The effects of odors generated by the Maillard reaction from amino acids and reducing sugars on physiological parameters (blood pressure, heart rate, and oxidative stress levels) in Wistar rats were investigated in the present study. The Maillard reaction samples were obtained from glycine, arginine, or lysine of 1.0 mol/L and glucose of 1.0 mol/L with heat treatment. The odor-active compounds in the Maillard reaction samples were identified using the aroma extract dilution analysis. Among the odor-active compounds identified, 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF, FURANEOL and strawberry furanone) had the highest odor activity and its concentration was affected by amino acid types. The Maillard reaction odors generated from glycine or arginine significantly decreased systolic blood pressure and heart rate in rats when inhaled. These physiological effects were associated with DMHF. Furthermore, oxidative stress marker levels in rat plasma were decreased by the inhalation of DMHF. The inhalation of DMHF appears to at least partly affect physiological parameters by decreasing oxidative stress. The inhalation of odors affects physiological parameters (e.g. blood pressure, heart rate, and blood components). For example, essential oils of lavender and grapefruit change blood pressure via the autonomic nervous system 1,2. Furthermore, the odor of a mixture containing (Z)-3-hexenol and (E)-2-hexenal attenuates the cold pressor testinduced blood pressure response in human 3. Odors may exert their effects through the direct activation of the olfactory system, which sends odor information to the brain, or indirectly through diffusion into the bloodstream after absorption or digestion. The former affects brain functions involved in the autonomic nervous system and immediately induces physiological changes. The latter exerts delayed effects because it requires 20-30 min to diffuse into the bloodstream and reach the brain through the blood-brain barrier. Odors exert their effects on physiological parameters through these pathways via the autonomic nervous system. The autonomic nervous system alters metabolism by changing physiological parameters, such as blood pressure, heart rate (HR), and oxidative stress 4-7. Long-term disturbances in physiological parameters also affect many diseases because of increases in oxidative stress 8-10. Cardiovascular modifications have been associated with an increase in metabolism with oxygen consumption and the promotion of oxidative stress. Hydroperoxides (ROOH), biomarkers of oxidative stress, are produced when reactive oxygen species react with lipids, proteins, and amino acids. Therefore, increases in hydroperoxide levels reflect the extent of oxidative stress in the body 11. Chronic odor inhalation has been reported to affect oxidative stress levels in the rat brain 12. Although odors may regulate oxidative stress levels through inhalation, the accumulation of further evidence is needed. The Maillard reaction, which plays a critical role in flavor and color development in foods sub...