holding yellow pummelo at Trader Joe's

What Is a Pomelo? Health Benefits & Nutrition Facts

[toc]Did you know that the oranges, lemons, limes, and grapefruits you eat were artificially created?

They’re non-GMO, however, they weren’t naturally occurring fruits.

They’re hybrids that were created by humans through the careful crossing of citrus species. This took place over hundreds and in some cases, thousands of years.

The original species that most of today’s citrus fruits come from are:

  • Pommelos (Citrus maxima)
  • True mandarins (Citrus reticulata)
  • Citrons (Citrus medica)

Using these original ancestors, humans have created everything from the common orange to the exotic Buddha’s hand. There are a few species whose origin are natural, like the Australian finger lime, but most of the citrus fruits you find for sale at the supermarket have their history rooted in these three ancestors.

Given that modern citrus fruits were cultivated over many generations, it’s impossible to know exactly what took place during each cycle of cultivation. What scientists can confirm though is that based on their genetic profiles, they can estimate what percentage of the plant’s DNA came from each of those original three citrus fruits.

diagram showing genetic history of citrus fruits and how they are related
By HLHJ via Wikipedia [CC BY-SA 4.0]

What is a pomelo?

Pomelos are one of the three original citrus fruits which modern citrus varieties come from.  They’re native to southeastern Asia. The region spanning Malaysia to Indonesia is where they come from.

It’s the largest citrus fruit; 6 to 10 inches in diameter (15-25 cm) and weighing 2-4 lbs (1-2 kg). Small ones are the size of a softball. Large ones are as big as volleyball.

The color of the outside rind can range from a bright yellow to a pale green. The inside of this pith (skin) is lined with a white fibrous sponge-like substance.

peeling a pomelo

The pith is much thicker than that of oranges, grapefruits, and other common citrus varieties. It’s up to an inch thick.

What is the difference between a pomelo and a grapefruit?

Since the pomelo has undergone little cultivation, it maintains some of the more wild attributes; a thick pith and more fibrous threads covering the flesh. Its closest cousin is the grapefruit, which has been cultivated to have a thin pith and different flavor.

As reported by the Journal of the American Society of Horticultural Science, it has been confirmed that the DNA of grapefruit is a cross between the pomelo and sweet orange. (1)

Yet ironically, the tartness of a grapefruit overpowers the underlying sweetness. Even though it still has a lot of sugar.

Whether it’s the white, pink, or ruby-red grapefruit, all of the common varieties have been cultivated to be tangy, while the pomelo isn’t.

While the US, Canada, UK, and many other western nations prefer the grapefruit, in China, Indonesia, and Thailand it’s the opposite.

There is such thing as a pomelo grapefruit. The Oro Blanco (white gold) comes from crossing an acidless pomelo with a seedy white grapefruit. Its characteristics and flavor are closer to that of a true pomelo.

Can you eat the white part of pomelo?

Yes, but most people don’t eat the white part. It has the texture of a sponge and not much taste. Some people cook with the white parts, so it can absorb the flavors of sauces and spices. Eating it raw on its own is rarely done.

It’s the juicy flesh underneath the pith which is the prize.

What does a pomelo taste like?

pummelo sliced in halves

A fresh pomelo fruit tastes just like a grapefruit but without the sourness. They’re not as sweet as an orange or tangerine, but they’re not bitter or tart, either. It’s that right amount of sweetness; enough to be enjoyable, while not so much that you’re going to have a sugar crash.

After you cut and peel away the unruly white parts, the smooth texture of the fruit flesh is comparable to grapefruit. Most varieties will be less juicy.

The color of the outside skin doesn’t tell you what color the flesh is. The inside of a pomelo fruit can be snow white, a faint green, or a bright pink. Often times, the grocery store selling them won’t even know what lies beneath.

History

They’re called shaddock fruit because Captain Shaddock, who was commander of an East India ship, brought pomelo seeds to Barbados in 1638. Other names for it include variations of the spelling (pummelo, pomello) and the Hawaiian name, jabong.

