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13.12.2019 Feature Article

Guava: More Powerful Antioxidants Than Almost Any Other Fruit, Treats Cancer and Lowers Blood Pressures

Guava:  More Powerful Antioxidants Than Almost Any Other Fruit, Treats Cancer and Lowers Blood Pressures
LISTEN DEC 13, 2019

Mostly everyone in Ghana has heard of a guava, maybe you are yet to hear about the numerous benefits derived from this noble fruit. I usually way back do not like the bitterness nature of it when I was a novice in the village of Suhum-Amrahia. However, I have come to like guava after my extensive research on guava than any other fruits.

Practically every other plant-based food, besides being delicious, this one has its own set of health qualities, and they’re quite impressive. For those living in Mexico, Central or South America, Malaysia, Vietnam, Hawaii, Peru, China and India, obviously may know a lot about guava because they are grown in such areas. They can grow more to more than 30 feet high.

Some had codenamed guava as a “magical” fruit because of its collection of nutrients and medicinal uses. Recently dubbed the ultimate superfood ”, this tropical fruit is considered one of the top antioxidant foods , with loads of vitamin C, vitamin A and lycopene.

Guava flesh can also be used as a cooking and baking ingredient. Its leaves, seeds, and even skin can also be eaten or used medicinally.

In India, it has the name ( “amrood” ), the exterior of the pale green, pink or white, round or oval fruits (considered berries by botanists) depends on the variety.

Before we delve into the numerous benefits, note that limiting your fruit intake to keep your total daily fructose consumption below 25 grams (or 15 grams if you have signs of insulin resistance) is recommended for optimal health.

Guava Nutrition composition:

Guavas are low in calories and are incredible sources of vitamin C, lycopene, vitamin A, potassium, and fiber. 100 grams of guava fruit contains the following according to

  • 68 calories
  • 14.3 grams carbohydrate
  • 2.6 grams protein
  • 228.3 milligrams vitamin C (381 percent DV)
  • 5.2 milligrams lycopene ( 52 percent DV)
  • 5.4 grams fiber (21.6 percent DV)
  • 624 IU vitamin A (12.5 percent DV)
  • 49 microgram folate (12.3 percent DV)
  • 0.2 milligram copper (11.5 percent DV)
  • 417 milligrams potassium (8.8 percent DV)
  • 22 milligrams magnesium (5.5 percent DV)
  • 40 milligrams phosphorus (4 percent DV)

Studies on Health Benefits of Guava.

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Traditional folk medicine also used parts of the guava plant to make things like guava leaf tea and extracts to use medicinally. Many of the folk recipes and treatments have been proven to be successful today. Here are specific health benefits based on how the fruit is used or consumed according to Gutiérrez et al 2008 titled Psidium guajava: a review of its traditional uses, phytochemistry and pharmacology published Journal Ethnopharmacology.

Surprisingly, a serving of guava provides over 350 percent (!) of the daily recommended amount of vitamin C, making it one of the best vitamin C foods . As a matter of fact, guava provides substantially more than an equal serving of oranges (87 percent DV).

Vitamin C has long been known for its immune system boosting benefits. As with other water-soluble vitamins, vitamin C does not get stored in the body, so it’s imperative to reach the dietary goals to maintain the supply. An adequate level of vitamin C in the body can ensure the vitality of a number of body functions, including the immune system.

Vitamin C helps in the prevention of cell damage thanks to its antioxidant qualities, which in turn helps prevent many diseases, even serious disorders like heart disease, arthritis and cancer. A 2012 study conducted by Javaria Gull et al titled Variation in Antioxidant Attributes at Three Ripening Stages of Guava (Psidium guajava L.) Fruit from Different Geographical Regions of Pakistan published in Mdpi in Pakistan concluded that fully ripe guava had the most concentrated contents of vitamin C, so it’s best to enjoy the mature fruit to get the best levels. The results also showed that different stages of maturation and geographical locations had profound effects on the antioxidant activity and vitamin C contents of guava fruit. Guavas contain several nutrients your body can’t do without. In every 1-cup serving you get 21 percent of the recommended dietary allowance (RDA) of vitamin A and 20 percent each of potassium (about the same amount as a banana) and folate.

