The review confirms avocado (Persea. Americana) components such as the peel, seed, flesh, and leaves as each having a specific effect on core biological functions.
"Avocado is a well-known source of carotenoids, minerals, phenolics, vitamins, and fatty acids," wrote the authors from the University of Medical Sciences, Mashhad in Iran.
"The lipid- lowering, antihypertensive, antidiabetic, anti-obesity, antithrombotic, antiatherosclerotic, and cardioprotective effects of avocado have been demonstrated in several studies."
Along with the avocado, nutritionally similarly botanicals such as cinnamon; garlic, grape, black cumin, saffron and its constituent, thymoquinone; and rutin have shown promising effects on disorders that make up Metabolic Syndrome (MetS).
The term refers to the cluster of related risk factors for cardiovascular disease that includes hyperglycaemia, hypertension and dyslipidaemia.
Not surprisingly, countries where overweight and obesity rates are rocketing are also seeing the MetS prevalence keeping pace.
MetS in the EU
A study that enrolled 8,468 subjects from 10 European countries and 1 from US found certain clusters that exhibited high triglycerides, elevated BP and abdominal obesity was observed in 32.3% of UK subjects, Sardinia in Italy (19.6%) and Germany (18.5%).
Less prevalence was observed in subjects from Sweden (1.2%), Spain (2.6%), and USA (2.5%).
Avocado’s positive effects on lipid profile, obesity, high blood pressure and atherosclerosis (artery wall thickening) was attributed by the review to its antioxidant activity, which can neutralize the oxidative stress and cellular oxidation reaction under certain conditions.
“Promising observations have been made on the andioxidant activity of avocado and its antidiabetic effect via different mechanisms such as inhibition of α-amylase and α-glucosidase,” the review outlined.
“Also the hypolipidemic effect of avocado has been demonstrated to be through its antioxidant activity because of its high carotenoid content.”
The review also identified the fruit’s hypotensive effect achieved via the improvement of biochemical and oxidative status, and protection of the liver, kidney, and vascular endothelium against oxidative stress
It is also believed that avocado in the diet played an important role in the prevention of cardiovascular disease through its effects on lipid metabolism and antioxidant properties.
Seeds show most activity
The review also ranked the seeds as the component of greatest antioxidant activity. This was closely followed by the peel.
“Among different parts, the seeds showed the highest antioxidant capacity,” the review said.
“Procyanidins were the major phenolic compounds that contributed to antioxidant capacity. This study suggested that avocado seeds and peels could be used as source of antioxidants.”
“The anticholinesterases and antioxidant activities of P. americana leaf and seed aqueous extracts were investigated via the activities of enzymes linked with Alzheimer disease. The leaf extract showed the highest phenolic content and radical scavenging activity.”
According to the researchers, the experimental studies reported in the literature placed the avocado’s health effect as most apparent on lipid profile.
The most affected biomarkers were low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), total cholesterol (TC), and phospholipids (PLs).
“In this review article, satisfactory clinical evidence suggested that avocado can be used as herbal dietary supplements for treatment of different components of MetS.”
Source: Phytotherapy Research
Published online ahead of print: DOI: 10.1002/ptr.5805
“Effects of Avocado (Persea americana) on Metabolic Syndrome: A Comprehensive Systematic Review.”
Authors: Jamshid Tabeshpour, Bibi Marjan Razavi, Hossein Hosseinzadeh