (NAFLD) results from a combination of metabolic factors such as Insulin Resistance (IR), Oxidative Stress (OS), Mitochondrial Dysfunction (MD), and lipid peroxidation.  NAFLD is proposed to occur because of a "two hit" hypothesis (like many people belief cancer occurs).  First, insulin resistance and fat accumulation occur.  Second invading macrophages secrete inflammatory signals like interleukin-6 and Tumor Necrosis Factor-alpha which makes the issue worse.  

Diet, exercise, drugs, and herbs can all effect the health of a hepatocyte (liver cell).  In the first paper, researchers assessed the effects of Baicalin, Berberine and Puerarin.  Berberine and baicalin were found to potent anti-inflammatories and puerarin was associated with reductions in lipids.  

Where can you find berberine?  Well if you live in the Pacific Northwest, just look outside and you'll probably find some.  

Berberine helps regulate blood sugar metabolism by it's ability to activate adenosine monophosphate activated protein kinase.  Think of diabetic cells being in a excess or full state.  BUT, if we have agents that help bring them into less full states, they can take up blood sugar and work better.  

Here's the crazy thing though.  Berberine doesn't just help with blood sugar.  It helps with infections of bacterial and viral origins too!  I use berberine quite a bit in clinical practice, especially for Small Intestinal Bacterial Overgrowth (SIBO). 

Have you used Chinese Skullcap or a berberine containing plant?  What for and what did you experience?  Please share your experience and wisdom.