Though this is very inspiring, it’s the vitamin C that outshines the others to a overwhelming degree: Each serving imparts 628 percent of this bacteria-buster, so it’s no surprise that it fights disease so powerfully. Guavas are even recommended for dengue fever according to StyleCraze 2016 . The same serving size nets 20 percent of the RDA of folate, which is good for brain health and crucial for helping to ensure a healthy nervous system for unborn babies. Those nutritive benefits translate to the prevention and treatment of numerous diseases through improved immune function according to the healthsite 2016

Traditional uses for guava over centuries included alleviating pain from toothaches and canker sores according to a 2014 study by K. Ravi and P. Divyashree titled Psidium guajava: A review on its potential as an adjunct in treating periodontal disease published in the journal Pharmacognosy Review and to help wounds heal when the juice is applied topically. Guavas were said to treat epilepsy and convulsions by making them less frequent.

Fibre in Guava Lowers Blood Pressure and provides Healthy -Heart

The high potassium levels in guava fruit has been proven to naturally lower blood pressure and blood lipids according to a study by Singh et al 1993 titled Can guava fruit intake decrease blood pressure and blood lipids? Published in journal of Human Hypertension. This study was a randomized, single-blind, controlled trial conducted to examine the effects of guava fruit intake on Blood Pressures and blood lipids in patients with essential hypertension. the study involved 145 hypertensives that entered the trial, 72 patients were assigned to take a soluble fibre and a potassium-rich diet containing 0.5-1.0 kg of guava daily (group A) and 73 patients to their usual diet (group B), while salt, fat, cholesterol, caffeine and alcohol intake were similar in both groups for four weeks. Potassium is one of the most important minerals in the human body, for it’s an electrolyte and combats the negative effects of too much sodium, a common feature of the Western diet. High sodium intake leads to heightened blood pressure and, ultimately, heart disease.

In fact, potassium is crucial for healthy heart function. It also plays a part in reducing kidney stones, risk of stroke and bone loss in one 2004 report by Janice Hopkins Tanne titled Americans are told to reduce sodium and increase potassium intake published Britsih Medical J ournal.

The report was based on a comprehensive review of the scientific literature and was sponsored by a number of US and Canadian governmental organisations and foundations. The report says unequivocally that blood pressure rises progressively as sodium intake increases. About 25% of Americans have high blood pressure, and more than half of people aged over 60 do.

Healthy adults aged between 19 and 50 years should consume 1.5 g of sodium (equivalent to 3.8 g of salt) a day to replace losses through perspiration but should not exceed 2.3 g (5.8 g of salt), the report said. The upper limit should be lower in people aged over 50 and people with hypertension, diabetes, or kidney disease, because they are especially sensitive to the hypertensive effects of salt.

"If people choose foods to meet this level of sodium intake, they should be able to meet the recommended intakes for other nutrients such as calcium and vitamin A as well," said Dr Lawrence Appel, chairman of the panel behind the report and professor of medicine, epidemiology, and international health at Johns Hopkins Medical Institutions.

The bad news is that more than 95% of American men, 90% of Canadian men, 75% of American women, and 50% of Canadian women regularly consume more than the recommended upper limit of sodium. Median daily salt intake ranges between 7.8 g and 11.8 g (according to age group) in US men, 5.8 g and 7.8 g in US women, 7.1 g and 9.7 g in Canadian men, and 5.1 g and 6.4 g in Canadian women. These figures do not include salt added at the table, so total intake is probably higher.

Furthermore, Americans and Canadians are consuming only about half the recommended daily amount of potassium: 4.7 g. Potassium blunts the effects of salt, lowers blood pressure, and reduces the risk of kidney stones and bone loss. US men consume 2.8 to 3.3 g of potassium and women 2.2 to 2.4 g. Canadians consume somewhat more potassium than Americans, but African-Americans in the United States consume less.

Increased potassium intake may be especially beneficial for African-Americans, the report says. The panel did not set an upper limit for potassium, but people with kidney dysfunction and people taking some drugs ought to take less.

"Eighty per cent of the sodium comes from processed food. There are very few high sodium foods. Almost all is added during processing," said one of the committee members, Dr Paul Whelton, professor of epidemiology and medicine at Tulane University Health Sciences Center, New Orleans. Fruit and vegetables are naturally high in potassium, low in sodium, high in fibre, and high in antioxidants, he said.

Speaking at a press conference, Dr Appel pointed out: "Two slices of pizza contain about half of the upper level of sodium. Consuming this one meal would leave little room for additional sodium intake at other meals throughout the day." He called for the government to work with the food industry to decrease the amount of sodium in prepared and processed foods.

Dr Whelton said that high sodium intake was implicated in major health problems: 15 million deaths a year worldwide from cardiovascular disease and stroke, three times as many serious incidents requiring hospitalisation, and 10 times as many less serious incidents.