Before ever making it to the Caribbean, they have a long history elsewhere.

A fruit called the Adam’s apple – a form of pomello – was documented as growing in the Holy Land around 1187 AD. Around that time, the Arabs brought it to Spain, which was its introduction to Europe. For more of the history, check out the Biology of Citrus.

Nutrition facts

Being that it’s rarely consumed here, the USDA only publishes what they call a “basic report” for the nutritional values of pummelo (that’s how they spell it). Here are the data points they provide…

Nutrition Facts
Serving Size: 1 cup of peeled fruit sections (190 g or 6.7 oz)
Calories 72
% Daily Value* % Daily Value
Total Fat 0.1 g 0% Thiamine (B1) 4%
Saturated Fat 0 g 0% Riboflavin (B2) 3%
Trans Fat 0 g 0% Niacin (B3) 2%
Sodium 2 mg 0% Vitamin B6 3%
Total Carbs. 18 g 6% Vitamin C 193%
Fiber 1.9 g 8% Calcium 1%
Protein 1.4 g Iron 1%
Phosphorus 3%
Potassium 12%
Magnesium 3%
*Percent Daily Values (DV) are based on a 2,000 calorie diet

Sugar content is not reported by the USDA. How many grams of sugar in a pomelo will be around 35 for a whole peeled fruit weighing 1.35 lbs (610g). One cup of the fruit sections will be 11 grams of sugar. This is based on what percentage of carbs are in the form of fructose, glucose, and sucrose in grapefruit. 60% of the carbs in a grapefruit are in the form of these sugars and it’s similar for pomelos. (2)

With 72 calories per cup, pomelo is lower in calories than many other citrus fruits. The same serving size of oranges is 85 calories, grapefruit are 97, and tangerines/Mandarin oranges are 104. That’s because these other citrus varieties have more carbs by weight.

Are pomelos good for you?

Large servings of any fruit at one time can be unhealthy due to sugar, but a moderate serving size is beneficial. With only 72 calories per cup, this superfood provides 193% of your daily value of vitamin C, 8% of fiber, 12% of potassium, and a reasonable 11g of sugar.

The best and healthiest way to eat them is raw, cut into sections or chunks. Juicing with pomello is possible but that will remove the fiber content, resulting in a higher glycemic index since the sugars will be digested faster.

Health benefits

The following have not all been proven, but scientific findings have suggested their possibility. More research is needed and therefore, this fruit and other parts of the plant should not be used for the treatment, prevention, or cure of any disease.

1. High in antioxidants

Being that one cup of fresh pomelo has almost double the daily value of ascorbic acid (vitamin C), it should come as no surprise that the fruit’s antioxidant activity, as measured using ORAC values, can rank quite high.

honey and pink pomelo fruits with green skin

Scientists in Thailand tested 6 different cultivars, which are pictured above. Their ORAC values ranged from 323 (for KT) to 5,281 (for TD). The latter is more antioxidants than conventional blueberries, when comparing equal weights of each. In addition to the vitamin C content, the main antioxidant contributors are gallic acid, hesperidin, naringin, and in the pink varieties, vitamin A.

While it’s not a perfect correlation, those with less pigment in their flesh tend to rank lower, while the yellow-green and pink pomelo rank higher.

Some people call the yellow-fleshed versions a honey pomelo. On average, those would be expected to contain less antioxidant content than the pinks, which contain vitamin A and other carotenoids. Those will be the healthiest type to eat. (3)

2. Low glycemic index

The glycemic index (GI) of fresh pomelo fruit has never been published. That requires at least 10 people to participate under a controlled study, which so far, has no one has undertaken.

However, researchers out of India did conduct a study using breads made with pomelo pulp in various concentrations. Their findings were:

“The pomelo incorporated bread had higher levels of resistant starch fractions (3.87-10.96%) with low predicted glycemic index (62.97-53.13%), despite their higher total starch (69.87-75.47%) content compared to control bread. Thus pomelo segments in the product formulations lowered the glycemic index probably by inhibiting carbohydrate hydrolyzing enzyme activity which could be attributed to naringin.”

