QUINCE & QUINCE SEED - USES, BENEFITS, SIDE EFFECTS - NEWSHA

Common Name: Quince, Quince Seed

Scientific Name: Cydonia oblonga Mill.

History and Origin

Quince belongs to the Maloideae subfamily of the Rosaceae family, which includes apples and pears. ⁽¹⁾ The ancient Greeks and Romans considered quince as one of their favorite fruits, particularly for its medicinal qualities. It was cherished as a symbol of love, happiness, and prosperity. During the middle ages, the Arabs also valued this fruit very much, owing to its numerous medicinal virtues. ⁽²⁾

It is native to western Asia, and its origin is considered to be the Caucasus region including Armenia, Azerbaijan, Iran, southwestern Russia, and Turkmenistan. During ancient times, quince spread from its wild center of origin to the countries bordering the Himalaya Mountains to the east, and throughout Europe to the west. ⁽³⁾

Nowadays, this fruit tree grows widely in countries with moderate and subtropical climates. ⁽⁴⁾ Turkey is the largest producer followed by China, Iran, Argentina, and Morocco. ⁽⁵⁾ The medicinal parts are the fruit and seeds ⁽⁶⁾ (Behidana). ⁽⁷⁾

Quince Plant Structure

Quince is a small deciduous tree, growing up to 8 m high. ⁽⁷⁾ Leaves are ovate to oblong. ⁽⁵⁾ The flowers are white ⁽⁵⁾ or pink, perfumed, relatively large, ⁽⁶⁾ and having 5 petals.⁽⁵⁾

The fruits, which are pear or apple-shaped, are golden yellow in color, juicy, fragrant, sub-acid or sour in taste and contain many seeds, closely packed in two vertical rows, ⁽⁸⁾ in each of the five cavities in the center of the fruit. ⁽⁷⁾ The peel is covered with abundant hairs, which disappears with fruit ripening. ⁽⁸⁾

Quince seeds are black or red. ⁽⁷⁾ They possess a taste resembling that of bitter almonds, but fainter. ⁽⁹⁾ Quince seeds embody a mucinous material. Upon soaking the seeds in water, the material is extracted into water, forming mucilage. ⁽¹⁰⁾

Fig. 1 Fruit of Cydonia oblonga Fig. 2 Quince Seeds

Quince Health Benefits

Quince Fruit Health Benefits:

1. Improving Digestive System Function

Increase in gastric acid secretion and pepsin activity can lead to gastric mucous damage. ⁽¹¹⁾ Pepsin is the powerful enzyme in gastric juice that digests proteins.⁽¹²⁾

In 2017, a study was carried out to investigate the protective effects of quince aqueous extract and quince hydroalcoholic extract on gastric ulcers in rats. Peels of quince fruits were off, sliced, and finely powdered to prepare extracts. Fruit powder was soaked in water (for aqueous extract preparation) or ethanol/water (for hydroalcoholic extract preparation) for 72 h. It was observed that both hydroalcoholic and aqueous extracts were effective in reducing ulcer area and severity.

Researchers suggested that the protective effect of both extracts on gastric ulcers was done by decreasing the secretion of gastric acid and pepsin activity. Furthermore, quince extracts are rich in tannins, polyphenols, and pectin, which normally contains calcium ions. The ions cause protection in the gastric wall against acid and pepsin attacks by binding both pepsin and mucus. ⁽¹¹⁾

Also, in 2012, a study was carried out to investigate the effect of quince juice and quince hydroalcoholic extract on ulcerative colitis in rats. ⁽¹³⁾ (Ulcerative colitis is an inflammatory bowel disease (IBD) that causes inflammation and ulcers in the innermost lining of your large intestine (colon) and rectum. ⁽¹⁴⁾) The results showed that quince juice and quince hydroalcoholic extract were effective to diminish inflammation and ulcer in the large intestine (colon) and rectum in the animal model.

Researchers attributed this property of quince fruit to antioxidant and anti-inflammatory effects of its phenolic compounds (including chlorogenic acid which is the main phenolic component of the fruit, and flavonoids (rutin, quercetin and kaempferol)). In addition, its tannins can protect intestinal mucosal layers against chemical injuries and proteolytic enzymes. Also, pectin in the fruit has a protective effect against ulcerative colitis. ⁽¹³⁾

2. Improving Liver Function

Diabetes and as well as taking certain medicines can damage the liver. Increasing the serum activities of alanine aminotransferase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) may indicate hepatic injury.

In 2015, the hepatoprotective effect of aqueous extract of quince fruit was evaluated in diabetic rats. For aqueous extract preparation, dried fruits were decocted in water for 30 min. The extract was administered orally once daily for 6 consecutive weeks.

It was observed that treatment of diabetic rats with the extract of quince fruit could significantly reduce the activities of ALT, AST and ALP enzymes.

