Guava is a fruit in the Myrtle Family – the same family as the powerful clove, eucalyptus, etc. Myrtle trees are mentioned in the Bible (Nehemiah 8:15; Isaiah 41:19, 55:13; Zech. 1:8). In the Isaiah references, the Lord promises that the wilderness and thorns will be replaced with myrtle trees in the coming Millennium. They are obviously a blessing.
The myrtle tree is listed among other valuable trees, such as the “oil tree” (i.e., olive tree). It is therefore not surprising to find that the fruits and leaves of trees in the myrtle family have amazing nutritional and healing properties. For example, the leaves of the guava tree have been found to have great benefits for those suffering from diabetes, obesity, etc.
“Effect of guava (Psidium guajava Linn.) leaf soluble solids on glucose metabolism in type 2 diabetic rats… Low-dose streptozotocin (STZ) and nicotinamide were injected into Sprague-Dawley (SD) rats to induce type 2 diabetes. Acute and long-term feeding tests were carried out, and an oral glucose tolerance test (OGTT) to follow the changes in plasma glucose and insulin levels was performed to evaluate the anti-hyperglycemic effect of guava leaf extracts in diabetic rats. The results of acute and long-term feeding tests showed a significant reduction in the blood sugar level in diabetic rats fed with either the aqueous or ethanol extract of guava leaves (p < 0.05). Long-term administration of guava leaf extracts increased the plasma insulin level and glucose utilization in diabetic rats…”
(Phytother Res. 2008 Nov)
“Anti-hyperglycemic and anti-hyperlipidemic effects of guava leaf extract…the leaf extract of guava has traditionally been used for the treatment of diabetes in East Asia and other countries…the anti-hyperglycemic activity of the extract has been reported in some animal models…The number of diabetes mellitus (DM) cases has been increasing worldwide in recent years…T2DM is generally characterized by hyperglycemia, insulin resistance (reduced insulin sensitivity) and obesity. Obesity is associated with not only T2DM but also hyperlipidemia and hypertension. Coexistence of these diseases is well known as metabolic syndrome, a high risk factor for cardiovascular disease…This metabolic abnormality is induced by obesity, especially increased visceral fat, via the enhancement of inflammation and hypoadiponectinemia…guava leaves have also attracted attention as a folk remedy for diabetes not only in Japan and East Asia…but also in Africa…To clarify the above-mentioned findings in animal models, a crossover study was designed to evaluate the effects of a single ingestion of Guava Leaf Tea on postprandial blood glucose elevation in normal and pre-diabetic subjects…The single ingestion of Guava Leaf Tea significantly reduced postprandial blood glucose elevation at 30, 90 and 120 min…In addition, the AUC of the glucose level after carbohydrate loading (ingestion of cooked rice) was significantly reduced by about 20%...these findings, suggest that the single ingestion of GvEx or Guava Leaf Tea can reduce postprandial glucose elevation via the inhibition of alpha-glucosidase in mice and human subjects with or without diabetes… after the ingestion of Guava Leaf Tea for 12 weeks, serum levels of total cholesterol (T-CHO) and triglyceride (TG) significantly decreased in the subjects with hypercholesterolemia and hypertriglycemia…There were no abnormal changes in the parameters of iron metabolism, liver and kidney functions, blood chemistry and on items covered in the physician's physical examination and health interviews…Taken together, it is suggested that the consecutive ingestion of Guava Leaf Tea with every meal improves diabetes symptoms, such as hyperglycemia, hyperinsulinemia, insulin resistance as well as hyperlipidemia [i.e. high cholesterol] in pre-diabetic and mild diabetic patients with or without hyperlipidemia…”
(Nutrition & Metabolism, 2010)
“The hypoglycemic effects of guava leaf (Psidium guajava L.) extract are associated with improving endothelial dysfunction in mice with diet-induced obesity… guava leaf extract reversed the endothelial dysfunction found in obese mice in terms of endothelium- and NO (nitric oxide)-dependent vasodilatation induced by acetylcholine in aortic rings. In conclusion, the beneficial effects of guava leaf extract in obese mice were associated with improved vascular functions altered by obesity, probably due to its phenolic content…”
(Food Res Int. 2017)
Guava leaves also contain quercetin which inhibits fat cell formation:
“Combination treatment with quercetin and resveratrol attenuates high fat diet-induced obesity and associated inflammation in rats via the AMPKα1/SIRT1 signaling pathway… Diet-induced obesity is associated with systemic inflammation, which is considered to originate predominantly from the adipose tissue. Quercetin and resveratrol are two dietary polyphenols that exhibit anti-inflammatory properties and anti-insulin resistance…At the end of week 11, HFD+CQR rats had a notably lower visceral (epididymal and perirenal) adipose tissue weight…and a significantly smaller adipose cell diameter compared with the HFD group…Subcutaneous adipose tissue weight did not differ significantly across all groups (Fig. 1D). These results suggest that CQR treatment may inhibit HFD-induced obesity…”
(Exp Ther Med. 2017 Dec; 14)
“Guava Leaf Extract Diminishes Hyperglycemia and Oxidative Stress, Prevents β-Cell Death, Inhibits Inflammation, and Regulates NF-kB Signaling Pathway in STZ Induced Diabetic Rats… Results from our findings suggest that GLE has the great ability to cut back plasma glucose and oxidative stress and conjointly ameliorates the burden of inflammation in STZ evoked diabetic rats as confirmation by reduced glucose and restored antioxidant levels, besides reduced expression of inflammatory proteins. The beneficial effects of GLE on oxidative stress and inflammation in diabetic rats were well visualized in our histological studies. The mechanism of action of GLE may be owing to its ability to suppress the hyperglycemia by regulating the secretion of insulin from the pancreatic beta-cells and in turns it may ameliorate the oxidative stress and confirm the availability of enough antioxidant enzymes…”
(BioMed Research International, Volume 2018)
Red onions are also high in quercetin.
In regard to obesity, no food supplement will combat the harmful effects of gluttony, lack of exercise, or the unwise use of cane sugar, high fructose corn syrup, MSG, etc., in the diet. But with a Biblically-healthy diet, there are things that can greatly aid in metabolism, digestion, etc.