The guava fruit is such an essential item to have in fruit salad, that we cannot imagine a fruit salad without it. When I was young we would get fresh guava juice delivered every morning in winter from the dairy, and I always preferred a glass of guava juice to orange juice. Perhaps it's the natural sweetness and fragrance of the guava that makes it so appealing to my senses, but I cannot imagine winter without my guava juice. I am ashamed to admit that I can easily flatten a liter of guava juice a day. And I am even guilty of putting at least an entire tin of canned guava into my fruit smoothies, when I'm looking for a quick meal. So what is so marvelous about guavas anyway?
(1) The guava fruit contains good levels of lycopene coming in third as far as fruits rich in lycopene are concerned (first were fresh tomatoes, second watermelon). Lycopene is a carotenoid which the human body cannot produce, thus we only get it from our diet or from supplementation. Lycopene is also present in other pink and red fruits such as watermelon grapefruit and tomatoes. It is interesting to note that the highest levels of lycopene in the body are found in the adrenals, liver and the testes. Lycopene reduces the risk of cancer and chronic heart disease.
(2) Both the guava pulp and peel are rich in dietary fiber. (3)The fiber in guava constitutes 12 % of the dried pulp. What makes guava different to other fruits is that it is classified as having antioxidant dietary fiber (AODF), meaning that the fiber of the guava is also rich in antioxidants. In this study guava's were examined for their free radical scavenging potential (which makes them an antioxidant). The research revealed that all portions of the guava fruit had an exceptionally high scavenging activity, with the fruit pulp exhibiting the highest scavenging ability of the whole fruit. (4) Antioxidant activity is linked to the reduction of incidence of arthritis, arteriosclerosis, cancer, heart disease, inflammation, brain dysfunction and has been linked to the retardation of ageing. Guava has a very high ascorbic acid (vitamin C) content (169 mg / 100g) and a very high phenolic content (192mg / 100g). However there is more benefit in eating the guava with its skin on than without.
(5) Guava juice has hypoglycemic action as it lowers blood glucose levels, with a study suggesting that guava improves the condition and helps to prevent, diabetes mellitus. (6) The guava is rich in phenols, essential oils and flavanoids. All of which have antibacterial activity. A study was conducted to see how effective guava juice is against several different strains of E.coli and the guava juice showed antimicrobial activity against all of them at 37ºC. (7) Even the guava seeds are good for us. Not only are they a good source of protein but they also contain a high level of tryptophan (essential for insomniacs). The protein in the guava seed is higher than that of the soy bean with a higher level of digestibility. This is great news for vegetarians. (8) Guava also helps to prevent plaque causing bacteria from adhering to saliva coated surfaces, making it beneficial for dental health.
(9) Eating guavas is also beneficial for decreasing blood pressure and lipids. Patients with hypertension were given guava daily for four weeks. The outcome was a drop in systolic and diastolic pressures, and the fiber content of the guava ingestion resulted in a significant decrease in serum total cholesterol, triglycerides and an increase in HDL cholesterol. This makes guavas highly beneficial for those at risk for heart disease and hypertension. (10) Another group of individuals with essential hypertension (EH) were fed a guava before every meal for twelve weeks. again revealed an increase in high-density-lipoprotein cholesterol and a decrease in blood pressure and serum cholesterol. Making guava incredibly helpful for anyone suffering from high blood pressure.
