Recent evidence indicates that elevating plasma nitrites through dietary nitrates (NO3−) supplementation is associated with enhanced muscle efficiency, fatigue resistance and performance. Beetroot (in various forms) is the dominant source of dietary NO3− primarily due to its vast availability and the simple form of preparation suitable for final consumption. After a few years of research and experimentation, our scientific team identified alternative source rich with dietary NO3− as possible nitric oxide precursor, amaranth (Amaranthus hypochondriacus) with a standardized concentration 9–11% of NO3−. This study aimed to evaluate the effect of single-dose (±400 mg of dietary NO3−) and long-term (6 days) supplementation of amaranth concentrate derived dietary NO3− on aerobic capacity in physically active young people. We conducted a randomized, double-blind, placebo-controlled human study. Thirteen healthy and physically active young male participants were randomized into experimental and placebo groups. The aerobic capacity was tested during increasing cycling exercise (ICE) with pulmonary gas exchange recording and analysis. The peak power of the ICE, the maximum oxygen consumption and the first ventilatory threshold were significantly increased after long-term consumption of dietary amaranth (from 4.44 ± 0.50 to 4.55 ± 0.43 W/kg; from 37.7 ± 2.7 to 41.2 ± 5.4 mL/kg/min and from 178.6 ± 30.3 to 188.6 ± 35.2 W, p < 0.05; respectively) in experimental group. Long-term (6 days) use of dietary NO3− from amaranth may improve the aerobic capacity during ICE in young physically active male persons. It can be recommended as the nutritional supplement during last week of preparation for competition in endurance events.

The recently defined and yet rather new topic of healthy aging is attracting more attention worldwide. As the world population is getting older, it is rapidly becoming essential to develop and maintain functional abilities at older age and develop mechanisms to protect the senior population from chronic diseases. One of the most effective components, as well as processes associated with aging, is the recently discovered and Nobel prize-awarded—nitric oxide (NO) (as a signaling molecule), which, followed by later discoveries, showed to have a positive metabolic, immunological, and anti-inflammatory effect. Nitrates are one of the most debated topics of the last decade in the scientific community due to their pathways involved in the production of nitric oxide. Thus, the objective of this study is to evaluate the effect of different potassium nitrate concentrate supplementation on Drosophila melanogaster longevity imitating a human carbohydrate-based diet with relationship to possible cause of oxidative stress. Influence of 0.5–3% potassium nitrate medium on the lifespan and motor function in different groups consisting of 100 fruit fly females in each was analyzed. In this assay, female fly species supplemented with potassium nitrate diet showed life span increase by 18.6% and 5.1% with 1% and 2% KNO₃, respectively, with a positive impact on locomotor function. In conclusion, we found that low concentration of potassium nitrate medium increased lifespan and locomotor function in Drosophila melanogaster.

Many short-term studies with dietary nitrate supplementation in humans and animal models reported positive effects on the cardiovascular system, exercise efficiency, and immune function. However, there has been long-standing concern related to cancer and adverse hormonal effects. We studied the long-term effects of different potassium nitrate (KNO₃) concentrations on laboratory mice longevity and structural changes in their organs. Four groups of male mice were treated with 0 mg (0%), 45 mg (1%), 90 mg (2%), and 140 mg (3%) KNO₃ in the drinking water. The groups were monitored for agility and health status daily. The lifespan of mice and organ pathological changes were analyzed. We found no detrimental effects of life-long supplementation of KNO₃ on the survival of mice in treatment groups. Nitrate supplementation was associated with a lower level of pathological changes (p = 0.002). We conclude that KNO₃ supplementation had no carcinogenic effect on mice and possibly prevented the organs from aging.

Adding potassium nitrate (KNO₃) to the diet improves the physiological properties of mammalian muscles (rebuilds weakened muscle, improves structure and functionality). The aim of this study was to investigate the effect of KNO₃ supplementation in a mouse model. BALB/c mice were fed a KNO₃ diet for three weeks, followed by a normal diet without nitrates. After the feeding period, the Extensor digitorum longus (EDL) muscle was evaluated ex vivo for contraction force and fatigue. To evaluate the possible pathological changes, the histology of EDL tissues was performed in control and KNO₃-fed groups after 21 days. The histological analysis showed an absence of negative effects in EDL muscles. We also analyzed 15 biochemical blood parameters. After 21 days of KNO₃ supplementation, the EDL mass was, on average, 13% larger in the experimental group compared to the controls (p < 0.05). The muscle-specific force increased by 38% in comparison with the control group (p < 0.05). The results indicate that KNO₃ has effects in an experimental mouse model, showing nitrate-diet-induced muscle strength. This study contributes to a better understanding of the molecular changes in muscles following nutritional intervention and may help develop strategies and products designated to treat muscle-related issues.

Aging research has traditionally focused on lifespan and healthspan as primary outcome domains, implicitly treating chronological time as a uniform container of value. The memory-structured reconstruction of extended chronological intervals has not been systematically examined as an aging-related variable. I introduce experienced longevity , defined as the amount of lived time subjectively contained within a fixed chronological interval. Drawing on established distinctions between retrospective and prospective duration judgments, I argue that long-interval temporal compression reflects memory-structured reconstruction rather than altered internal timekeeping. Building on event segmentation theory, I propose that experiential density - the number and distinctiveness of retrievable experience units per unit time - determines whether extended intervals are remembered as compressed or expanded. I present the Neuroenergetic Constraint Model, which posits that aging-related reductions in mitochondrial efficiency, increased vascular stiffness, and diminished nitric oxide–mediated neurovascular coupling constrain neuroenergetic flexibility. Reduced energetic reserve may limit high-fidelity updating during ongoing experience, weaken event segmentation, decrease experiential density, and increase the probability of retrospective temporal compression. The model generates falsifiable predictions linking biological markers of neuroenergetic reserve (e.g., metabolic efficiency, arterial stiffness, endothelial function) to segmentation performance and retrospective duration judgments, particularly under high-demand conditions. If supported, this framework expands aging science beyond survival and function to include the biological structuring of lived time.

Over the past five years, the popularity of dietary nitrates as an ergogenic device among athletes has increased significantly. Hypoxic and acidic conditions that occur during exercise facilitate the conversion of nitrite to nitric oxide (NO) and increase the physiological efficiency of exogenously produced nitrite. After a few years of our team predicted experiments, as a nitric oxide precursor, amaranth (Amaranthus hypochondriacus) was identified as a source of dietary nitrates (concentrations 9-11%). The aim of this study was to evaluate the effect of single-dose and long- term doses of dietary nitrates from amaranth concentrate on the aerobic capacity of physically active young persons. Thirteen healthy and physically active young participants were randomized to experimental and placebo groups using a increasing cycling exercise (ICE) and placebo- controlled design. Pulmonary gas exchange recording (oxygen uptake (VO 2 ), pulmonary ventilation (VE), respiratory exchange ratio (RER)) and analysis of blood lactate samples were obtained. Our findings indicate that the single dose of dietary amaranth (400 mg) significantly improved only the power of the test performance. Long-term (6 days) intake significantly increased the power of the test performance, the maximum oxygen consumption and the power of the test for the first ventilation threshold value (from 37.7±2.7 mL/kg/min during the first test to 41.2±5.4 mL/kg/min during the third test, p <0.05).