Study on spinach extract shows positive effects on skeletal muscle fitness
A study published by the sports physiology department at the Universidad Católica San Antonio de Murcia (UCAM)1, Spain, has revealed significant improvement in muscle strength and muscle fitness in subjects aged 50-plus who combined moderately intense strength training with a 12-week daily supplementation of natural extract of Spinacia oleracea L. Maintaining muscle health and functional capability is a key component of healthy ageing, while improvement in muscle fitness may appeal to a wider audience of sports enthusiasts.
Researchers investigated the efficacy of daily consumption of four 500mg capsules of Spisar spinach extract or a placebo, combined with a resistance training programme, on skeletal muscle fitness during a 12-week randomized, double-blind, placebo-controlled clinical trial. Study subjects – 45 healthy males and females aged over 50 – had to undertake three one-hour, moderate-intensity training sessions per week.
At the end of the study, both the experimental and placebo groups had better muscle strength, as evaluated by isokinetic and isometric dynamometry, yet the improvement was significantly higher with Spisar than the placebo. Compared to the placebo, muscle quality also improved to a greater extent when combining training and Spisar intake.
Better muscle quality is an important contributor to muscle health and healthy ageing. Increased muscle mass and improvements in quality of life questionnaires were also greater with Spisar than the placebo group, although not significantly.
The authors conclude that Spisar in conjunction with physical exercise may exert overall “all-body strengthening” adaptogenic activity, and may be beneficial for improving muscle fitness and the maintenance of muscle health, both of which are crucial for healthy ageing.
Spisar is obtained from the nutrient-rich leaves of spinach cultivated in Southern Spain and gently processed with the Pure-Hydro Process, an eco-friendly, proprietary extraction technology using only purified water as a solvent. Spinach leaves have a naturally high content of phytoecdysteroids, plant secondary metabolites with a wide range of potential physiological and health benefits, such as improved physical performance and enhanced stress resistance. Spisar is standardised for 20-hydroxyecdysone (20E) – the major naturally-occurring ecdysteroid in plants.
Andrea Zangara, head of scientific communications and marketing, said: “In an ever-ageing society, it is of major importance to maintain mobility and overall wellbeing for as long as possible. Our spinach extract can contribute to that in an entirely natural but efficient way, and therefore allows manufacturers to react to emerging market demand for muscle fitness safe ingredients that can be used by a wider age-range.”
The newly launched Spisar expands the company’s portfolio of Mediterranean fruit and vegetable extracts designed to support healthy ageing. It perfectly complements Wellemon lemon extract which offers potential health-promoting properties for cardiometabolic, vascular, cognitive and nutriti-cosmetic applications, overcoming the low solubility and, therefore, low bioavailability of most citrus flavanones such as hesperidin. Once ingested, flavanones exert health benefits through their metabolites circulating in the body, therefore bioavailability is crucial.
A recent clinical study of the CEBAS-CSIC – a research centre within the Spanish National Research Council (CSIC) – compared the eriocitrin-rich Wellemon extract with an hesperidin-rich orange extract2. The researchers compared the metabolism and bioavailability of flavanones from Wellemon as well as the orange extracts, and analysed changes in metabolites in the participants’ blood and urine.
The study demonstrated that eriocitrin in Euromed’s Wellemon has high bioavailability compared to hesperidin (equal amounts), thanks to its superior water-solubility, chemical structure and extraction technology. Concentrations of all metabolites, including hesperidin metabolites, were higher and more quickly detected after Wellemon intake, than after the consumption of orange extract. Therefore, Wellemon can provide a higher total concentration of bioactive metabolites not achievable with the intake of hesperidin alone. It even appeared to compensate for the high interindividual variability in the production of derived bioactive intestinal metabolites.
Moreover, the pharmacokinetic study showed for the first time in humans, that intake of eriocitrin from lemon extract yields both lemon and orange metabolites, meaning the intake of Wellemon provides both eriocitrin and hesperidin metabolites, at a lower dosage compared to hesperidin. It is also worth noting that systolic blood pressure remained stable in subjects consuming Wellemon, but increased slightly in those supplementing with orange extract following the high-fat, high sugar meal given to participants.
1 Pérez-Piñero, S.et.al (2021): A 12-Week Randomized Double-Blind Placebo-Controlled Clinical Trial,Evaluating the Effect of Supplementation with a Spinach Extract on Skeletal Muscle Fitness in Adults Older Than 50 Years of Age. Nutrients 2021, 13, 4373.
2 Avila-Galvez M. et al. (2021): New Insights into the Metabolism of the Flavanones Eriocitrin and Hesperidin: A Comparative Human Pharmacokinetic Study. Antioxidants 2021, 10, 435. https://doi.org/10.3390/antiox10030435