Tuesday, November 6, 2018

Protein and Kidneys

When I was diagnosed with type 2 diabetes in 1996, a nurse handed me the American Diabetes Association 1500-calorie diet, which said I should eat 179 grams of carbohydrate a day. That made no sense to me. So when I saw my doctor, I asked, "If diabetes is a disease in which you can't deal with carbohydrates, why did the nurse tell me to eat all this starch?"

The doctor looked surprised at the question and then thought and answered, "Well, protein damages kidneys, and as a diabetic, you're at increased risk of kidney damage. Fat causes heart disease, and as a diabetic, you're at increased risk of heart disease. The only thing left is carbohydrate."

Many of us have questioned the assumption that protein damages healthy kidneys, so it's nice to see some research supporting that idea. True, this study is a meta-analysis, in which researchers do statistical analyses of previously published research, and meta-analyses can have problems. For instance, the populations studied by each group may not be very similar. The end points may vary. Nevertheless, such studies give suggestions about the issue at hand.

This study says nothing about protein consumption by people who already have damaged kidneys. In such cases, some people think plant proteins are better than animal proteins.

My doctor's statement about fat causing heart disease has also mostly been disproven, but I won't get into that here.


  1. Researchers are sincerely trying to understand the functions of all of the chemistry of the human body including its interaction with the outside world. However, the human body is amazingly complex. I think, more complex than any other science that we study. The human body is truly a wonder.

    To better understand the limitations that researchers, doctors and patients face, a very old fable is useful.

    Three blind men approach an elephant. They were asked to describe what an elephant is. One blind man felt one of the elephants leg. He concluded that an elephant is like a tree. The second elephant felt the tail. He concluded that an elephant is like a rope. The third blind man felt the trunk of the elephant. He concluded that the elephant is like a snake. This fable illustrates very well what are problem is in studying the human body. Researchers are often essentially correct within the limitations of their test data, but, are frequently incorrect in their interpretations of their results effects on the human body and its interaction with the environment including food.

    But, in spite of all of the confusion, we are making progress....much slower than we would like...but, it is progress. So, we need to be very careful in accepting new research and wait for confirmations and incorporating a wider range of understanding, in spite of our common impatience.

    1. I agree with you about the complexity of the body. And I agree we're making progress. But patients don't always have time to wait for the perfect study. We have to find out what works for us, even if there's no controlled study showing that it works for everyone.