The guava plant:
If you are lucky enough to own your own guava tree, you can benefit from ingesting guava leaves in a tea, or added to salads. (11) Guava leaves contain flavonoids; morin glycosides, quercetin glycosides and quercetin. These have potent antibacterial activity and were studied against the bacterial strains; Bacillus Cereus and Salmonella enteritidis. The guava was effective against both test strains of bacteria. Thus guava leaves are both (12) antioxidant and antibacterial. (13) The leaf of this plant is also effective as an antidiarrheal when boiled fresh. (14) The guava leaf has an anti-spasmodic effect on diarrhea symptoms and also reduced the duration of abdominal pain. (15) A different study revealed that the leaf has anti-inflammatory and analgesic properties, making the leaf helpful for conditions such as arthritis. (16) The guava leaf is also a fabulous find for acne sufferers. A study using guava leaf and walnut leaf extract against the bacteria which cause acne inflammation, revealed that the leaf had a high rate of inhibition on the acne and its associated inflammation. Revealing that a face wash made with the leaves is beneficial. (17) The guava was studied as a treatment for infantile rotaviral enteritis (enteritis is the inflammation of the small intestine). The rate of the recovery of the patients treated increased from 58% to 87%, with the treated group recovering within three days. The associated diarrhea stopped within 9 hours of the treated group (compared to 15.5. hours in the untreated group) and glucose loss in stools was also greatly reduced. Concluding that guava is an effective treatment for this infantile condition.
Medical research has revealed a lot of secrets about one of my favorite fruits. Eating guavas and drinking guava juice has wonderful health benefits. The guava is also packed full of nutrients. (18) One cup of fresh guava supplies us with 17 amino acids and protein. It gives us 21% of our daily vitamin A requirement, has retinol activity (51.2mcg), beta carotene, huge amounts of lycopene (8586mcg), vitamin C, E, K, thiamin, riboflavin, niacin, B6, folate and pantothenic acid. This one cup also includes 185 mg of Omega-3-fatty acids, and 475 mg of Omega-6-fatty acids, calcium, iron, magnesium, phosphorus, potassium (20% of our daily requirement), sodium, zinc, copper, manganese and selenium. And to be quite honest, I could easily drink more than one cup of pulverized pulp a day.
Enjoy our winter fruits with relish, guava's are one of our unsung heroes.
References: (1) Phytochemsitry 54 (2000) 233-236 Molecules of interest Is lycopene beneficial to human health Peter M Bramley School of biological sciences, Royal Halloway, University of London, Egham, Surrey
(2) J. Agric. Food Chem. 2001, 49, 5489?5493 Guava Fruit (Psidium guajava L.) as a New Source of Antioxidant Dietary Fiber Antonio Jime nez-Escrig, Mariela Rinco, Raquel Pulido ,Fulgencio Saura-Calixto Departamento de Metabolismo y Nutricio, Instituto del Frı, Consejo Superior de Investigaciones Cientı, Madrid, Spain Unidad de Investigacionde AlimFacultad de Farmacia, Universidad Central de Venezuela, Caracas, Venezuela
3) Santosh Khokhar1 and Amin C. Kapoor1 Department of Foods & Nutrition, Haryana Agricultural University, 125 004 Hisar, India 28 May 1990
(4) Sunway Academic Journal 3, 9–20 (2006) ANTIOXIDANT PROPERTIES OF GUAVA FRUIT: COMPARISON WITH SOME LOCAL FRUITS LIM YAU YAN a LIM THENG TENG TEE JING JHI Monash University Malaysia
(5) Am J Chin Med. 1983;11(1-4):74-6. Hypoglycemic effect of guava juice in mice and human subjects. Cheng JT, Yang RS.
(6) Antimicrobial effect of guava and guava extracts on Escherichia coli O157:H7 in liquid medium S. A. IBRAHIM, G. Yang, C. E. Niedziela, and T. S. F. Ts1. Food Science & Nutrition Program, North Carolina A&T State Univ., Dept. of Human Environment & Family Sciences, 171-B Carver Hall, Greensboro, NC 27411-1064, (2) Dept. of Natural Resources & Environmental Design, North Carolina A&T State Univ., 238 Carver Hall, Greensboro, NC 27411-1064
7) Journal of Food Biochemistry GUAVA SEED PROTEIN ISOLATE: FUNCTIONAL AND NUTRITIONAL CHARACTERIZATION A. BERNARDINO NICANOR1, A. ORTIZ MORENO1, A. L. MARTINEZ AYALA2 G. DÁVILA ORTÍZ13 1Departamento de Graduados e Investigatión en Alimentos Escuela National de Cientias Biológicas Institute Politécnico National C.P. 06470, A.P. 42–186, Mexico D.F. 2Departamento de Biotecnología Centra de Desarrollo de Productos Bióticos Apdo.
