Spinacia Extract
Also known as: Spinach, Spinacia Extract, Spinacia oleracea
Overview
Spinacia extract is derived from the leaves of the spinach plant (*Spinacia oleracea*), a leafy green vegetable renowned for its rich content of dietary nitrates, flavonoids, and antioxidants. It is primarily utilized as a nutritional supplement to enhance physical performance, promote wound healing, and potentially support muscle health, particularly in aging populations. The extract's efficacy stems from bioactive compounds like nitrates, which serve as precursors to nitric oxide. Nitric oxide plays a crucial role in vascular function, improving blood flow and oxygen delivery, and enhancing muscle efficiency. Research on spinach extract is moderately mature, with several randomized controlled trials (RCTs) and systematic reviews focusing on its ergogenic (performance-enhancing) effects and wound healing properties. While the quality of evidence is generally good, some studies are limited by relatively small sample sizes and short follow-up durations.
Benefits
Spinach extract offers several evidence-based benefits. A systematic review of four randomized controlled trials (n=94) indicated that supplementation with 1–2 grams of spinach extract daily significantly improved various physical performance parameters, including muscle strength and endurance, without reported adverse effects. The optimal dosage range for performance enhancement is suggested to be between 300 to 1041 mg of nitrate content daily. Regarding body composition, some studies have shown minor improvements in muscle mass or a reduction in sarcopenia markers in older adults after 12 weeks of supplementation, though results are mixed. In a controlled animal study, spinach extract accelerated wound healing by enhancing vascular endothelial growth factor (VEGF) expression and reducing inflammation, suggesting potential benefits for diabetic ulcer regeneration. Specifically, older adults (>50 years) have shown a reduction in sarcopenia prevalence after 12 weeks of supplementation, highlighting its potential utility in combating age-related muscle loss.
How it works
Spinach extract's primary mechanism of action involves its rich dietary nitrate content. These nitrates are converted in the body to nitric oxide (NO), a potent vasodilator that improves blood flow, oxygen delivery, and muscle contractility during exercise. This enhanced circulation contributes to improved physical performance. Additionally, the flavonoids and other polyphenols present in spinach exert significant antioxidant and anti-inflammatory effects. These properties help reduce oxidative stress and inflammation, which are crucial for tissue repair and optimal muscle function. Molecularly, the nitric oxide synthase pathways and VEGF signaling are implicated in the observed effects on vascular function and wound healing. The bioavailability of nitrates depends on oral bacterial reduction and systemic conversion, while flavonoid absorption varies based on the extraction method and individual metabolism.
Side effects
Spinach extract supplementation is generally well tolerated, with no serious adverse effects reported in randomized controlled trials lasting up to 12 weeks. At typical clinical trial doses (1–2 grams daily), no common side effects have been reported. While no significant uncommon or rare side effects have been documented, theoretically, very high nitrate intake could affect individuals with specific conditions, such as kidney disease, although direct evidence from trials is lacking. Potential interactions with antihypertensive drugs are a theoretical concern due to the vasodilatory effects of nitrates, but no direct clinical evidence of such interactions has been reported. There are no formal contraindications identified in the literature; however, caution is advised for populations known to be sensitive to nitrate intake. Special populations, such as older adults, appear to tolerate supplementation well, and diabetic populations may potentially benefit from its wound healing effects, though further human studies are needed to confirm this.
Dosage
The minimum effective dose for spinach extract, based on performance studies, is approximately 300 mg of nitrate content daily, which corresponds to about 1 gram of spinach extract. The optimal dosage range identified in randomized controlled trials is 300 to 1041 mg of nitrate (5 to 16.8 mmol) daily, typically corresponding to 1–2 grams of spinach extract. The maximum safe dose is not yet well established, but doses up to 2 grams daily for 12 weeks have shown no adverse effects in clinical trials. For ergogenic effects, supplementation prior to exercise may be beneficial, while chronic daily intake is recommended for muscle and wound healing benefits. Both aqueous and alcoholic extracts have been studied, and the bioactive compound profiles may vary. It's important to note that oral nitrate conversion relies on oral microbiota, so co-administration with antibacterial mouthwash may reduce efficacy. Adequate dietary nitrate intake and oral bacterial activity are essential cofactors for nitric oxide production.
FAQs
Is spinach extract safe for long-term use?
Current evidence supports its safety for up to 12 weeks; however, longer-term studies are needed to confirm extended safety.
Does it improve exercise performance?
Yes, spinach extract has been shown to improve muscle strength and endurance, primarily through nitrate-mediated nitric oxide production.
Can it help with muscle loss in older adults?
Preliminary evidence suggests potential benefits in reducing sarcopenia markers in older adults, indicating its utility for age-related muscle loss.
Are there differences between spinach extract and whole spinach?
Extracts provide concentrated bioactive compounds and standardized nitrate doses, potentially offering more consistent and potent effects compared to whole spinach.
Does it interact with medications?
No significant interactions have been reported, but caution is prudent when combined with vasodilators due to its nitrate content.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11845096/ – This systematic review, including 4 RCTs (n=94), found that spinach extract supplementation (1–2 g daily for 7–84 days) significantly improved physical performance metrics, such as muscle strength and endurance, with no reported adverse effects. The study highlights the ergogenic potential of spinach extract, though it notes limitations due to small sample sizes and short durations.
- https://www.cureus.com/articles/334186-improved-effect-of-spinach-extract-on-physical-performance-a-systematic-review-of-randomized-controlled-trials – This systematic review, also encompassing 4 RCTs, concluded that spinach extract improves physical performance. It specifically noted improvements in muscle strength and endurance, attributing these effects to the nitrate content. The review reinforces the safety profile, reporting no adverse effects at the tested dosages.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8706266/ – This 12-week double-blind placebo-controlled RCT (n=45) in adults over 50 years old demonstrated that daily spinach extract supplementation decreased sarcopenia prevalence. The study found no adverse effects, suggesting its potential for mitigating age-related muscle loss. It was a high-quality study with adequate controls.
- https://www.nature.com/articles/s41598-023-42033-0 – This animal study, conducted on 72 diabetic rats, showed that spinach extract accelerated diabetic ulcer healing. The mechanism involved increased vascular endothelial growth factor (VEGF) expression and reduced inflammation. While preclinical, this research provides strong evidence for the wound-healing potential of spinach extract.
- https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2025.1496200/full – This article discusses the general properties and potential applications of *Spinacia oleracea* extracts. It delves into the bioactive compounds, including flavonoids and other polyphenols, and their antioxidant and anti-inflammatory effects. The research provides foundational understanding of the plant's chemical composition and its potential health benefits beyond nitrate content.