In plain English, you may not be not digesting all the starches due to a special enzyme in the fruit. In moderation, this makes it an excellent choice for type 1 and 2 diabetics, and frankly, all of us. (4)

3. Peels may help protect brain

While the peels normally aren’t eaten due to their lack of flavor and tough texture, perhaps we should look at ways of incorporating them into our diet.

Nigerian researchers reported that in a dose-dependent manner, extracts of the shaddock (which is what they call it there) inhibited lipid (fat) peroxidation (oxidation) in the brains of rats caused by iron. (5)

People regularly use raw lemon peel zest in recipes. Why not try the same with this citrus rind?

4. Anti-aging and CVD risk

Oxidative damage to the lining of blood vessels (endothelial cells) plays a significant role in the development of cardiovascular disease (CVD). This is a broad category of diseases which includes heart attacks, ischemic strokes, atherosclerosis, congestive heart failure, arrhythmia, and heart valve problems.

Some studies have found that citrus consumption correlates with a lower risk of developing CVD and the antioxidants may be responsible for that, at least in part. (6)

A university out of Bangkok tested freeze-dried extracts of the fruit on cultured human umbilical vein endothelial cell (HUVECs).

Using well plates, they inflicted injuries (scratches) on these living cell cultures and then monitored how they healed with and without the extract.

charts showing blood vessel health with pomelo extract treatment

At a concentration of just 1000 µg/mL (0.1%), they observed significantly improved healing when treated with the pomelo extract. Even with 1/100th that amount (0.001%) there was still a big difference versus the untreated, which are represented by the black line.

The antioxidant activity (right chart) shows how fewer reactive oxygen species (ROS) were generated.

This led them to conclude the fruit may offer:

“…improved cell migration and hinder the onset of phenotypical aging…”

While this is only a lab study, it’s encouraging scientific evidence that pomelos are good for you beyond their basic nutrition. (7)

5. May lower blood pressure and cholesterol

No plants contain cholesterol, so that in and of itself makes this a healthy food choice over those which are animal-derived (they contain cholesterol).

In addition, there may be an anti-cholesterol benefit, as well as one for blood pressure.

In rodent research, it has been reported that pomelo and grapefruit juices inhibit the angiotensin-1-converting enzyme (ACE), which is a key regulator in blood pressure.

But wait, there’s more good news…

“Furthermore, administration of the juices to rats fed a high-cholesterol diet caused a significant reduction in plasma total cholesterol, triglyceride, and low-density lipoprotein-cholesterol levels and an increase in high-density lipoprotein-cholesterol levels.”

In short, it boosted HDL cholesterol (the good kind) while lowering LDL cholesterol (the bad kind) and triglyceride levels. (8)

This perk hasn’t been tested in humans, so it remains theoretical.

6. Anti-depressant effect seen with leaf extract

ripe pomelo growing on tree branch with leaves

While people normally don’t eat the leaves, perhaps findings like this may change that in the future.

By boiling the leaves and using the water-based extract left behind, scientists report antidepressant activity being observed in mice, based on multiple testing methods; locomotor activity test, modified forced swimming test, and tail suspension test. Those are all widely used tests for evaluating depression in rodents. (9)

The improvement in the modified forced swimming test was as good as the mice treated with imipramine (Tofranil), which is an antidepressant drug.

7. Anti-tumor activity seen in mice

Using a methonol (alcohol) based extract of the Citrus maxima leaves, scientists tested it on Swiss albino mice with tumors.

Using a daily dosage of 200 and 400 mg of extract per kg of body weight, the mice were treated for 10 days, at which time they were killed and dissected so their tumors could be studied. The results?

“Experimental design exhibits significant antitumor activity of the extract (MECM) in a dose dependent manner.”

That was based on their tumor volumes, cell counts, body weights, and other health parameters. (10)

There are only a couple pieces of research on the topic of pomelo fruit and cancer. It’s only lab experiments and it’s far too early to know if it’s helpful. Please do not use it for cancer or any disease. (11)

8. Essential oil has antibacterial properties

dropper with one drop of essential oilYou won’t find Doterra or other major brands selling it, but pomelo essential oil is for sale online. You can get it on Amazon.