"You can't treat sudden death, but you can treat the precursors. Long term, we have to tackle the issue of diets and blood pressure and cholesterol," he said. This is the landmark case to get guava in your diet to avoid low potassium levels. Also according to the Harvard Health 2010 and 2016 By preventing your blood from thickening too much, guava consumption may help lower your blood pressure. Food containing little or no fiber, such as refined flour, can make high blood pressure (aka hypertension) worse because these foods tend to turn to sugar.

Another study in India by Singh et al 1992 titled ‘Effects of guava intake on serum total and high-density lipoprotein cholesterol levels and on systemic blood pressure’ published in Amercican Journal of CardiolOGY involved 120 participants with high blood pressure who were given guava to eat before meals for 12 weeks. This brought about an overall decrease in study subjects’ blood pressure levels. Further, “total and soluble fiber and vitamins and mineral intakes were significantly higher.

One interesting study by Kim et al 2016 titled Protective effects of polysaccharides from Psidium guajava leaves against oxidative stresses published in the International Journal Biolological Macromolecules. reported that the leaves “inhibited hydrogen peroxide-induced reactive oxygen species (ROS) production, lipid peroxidation and cell death.

The potassium and fiber content exerts positive leverage on your heart, even as it’s helping to reduce blood pressure, as well as stroke, which is closely interrelated with your heart according to a study by Ojewole JA 2005 titled Hypoglycemic and hypotensive effects of Psidium guajava Linn. (Myrtaceae) leaf aqueous extract published Methods and Findings in Experimental Clinical Pharmacology. Guava fruit is one of the best high-fiber foods , for it offers over 20 percent of your daily value of fiber (even more if the skin is consumed) and is considered a great source of antioxidant dietary fiber by the Journal of Agricultural and Food Chemistry. Guava seeds are also edible and are packed with fiber.

Although most people associate fiber with digestive health and treatment, fiber can do so much more. Because fiber helps to remove fats, sugars, bacteria and other toxins out of the body, it can help prevent diabetes and heart disease by lowering blood pressure, as well as prevent or reduce diverticulitis and constipation. Because fiber makes us full faster, eating guava fruit can also be a useful weight loss tool.

4. More Powerful Antioxidants Than Almost Any Other Fruit

In 2013, a study by Hyderabad’s National Institute of Nutrition in India, investigated the antioxidant characteristics of a number of Indian fruits including apples, bananas, grapes and more. The study concluded that guava fruit packed the biggest antioxidant punch when compared to other fruit . Antioxidants are powerful tools in preventing free radicals from damaging cells and developing diseases. The study was led by D. Sreeramulu titled Natural Antioxidant Activity of Commonly Consumed Plant Foods in India: Effect of Domestic Processing published in Oxidative Medicine and Cellular Longevity. The study was a revelation in India, where the fruit is considered a “poor man’s food.” If you are looking for the fullest range of guava’s antioxidant free-radical scavenging, the Pakistani study mentioned earlier recommends consuming an unripe fruit.

5. Prevent and Treat Cancer

Lycopene is also a powerful antioxidant, and there is a lot of it available in guava. One serving provides over half of your daily supply of lycopene. Known more commonly for being a beneficial ingredient in the nutrition-rich tomato , lycopene is available in many forms. It has a strong and proven reputation as a cancer fighter, due to its ability to inhibit the growth of multiple types of cancer cells according to a study by Ono M et al 2015 titled Mechanism of the Anticancer Effect of Lycopene (Tetraterpenoids) published in the journal Enzymes.

guavas have been shown to have dramatically positive results in cancer studies , by inhibiting cancer cell growth and metastasis in particular.

Lycopene works with flavonoids, lutein, quercetin and cryptoxanthin to prevent the growth of cancer cells. According to Organic Facts:

“There have been numerous studies done in recent years on guava’s effects primarily on prostate cancer, breast cancer and oral cancers. Guava leaf oil is extremely successful as an anti-proliferative substance, and has actually been shown to be more effective than some leading modern medicines in reducing cancerous growth.

