By Dr. Mercola
Mostly everyone in the U.S. has heard of a guava. Many have never tasted one, however, with all the apples, bananas and grapes available. But like virtually every other plant-based food, besides being delicious, this one has its own set of health qualities, and they’re quite impressive.
From the Myrtle family, guavas are common as shade trees, because they can grow to more than 30 feet high in South and Central America, indicating they like a warm climate. In Florida, where they’re more like 20 feet high, it’s advised that growth be curtailed because they can be invasive.
Guava trees are grown in Malaysia, Vietnam, Hawaii, Peru, Mexico, China, India and the extreme Southern U.S. They can have a single trunk or several to create a canopy, with flowers that look like a tiny, white firework explosion, and oval or teardrop-shaped leaves.
With a different name in every port (such as “amrood” in India), the exterior of the pale green, pink or white, round or oval fruits (considered berries by botanists) depends on the variety.
Inside, they’re generally one of the same colors, with small, edible brown seeds. The taste can be sweet to tart, similar to both a pear and a strawberry.
Just keep in mind 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.
Guavas are used in desserts and smoothies, as well as sauces and savory dishes, but what’s added determines how good they are for you. Prepared so they’re both tasty and healthy, they may impart dramatic improvement in a number of diseases and disorders.
Nutrients in Guavas Improve Immunity
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.
While that’s impressive, it’s the vitamin C that outstrips the others to a staggering 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.2
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.3
Traditional uses for guava over centuries included alleviating pain from toothaches and canker sores4 and to help wounds heal when the juice is applied topically. Guavas were said to treat epilepsy and convulsions by making them less frequent.
Guavas Help Improve Skin, Fight Coughs and Colds
The astringents in guavas, particularly the fruits that are not quite ripe, can treat acne and smooth the texture of your skin. This benefit comes through both eating them and rinsing your skin with an emulsion of the pulp, juice and leaves, which serves to tighten, tone and detoxify.5
In fact, studies show guavas work even better for this purpose than the leading lotions, creams and potions. Guavas can also help prevent wrinkles and slow other signs of aging, while removing dead skin cells and brightening your complexion.6
It’s predominantly vitamins A, B and C together that pass along these benefits, along with potassium, as all of the above have antioxidant properties. The vitamin C combined with biotin also helps remedy hair loss.
Vitamin C is one reason traditional treatments for coughs and colds in Mexico, South America and India relied heavily on guavas; however, it’s important to note that it was the juice from immature guavas, not the ripe fruit, because ripe guava is said to make respiratory and cold problems worse.
Not-quite-ripe guavas relieve symptoms such as sore throat while reducing mucus in the respiratory tract, and also help prevent microbial activity from spreading germs.
Fiber: 1 of the Most Important Guava Ingredients
Nutrition Data7 notes that the fiber contained in guavas is 36 percent of the RDA, which means it’s more adept at moving waste through your colon than most other foods. This is important for staving off bowel trouble, such as constipation and even colon cancer.
Guavas have been useful as a folk medicine to treat both diarrhea and dysentery. Astringents contained in raw guavas, as well as their leaves, make your gums feel “tighter” and your mouth fresher. This same effect takes place in your bowels due to alkaline content, which is both anti-bacterial and disinfectant.
Dysentery, which involves microbial growth, is inhibited while excess mucus is eradicated from your intestines. The vitamin C in guavas, as well as potassium and carotenoids, support the digestive system and may be useful for improving hemorrhoids and symptoms of gastroenteritis.
At the same time, constipation can also take a back seat when you eat guavas, in part because of laxatives in the seeds, whether they’re chewed or eaten whole.
The seeds are responsible for some of the most advantageous health benefits. Both the seeds and skin contain carotenoids, glycosides and other phenolic and flavonoid elements.
You may have heard that “death starts in the colon.” That’s because constipation is linked to more than 70 different ailments, so getting rid of waste quickly is critical. Fiber also helps your body retain water, improving bowel movements by helping to flush everything through.
Guavas also help your body by regulating your metabolism and aiding in the absorption of all those minerals and vitamins.
Fiber in Guavas Can Positively Affect Your Blood Pressure and Heart Health
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.8
A study in India 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.”9
Heart health is another benefit of eating this tropical fruit, and in several ways. Antioxidants play an important part, as they zap free radicals that can cause oxidative stress and damage.
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.11
Fiber in Guavas: Linked to Lowering Blood Sugar
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.12
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.”13
Guava Consumption and Cancer Prevention
If anything can be proven to be a dramatic game changer in a plant-based food, its effect on cancer will do it. Not wanting to disappoint, 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.15 Science Direct also mentions apoptosis in gastric cancer cell proliferation.16
Other Health Problems That Guavas May Help Improve
All the other nutrients in this exotic fruit certainly don’t go to waste. Your body uses them to fight disease and help you in numerous ways:
- Thyroid — Copper, another mineral found in abundance in guavas, has the ability to regulate your thyroid metabolism in two ways: production and absorption. It helps regulate hormones throughout your body and optimizes the function of all the rest of your organs, as well.
- Eyesight — Vitamin A, or retinol, one of the most prominent nutrients in guavas, is known for its ability to improve eyesight, and in several different ways. Cataracts, macular degeneration and other maladies affecting your vision have been shown to improve, and, amazingly, this nutrient may even reverse damage that’s already been done.
- Scurvy — This “scourge of sailors” was once largely eradicated, but there’s been a resurgence in recent years. Vitamin C is the only cure. Luckily, the vitamin C in guavas eclipses even that of most citrus fruits. Guavas contain around 125 milligrams (mg), while oranges have 51, grapefruits have 38 and lemons around 31, Nutrition Data reports.17
- Brain health — Vitamin B3 (also known as niacin) and vitamin B6 (aka pyridoxine) help improve the function of the nerves of your brain, which in turn helps increase blood flow and may stimulate cognitive function, even for things like staying on task.
- Weight loss — The roughage in fiber is one of the reasons why guavas are good for anyone wanting to slim down. They’re also very filling, which may translate to eating less, and contain less sugar in comparison to fruits like apples and grapes.18
Painful Menstrual Cramps Relieved by Eating Guavas
Dysmenorrhea is the medical term for the painful menstrual cramps women can experience during their period, a problem that affects more than a few. But studies show guava consumption can help relieve the pain.
In one study, 197 women with this problem were given 6 mg of guava leaf extract every day, which helped reduce the pain even more than conventional treatments.19 Researchers determined that pain relief comes about via the “spasmolytic” or spasm-lowering effect the extract has on the uterus.20