Blackcurrant: Benefits, Uses and Precautions

Dr. Boris Wydoff

Blackcurrant is best known for its high vitamin C content. The berries are used fresh, dried and processed, and are also added to vitamin-rich teas. The leaves are harvested separately: in traditional herbal medicine, they are used to prepare decoctions and are included in herbal blends.

Practical uses depend on which part of the plant is used. The berries are suitable for everyday eating, while the leaves are used as herbal material, with safety restrictions taken into account. There is a specific recipe for a vitamin tea made with rose hips and blackcurrants: steep 2 teaspoons of the mixture in 2 cups of boiling water for 1 hour, then strain. Drink 1/2 cup 3–4 times a day.

Below, we'll look at the differences between the berries and leaves, how to harvest, dry and prepare them properly, and when it is better to avoid using preparations made from the leaves.

What Do Blackcurrant Berries and Leaves Contain?

Blackcurrant berries are valued primarily for their vitamin content. Herbal medicine reference books list ascorbic acid (vitamin C), carotene, vitamins E, B5, B1, B2 and K. The fruit also contains nicotinic acid, folic acid, vitamin P, sugars, organic acids and pectin.

One distinctive feature of blackcurrants is their high vitamin C content. One reference book states that, in this respect, they are surpassed only by rose hips and Far Eastern kiwi berries. Compared with red currants, blackcurrants contain 6–10 times more vitamin C.

Another feature of the berries is the absence of the enzyme ascorbinase. This helps preserve vitamin C during processing. That is why blackcurrants are used not only fresh but also dried, added to drinks and preserved for later use.

The leaves have a different chemical composition. They contain vitamin C, essential oil and other substances. This is why blackcurrant leaves are considered a medicinal herbal material in their own right. The composition of the berries cannot automatically be applied to infusions, decoctions and other preparations made from the leaves.

Blackcurrant: Benefits of the Berries and Leaves

The main nutritional value of blackcurrants comes from the vitamin content of their berries. They can be eaten on their own, added to the diet fresh or dried, and used to prepare drinks and vitamin-rich teas.

Pectins, organic acids and sugars add to the nutritional composition of the fruit. Herbal medicine reference books classify blackcurrants as a vitamin-rich plant material. This explains their traditional use in nutrition, but it does not mean that the berries can treat diseases on their own.

The leaves are used for different purposes. Herbal guides describe decoctions made from dried leaves as traditional diuretic and diaphoretic remedies. Blackcurrant leaves are also included in vitamin-rich herbal blends. Older descriptions mention a tincture made from the leaves that was used as a laxative.

It is important to distinguish traditional use from proven therapeutic effects. The fact that a plant is mentioned in a herbal medicine reference book does not, by itself, prove that it is effective for treating a particular condition.

For everyday nutrition, the berries are the more practical choice. If you intend to use the leaves as medicinal herbal material, you need to consider the form of the preparation, its composition and its safety restrictions. The European Medicines Agency (EMA) monograph concerns medicinal products made specifically from blackcurrant leaves, not all products derived from the plant.

How to Use Blackcurrant Berries in Your Diet

The berries can be eaten fresh, dried or processed. Naturopathy books recommend eating them raw whenever possible, but also describe stewing and baking.

Dried berries allow you to use your harvested blackcurrants throughout the year. You can add them to drinks and vitamin blends. In Dr. Boris Wydoff's books, blackcurrants are also mentioned among the dried fruits suitable for eating. His practical recommendation when choosing these products is to opt for dried fruit that has not been chemically treated.

When preparing berries at home, you can follow a few simple principles:

• Choose fully ripe berries for drying.
• Spread the berries in a thin layer before drying.
• Dry them outdoors in the shade, in an attic or in a dehydrator.
• For dehydrators, the reference book specifies a temperature of 50–60 °C.
• Store the finished dried berries in a dry place, separately from other plants.

The doctor's books also point out that homemade fruit and berry preserves are best prepared without excessive sugar or unwanted preservatives. This helps prevent a berry product from turning into an overly sweet dessert.

In addition to berries and leaves, older reference books also contain information about blackcurrant buds. They were collected in early spring and preserved in alcohol for use in the food industry because of their pleasant aroma. However, this is a separate way of using the plant and is unrelated to making ordinary vitamin tea.

How to Brew Blackcurrant Berries

One recipe described in herbal reference books is a vitamin tea made with rose hips and blackcurrants.

Vitamin Tea Recipe:

• Take equal parts rose hips and blackcurrants.
• Steep 2 teaspoons of the herbal mixture in 2 cups of boiling water.
• Leave the drink to infuse for 1 hour.
• Strain after infusing.
• Add sugar to taste, if desired.

The recommended serving described in the reference book is 1/2 cup 3–4 times a day.

Blackcurrants also appear in other vitamin-rich combinations. For example, one herbal blend combines rose hips, rowan berries and blackcurrants. In these recipes, the plant ingredients are used as sources of vitamins.

Do not confuse this berry drink with medicinal preparations made from the leaves. These require different preparation methods and have their own safety restrictions. The recipe above is specifically for berries and rose hips.

Can You Brew Blackcurrant Leaves?

Yes, the leaves have traditionally been used to prepare herbal drinks and vitamin-rich blends. Reference books describe a decoction made from dried leaves that was traditionally used as a diuretic and diaphoretic remedy.

However, an ordinary homemade tea and a medicinal preparation made from the leaves are not necessarily the same thing. The modern EMA safety requirements apply to medicinal products made from blackcurrant leaves. They cannot automatically be extended to fresh or dried berries.