8) J Oral Sci. 2003 Dec;45(4):201-6 The anti-adherence effect of Piper betle and Psidium guajava extracts on the adhesion of early settlers in dental plaque to saliva-coated glass surfaces. Razak FA, Rahim ZH. Department of Oral Biology, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia.
9) J Hum Hypertens. 1993 Feb;7(1):33-8 Can guava fruit intake decrease blood pressure and blood lipids? Singh RB, Rastogi SS, Singh NK, Ghosh S, Gupta S, Niaz MA. Medical Hospital and Research Centre, Moradabad, India.
10) Am J Cardiol. 1992 Nov 15;70(15):1287-91 Effects of guava intake on serum total and high-density lipoprotein cholesterol levels and on systemic blood pressure. Singh RB, Rastogi SS, Singh R, Ghosh S, Niaz MA. Heart Research Laboratory, Medical Hospital and Research Centre, Moradabad, India.
(11) Biosci, Biotechnol, Biochem, 66 (8), 1727-1730, 2002 Isolation of antimicrobial compounds from guava and their structural elucidation. Hidetoshi A, Gen-ichi D. Division of life science, graduate school of science and technology, Kobe University, Japan
12) Guava extract ( Psidium guajava ) alters the labelling of blood constituents with technetium-99m Journal of Zhejiang University - Science B 1673-1581 Volume 7, Number 6 / June, 2006 429-435 Abreu P. R. C. 1, Almeida M. C. 1, Bernardo R. M. 1, Bernardo L. C. 1, Brito L. C. 1, Garcia E. A. C. 2, Fonseca A. S. 3 and Bernardo-Filho M. 1
(13) Southeast Asian J Trop Med Public Health. 1995;26 Suppl 1:306-10. Study of genotoxic effects of antidiarrheal medicinal herbs on human cells in vitro. Settheetham W, Ishida T. Department of Physiology, Faculty of Medicine, Srinakharinwirot University, Bangkok, Thailand.
14) J Ethnopharmacol. 2002 Nov;83(1-2):19-24 Intestinal anti-spasmodic effect of a phytodrug of Psidium guajava folia in the treatment of acute diarrheic disease. Lozoya X, Reyes-Morales H, Chavez-Soto MA, Martinez-Garcia Mdel C, Soto-Gonzalez Y, Doubova SV. Laboratory of Medicinal Plants at Research Unit of Neurological Diseases, Mexican Institute of Social Security (IMSS), Mexico City, Mexico.
15) Methods Find Exp Clin Pharmacol. 2006 Sep;28(7):441-6 Antiinflammatory and analgesic effects of Psidium guajava Linn. (Myrtaceae) leaf aqueous extract in rats and mice. Ojewole JA. Department of Pharmacology, Faculty of Health Sciences, University of KwaZulu-Natal, Durban, South Africa.
16) Am J Chin Med. 2005;33(2):197-204 The antimicrobial activities of Psidium guajava and Juglans regia leaf extracts to acne-developing organisms. Qadan F, Thewaini AJ, Ali DA, Afifi R, Elkhawad A, Matalka KZ. Faculty of Pharmacy and Medical Technology, The University of Petra, Amman, Jordan.
17) Zhongguo Zhong Xi Yi Jie He Za Zhi. 2000 Dec;20(12):893-5 [Clinical study on treatment of infantile rotaviral enteritis with Psidium guajava L.] Wei L, Li Z, Chen B. Nanfang Hospital, First Military Medical University, Guangzhou 510515