Concentrated Spinach Extract
Also known as: Spinacia oleracea, Amaranthus dubius, Spinach extract, Concentrated spinach extract, Red spinach extract
Overview
Concentrated spinach extract is a botanical dietary supplement derived from the leaves of Spinacia oleracea (common spinach) and sometimes Amaranthus dubius (red spinach). It is primarily used as an ergogenic aid to enhance physical performance and support cardiovascular health. The extract is rich in dietary nitrates, flavonoids, and antioxidants. Its ergogenic effects are largely attributed to its high nitrate content, which the body converts into nitric oxide (NO). Nitric oxide is a potent vasodilator, improving blood flow, oxygen delivery to muscles, and overall exercise efficiency. While research is emerging, several randomized controlled trials and systematic reviews support its benefits for physical performance. It is generally well-tolerated, with a favorable safety profile in short-term use, and also shows potential for wound healing, particularly in diabetic models.
Benefits
Concentrated spinach extract offers several evidence-based benefits, primarily as an ergogenic aid. The most significant benefit is the improvement in physical performance parameters, including endurance, strength, and resistance to fatigue in healthy adults and athletes. This effect is consistently observed in randomized controlled trials (RCTs) and systematic reviews, with statistically significant improvements (p < 0.05) reported with doses of 1–2 g/day over 1–12 weeks. The strength of evidence for performance enhancement is moderate, based on systematic reviews of multiple RCTs. While the primary benefits are related to exercise, there are also secondary effects. Preliminary animal studies suggest potential for accelerated wound healing in diabetic models, linked to improved vascular endothelial growth factor (VEGF) modulation and ulcer regeneration. However, human data for wound healing are currently lacking. Healthy adults and athletes are the populations most likely to benefit from the performance-enhancing effects, with benefits typically observed within 1–12 weeks of consistent supplementation.
How it works
The primary mechanism of action for concentrated spinach extract revolves around its high dietary nitrate content. Once ingested, these nitrates are converted by oral bacteria into nitrites, which are then further reduced to nitric oxide (NO) in the body, particularly under hypoxic conditions. Nitric oxide is a crucial signaling molecule that promotes vasodilation, leading to improved blood flow and oxygen delivery to working muscles. This enhanced oxygenation and nutrient supply contribute to increased exercise efficiency, reduced fatigue, and improved physical performance. Beyond its cardiovascular effects, spinach extract may also influence wound repair systems through the modulation of vascular endothelial growth factor (VEGF), as observed in preclinical models, suggesting a role in tissue regeneration.
Side effects
Concentrated spinach extract is generally well-tolerated, with no significant adverse effects reported in randomized controlled trials at doses up to 2 g/day for durations of up to approximately 6 weeks. Common side effects have not been reported to occur in more than 5% of participants in clinical trials. Uncommon or rare side effects are not well-documented in the current research. However, due to its vasodilatory effects via nitric oxide pathways, there is a potential for interactions with certain medications. Individuals taking nitrates or nitrites for cardiovascular conditions, or antihypertensive medications, should exercise caution and consult a healthcare professional before using spinach extract, as it could potentially lead to an additive hypotensive effect. While no specific contraindications have been established, caution is advised for individuals with pre-existing hypotension or those already on nitrate-based medications. Data on special populations, such as pregnant or breastfeeding women, children, or individuals with specific medical conditions (other than the promising but unconfirmed diabetic wound healing effects), are limited, and further research is needed to establish safety in these groups.
Dosage
The minimum effective dose for concentrated spinach extract, particularly for improving physical performance, appears to be approximately 1 g per day, especially when standardized for nitrate content. The optimal dosage range identified in current research for enhancing exercise performance is between 1 and 2 g per day. The maximum safe dose has not been definitively established, but no adverse effects have been reported in trials using up to 2 g per day. For best results, daily supplementation is recommended. While the specific timing relative to exercise is not definitively established, the effects of dietary nitrates often peak within a few hours of ingestion. It is important to use extracts standardized for nitrate content, as red spinach extract variants may naturally contain higher levels of nitrates. To maximize the conversion of nitrates to nitric oxide, it is advisable to avoid antibacterial mouthwash around the time of dosing, as oral bacteria play a crucial role in this conversion process. No specific cofactors are required, but a generally healthy diet supports overall efficacy.
FAQs
Is spinach extract safe for long-term use?
Current short-term randomized controlled trials show good safety and tolerability for spinach extract. However, long-term safety data are still limited, and more research is needed for extended use.
Does it improve endurance or strength?
Evidence from multiple studies supports that concentrated spinach extract can improve endurance and fatigue resistance. Some studies also indicate benefits for strength parameters, making it a promising ergogenic aid.
How quickly does it work?
The performance-enhancing effects of concentrated spinach extract have been observed within 1 to 6 weeks of consistent daily supplementation in various randomized controlled trials.
Is red spinach extract better?
Red spinach extract may have a higher natural nitrate content compared to common spinach extract, potentially leading to stronger effects. However, direct comparative efficacy data between the two are currently limited.
Can it replace nitrate supplements like beetroot?
Spinach extract is a natural source of nitrates and works through similar nitric oxide pathways as beetroot. While it offers similar benefits, direct comparative efficacy data are limited, and it can be considered an alternative natural nitrate source.
Research Sources
- https://pubmed.ncbi.nlm.nih.gov/39991395/ – This systematic review and meta-analysis, including 4 RCTs with 94 healthy adults, found significant improvements in physical performance parameters with spinach extract supplementation. It noted mixed results on body composition and reported no adverse events, highlighting the need for larger, more diverse studies.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11845096/ – This article, likely a follow-up or related publication to the previous one, further details the findings of the systematic review on spinach extract. It reinforces the ergogenic benefits for physical performance and discusses the safety profile observed in short-term trials.
- https://www.nature.com/articles/s41598-023-42033-0 – This animal study on diabetic rats demonstrated that spinach extract accelerated wound healing, increased vascular endothelial growth factor (VEGF), and improved ulcer regeneration. The findings suggest a potential therapeutic role for spinach extract in wound care, though human trials are needed.
- https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2025.1496200/full – This research focuses on the analytical methodology for profiling flavonoids in spinach using UHPLC-MS/MS. While not a clinical study, it provides crucial insights into the chemical composition and antioxidant potential of spinach extracts, supporting the understanding of their bioavailability and diverse effects.
- https://nutrigardens.com/blogs/blog/red-spinach-extract-in-spin-boost%C2%AE-reduces-athletic-fatigue – This blog post discusses the benefits of red spinach extract, particularly its role in reducing athletic fatigue. It highlights the higher nitrate content in red spinach and its potential for enhanced ergogenic effects, aligning with the general understanding of nitrate-rich supplements for performance.
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