Can high-protein diets reduce inflammation enough to affect disease risk?

What the strongest evidence shows: high-protein diets can lower inflammation and reverse disease

The most direct evidence comes from a 6-month randomized controlled trial where obese adults with type 2 diabetes were assigned to either a high-protein diet (30% protein, 40% carbs) or a high-carb diet (15% protein, 55% carbs). After 6 months, the high-protein group had a significant reduction in inflammatory cytokines (p = 0.001) and a 100% remission rate of diabetes to normal glucose tolerance, compared to just 16.6% in the high-carb group [1]. This means that for every 100 people on the high-protein diet, all 100 reversed their diabetes, while only about 17 did on the high-carb diet. The study also found improvements in cardiovascular risk factors, insulin sensitivity, and oxidative stress—all linked to chronic inflammation [1].

A second randomized trial in middle-aged obese adults added exercise to the mix. After 12 weeks, those on a high-protein diet plus exercise saw their C-reactive protein (CRP)—a key marker of systemic inflammation—drop significantly (p = 0.008), along with better insulin sensitivity and lower total cholesterol and triglycerides [3]. The exercise-only group did not show these inflammatory improvements, suggesting the protein component was crucial [3]. Together, these two trials provide strong evidence that a high-protein diet can reduce inflammation enough to meaningfully lower disease risk, especially for type 2 diabetes and cardiovascular disease.

Not all protein is equal: plant-based sources may be better for inflammation

A large 2023 study of nearly 28,000 adults from the National Health and Nutrition Examination Survey (NHANES) found that the type of protein matters. People who ate a healthy plant-based diet (rich in whole grains, legumes, nuts) had 21% lower odds of high systemic inflammation compared to those with the lowest intake (odds ratio 0.79, 95% CI 0.71–0.88) [4]. In contrast, an unhealthy plant-based diet (loaded with refined grains, sugary drinks, and processed foods) was linked to 18% higher odds of inflammation (odds ratio 1.18, 95% CI 1.06–1.31) [4]. This suggests that simply eating more protein isn't enough—the quality of the protein source is key.

A 2022 study on protein intake and non-communicable disease risk in 347 adults found that consuming more than 40% of protein from plant sources reduced the risk of chronic diseases, but only in older adults [7]. The study also noted that the effects on inflammatory markers like TNF-α and IL-6 varied by gender and age, meaning the anti-inflammatory benefit of plant protein may not be universal [7]. So, while high-protein diets can reduce inflammation, swapping some animal protein for plant sources (like beans, lentils, and tofu) may amplify the benefit.

Caveats and limitations: when high-protein diets might not help or could even harm

The evidence isn't all one-sided. A large observational study combining data from over 126,000 pregnancies in Denmark and Norway found that high protein intake (over 100 grams per day) was only weakly associated with a 10% increased risk of preterm delivery (odds ratio 1.10, 95% CI 1.01–1.19), and this was driven by late preterm births (weeks 34–37) [2]. Importantly, there was no link to low birth weight or fetal death, contradicting a much older 1970s study that had raised safety concerns [2]. This means that for pregnant women, high protein intake appears safe for fetal growth, but the slight preterm risk warrants caution.

Another study in older adults (average age 71) found that a high-protein diet combined with exercise actually decreased some anti-inflammatory markers like interleukin-10 and IL-1 receptor antagonist, which might seem counterintuitive [5]. However, in men, the same diet also reduced pro-inflammatory markers, suggesting the overall effect is complex and may depend on sex and baseline health [5]. Finally, a 2025 review of young athletes noted that while high-protein diets are common, they can affect liver function and lipid metabolism, though the review didn't find direct harm [6]. The takeaway: high-protein diets are generally safe and anti-inflammatory for most people, but individual factors like pregnancy, age, and sex can modify the effects.

About These Sources

This answer is built on 7 peer-reviewed studies — published from 2021 to 2025, 1 from 2024 or later, 4 in Q1 journals, collectively cited 144 times — selected as the most relevant from 7 studies that passed quality screening, drawn from 55 papers retrieved from a database of over 500 million.

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