Guavas are also rich in lycopene, a powerful antioxidant that has been shown to be wildly successful in reducing prostate cancer risk. That same antioxidant has also shown to inhibit the growth of breast cancer cells, although further human trials need to be done.”14

The Health Site notes that there’s “strong evidence” that shows eating guavas can also help prevent cancer of the skin , colon and lungs. Science Direct also mentions apoptosis in gastric cancer cell proliferation in a study by Na jia 2012 titled Radical scavenging activity of black currant (Ribes nigrum L.) extract and its inhibitory effect on gastric cancer cell proliferation via induction of apoptosis

Studies have proven inverse relationships between increased levels of lycopene and the risk of prostate cancer in a study by Wang et al 2015 titled Effect of Carotene and Lycopene on the Risk of Prostate Cancer: A Systematic Review and Dose-Response Meta-Analysis of Observational Studies published in PLoS one and also another study by Ellinger et al 2006 titled Tomatoes, tomato products and lycopene in the prevention and treatment of prostate cancer: do we have the evidence from intervention studies? Published in the journal Current Opinion Clinical Nutrition Metabolic Care. There has also been positive studies showing that diets containing lycopene can slow the progression of cancer by Rotelli et al 2015 titled IN-VITRO evidence for the protective properties of the main components of the Mediterranean diet against colorectal cancer: A systematic review published in the journal Surgical Oncology. And if a natural cancer treatment wasn’t good enough, lycopene has recently been linked to protection from stroke by Karppi et al 2012 titled Serum lycopene decreases the risk of stroke in men. A population-based follow-up study published in the journal Neurology

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Benefits from Leaves (Tea and Extracts):

Guava leaves can be used in multiple ways. The most common is by drying the leaves for tea, using the leaves to make an extract, or by simply chewing on them.

1. Treat and Prevent Diabetes

Guava leaf has long been used in traditional folk medicine to reverse diabetes naturally and, specifically, treat type 2 diabetes in East Asia in a study by Yoriko Deguchi and Kouji Miyazaki 2010 titled Anti-hyperglycemic and anti-hyperlipidemic effects of guava leaf extract published in the journal Nutrition and Metabolism.

Aside from the fruit being an overall healthy snack for diabetics, guava leaf extract can lower glucose levels in the blood and fight against type 2 diabetes in a study by Shen et al 2008 titled Effect of guava (Psidium guajava Linn.) leaf soluble solids on glucose metabolism in type 2 diabetic rats published in the journal Phytotherapy Research. Drinking guava leaf tea can benefit diabetic and pre-diabetic individuals, as it can improve diabetes symptoms and insulin resistance in a study by Rai et al 2010 titled Hypolipidaemic & hepatoprotective effects of Psidium guajava raw fruit peel in experimental diabetes published in the journal Indian Journal Medical Research.

Fiber can also be thanked for balancing the sugar your body absorbs, which lowers the risk of either a spike or drop in glucose and insulin levels. A clinical study indicated that drinking tea made from guava leaves lowered the blood sugar levels of 19 people and was effective for as long as two hours in a study by Yoriko Deguchi 1 and Kouji Miyazaki 2010 titled Anti-hyperglycemic and anti-hyperlipidemic effects of guava leaf extract published in the journal Nutrition and Metabolism.

Further testing by the same group in Japan, using 20 participants with type 2 diabetes, revealed that when study participants drank guava-leaf tea after a meal, their blood sugar levels dropped by more than 10 percent.

Multiple animal and test-tube studies have shown guava extract to decrease blood sugar levels, improve its control in the long term and reduce insulin resistance. One study observed:

“Although PG [Psidium guajava leaves] is known for its beneficial role in diabetes mellitus, for the first time we report its potential in the management of lifelong pathologies arising from high fructose intake initiated during developmental years.” Says Mathur et al 2015 titled Psidium guajava Linn. leaf extract affects hepatic glucose transporter-2 to attenuate early onset of insulin resistance consequent to high fructose intake: An experimental study published in the journal Pharmacognosy Research

2. Prevention of Gastroenteritis and Diarrhea

Guava leaf extract, tea or essential oil has shown outstanding results in treating infectious diarrhea in three significant studies:

  1. Gupta P and Birdi T 2015 titled Psidium guajava leaf extract prevents intestinal colonization of Citrobacter rodentium in the mouse model in the journal J Ayurveda Integritive Medicine.
  2. WB et al 2010 titled Screening of anti-diarrhea effective fractions from guava leaf in the journal Zhong Yao Cai.
  3. Gonçalves et al 2008 titled Antibacterial activity of GUAVA, Psidium guajava Linnaeus, leaf extracts on diarrhea-causing enteric bacteria isolated from Seabob shrimp, Xiphopenaeus kroyeri (Heller) titled Revista Instituto de Medicina Tropical Sao Paulo.

This method has been used in rural communities all over the world to treat gastrointestinal infections and illnesses and is successful in part because of the plant’s astringency.

There is not a definitive reason for why guava leaf can prevent and treat these issues, but it most likely has to do with guava’s antimicrobial and antibacterial capabilities according to study by OJEWOLE et al 2008 titled Antidiarrhoeal activity of Psidium guajava Linn. (Myrtaceae) leaf aqueous extract in rodents published in the journal J. Smooth Muscle Res.

