Can too much protein be toxic?

• A. Yes, in all individuals
• B. Not toxic unless kidney problems; nitrogen excreted; relatively non-toxic
• C. No, it's never toxic
• D. Only if combined with fats

Answer: (B)

Protein isn’t inherently toxic for healthy people because your body handles its nitrogen waste efficiently. When you eat more protein than you need, the amino acids are deaminated, producing ammonia that’s quickly converted to urea in the liver. Urea is then excreted in the urine by the kidneys. This waste product is relatively non-toxic at normal levels, which is why protein itself isn’t seen as a toxin in healthy individuals.

The real caveat is kidney function. If the kidneys are compromised, they have to work harder to remove the extra nitrogen, and nitrogenous waste can accumulate. In that context, high protein intake can pose problems. So the best answer reflects that protein is not toxic unless kidney problems are present, with nitrogen being excreted as a waste product.