Grapefruits and Their Effects: Nutrition Facts, Health Benefits, Types, and More

White And Red Grapefruits

The grapefruit ( Citrus paradisi ) is the fruit of the grapefruit tree that grows in subtropical countries. Like oranges, mandarins, and clementines, it belongs to the rhombus family. The sweet and sour citrus fruit is available in two varieties: the white grapefruit, whose flesh is light yellow, and the red grapefruit, whose flesh is pink to red.

The grapefruit got its name because the fruits grow close together on the tree, similar to grapes. Other names are Adam’s apple or paradise apple, which is indicated by the Latin name Citrus paradisi.

The Difference Between Grapefruit, Grapefruit, and Pomelo

Colloquially, the grapefruit is also called grapefruit. Contrary to popular belief, grapefruit is not the same as a grapefruit. Instead, the grapefruit is a cross between grapefruit ( Citrus maxima ) and orange.

While the grapefruit is round and has a light yellow-orange skin, grapefruits are more pear-shaped or flattened and have yellow-green skin.

Also different from grapefruit is pomelo – a cross between grapefruit and grapefruit. The pomelo, however, is not a separate species but is counted as a grapefruit. It has yellow to pink pulp and a green-yellow skin, so it looks more like grapefruit than grapefruit. The name is also a bit confusing, as pomelo means grapefruit in English and grapefruit in French.

It is believed that grapefruit was first discovered in Barbados in 1750. Later it came to Florida, where the main plantations of the USA are located next to California and Texas to this day. The grapefruit is now grown in almost all subtropical areas of the world.

Grapefruits – The Nutritional Values, Vitamins, and Minerals

Fresh grapefruit consists of around 86% water and is very low in calories (50 kcal per 100 g). It is particularly rich in Vitamin C . Below you will find the nutritional values, vitamins, and minerals per 100 g. For orientation: A grapefruit weighs on average about 270 g ( 2 ).

Nutritional Values

Some people might be tempted to sweeten the grapefruit with sugar if it tastes too bitter. However, 100 g grapefruit already contains around 2.9 mg glucose (grape sugar) and 2.5 mg fructose (fruit sugar). The sugar contained in fruit and vegetables is not harmful, but industrially produced sugar is.

Grapefruit and Lycopene

Lycopene is a secondary plant substance that gives fruits and vegetables their red color, such as tomatoes, watermelons, and red grapefruits. Red grapefruits contain approx. 3.4 mg lycopene per 100 g.

For comparison: tomatoes contain between 0.9 and 4.2 mg lycopene per 100 g. Lycopene is one of the carotenoids. It has an antioxidant, anti-cancer, and preventive effect on cardiovascular diseases.

Lycopene is particularly well known in connection with prostate cancer. However, science disagrees about how and whether lycopene can help with prostate cancer, as the results are contrary.

Based on a review from 2016, Chinese scientists explained that the study results differed so often because the studies were structured so differently that they could not be compared with one another.

Research from Asia and Oceania, for example, showed that lycopene protects against prostate cancer, while studies from other regions of the world have not been able to confirm this. In western countries, the risk of prostate cancer is higher than in Asian countries, which could also play a role.

In a new study from 2020, American researchers examined the data of around 28,000 men. Questionnaires showed how often the men consumed tomato products – because tomatoes are one of the foods richest in lycopene.

It was found that the consumption of cooked tomato products such as B. Tomato sauce may reduce the risk of prostate cancer. If lycopene is heated, its bioavailability increases, which is why processed tomato products are more effective with regard to lycopene.

However, an earlier test-tube study showed that raw red grapefruit also contains relevant amounts of lycopene to inhibit the growth of prostate cancer tumors.

Lose Weight With The Grapefruit

Traditionally, the paradise apples have long been said to help you lose weight, which is why numerous grapefruit diets are offered on the Internet. What is the truth of the claim that grapefruits are supposed to be a “fat burner”?

Mexican scientists have summarized the research results on the influence of plant-based foods on weight in a review. The grapefruit was also examined:

Several studies in rats and one in humans have confirmed that the consumption of grapefruit helps with obesity and also lowers the cholesterol level and thereby the risk factors for cardiovascular diseases.

