A new wave of research is stirring up the conversation around diet, inflammation, and long-term health.

The systematic review and meta-analysis, published in the respected journal Nutrition, is making headlines for its nuanced look at how intermittent fasting and energy-restricted diets may help lower inflammation—a key player in chronic diseases like heart disease, diabetes, and certain cancers.

The findings are both promising and sobering, offering a fresh perspective on what dietary interventions can and cannot achieve in the battle against chronic inflammation.

Inflammation is a word that’s been cropping up everywhere, from medical journals to wellness blogs. It’s the body’s natural defence mechanism, a rapid-fire response to injury or infection.

In the short term, inflammation is a lifesaver, helping us heal and recover. But when it lingers, quietly simmering for months or even years, it can wreak havoc. Chronic inflammation is now recognised as a silent driver behind many of the world’s most prevalent diseases. It damages tissues, disrupts hormones, and sets the stage for a host of health problems.

To measure inflammation, scientists often turn to biomarkers in the blood. Three stand out: C-reactive protein (CRP), tumour necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6).

CRP, produced by the liver, is a general marker that rises whenever there’s inflammation anywhere in the body. TNF-α and IL-6 are cytokines—signalling molecules that orchestrate immune responses and can fuel inflammatory processes.

Lowering these markers, especially when they’re elevated, is seen as a way to reduce the risk of chronic disease. It’s no wonder that researchers are keen to understand how diet might influence these numbers.

Intermittent fasting has exploded in popularity over the past decade. It’s not just a weight loss trend; it’s touted for its potential metabolic and anti-inflammatory benefits. The approach is simple in theory: alternate periods of eating with periods of fasting.

Some people eat all their meals within an eight-hour window, others fast every other day, and some opt for longer cycles of periodic fasting. The appeal lies in its flexibility and the promise of health benefits beyond mere calorie counting.

Energy-restricted diets, meanwhile, are the old guard of weight management. They involve consistently reducing daily calorie intake, without changing when meals are eaten. The goal is a steady calorie deficit, achieved through portion control and careful food choices.

Both strategies limit energy intake, but researchers have long wondered whether the unique biological changes triggered by fasting—shifts in hormones, metabolism, and cellular clean-up processes known as autophagy—might influence inflammation differently from standard calorie restriction.

To cut through the noise of conflicting studies, an international team of researchers from China, Brazil, Iran, and New Zealand undertook a systematic review and meta-analysis. This rigorous approach pools data from multiple randomised controlled trials (RCTs), offering a more robust picture than any single study could provide.

The team combed through major scientific databases, including PubMed, Web of Science, Scopus, and Google Scholar, searching for human trials published up to June 2019. They included studies that tested both intermittent fasting regimens and energy-restricted diets, focusing on changes in blood levels of CRP, TNF-α, and IL-6.

Eighteen eligible RCTs made the final cut. The researchers used a random-effects statistical model to calculate weighted mean differences between intervention and control groups, accounting for variations in study populations. The results were illuminating.

Both intermittent fasting and energy-restricted diets significantly reduced CRP levels overall. The weighted mean difference was -0.024 mg/dL, a modest but statistically significant drop.

Intermittent fasting emerged as the more effective strategy, with a mean reduction of -0.029 mg/dL compared to just -0.001 mg/dL for energy-restricted diets. The effect was most pronounced in overweight and obese individuals, who saw a mean reduction of -0.03 mg/dL.

This suggests that people carrying excess weight may benefit particularly from these dietary approaches when it comes to lowering inflammation.

Duration mattered. The benefits for CRP were stronger when interventions lasted eight weeks or longer. Consistency, it seems, is key. Short-term efforts may not be enough to move the needle on inflammation; sustained commitment is required.

But the news was less encouraging for TNF-α and IL-6. Neither intermittent fasting nor calorie restriction produced significant changes in these markers. The findings highlight the complexity of inflammatory pathways.

Reducing one marker does not guarantee that all will respond in kind. TNF-α and IL-6 are deeply embedded in immune signalling networks, and may require more substantial or targeted interventions to shift.

Why does CRP respond more readily? Experts point out that CRP is an acute-phase protein, highly sensitive to lifestyle changes like diet and physical activity. TNF-α and IL-6, on the other hand, are regulated by intricate immune mechanisms.

Their levels can fluctuate wildly depending on stress, sleep, infections, and other factors, making them harder to pin down in dietary studies. Variations in study design, participant characteristics, and measurement methods may also play a role.

The changes in CRP, while modest, are not insignificant. Even small reductions in chronic low-grade inflammation can contribute to improved vascular health, better metabolic function, and a lower risk profile for disease over time.

Think of it as a slow, steady drip cooling down a pot of water. The shift may be subtle at first, but over the years, it adds up to a healthier balance.

For individuals seeking to improve their health and reduce inflammation risk, these results suggest that intermittent fasting could be a valuable tool—especially for those who are overweight or obese.

But the benefits are not magical or instantaneous. Achieving noticeable reductions in CRP requires sustained effort, with interventions of two months or more showing the greatest benefit.

Importantly, the study did not find a clear advantage for intermittent fasting or calorie restriction in lowering TNF-α or IL-6. If someone’s goal is to target these specific inflammatory pathways, dietary changes alone may not be enough.

Other strategies—physical activity, stress reduction, better sleep, or medical interventions—may need to complement nutrition efforts.

As with all research, there are caveats. The included trials varied in design, fasting methods, duration, and participant characteristics, introducing heterogeneity. CRP reductions, while statistically significant, were relatively small and may not translate to large short-term clinical improvements.

The lack of change in TNF-α and IL-6 could reflect the limitations of diet alone in modulating certain inflammatory processes. Future studies could explore whether longer or more intense fasting regimens, in combination with other lifestyle changes, might influence these cytokines more meaningfully.

For those interested in trying intermittent fasting, experts emphasise that it’s not suitable for everyone. People with certain medical conditions, pregnant or breastfeeding women, and those with a history of eating disorders should seek medical advice before starting fasting regimens.

The appeal of intermittent fasting often comes from its flexible structure—it doesn’t necessarily require counting calories—but as this meta-analysis shows, duration matters. Committing to a plan for at least eight weeks may be necessary to see measurable results in inflammation markers.

The quality of food consumed during eating periods remains crucial. A diet rich in fruits, vegetables, lean proteins, and whole grains, with limited processed foods, helps ensure that fasting’s benefits are maximised rather than undermined. It’s not just about when you eat, but what you eat.

The new analysis in Nutrition adds weight to the idea that intermittent fasting and calorie restriction can modestly lower CRP, a key marker of inflammation, with intermittent fasting showing a slight edge.

The effects are most pronounced in overweight and obese individuals and when sustained over weeks or months. However, not all inflammation-related biomarkers respond equally. TNF-α and IL-6, both important in immune signalling and chronic disease processes, showed no significant changes in the reviewed trials.

This serves as a reminder that while diet is a powerful tool in managing inflammation, it is just one piece of a bigger health puzzle. Lifestyle choices, genetics, environment, and underlying health conditions all interplay in shaping our inflammatory state.

Those considering intermittent fasting can feel confident that it may contribute to lowering certain inflammatory markers, but should view it as part of an integrated approach to wellbeing rather than a standalone solution.

As the science evolves, so too will our understanding of how best to harness the power of diet in the fight against chronic disease.

For now, intermittent fasting stands out as a tool worth considering, but only as part of a broader strategy that includes regular exercise, stress management, and quality sleep.

The quest to cool the fires of inflammation continues, and with each new study, we get a little closer to unlocking the secrets of long-term health.