Oak: benefits, dosage, contraindications

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Oak is a slow-growing tree in the Fagaceae family, capable of reaching large dimensions. It is characterized by its great size and thick trunk, green lobed deciduous leaves, and fruits called acorns. It lives for at least 500 years in mixed forests of the Northern Hemisphere. The bark, buds, and leaves are used in therapeutics. Oak contains saponins, tannins, pectin, and triterpenic glycosides, including roburins, castalagin, vescalagin, and grandinin. Oak bark is used as a tea for arthritis, diarrhea, fatigue, to stimulate appetite, and improve digestion. In gemmotherapy, oak buds have regenerative and tonic effects on the adrenal glands. They are used particularly for general and sexual fatigue.

Other name(s) 

White oak

Scientific name(s)

Quercus pedunculata, Quercus robur, Quercus petraea, Quercus pubescens

Family or group: 

Plants

Active ingredients:

Saponins

Tannins

Pectin


Indications

Rating methodology

EFSA approval.

Several clinical trials (> 2) randomized controlled with double blind, including a significant number of patients (>100) with consistently positive outcomes for the indication.
Several clinical trials (> 2) randomized controlled with double blind, and including a significant number of patients (>100) with positive outcomes for the indication.
One or more randomized studies or multiple cohorts or epidemiological studies with positive outcomes for the indication.
Clinical studies exist but are uncontrolled, with conclusions that may be positive or contradictory.
Lack of clinical studies to date that can demonstrate the indication.


Fatigue
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Several preliminary clinical studies conducted on a patented Robuvit® oak bark extract (Quercus robur) show improvements in fatigue and oxidative stress markers. In another study, the same extract was examined. 70 women were divided into two groups: one received 300 mg/day of Robuvit® and the other a placebo, for 8 weeks. After 4 weeks, a significant improvement in general and mental health was observed in the Robuvit® group compared to the placebo. In gemmotherapy, oak is recommended for fatigue or overwork and during convalescence. The buds are said to have a regenerative and stimulating effect on the adrenal glands.

Posologie

posologieOral: buds, bark

posologie300 mg

formulationgemmotherapy, standardized extract


Sexual disorders
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Oak bud is known for its action on sexual disorders: as a stimulant, it can be used to combat male impotence, frigidity, and lack of libido (sexual asthenia).

Posologie

posologieOral: buds, bark

posologie300 mg

formulationgemmotherapy, standardized extract


Diarrhea
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For a long time, barks have been used as an astringent remedy for diarrhea, vomiting, bleeding... The EMA indicates that oak bark is used for the symptomatic treatment of mild diarrhea.

Posologie

posologieOral: bark

posologie560 mg

formulationtea/infusion, aqueous decoction, dry extract


Stomatitis
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The EMA indicates that oak bark is used for the symptomatic treatment of minor inflammations of the oral or skin mucosa.

Posologie

posologieOral: bark

posologie560 mg

formulationtea/infusion, aqueous decoction, dry extract


Hemorrhoids
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The EMA indicates that oak bark is used for the symptomatic relief of itching and burning associated with hemorrhoids.

Posologie

posologieSitz bath: bark

posologie560 mg

formulationtea/infusion, aqueous decoction, dry extract


Properties


Hormonal metabolism

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In gemmotherapy, buds are used as adrenal cortex stimulants. A patented oak wood extract from the species Quercus robur (Robuvit®) is obtained by water extraction. It contains a mixture of antioxidants, ellagitannins, roburins, and bioflavonoids. This extract works at the cellular level on mitochondria, thanks to its metabolite, Urolithin A, which activates mitophagy (degradation and recycling of mitochondria) for mitochondrial regeneration. It also has effects on muscle growth and protein synthesis, thanks to Urolithin B, and reduces oxidative stress by increasing the antioxidant capacity of blood plasma. Clinically, the use of Robuvit® has shown improvements in sleep, sports performance, reduction of chronic fatigue symptoms, mood enhancement, erectile function, and recovery after surgery.

Usages associés

Fatigue, Sexual disorders

Antioxidant

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Laboratory research suggests these antioxidant activities play a role in anti-inflammatory effects. In humans, the use of a specific oak wood extract (Robuvit) increases the total antioxidant capacity of blood, likely by boosting antioxidant enzyme activities. Lipid and protein oxidation is reduced. These antioxidant activities are believed to play a role in the diverse clinical effects observed in clinical research, including the reduction of edema, fatigue, and liver damage. The antioxidant effects of oak bark extract may also contribute to improved physical performance and increased energy in aging individuals. The antioxidant activity of oak leaves has also been demonstrated in laboratory models and may be superior to that of oak bark.


Anti-inflammatory

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Oak has cortisone-like action, used for gastrointestinal inflammations.

Usages associés

Diarrhea, Stomatitis, Hemorrhoids

Astringent

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The tannin content in oak bark promotes astringent properties.


Safety dosage

Adult from 18 years: 300 mg - 560 mg (dry extract)

Oral use of oak bark is safe for adults, for a duration of 3 to 4 days, especially in the treatment of diarrhea. Orally: - 3 g in 250 ml of water, 3 times a day. - 1 g of powdered capsules, 3 times a day. - Dry extract 140 mg; 4 times a day. For mouthwash: - Decoction 20 g per liter of water. For sitz bath: - 5 g per liter of water, bath duration 20 minutes.


Precautions

Child up to 18 years: avoid

Use in children and adolescents under 18 years is not recommended.

Pregnant woman: avoid

Due to insufficient data, use during pregnancy and breastfeeding is not recommended.

Breastfeeding woman: avoid

Due to insufficient data, use during pregnancy and breastfeeding is not recommended.

Liver disorders: avoid

Theoretically, oral use of white oak bark could worsen liver dysfunction.

Kidney insufficiency: avoid

Theoretically, oral use of white oak bark could worsen kidney disorders.