A possible explanation for the hepatoprotective effects of the extract is that this fruit may inhibit the liver damage induced by the antibiotic drug (streptozotocin). ⁽¹⁵⁾

3. Improving Respiratory Tract Function

In Europe, a combination of lemon juice and quince aqueous extract has been used traditionally for treating asthma and allergic rhinitis ^{(5, 16)} (also called hay fever, which is an allergic reaction to allergens such as pollen ⁽¹⁷⁾).

In a 2011 study, the anti-allergic effects of this combination were investigated. Finally, researchers found that it is effective in the treatment of allergic disorders. ⁽¹⁶⁾

4. Regulating Blood Glucose Levels

Diabetes mellitus is associated with complications in several different systems of the body. A 2015 study in this field indicated that aqueous extract of quince fruit can improve some of the symptoms associated with diabetes and possesses hypolipidemic, hepatoprotective, and renoprotective effects in diabetic rats. For aqueous extract preparation, dried fruits were decocted in water for 30 min. The extract was administered orally once daily for 6 consecutive weeks. The results of this study showed that the oral administration of the extract improved renal function in diabetic rats by reducing serum urea and creatinine levels as the markers of renal dysfunction. ⁽¹⁵⁾

5. Regulating Blood Pressure

In a 2014 study, it was demonstrated that aqueous and ethanol extracts of quince fruit have antihypertensive activity in renal hypertensive rats. 80 and 160 mg/kg aqueous or ethanol extracts of the fruit were given orally once daily for 8 weeks. Their effect was compared with 25 mg/kg captopril (a medication for treating high blood pressure). With the quince fruit extracts, the effect on blood pressure was notable after 4 weeks. At 8 weeks, blood pressure was similar to captopril.⁽¹⁸⁾

6. Regulating Blood Cholesterol Levels

In 2015, a study was conducted to investigate the effects of quince fruit flavonoids on the blood lipid in hyperlipidemic rats. Rats were treated with the flavonoids. After four weeks, serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL) and high-density lipoprotein cholesterol (HDL) were measured.

It was demonstrated that quince fruit flavonoids significantly reduced serum TC, TG, LDL and increased HDL. This result confirms the effectiveness of quince fruit in the prevention and treatment of hyperlipidemia. ⁽¹⁹⁾

7. Boosting Libido

Quince is regarded as a potent libido invigorator in traditional medicine.

In a 2014 study, the results showed that after oral administration of hydroalcoholic extract of quince fruit (for 28 days) libido and the mating performance of male rats increased remarkably.

The aphrodisiac potential of quince fruit may be due to flavonoids, glycosides, tannins, and phenolic compounds present in the extract. ⁽²⁰⁾

8. Anti-cancer

According to a 2018 study, quince fruit has high content of phenolic compounds and strong antioxidant capacity. Therefore, the use of quince fruit as source of antioxidant can be valuable. ⁽²¹⁾Also, according to a 2010 study, quince fruit (pulp, peel, and seed) has distinctive antiproliferative properties. ⁽²²⁾ Antiproliferative property means preventing or delaying the spread of cancer cells into surrounding tissues or other parts of the body. ⁽²³⁾

Quince Seeds Health Benefits:

1. Improving Respiratory Tract Function

During an asthma attack, the muscle wall of the airways contract and the lining of the airways become swollen and inflamed. ⁽²⁴⁾

In a 2013 study, the medicinal use of quince seeds in airways diseases was evaluated. For this purpose, the relaxant property of quince seeds extract was examined by its relaxant effect on precontracted smooth muscles [by carbachol and K⁺] of trachea isolated from a rabbit. ⁽²⁵⁾

Results showed that the extract of quince seeds relaxed carbachol and K⁺-induced contractions of isolated rabbit tracheal tissue, similar to the effect produced by verapamil ⁽²⁶⁾ (a drug for relaxing the muscles). These data validate the medicinal use of Cydonia oblonga in airways disorders like cough, bronchitis and asthma. ⁽²⁵⁾

2. Alleviating Peptic Ulcer Disease

In traditional Iranian medicine (TIM), several edible spices and fruits including quince and quince seeds are thought to have protective and healing effects on peptic ulcers (PU).

To support the claims of TIM about the efficacy of quince seeds in PU, in 2013, researchers investigated modern medical studies in this field.

According to the results of modern research, quince seeds can have shown their effectiveness on PU via two mechanisms of action including antioxidant and wound healing activities. ⁽²⁷⁾

3. Anti-Microbial

In a 2013 study, the antibacterial effect of aqueous extract obtained from quince seed on Enterobacter aerogenes bacteria (entroinfectious agent for diseases such as diarrhea) was investigated. The results showed that E.aerogenes was sensitive to the extract. Therefore, the aqueous extract can be useful in controlling of infections caused by E.aerogenes. ⁽²⁸⁾

What Are Quince Side Effects?