How To Lowering Blood Sugar Levels

In one of the studies, eating half a grapefruit before each meal for 3 months resulted in a weight loss of 1.6 kg in overweight individuals.

Exactly how consuming grapefruit leads to weight loss is not yet clear. An obvious possibility would of course be that eating a grapefruit before each meal is simply filling, which means that you then consume fewer calories.

However, one study also described the possibility that grapefruit has a positive effect on fat metabolism (lipid metabolism) by breaking down fatty acids. However, the substances in grapefruit that could make this possible have not yet been adequately researched. Secondary plant substances such as B. lycopene, naringin, or furocoumarins (more on this later) can be involved.

Another theory is that the fiber pectin is at least partially responsible for the positive influence on weight, as it decreases appetite, stimulates digestion, and stimulates gastric juices. Pectin is also found in other fruits, with citrus fruits having a comparatively high pectin content – especially in the peel and smaller amounts in the skins and pulp.

In the peel of citrus fruits, the pectin content is around 34%, in the pulp of grapefruit around 3.14% (for comparison: in apples, it is between 0.14 and 0.96%).

Grapefruits lower blood sugar levels

In addition to their positive effect on weight, grapefruits also naturally lower blood sugar levels. Naringin is said to be responsible for this. Naringin is a flavonoid, a phytochemical that is also found in grapefruit and pomelos. The bitter substance also gives these fruits their bitter taste.

Grapefruits For Diabetes

The study mentioned above showed that eating half a grapefruit before each meal helps with obesity and lowers blood sugar levels, which means that less insulin is produced. Participants’ insulin levels fell within two hours of each meal.

The grapefruit is therefore considered to be a fruit that can reduce the risk of diabetes. But even with existing diabetes, the grapefruit can be wonderfully integrated into the menu.

However, there can be a difference between grapefruit and diabetes medicines, such as B. the active ingredient metformin, interactions occur (further information below in the section “Interactions between the grapefruit and medication”). So if you are already taking medication, grapefruit is often no longer an option as a vital substance-rich component of your daily diet.

Grapefruits Could Be Used For Various Diseases

Researchers assume that, among other things, the naringin contained in grapefruit is responsible for the many positive properties of health. In addition to the health benefits mentioned above, tests in test tubes showed anti-inflammatory and anti-cancer effects.

The researchers also found that grapefruit could help with oxidative stress, bone regeneration, and diseases of the central nervous system such as Alzheimer’s and epilepsy.

The research results so far are very promising – unfortunately, there are no studies that have been carried out on the human organism.

The Effects of Grapefruit Seed Extract

Grapefruit seed extract – made from the ground and peel of grapefruit – is also attracting scientific interest. Various studies show that grapefruit seed extract is an effective remedy against viruses, bacteria, and fungi.

Grapefruit seed extract can be used externally, but can also be taken diluted with water. For flu and colds, for example, you can slowly increase the dose from 1 to 3 drops per day up to a dose of 3 to 15 drops taken three times a day.

Interactions Between The Grapefruit and Medication

Again and again, warnings are given against grapefruit and grapefruit juice, because they can interfere with some drugs, such as the birth control pill, cholesterol-lowering drugs (statins such as Lovastatin), and antihypertensive drugs or heart medication (calcium channel blockers such as amlodipine).

The interaction varies from drug to drug: Grapefruits can increase or decrease the effect, increase the risk of side effects and even intensify some drugs so enormously that they become toxic. If the effect is weakened, the desired effect of the drug does not materialize, which can lead to a flare-up of the respective symptoms.

This is due, among other things, to the furocoumarins, secondary plant substances that inhibit a certain enzyme in the body, which in turn breaks down active pharmaceutical ingredients in the body. This breakdown function is included in the dosage – if the enzyme is now inhibited, it can no longer break down the drugs as usual, which can lead to an overdose.

Interactions With Grapefruit in At Least 85 Drugs

In a review, Canadian researchers identified a total of 85 drugs that regularly interact with grapefruit. The results were published in the Canadian Medical Association Journal in 2013. These include antidepressants, blood thinners, and cancer drugs.

You can find a list of medicinal substances that interact with grapefruit under the previous link. The mode of action of the furocoumarins is also described in more detail there.

