Pomegranate Tree - Nutritional Value, Influence on Health, Application and Contraindications

The pomegranate tree is one of two known species of plants from the pomegranate family (Latin: Punicaceae) and the order Myrtales. These small trees or shrubs reach a height of 3 to 7 meters and have opposite, single leaves and prickly branches. Their flowers are hermaphroditic, red, and highly intense [2]. The most recognizable species is the pomegranate tree (lat. Punica granatum), also known as the pomegranate tree or shrub. It probably originates from Iran, Afghanistan, and Central Asia [4]. Today, it is grown in many parts of the world, including the Mediterranean region, India, Malaysia, Southeast Asia, China, Japan, Russia, and the United States, especially in California and Arizona [4]. Depending on the location of cultivation, it can vary in terms of size, ripening time, juice volume, and content of other components. It grows without problems on poor soil, but the best soils are fertile, clayey, and rich in humus [4]. It tolerates a wide temperature range and is not sensitive to frost, even to frost up to minus 15 degrees Celsius. Pomegranate trees begin to bear fruit only after four years. The fruits reach full maturity in late autumn and can weigh up to about one kilogram. From such an amount, about 500 to 750 grams of juice can be obtained [4]. One tree or shrub can produce up to 50 kilograms of pomegranate. It is a product that is easily recognizable by its purple skin with irregular cracks. Inside it, in its chambers, there are up to 1300 cubic seeds [2]. The second insignificant species from an economic point of view and little known is Punica protopunica, which occurs only on the island of Socotra [2].

Since 2010, three independent research teams have been working on determining the nutritional value of pomegranates. The chemical composition of the fruit is dependent on many factors, such as the variety, climate, growing conditions, ripeness of the harvested crop, and the way in which it is stored. It has been found that pomegranate has a low calorie content, ranging between 65 kcal to a maximum of 78 kcal per 100 g of raw material. When it comes to macronutrients, carbohydrates predominate in pomegranates. There are 14.5 to 18.7 g in 100 g, while the protein content does not exceed 2 g and the fat content is about 1 g. Pomegranate is also a source of large amounts of dietary fiber, from 4 g to 5 g per 100 g. Pomegranate is also rich in many micronutrients, such as vitamin C, E, pantothenic acid, potassium, calcium, magnesium, and phosphorus [4]. The peel of the pomegranate makes up half of its weight. It contains many bioactive compounds that are important for human health, such as phenolic compounds, including flavonoids, ellagic acid, and proanthocyanidins. The hull, which makes up 40% of the fruit mass and the seeds, whose weight share does not exceed 10%, is the edible part of the pomegranate. In the chemical composition of the main component of the pomegranate that can be consumed, 85% is water. The rest are fructose, glucose, and pectins. The most important health-related component of the hull is organic acids, such as ascorbic acid, citric acid, and malic acid, as well as flavonoids and anthocyanins. Seeds are mainly a source of fats, including polyunsaturated fatty acids such as linoleic and linolenic acids. The fats contained in pomegranate seeds also include stearic acid, punicic acid, oleic acid, and palmitic acid. Pomegranate oil makes up almost 20% of the weight of the seeds. The remaining components of the seeds are proteins, sugars, dietary fiber, mineral compounds, vitamins, polyphenols, and genistein from the group of isoflavones [4]. Pomegranate juice and the fruit itself are sources of many bioactive compounds, such as anthocyanins, ellagic acid, gallic acid, caffeic acid, gallate epigallocatechin, quercetin, rutin, citric acid, malic acid, tartaric acid, fumaric acid, succinic acid, chlorogenic acid, p-coumaric acid, quinic acid, catechins, epicatechins, cyanidin glucoside, pelargonidin, and delphinidin [2,3]. Pomegranate also contains in its composition catechins, epicatechins, gallate epigallocatechin, flavan-3-ol, kaempferol, luteolin, naringin, pelargonidin, prodelphinidin, quercetin, rutin, hydroxybenzoic acid, ellagic acid, caffeic acid, chlorogenic acid, p-coumaric acid, quinic acid, punicalagin, corilagin, pedunculagin, telimagrandin, delphinidin, epigallocatechin, 3-O-glucoside of kaempferol, and 3-O-rhamnoside of kaempferol [1,5].

Pomegranate, due to its richness in vitamins, minerals, and bioactive compounds, has an exceptionally positive and varied impact on the human organism. It is particularly distinguished by its high antioxidant, cardioprotective, hypoglycemic, anticancer, and probiotic activity, which has been confirmed by numerous scientific studies over many years [4].

Due to its numerous properties and rich chemical composition, the pomegranate fruit has found use in various industries, especially in the food, leather, and cosmetic industries. Pomegranates are primarily used for preparing juices, wine, jellies, jams, jellies, dried kernels, as well as syrups and liqueurs [4]. Pomegranates are particularly known for the production of ponch and alcohol, especially in the Caucasus region [2]. The leaves and bark of the pomegranate tree are used for the production of safian, a fine leather, due to their high tannin content, which is used for the production of luxury shoes and handbags. Increasingly, it is also used for the upholstery of furniture and the creation of unique book covers. Surprisingly, the colors obtained from the shells of pomegranates are responsible for the beautiful colors of oriental rugs. These same dyes are also used to produce ink for tattooing. The intense shades obtained from the flowers of the pomegranate tree are also used for dyeing linen, cotton, silk, and wool [2]. In the cosmetics industry, pomegranates are an important component of many cosmetics due to their anti-inflammatory and rejuvenating effect on the skin. Studies on hairless guinea pigs have shown that extracts from these fruits reduce skin pigmentation exposed to UV radiation. In another experiment, it was found that polyphenols from pomegranate prevent skin aging caused by UVB radiation and inhibit the activity of peroxidase in connective tissue, showing an antioxidant effect [5]. The oil from the seeds of the pomegranate, which is rich in punicic acid from the omega-5 family, has a strong antioxidant effect. In addition, it is characterized by soothing and regenerative properties. The composition of this oil also includes polyunsaturated lipids, also known as vitamin F, which have a positive effect on the regeneration speed of the skin, its nutrition, hydration, and the feeling of refreshment [5]. Therefore, they are used for the treatment of sunburn and injuries, as well as in the treatment of rosacea.

Unfortunately, despite its numerous beneficial features, pomegranate cannot be consumed by individuals taking medications at any time of the day due to its significant impact on their metabolism. The significance of consuming juices from this exotic fruit is particularly emphasized here. Studies indicate that beverages made from tropical fruits, including pomegranate, inhibit the action of cytochrome P450, which plays a crucial role in the detoxification and metabolism of medications in the liver. Pomegranate is one of the strongest inhibitors of this enzyme, which can lead to an enhancement of the effect of medications such as statins used in the treatment of cholesterol. Other contraindications for the consumption of pomegranate by individuals taking medications include: excessive acidity, peptic ulcer, and inflammation of the gastric mucosa.

Both pomegranate and the juice derived from this fruit are currently not popular in the daily diets of the average Polish person. This is likely due to the low awareness of the valuable attributes of regular consumption of this fruit, both preventatively and therapeutically. Furthermore, pomegranate provides significant support in the treatment of both individuals with diagnosed cancer and those at increased risk. Pomegranates can be successfully utilized in patients with disrupted glycaemia or lipid profile – it should be emphasized, however, that consumption of this fruit does not substitute for conventional therapy. Particular attention should be paid by individuals with chronic diseases who take daily medication, to avoid potential interactions between pomegranate or its juice and the ingested medication, especially those containing statins in their composition. At least a 2-hour interval should be maintained between taking medication and consuming the described product.