While it should not be used for this purpose, Romanian researchers found that even tiny amounts inhibited bacterial biofilms of staphylococci and enterobacteriaceae strains on soft contact lenses.

More research is needed before it can be used for any medical purpose or food sanitization, but perhaps it wouldn’t hurt to add a little of the essential oil to your household cleaners, such as shower sprays and the like. It’s a delightful smelling citrus scent that might offer a bacteria-killing benefit to boot. (12)

Side effects

There are potential health risks and disadvantages to be aware of:

Interference with medications

Drug interactions for pomelo fruit and juice include cholesterol lowering statins like Lipitor, calcium-channel blockers for high blood pressure like Cardizem and Plendil, immunosuppressants, sedatives, erectile dysfunction (ED) drugs like Viagra and Cialis, antihistamines like Allegra, and some neurological/psychiatric medications. (13)

Pomelo and grapefruit contain furanocoumarins. These compounds block the action of an enzyme called P-450 3A4 (CYP3A4). This enzyme plays an important role in breaking down certain medications and when its activity is suppressed, it can result in too much of the drug being in your body since it’s not being metabolized normally. According to Harvard Health:

“One glass of grapefruit juice, or eating half a grapefruit, is enough to suppress CYP3A4 activity by half, and the effect lasts up to 24 hours. The accumulation of active statin in the bloodstream could cause muscle or liver problems.”

A similar effect would be expected with pomelo. This is why you should consult your doctor prior to eating if you are on any prescription medications, particularly statins. Some cholesterol medications like Crestor and Pravachol aren’t affected by pomelo or grapefruit. (14)

May amplify effect of caffeine

man holding paper cup of coffee with plastic lidThe same enzyme that slows down the metabolism of certain cholesterol medications and other drugs may do the same for caffeine. There is conflicting data on this, as at least one study involving 10 people found no variation in the half-life of caffeine when drinking grapefruit. (15)

If it really does have an effect on caffeine metabolism, then your java jolt may last longer than it otherwise would. For many that would be a benefit, but not if it lingers into the evening hours and interferes with your sleep.

Allergic reactions

Unlike gluten and tree nuts, having a pomelo allergy is extremely rare. In the US government’s PubMed database, there is only one patient case study of phytophotodermatitis. That’s a reaction where the skin is hypersensitive to UV light. (16)

Eating grapefruit makes lips tingle, or causes a burning sensation, in some individuals. This is not always a sign of an allergy. It may just be the acidic juices irritating the mucous membranes.

If you have a tingly tongue or lips from pomelo or grapefruit, it may be a good idea to avoid until you can determine whether or not you’re allergic. There is an IgE allergy test available.

Increased blood sugar

Even though it has lower sugar content than many other citrus fruits, pomelo and particularly its juice will still contain a high amount.

Side effects of eating too much pomelo at one time will be a blood sugar spike. For non-diabetic individuals, this is unhealthy but not dangerous.

Pregnancy and breastfeeding safety

Is it safe to pomelo during pregnancy?

There are two schools of thought on this.

Because it’s high in vitamin C and nutritious, many expecting moms and healthcare practitioners believe that regular consumption of pomelo or grapefruit is good during pregnancy and breastfeeding.

Others argue that there is not enough clinical data to determine whether or not consuming high amounts is safe while pregnant. There is no evidence to suggest it’s dangerous, however there may be unknown risks lurking.

The limited amount of data on this fruit is not unusual, as many pregnancy superfoods don’t have controlled human studies to back their safety.

The takeaway?

peeled pomelo

Due to its thick rind and limited availability in many parts of the world, choosing pomelo versus grapefruit may seem like it’s not worth the fuss. While both are healthy, the pomelo offers a subtly sweet flavor – which is arguably better – and a lower calorie count. It’s a rewarding choice, even with the added legwork.