So if you are taking one of these medications, check the package insert for information on interacting with the grapefruit or ask your doctor or pharmacist and, if in doubt, do not consume grapefruit, grapefruit juice, or multivitamin juices containing grapefruit.

The interactions are also influenced by the amount of grapefruit or grapefruit juice consumed. For some drugs, one grapefruit was sufficient, for others, interactions only occurred through regular consumption of grapefruit or grapefruit juice.

For example, in the case of felodipine, an active ingredient that lowers blood pressure, the consumption of a single grapefruit led to three times higher concentrations of an active ingredient in the blood, which can then lead to blood pressure that is too low.

Grapefruits During Pregnancy and Breastfeeding

If you do not take any medication during pregnancy, grapefruit and grapefruit juice are safe. If you are taking medication, you should read the package insert and ask your doctor.

This question is a little more difficult when it comes to breastfeeding. It can be read again and again that the mother should not consume citrus fruits while breastfeeding, as too much acid in the baby’s stool could lead to a sore bottom. However, there is no scientific evidence for this, and not every baby reacts in the same way to different foods.

If you are concerned, you could be careful not to eat large amounts of citrus fruit when you start breastfeeding and see how your baby reacts to it first. However, it does not make sense to completely avoid citrus fruits from the start, as infants can also get sore buttocks because of the diaper brand, skincare products, or for other reasons.

In addition, your baby knows your eating habits from the long period of pregnancy, so that it might miss regular citrus fruit consumption if you suddenly stop after giving birth.

Grapefruits For Gout

Anyone who suffers from gout will find information on the Internet that gout patients should better avoid grapefruit – often without justification.

In gout, too much uric acid builds up in the blood, which can lead to the formation of tiny uric acid crystals that are now deposited in the joints and cause pain. Uric acid is formed when the body breaks down so-called purines, which is why foods low in purines are advised in gout.

However, 100 g of grapefruit contains just 5 mg of purines, while 100 g of chicken wings contains 53 mg of purines. So it cannot be the reason why gout patients are not given grapefruit.

Presumably one warns against the grapefruit with gout because one assumes that gout patients always take medication, e.g. B. the gout drug colchicine. The effect of colchicine, however, is enhanced by grapefruit, which could be dangerous, since colchicine is already considered to be rich in side effects.

It is best to try to treat gout with holistic measures so that you can do without medication in the future. Because then you can enjoy grapefruits again as you wish. With the right diet, for example, it is possible to naturally lower uric acid levels. Further information can be found under the previous link.

Who Shouldn’t Eat Grapefruit

In a nutshell, you should be careful when consuming grapefruit if:

1. You are taking medication. However, it can be assumed that other medicinal products can also interact with the grapefruit, even if nothing is mentioned in the package insert.
2. Even with other citrus fruits, such as B. bitter oranges (often in orange jam), grapefruit, and limes, interactions are possible, which is why caution should be exercised when consuming them. In a study from 2018, researchers also found that drug interactions can also occur with orange and apple juice, albeit to a lesser extent than with grapefruit. The researchers assume that interactions cannot be ruled out when eating fresh oranges and apples, although this has not yet been investigated in more detail. It is, therefore, best to ask your doctor or pharmacist for any medication and whether there could be any interactions with your diet.
3.  You are taking birth control pills.
4.  Your child gets a sore bottom while breastfeeding. Then go without citrus fruits for the time being to find out if that’s the trigger.
5.  You suffer from histamine intolerance, as grapefruits are considered to be rich in histamine.
6.  You are fructose intolerant. Compared to other citrus fruits like tangerine, grapefruit contains a relatively high amount of fructose (2.5 mg per 100 g compared to 1.3 mg for the tangerine).

Everyone else can incorporate grapefruit into their diet with a clear conscience and benefit from the healthy properties of citrus fruit.

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Buy Grapefruit: Organic or Not

The Lower Saxony State Office for Consumer Protection and Food Safety has investigated 2016 Grapefruit samples for residues of pesticides, including two samples from organic farming. Of the total of 24 samples, 21 had residues.

A sample from Spain even exceeded the maximum level and should not have been sold at all. Tests were carried out on 20 different pesticide active ingredients.

