Obesity and diabetes are escalating worldwide health concerns, prompting the use of non-caloric sweeteners such as aspartame and stevia as substitutes for sucrose; however, their long-term physiologic Show more
Obesity and diabetes are escalating worldwide health concerns, prompting the use of non-caloric sweeteners such as aspartame and stevia as substitutes for sucrose; however, their long-term physiological and behavioral consequences remain incompletely understood. This work presents a comparative experimental study examining the long-term effects of sucrose, aspartame, and stevia intake on liver, heart, and brain functions in rats, while exploring the capacity of astaxanthin (ASTX) to attenuate the resulting tissue impairments. Seven rat groups-including control, sucrose, aspartame, stevia, and each sweetener combined with ASTX-were treated for 8 weeks to compare the organ-specific toxicity of the sweeteners and assess the protective effects of ASTX. Comprehensive evaluations of liver, heart, and brain were conducted using biochemical, behavioral, and histopathological analyses. All three sweeteners induced hyperglycemia, disrupted lipid metabolism (triglycerides, LDL, HDL), and increased oxidative stress (MDA), suppressing Nrf2/HO-1 antioxidant pathway and activating TLR4/NF-κB-mediated inflammation, leading to apoptosis. Biomarkers revealed liver dysfunction (ALT, AST, ALP), cardiac injury (troponin I, CK-MB, MEF2), and cognitive impairment (amyloid-beta, tau, BDNF), alongside altered monoamine neurotransmitters and Wnt3a/GSK-3β/β-catenin dysregulation. Bax/Bcl-2 ratio indicated enhanced apoptosis, with aspartame exerting the highest toxicity and stevia the least. While ASTX effectively alleviated these biochemical, histological, and functional changes. These findings suggest that aspartame has the strongest negative impact on liver, heart, and brain health, while stevia has the least, and that ASTX may serve as a potential protective agent against these harmful impacts. Show less
Genome-wide association studies (GWAS) have identified >250 loci for body mass index (BMI), implicating pathways related to neuronal biology. Most GWAS loci represent clusters of common, noncoding var Show more
Genome-wide association studies (GWAS) have identified >250 loci for body mass index (BMI), implicating pathways related to neuronal biology. Most GWAS loci represent clusters of common, noncoding variants from which pinpointing causal genes remains challenging. Here we combined data from 718,734 individuals to discover rare and low-frequency (minor allele frequency (MAF) < 5%) coding variants associated with BMI. We identified 14 coding variants in 13 genes, of which 8 variants were in genes (ZBTB7B, ACHE, RAPGEF3, RAB21, ZFHX3, ENTPD6, ZFR2 and ZNF169) newly implicated in human obesity, 2 variants were in genes (MC4R and KSR2) previously observed to be mutated in extreme obesity and 2 variants were in GIPR. The effect sizes of rare variants are ~10 times larger than those of common variants, with the largest effect observed in carriers of an MC4R mutation introducing a stop codon (p.Tyr35Ter, MAF = 0.01%), who weighed ~7 kg more than non-carriers. Pathway analyses based on the variants associated with BMI confirm enrichment of neuronal genes and provide new evidence for adipocyte and energy expenditure biology, widening the potential of genetically supported therapeutic targets in obesity. Show less