1. When taken by mouth (Oral drugs): Health risks or side effects following the proper administration of designated therapeutic dosages are not recorded. ⁽⁶⁾

2. Pregnancy and breast-feeding: There isn't enough reliable information to know if quince or quince seed is safe to use when pregnant or breast-feeding. Stay on the safe side and avoid it. ⁽²⁹⁾

Generally, every person may be allergic to certain herbs and spices. This sensitivity must be first diagnosed by the person and secondarily by the physician. However, these allergic reactions do not cause chronic or acute side effects, and after identifying the allergenic plant and removing it from the diet, allergy-related complications will be eliminated. No company or product can be aware of the allergic reactions of different bodies in advance. The body's incompatibility

Nutritional Information

According to a 2016 review study, the main nutritional composition of quince fruits in 100 g fresh weight includes energy: 176 kj, protein: 0.6g, acid: 0.9 g, carbohydrate: 9.1 g, water: 86.9 g, ash: 0.6 g and fiber: 1.9 g.

Mineral element contents in 100 g quince fruits include Na: 9.2 mg, K: 189 mg, Ca: 66 mg, Mg: 10 mg, Fe: 1.1 mg, P: 25 mg, Cu: 0.006 mg, Zn: 0.013 mg, and Mn: 0.002 mg.

The vitamin contents in 100 g fresh quince fruit include retinol (vitamin A₁): 5.5 μg, thiamine (vitamin B1): 30 μg, riboflavin (vitamin B₂): 30 μg, niacin (vitamin B3): 0.2 mg and ascorbic acid (Vitamin C): 13 mg. ⁽³⁰⁾

Quince Daily Dosage

Mix 1 tablespoon of quince seeds with 1 cup of water ⁽⁶⁾ and boil for 5-6 minutes to obtain a thick mucilage. Remove seeds and drink the liquid warm.

* Do not boil crushed or powdered quince seeds. Also, avoid chewing whole quince seeds.

Bioactive Compounds

- Several studies have shown that quince fruit is rich in polyphenols, organic acids, and amino acids. Quince polyphenols are mainly hydroxycinnamic acids (caffeoyl and coumaroyl derivatives), flavonols (quercetin and kaempferol derivatives), and, in minor proportion, flavanols (catechin and epicatechin). ⁽¹⁾

Also, in a study, phenolic compounds (including chlorogenic acid, which is the main phenolic component of the fruit, and flavonoids (rutin, quercetin and kaempferol)), tannins and pectin were introduced as active ingredients of quince fruit. ⁽¹³⁾

- According to a 2005 study, quince seeds contain both essential and nonessential amino acids and the three most abundant are glutamic and aspartic acids and asparagine. ⁽³¹⁾ Vitamin C and mucilage are also important active ingredients of quince seeds. ⁽⁶⁾

Quince seeds mucilage contains cellulose, water-soluble polysaccharides ⁽³²⁾ like pectin, ⁽³³⁾flavonoids, sterols, alkaloids, tannins, saponins, resin, phenol, and terpenoids. ⁽³⁴⁾

Best Time to Consume

Quince seeds mucilage may decrease how much oral drugs (medications taken by mouth) the body absorbs. Thus, it can decrease the effectiveness of the medication. So drink quince seed decoction at least one hour after medications you take by mouth. ⁽³⁵⁾

Possible Drug Interactions

We currently have no information for quince fruit or quince seed Interactions. ⁽²⁹⁾

Traditional Use

The seeds of Cydonia oblonga have been used traditionally in diarrhea, dysentery ⁽³⁶⁾ (an infection in your intestines that causes bloody diarrhea ⁽³⁷⁾), cough, sore throat and bronchitis, constipation and intestinal colic. ⁽³⁶⁾

(Intestinal colic manifests with a cramp-like pain that may occur when the gastrointestinal tract is blocked, preventing food and liquid from passing through the body. ⁽³⁸⁾)

Also, in Unani Medicine, quince and/or quince seed is used as anti phlegmatic, dry cough suppressant, anti-tuberculosis, exhilarant, heat suppressant, astringent, laxative, aphrodisiac, stomachic, heart and brain tonic. ⁽⁷⁾

Some Questions about Quince and Quince Seed

How do you make quince seed tea? / How do you eat quince seeds?

Mix 1 tablespoon of quince seeds with 1 cup of water ⁽⁶⁾ and boil for 5-6 minutes to obtain a thick mucilage. Remove seeds and drink the liquid warm.

Is quince good for Crohn's disease? / Is quince OK for ulcerative colitis?

