T Nation

Protein/kidney

A my friend indicated me some studies have shown that a consuming high levels of protein can cause kidney stones. I looked online, and found studies indicating a low carb (<20g) and high protein/fat diet seems to indicate this.

Does anyone know of conflicting studies, or if this may be true? In looking at the article on the study, it seemed like other variables were in place that could increase the risk of kidney stones, but I’d rather verify this from someone who knows.

From what I’ve read all kidney problems from high protein intake can be counteracted with sufficient veggies.

what were the subjects of the study? most of the time these studies are done on people with existing kidney problems. This wont apply to you if you are healthy.

Fluid balance and acid load (see a great article by JB on this can make a difference. The box in the text below is a +/- symbol that did not transfer.

In the meantime, here is a synopsis of a study we published a few years back:

Abstract #631.14- Experimental Biology(FASEB) March 31-April 4, 2001. Orlando, FL.

The Effects of a High Protein Intake on Markers of Health in Weight Trained Athletes.
D. Kalman1, J. Antonio2. 1Miami Research Associates, Miami, FL 2University of Delaware, Newark, DE.

The purpose of this study was to evaluate the effects of a high protein intake on markers of safety (leukocytes, liver and renal function, urinary ketones and protein) in 20 healthy resistance-trained males. At baseline, subjects? average macronutrient intake consisted of 27% protein (1.5 g/kg), 47% carbohydrate and 26% fat. Protein intake was increased to 40% (2.88 g/kg) of total calories, which resulted in CHO intake decreasing to 37% and fat intake to 23% for 28 days. Each subject was allowed to follow their normal exercise routines (weight-training, 4-days per week, split body workouts). At baseline, day 14, and day 28, each subject underwent anthropometric testing, urinalysis, and full blood chemistry analysis. Baseline characteristics: age 32.32 11.1 yr, height 180.55.1 cm, weight 87.4912.4 kg. Data was analyzed via the Signed Rank Test for significant changes over time (p<0.05). Pre weight 87.49-Post 88.05 kg:NS; Pre urinary ketones 3.95-Post 1.58:NS; Pre urinary protein 11.58-post 11.68:NS; Pre WBC 7.78-post 7.83x10x9/L:NS; Pre BUN 18.21-post 21.05 mg/dl:p=0.02; Pre creatinine 1.12-post 1.21mg/dl:p=0.006; Pre AST 27.21-post 29 U/L:NS; Pre ALT 28-post 29.89 U/L:NS; Pre GGT 27.21-post 25.37U/L:NS and dietary protein intake 27 to 40%:p=0.0001. Although still remaining within normal limits, the significant changes observed in the BUN and creatinine over the 28 days were due to normal healthy renal adaptation to a higher protein load. In conclusion, the daily high protein intake (3.6x RDI) had no untoward or negative effects on the immune system, renal and hepatic function nor did it induce ketosis or dehydration, thus it appears safe for short-term daily intake.

From everything I’ve read, the only way high protein causes kidney problems is when the person already had kidney problems. So if you have never had kidney problems, you should be fine. If it was actually a problem, I think we would have heard about it with so many people consuming lots of protein.

Also, there were several native peoples that consumed very large quantities of meat with no kidney problems.

My husband gets kidney stones and I heard research along those lines and went insane trying to limit his protein intake. then i read more, and even found a book on the topic (can’t remember the name, sorry). now, i don’t try to limit his protein intake in anyway, but rather encourage him to limit his consumption of oxalic acid containing foods (tea, tomatoes, spinach etc.) and it seems to be helping so far. but only time will tell, two years is not enough time in my opinion. but the fairly high protein diet he’s been on with me for over a year hasn’t affected him. i try to keep it high quality protein though.

I’ve suffered from kidney stones twice in my life with five years elapsing between so I may be hurting again soon. Anyhow, I was eating a high protein diet and lifting the first time in the early 90’s but I had long given up the lifestyle when I had a reoccurence in 98 so I don’t buy that theory.

my cousin got a kidney stone when he was 10. He definitely wasnt eating a high protein diet.