Antioxidant-Rich Lifestyles Tied to Sharply Lower Diabetes Risk in 12-Year Study

A long-running population study from Iran has delivered one of the clearest signals yet that the body’s overall oxidative balance — the tug-of-war between antioxidant defenses and pro-oxidant exposures — may help determine who slides into prediabetes and type 2 diabetes. Researchers followed thousands of healthy adults for up to twelve years as part of the Tehran Lipid and Glucose Study and found that those with the most favorable oxidative balance scores were substantially less likely to develop either condition. The findings, published in BMC Endocrine Disorders, add weight to a growing body of evidence that oxidative stress is not merely a byproduct of metabolic disease but may be an active participant in its earliest stages.

The oxidative balance score, or OBS, is a composite measure designed to capture a person’s total oxidant-antioxidant profile in a single number. Rather than focusing on one nutrient or one behavior, the score aggregates multiple dietary components — including vitamins, minerals, and other antioxidant or pro-oxidant factors — alongside non-dietary contributors such as physical activity, smoking status, and obesity. Each component is assigned a value reflecting whether it pushes the body’s chemistry toward oxidative damage or toward antioxidant protection, and the values are summed. A higher score signals a predominance of antioxidant exposures over pro-oxidant ones. The approach acknowledges that oxidative stress in real life is the net result of many simultaneous influences, not the effect of any single molecule in isolation.

To test whether this integrated measure predicts future metabolic disease, the research team drew on participants in the third phase of the Tehran Lipid and Glucose Study, conducted between 2006 and 2008. Two analytic cohorts were assembled: 1,950 adults who were free of both type 2 diabetes and prediabetes at baseline, followed for the incidence of prediabetes over a median of 7.3 years, and 2,325 adults free of type 2 diabetes, followed for the incidence of full-blown diabetes over a median of 9.6 years. All participants provided written informed consent, and the protocol was approved by the ethics research committee of Maragheh University of Medical Sciences in accordance with the Declaration of Helsinki.

The scale of disease progression during follow-up was striking. Nearly half of the participants — 44.3 percent — progressed to prediabetes, while 14.6 percent developed type 2 diabetes. These figures underscore why prevention research in this population matters: the transition from normal glucose metabolism to disordered glucose handling was the rule rather than the exception over the observation window, making the cohort a rich testing ground for identifying modifiable risk factors.

Using Cox proportional hazards regression, the investigators calculated hazard ratios comparing participants across tertiles of the oxidative balance score, adjusting for potential confounders. The results were consistent and statistically significant. A higher overall OBS was associated with a 19 percent lower risk of developing prediabetes, with a hazard ratio of 0.81 and a 95 percent confidence interval of 0.67 to 0.99, and a statistically significant trend across score categories. For type 2 diabetes the association was even stronger: higher overall OBS corresponded to a 39 percent lower risk, with a hazard ratio of 0.61 and a confidence interval of 0.43 to 0.86, and a trend P value of 0.005.

When the team decomposed the score into its dietary and lifestyle components, a revealing pattern emerged. The lifestyle portion of the score — encompassing physical activity, smoking, and obesity — showed a robust independent relationship with diabetes risk. Participants in the highest tertile of the lifestyle OBS had a 41 percent lower risk of developing type 2 diabetes, with a hazard ratio of 0.59 and a confidence interval of 0.45 to 0.78. In contrast, the dietary OBS alone showed no statistically meaningful association with the risk of either prediabetes or type 2 diabetes in this cohort.

That divergence between the dietary and lifestyle components is one of the study’s most thought-provoking findings. It suggests that the behavioral factors with systemic physiological reach — staying physically active, avoiding smoking, and maintaining healthy body weight — may dominate the protective signal, while the contribution of dietary antioxidants, at least as captured by the OBS framework in this population, was too weak to detect on its own. This does not necessarily mean that antioxidant-rich foods are irrelevant; it may reflect the limitations of estimating nutrient intake from dietary assessment, the complexity of how food antioxidants are absorbed and utilized, or the possibility that dietary effects on glucose metabolism operate through pathways other than oxidative balance.

From a biological standpoint, the results fit a coherent mechanistic picture. Oxidative stress arises when reactive oxygen species overwhelm the body’s antioxidant defenses, damaging lipids, proteins, and DNA. In metabolic tissue, this damage impairs insulin signaling in muscle and liver, stresses the insulin-producing beta cells of the pancreas, and promotes the low-grade inflammation that accompanies insulin resistance. Beta cells are particularly vulnerable because they possess comparatively low levels of endogenous antioxidant enzymes. A lifestyle that keeps reactive oxygen species in check — through exercise, weight control, and avoidance of cigarette smoke — could therefore preserve insulin sensitivity and beta-cell function long enough to delay or prevent the clinical onset of dysglycemia.

The study’s strengths include its prospective design, its long follow-up, and its use of a population-based cohort drawn from the Tehran Lipid and Glucose Study, one of the region’s most established longitudinal health investigations. By measuring exposure before disease onset, the design avoids the reverse-causation problems that plague cross-sectional studies, in which disease itself alters antioxidant status. The use of hazard ratios across score tertiles, with formal tests for trend, provides a dose-response dimension that strengthens the plausibility of a protective relationship. Nevertheless, as with all observational research, residual confounding cannot be excluded, and the findings demonstrate association rather than proven causation.

The practical implications are considerable. Prediabetes and type 2 diabetes affect hundreds of millions of people worldwide, and rates continue to climb in middle-income countries undergoing rapid nutritional and lifestyle transitions — the very context this study captures. If a favorable oxidative balance, maintained largely through everyday behaviors, genuinely lowers the risk of progressing to dysglycemia, then the OBS could serve as a useful screening and counseling tool, summarizing in one metric how a patient’s combined exposures tilt toward protection or harm. The authors conclude that a higher oxidative balance score, reflecting a predominance of antioxidant over pro-oxidant exposures, acts as a protective factor against the development of both prediabetes and type 2 diabetes. For now, the message for the public aligns squarely with long-standing guidance: move more, keep weight in check, and avoid smoking — habits that, according to this twelve-year analysis, may quietly defend the body’s glucose machinery against the cumulative wear of oxidative stress.

Subject of Research: The association between oxidative balance score and the incidence of prediabetes and type 2 diabetes in adults

Article Title: The association between oxidative balance score and risk of developing prediabetes and type 2 diabetes in adults: a 12-year population-based cohort study

Article References: Hosseini, M. S., Hosseini-Esfahani, F., Bahadoran, Z., Koochakpoor, G., Mirmiran, P., & Azizi, F. (2026). The association between oxidative balance score and risk of developing prediabetes and type 2 diabetes in adults: a 12-year population-based cohort study. BMC Endocrine Disorders. https://doi.org/10.1186/s12902-026-02610-6

Image Credits: AI Generated

DOI: 10.1186/s12902-026-02610-6

Keywords: oxidative balance score, oxidative stress, prediabetes, type 2 diabetes, antioxidants, cohort study, insulin resistance, lifestyle factors, physical activity, obesity, smoking, Tehran Lipid and Glucose Study