According to a 2012 study, quince juice and quince hydroalcoholic extract are effective on ulcerative colitis, ⁽¹³⁾ which is an inflammatory bowel disease (IBD). ⁽¹⁴⁾ Researchers attributed this property of quince fruit to the antioxidant and anti-inflammatory effects of its phenolic compounds. In addition, its tannins and pectin have a protective effect against ulcerative colitis.⁽¹³⁾

Is quince good for cough? / Is quince good for sore throat?

In Europe, a combination of lemon juice and quince aqueous extract has been used traditionally for treating asthma and allergic rhinitis (hay fever). ^{(5, 16)} In a 2011 study, researchers found that it is effective in the treatment of allergic disorders. ⁽¹⁶⁾

How do you use quince seeds for a cough?

Quince seeds contain a high proportion of mucilage medicinally used as a demulcent in the treatment of asthma, bronchitis, sore throat, and cough. ⁽³⁹⁾Quince seeds extrude mucilage when soaked in water. ⁽³²⁾For more information, see the “How do you make quince seed tea?”.

Are quince seeds toxic or poisonous? / Are quince seeds safe?

The content of cyanogenic glycosides (mainly amygdalin) in the seeds of plants from the Rosaceae family is an important issue that must be taken into account. The potential toxicity of amygdalin results from the enzymatic degradation that occurs in the human digestive system, leading to the production of poisonous hydrogen cyanide (HCN). ⁽⁴⁰⁾

However, because quince mucilage is prepared from the whole seeds, the cyanogenic glycosides are credited with a slight toxicological relevance.

In addition, health risks or side effects following the proper administration of designated therapeutic dosages are not recorded. ⁽⁶⁾ In other words, the seeds are only toxic if eaten in large quantities. For more information about recommended daily dosage of quince seed, see the “Quince Daily Dosage” section.

What are quince fruit and quince seeds nutrition facts? / Is quince high in sugar?

The main nutritional composition of quince fruits in 100 g fresh weight include: energy (176 kj), protein (0.6g), acid (0.9 g), carbohydrate (9.1 g), water (86.9 g), ash (0.6 g) and fiber (1.9 g). Quince fruits also include mineral element (Na, K, Ca, Mg, Fe, P, Cu, Zn, and Mn) and vitamins (A1, B1, B2, B3 and C). ⁽³⁰⁾

Vitamin C and mucilage are also important active ingredients of quince seeds. ⁽⁶⁾

What are the benefits of quince seeds? / What are quince seeds used for?

Quince seeds have medicinal use in airway disorders like cough, bronchitis, and asthma. These valuable seeds have protective and healing effects on peptic ulcers (PU). Also, the antibacterial effect of quince seeds makes them an ideal treatment for infectious diseases such as diarrhea.

What are the health benefits of quince fruit?

Several studies have revealed that quince fruit is useful for improving the digestive system, liver, and respiratory tract functions, boosting libido, and regulating blood glucose, blood pressure, blood cholesterol and triglyceride levels. Quince fruit also has a high content of phenolic compounds. Therefore, the consumption of quince fruit as a source of antioxidants can be valuable.

For more information, see the “Quince Health Benefits” section.

Is quince safe to eat raw?

Usually, quince fruit is cooked or turned into jam. However, the fruit can be eaten raw. To eat a quince raw, you should cut very ripe fruit into thin slices.

Why do you have to cook quince before eating?

Due to their hardness and astringent taste, fruits are usually eaten after cooking. ^{(1, 8)}

How is quince seed used in skin care?

According to a study on rabbits, topical use of quince seed mucilage can speed up the injured skin healing process. In this study, the quince seeds were soaked in moderately warm water, and their mucilage was extracted. Quince seed mucilage was applied to the wound area twice daily for 13 days in wound healing cream (eucerin cream). Quince seed mucilage proved to accelerate wound healing more than eucerin cream without mucilage. ⁽⁴¹⁾

However, to know if quince seed mucilage is safe for applying to injured skin, please check with your healthcare provider before using quince seed mucilage.

Is quince good for diabetes?

According to a 2015 study, a decoction of dried quince fruit may have hypolipidemic, hepatoprotective, and renoprotective effects in diabetic. ⁽¹⁵⁾

Is quince good for kidneys?

According to a 2015 study, oral administration of a decoction of dried quince fruit may improve renal function by reducing serum urea and creatinine levels as the markers of renal dysfunction. ⁽¹⁵⁾

For this purpose, dried quince fruits were decocted in water for 30 min. The extract was administered orally once daily for 6 consecutive weeks.

Is quince good for liver?

Increasing the serum activities of alanine aminotransferase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) may indicate hepatic injury.

According to a 2015 study, oral administration of a decoction of dried quince fruit can significantly reduce the activities of ALT, AST, and ALP enzymes. ⁽¹⁵⁾