Key Points

• A higher intake of proteins, particularly leucine and lysine, correlates with a reduced risk of diabetic kidney disease (DKD) in individuals with diabetes.
• Both plant and animal sources provide beneficial amino acids, and having a diverse diet is essential for kidney health.
• Plant-based proteins, which often include fiber, may enhance blood sugar management and kidney functionality.

Type 2 diabetes is increasingly prevalent, bringing along complications like diabetic kidney disease (DKD). DKD is a major cause of chronic kidney disease (CKD) and significantly contributes to end-stage renal disease (ESRD). CKD also heightens the risk of heart disease.

If you’re living with diabetes, you probably understand the critical role protein plays in maintaining stable blood sugar levels. However, there are hints that consuming too much protein—especially from animal sources—might increase the likelihood of kidney issues. On the flip side, plant proteins appear to hold promise in slowing or preventing the decline in kidney function. But, it’s worth noting that the research isn’t definitive. The 2022 Kidney Disease Outcomes Quality Initiative, for instance, hasn’t established a clear preference for one protein type over another.

This is why the Initiative generally recommends those with diabetes or kidney disease, who aren’t on dialysis, limit their protein consumption to 0.8 grams per kilogram of their ideal body weight each day. Interestingly, this level is also suggested for those without diabetes, though it might be too low for some individuals.

Researchers from Taiwan investigated the impact of proteins and amino acids on diabetic kidney disease, sharing their findings in the journal Nutrients. Let’s take a closer look at what they discovered.

How Was This Study Conducted?

The study involved 378 participants with type 2 diabetes, averaging 63 years old, with about half being women. Participants were categorized into two groups based on urine tests: those with just diabetes and those with DKD. Of the total, 237 were classified as having diabetes alone, while 141 met the criteria for kidney disease.

Using structured interviews conducted by registered dietitians, participants provided 24-hour dietary recalls and completed food frequency questionnaires. Their consumption of protein was then analyzed, categorizing them into three groups based on their intake: less than 0.8 grams per kilogram (Group 1), 0.9-1.2 g/kg (Group 2), and over 1.3 g/kg (Group 3).

Demographic data including age, sex, diabetes duration, medication use, Body Mass Index (BMI), and waist circumference were collected at the beginning. Blood pressure measurements were taken, along with blood tests for fasting glucose, HbA1c, total cholesterol, triglycerides, creatinine, blood urea nitrogen, and microalbuminuria. Metrics like urinary albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) were calculated to screen for kidney disease.

What Did This Study Find?

The group with the lowest protein intake (Group 1) also displayed the lowest mean eGFR at 78, while Group 2 had 85 and Group 3 had 87. Generally speaking, normal eGFR levels are 90 or higher, and readings between 89 and 60 indicate mild kidney function loss.

Moreover, Group 1 showed lower serum creatinine levels, which pointed to reduced kidney function. They also had the highest fasting blood glucose, HbA1c averages, and microalbumin levels.

Further analysis by researchers focused on amino acids, the building blocks of proteins. There are 20 primary amino acids necessary for human health, nine of which are essential, meaning they must be obtained through diet.

Statistical analysis revealed that higher overall protein intake, along with increased consumption of branched-chain (BCAA), aromatic (AAA), and ketogenic amino acids, were all linked to a decreased risk of DKD. In particular, leucine and lysine were most significantly connected to the lower likelihood of developing this kidney condition.

Researchers concluded that for those with chronic kidney disease who aren’t on dialysis, it’s important to not just focus on total protein intake but also on the balance of amino acids in their diet. They suggested that incorporating branched-chain amino acids and histidine while limiting tyrosine, methionine, and glutamic acid—amino acids more prevalent in meats—could be beneficial for kidney health.

How Does This Apply to Real Life?

The study’s authors believe their findings support previous research indicating that ketogenic amino acids, particularly leucine and lysine, might offer protection against DKD. You can find these amino acids in various foods such as:

• Dairy products like milk, yogurt, and cheese
• Fish and shellfish
• Legumes
• Nuts and seeds
• Meat varieties like chicken, pork, turkey, venison, bison, and lean beef
• Soy products including tempeh, tofu, and edamame
• Eggs
• Whole grains like quinoa, buckwheat, and amaranth

This provides a balanced mix of both animal and plant proteins rich in essential amino acids. Regardless of whether you have diabetes, incorporating a range of protein-rich foods is crucial. Plant proteins, in particular, should be emphasized as they often come with added fiber and healthy fats.

If you’re considering increasing your plant-based protein intake but don’t know how, there are resources available, including meal plans tailored for those with diabetes, that offer delicious plant-based meals and snacks, sometimes with dairy and eggs included.

For individuals with diabetes working to maintain stable blood sugar levels, it’s important to think about your protein consumption. Fiber also plays a significant role in blood sugar control, and it works even better in combo with protein. Many plant protein sources provide both nutrients. And, mixing animal proteins with plants is another effective way to boost both protein and fiber in your diet. Think yogurt with fruit and nuts or tuna paired with veggies—both filling and tasty choices.

Our Expert Take

This study suggests that incorporating more leucine and lysine-rich foods into your diet may lower the risk of kidney issues for those with diabetes. There’s likely something in that list of foods that you’d enjoy. If meat is your main source of protein, consider adding some plant-based options into your meals and snacks. A diet rich in plants can provide numerous benefits, including lowering disease risk, reducing belly fat, and improving gut health.