In contrast, the two biosamples showed no residues at all. One of the biosamples came from Israel, the other could not be assigned because the country of origin was not specified. The grapefruits sold in Europe come mainly from Spain, Cyprus, and Israel and are available all year round.

When buying grapefruits, look for organic quality. You can tell whether the fruit is ripe when the skin gives way slightly to pressure.

Grapefruits From The Glass or From The Can

Grapefruits in a jar – for example as jam – or in a can unfortunately no longer have the same healthy properties as they are heated (pasteurized) to preserve them. Vitamin C, Vitamin B1, and B5, for example, are heat-sensitive vitamins and when pasteurizing the food is raised to 60 to 100 degrees to kill bacteria.

Vitamins E and K as well as minerals and the secondary plant substance lycopene, on the other hand, are not sensitive to heat. Naringin also only degrades from a temperature of 100 degrees.

This is How Grapefruits Are Sored Properly

Grapefruits like it cool and dry: They can be kept for up to two weeks at a room temperature of around 20 degrees. If they are stored at 10 to 15 degrees, they can even keep them for several months.

This is How Grapefruits Are Processed

Grapefruits are very easy to process. Of course, it also depends on what you intend to do with it:

Cut Grapefruits

If you just want to enjoy the grapefruit unprocessed, halve it in the middle and then cut the individual segments that have grown together along with the white skins. There are even specially curved grapefruit knives for this. You can then simply spoon out the individual pieces. In the end, you can squeeze out the rest of the grapefruit juice and drink it either diluted with other fruit juices or straight.

Peel The Grapefruit

If you want to process the grapefruit further, peel the grapefruit-like orange: cut off the two ends and cut the remaining peel about six times from top to bottom. Then simply peel off the individual strips.

Of course, you can also cut the peel directly with a knife – but then more of the pulp will be lost. In return, there is less of the white skin left that you would otherwise have to uncoil if you don’t want to eat them.

Fillet the grapefruit

Once you have peeled the delicious fruit, simply cut out the fillets along the white skin. Be sure to collect the grapefruit juice in a bowl because it would be a shame not to drink it. The fillets can then be used wonderfully in salads, for example in a fruity avocado salad.

This is How Grapefruits Are Frozen

Grapefruits can also be frozen, although a fresh grapefruit tastes much better and can be kept for a long time even without freezing (see above “Storing grapefruits correctly”). In addition, the consistency can change when frozen.

If you still want to freeze the paradise apples, there are different options: Either you squeeze out the grapefruit and only freeze the juice, or you cut the fruit into slices, put them in a small container or a freezer bag, and freeze them in this way.

You can also freeze the whole fruit in one piece. To do this, wash them thoroughly, pat them dry, put them in a freezer bag and force the air out. It can then be kept for several months in the freezer.

Perhaps you would prefer to grow your own grapefruit instead and harvest it fresh?

A Grapefruit Tree as a Container Plant

Planting an orange tree in a tub on the balcony is not uncommon in our latitudes. You can take care of a grapefruit tree in the same way. The decisive factor in whether you can harvest the fruits is the location: It should be sunny and warm (preferably over 20 degrees).

The grapefruit tree is ideally placed in a winter garden or greenhouse. Because it can stay there for the winter. If your grapefruit tree is on the balcony, on the other hand, you have to find suitable winter quarters for it, so that you can enjoy it for the next year as well, because it does not tolerate frost. Ideally, it winters indoors in a bright, unheated location at 5 to 10 degrees.

Recipes With Grapefruit

If you now feel like incorporating the healthy citrus fruit into your diet more often, here are some suggestions:

1. Grapefruit juice is incredibly refreshing. If the pure juice tastes too sour for you, you can also mix it with other freshly squeezed fruit juices, such as orange juice, or add it to your smoothie.
2. Delicious salads can be made from grapefruit fillets.
3. Grapefruit fillets also taste wonderful in dessert, e.g. B. as a hearty grapefruit cake or in a delicious fruit salad.
4. For breakfast, you could spoon half a grapefruit and drink the rest of the grapefruit juice.
5. Add the grapefruit to your muesli in the morning for a delicious kick of freshness.
6. It might sound strange, but the grapefruit is delicious on the grill too – give it a try!