Aspartame, a widely used artificial sweetener, is consumed daily by approximately 25.1% of children globally, with reports of intake exceeding the acceptable daily intake (ADI) by 246% among children in China [1,2]. Despite its approval by regulatory agencies, concerns persist about its safety, particularly during critical developmental stages such as pregnancy and early childhood [3]. Emerging evidence suggests that prenatal aspartame exposure can disrupt metabolic function [4] and induce hyperglycemia [5] in offspring. However, its long-term effects on reproductive health, particularly from prenatal exposure through postnatal development, remain poorly understood.

Pubertal timing, regulated by the hypothalamic–pituitary–gonadal (HPG) axis, is essential for fertility and reproductive health. Factors such as environmental toxins and dietary components can disrupt the HPG axis and impair mitochondrial function, leading to delayed sexual maturation [[6], [7], [8], [9]]. Such disruptions can lead to a delay in pubertal onset. Our recent study revealed that long-term consumption of aspartame impairs ovarian function through mitochondrial dysfunction, thereby increasing infertility risk among women of reproductive age [10]. In another study conducted among prepubertal female rats, the T-2 toxin, derived from grains, was found to interfere with the function of the HPG axis, slowing the maturation of reproductive organs [11]. We recently reported that aspartame reduces the chance of puberty occurring earlier than usual in female offspring and girls. Remarkably, 60 mg/kg aspartame-fed female offspring delays pubertal onset through the dysregulation of HPG axis and gut microbial composition by inhibiting the Kiss1/GPR54 system and inducing the RFRP-3 [12]. It remains unexplored whether the Aspartame-induced changes in the puberty timing were through mitochondrial dysfunction.

The long-term consumption of aspartame is associated with increased oxidative stress in various organs, including the brain [13], heart [14], and ovaries [10]. Mitochondria are crucial in balancing oxidative stress within the cytoplasm. They are vital sites for energy production, message transmission, regulation of the redox balance, and fatty acid β-oxidation in organisms, and their functions also impact the developmental capacity of eggs and embryos. Impaired mitochondrial function in ovarian cells can cause reduced steroidogenesis, low oocyte maturation rates, and ultimately delay sexual maturation [10]. Nevertheless, no experimental study among humans or animals has investigated aspartame-induced oxidative stress in the alteration of puberty timing.

This study aims to address these gaps by investigating the effects of prenatal and postnatal aspartame administration on puberty onset in female rats, focusing on mitochondrial dysfunction, oxidative stress, and dysregulation of the HPG axis. Using data from the Taiwan Pubertal Longitudinal Study (TPLS), we explore potential associations between aspartame consumption and the risk of precocious puberty in humans [15]. These findings will provide new insights into the reproductive risks of long-term aspartame exposure during critical developmental windows.