Are High Protein Foods Bad For The Kidneys?

Protein and kidneys: what we need to know

Importance and benefits

Protein-rich foods have multiple benefits. This is because protein is one of the primary elements required not only for the formation of skin, bones, and muscle but also for their repair and recovery. Protein is also a key component of red blood cells and facilitates the transport of oxygen and nutrients throughout the body.¹

Having a protein-rich diet therefore can help you remain healthy and active. In addition, protein makes you feel satiated for long periods of time - thereby indirectly aiding in weight loss. It also aids in muscle recovery, which means for those looking to build muscle mass, having a protein-rich diet is pertinent. ²

Sources of protein

For meat and seafood lovers, there are plenty of healthy and delicious sources of proteinsuch as chicken breast, pork chop, beef steak, and lamb chop. These foods have some of the highest sources of protein ranging from 29-32g/protein per 100 grams. In terms of fish and seafood, there is a wide variety ranging from tuna and cod to crabs and prawns. Whole-boiled chicken eggs also have a decent amount of protein at 14 g/100 g. Among dairy products, Cheddar cheese and reduced-fat cheese have the highest protein content, at 25.4g and 27.9 g per 100g.³

If you’re vegetarian or vegan, there is a wide array of options too - Pulses such as red lentils and chickpeas, beans like tofu, kidney, and baked beans, and nuts such as almonds, walnuts, and hazelnuts have quite a high amount of protein.³

Side effects

Diet high in protein can lead to loss of calcium from the body and excess excretion of calcium in the urine (hypercalciuria) - this can in turn lead to osteoporosis. Similarly, a study found that women who consumed more than 95g of protein per day had a higher risk of a forearm fracture, compared to those who consumed 68g of protein per day. In addition, forearm fracture was also more common in women who consumed 5 or more servings of red meat per week than those who didn't.⁴

Can high-protein foods damage our kidneys? 

While there isn't a clear consensus on how much impact high protein foods can have on our kidneys, recent research has suggested that they may worsen renal function in individuals with existing kidney complications and potentially in those without. In addition, it is now also postulated that it can lead to chronic kidney disease. The main filtration unit in the kidneys is known as the glomerulus. Consistently increased intake of protein could lead to glomerular damage possibly leading to the passage of protein in the urine (proteinuria).⁵

How much is enough? 

The British Nutrition Foundation recommends that adults consume 0.75 grams of protein per kg of their body weight every day - this comes out to 56g/day for men and 45g/day for women.³

Which protein is good for the kidneys?

There are various animal and plant-based protein sources that are considered kidney-friendly:⁶

 Animal-based:

1. Meat: Pork, Chicken, beef, fish
2. Dairy: Cheese, Yogurt     
3. Eggs 

Plant-Based:

1. Beans, peas, or lentils
2. Soy 
3. Tofu
4. Nuts/Seeds

These protein-rich foods are also considered safe in cases of kidney disorders.

Things to remember

As with most things, moderation is key. Unless you’re training as a bodybuilder/looking to gain muscle or are an athlete, it would be best to stick to the amount of protein recommended by nutritionists/physicians. Furthermore, If you’re looking to get into bodybuilding or other forms of training, it would be best to do thorough research and if possible, speak to a nutritionist or physician before you start a high-protein diet. 

Summary

In conclusion, it is important to understand that protein is vital to maintain basic body functionsand even more so in cases where you might be training as an athlete or bodybuilder. But it is also important to understand the needs of your body and appropriately consume the right amount of protein. As we have seen in the article, high protein can cause issues with the kidney especially if you're already suffering from kidney-related disorders. Hence it is always advisable to consult your nutritionist/physician before going on a high-protein diet.