3. Anti-Inflammatory

A study by Sen et al 2015 titled Flavonoid fraction of guava leaf extract attenuates lipopolysaccharide-induced inflammatory response via blocking of NF-κB signalling pathway in Labeo rohita macrophages published in the journal Fish Shellfish Immunolology , Guava leaf extract has anti-inflammatory qualities thanks to flavonoids (also an antioxidant) contained in the leaves

Inflammation is at the core of most illness and disease, and including foods and supplements that work as anti-inflammatories helps to keep body systems working properly.

4. Prevent Fatty Buildup in Arteries

Because of guava leaf’s anti-inflammatory and antioxidative qualities, it’s a strong fighter against atherogenesis (fatty deposits and degeneration of arteries). Study by Takahashi et al 2015 titled Inhibition of leukocyte-type 12-lipoxygenase by guava tea leaves prevents development of atherosclerosis published in the Science Direct revealed that The tea leaves inhibit an enzyme responsible for the onset of atherogenesis. This condition can lead to numerous other cardiovascular issues.

5. Antimicrobial and Antibacterial

Thanks to guava’s extensive flavonoids, guava leaves have proven to be antibacterial, antifungal and antimicrobial when up against a number of invaders. A study by Metwally et al 2010 titled Phytochemical investigation and antimicrobial activity of Psidium guajava L. leaves published in the journal Pharmacognosy Magazine explained that the traditional uses for guava leaf are valid and successful as treatment for illness such as cough , diarrhea, oral ulcers and inflamed gums.

Other studies have shown successful examples of antibacterial activity from the guava leaf in cases of bacteria-caused diarrhea, where antibiotics may not have been available . In folk medicine, guava leaves were even crushed and used on open wounds and ulcers.

Purchasing and Preparing Guava

Guava can be found at most major grocery stores in the fruit section. You will find that guava come in a variety of shapes and colors, ranging from round to oval, green to yellow, pink to dark red. It’s recommended guava be selected like a pear: firm but slightly squishy. They are typically sold when they are still very firm, so ripening at home for a few days after purchase may be necessary. Make sure to wash the outer skin of the guava if you plan to eat it.

The best part about guava is that along with it being available at your local grocery store, you can even grow a tree in a pot in your home. When grown from seed, the plant will produce fruit in as little as two years and continue for up to 40!

Guava can be prepared in many ways:

  • Juices
  • Candies
  • Dried snacks
  • Fruit bars
  • Alcohol
  • In a salad
  • Jams & jellies
  • Made into a rich paste and turned to cheese

Recipes made with guavas:

Potential Side Effects

There are no known side effects when guava fruit is eaten as a food. When used as medicine (in larger amounts), the only potential dangers are to pregnant or nursing women. There is not sufficient evidence to ensure safety.

Take Home

  • Guava can be eaten whole, as the seeds, skin and flesh are all edible. Each part contains essential nutrients for optimum health.
  • Eating the fruit, it can help boost the immune system, lower blood pressure, support digestion with its fiber content, combat cancer and provide an insane amount of antioxidants.
  • In tea and extract form made from the leaves, it can help treat and prevent diabetes, stave off GI discomfort and diarrhea, fight inflammation, and prevent fatty buildup in the arteries

Disclaimer: As pertains to all my articles: This work is intended for educational use only, it does not constitute Medical advice and should not be relied upon to advice clients on Medical matters.

Dr. Raphael Nyarkotey Obu, PhD, Is an honorary Professor of Naturopathic Medicine with research interest in Naturopathic & Holistic Urology, Vinnytsia State Pedagogical University, Ukraine. President of Nyarkotey College of Holistic Medicine- Formulator of FDA approved Men’s Formula for Prostate Health, Women’s Formula for wellness & Nyarkotey Tea for cardiovascular Health. 0241083423 or 0541234556


    2. Gutiérrez RM Mitchell S, Solis RV(2008) Psidium guajava: a review of its traditional uses, phytochemistry and pharmacology. J Ethnopharmacol.
    3. 11 Important Benefits Of Guava Fruit + Guava Nutrition Facts
    4. Top 10 healthy reasons to eat guavas this season!
    5. K. Ravi and P. Divyashree(2014) Psidium guajava: A review on its potential as an adjunct in treating periodontal disease. Pharmacognosy Review
    6. Singh et al 1993 . Can guava fruit intake decrease blood pressure and blood lipids? Published in journal of Human Hypertension