When choosing a ready-made product, check which part of the plant it contains. The packaging may list leaves, berries or buds. These are different types of herbal material, so products bearing the same plant name should not be considered interchangeable.

If you plan to use a preparation made from the leaves regularly, especially if you have a chronic condition or take medication, it is best to discuss this with your doctor or pharmacist.

When and How to Harvest Blackcurrant Berries and Leaves

Herbal reference books specify different harvesting periods for the plant's medicinal parts.

Harvest the leaves in June–July. Choose the middle leaves, leaving the uppermost and lowest ones on the bush. This harvesting method helps avoid damaging the bush's fruit production.

Harvest the berries in July–August, once they are fully ripe. Remove the berries without their stalks.

There are several ways to dry the berries. Spread them in a thin layer in an attic or outdoors in the shade. You can also use a dehydrator, maintaining a temperature of 50–60 °C.

Dry the leaves outdoors in the shade. Once dried, the herbal material should retain the plant's characteristic features. The reference book describes the berries as having a faint, pleasant aroma and a sour, slightly astringent taste.

How to Tell Blackcurrants Apart from Similar Plants

When gathering berries yourself, you should never rely on their black color alone. Reference books describe several features that help distinguish blackcurrants from blueberries and black elderberries.

Blackcurrants are round, black berries measuring up to 10–12 mm. Their surface has visible glandular dots, and a dried flower remnant remains at the top. The berries have a distinctive fragrant smell.

Blueberries are smaller, measuring around 5–6 mm. They have a bluish coating and a circular rim at the top. Black elderberries are also usually smaller, measuring around 5–7 mm, with a circular rim at the top.

When identifying a plant, it is important to consider several features together: size, surface, the structure of the top and smell. Black color alone does not confirm that you are looking at a blackcurrant.

Blackcurrant is a shrub with palmately lobed leaves. It is found both in cultivation and growing wild. Reference books mention thickets along river and stream banks, where the shrub grows alongside other wild plants.

The berries and leaves are used for medicinal purposes and are listed in reference books as *Fructus et Folium Ribis nigri*. The herbal material is collected from both wild and cultivated bushes.

How to Check the Quality of Dried Herbal Material

Proper drying is only one part of harvesting. Selecting good-quality berries and leaves is just as important.

Older standards took into account over-dried and greenish berries, stalks, parts of other plants and mineral impurities. For leaves, the permitted amount of brown and blackened specimens was regulated separately.

The following moisture limits are specified for medicinal herbal material:

• Berries — no more than 18%.
• Leaves — no more than 14%.

The standards also take into account the amount of damaged, discolored, foreign and other plant parts.

The practical meaning of these requirements is simple: choose uniform herbal material for harvesting, do not mix good-quality berries with spoiled ones, and make sure the dried plant parts remain dry. It is best to store the harvested leaves and berries separately, without mixing them with other plants.

How to Find Blackcurrants Abroad

If you need blackcurrants specifically, or their leaves for herbal medicine, it is useful to know their local names:

• USA: black currant or blackcurrant; leaves — blackcurrant leaf.
• Germany: Schwarze Johannisbeere; leaves — Schwarze Johannisbeerblätter.
• France: cassis; leaves — feuilles de cassis.
• Latin name: *Ribes nigrum*.

Products available for sale include loose dried leaves and tea bags, tinctures, liquid leaf extracts and capsules. Dried berries, berry capsules and bud extracts are also sold separately.

When buying, do not rely on the label "blackcurrant" alone. Check exactly which part of the plant is included in the product. Berry products are not a substitute for leaf preparations: the European herbal monograph applies specifically to the leaves.

You can look for these products in herb and health food stores, tea shops and online. In Germany, they are also available in pharmacies, while in France you can find them in pharmacies and herboristeries.

Before buying, check the following:

• Whether the name *Ribes nigrum* is listed.
• Which part of the plant is used: leaves, berries or buds.
• Whether the product contains a single ingredient or is an artificially flavored blend.
• Whether it is labeled as a medicinal product, herbal tea or supplement.
• Whether the organic status is actually stated or certified.

The rules governing these products vary from country to country. In the USA, dietary supplements do not receive prior approval from the FDA. In the EU, recognition of the traditional use of blackcurrant leaves does not mean that every tea containing blackcurrants automatically qualifies as a medicinal product.

Blackcurrant: Benefits, Risks, Contraindications and Precautions

When assessing the benefits and possible risks of blackcurrants, the first thing to distinguish is eating the berries as food from using the leaves medicinally. Different recommendations apply to these products. Current EMA information concerns medicinal products made from blackcurrant leaves. The main contraindication is hypersensitivity to the plant or to a specific preparation.

When using leaf preparations for urinary tract health, you need to take into account conditions in which a doctor recommends limiting fluid intake. The EMA monograph lists severe heart or kidney disease among these conditions. In such cases, you should not use an herbal remedy on your own to increase urine production.

No confirmed medicinal interactions have been reported for leaf preparations. However, no specific interaction studies have been conducted. Therefore, the absence of reported cases does not prove that combining these products with any medication is safe.

A theoretical possibility has been described that blackcurrant seed oil may enhance the effects of anticoagulants such as warfarin. This is not considered a clinically proven interaction. Nevertheless, if you take anticoagulants or other medication, you should discuss the use of herbal supplements with your doctor or pharmacist beforehand.

The safety of medicinal use of blackcurrant leaves during pregnancy and breastfeeding has not been established. The EMA does not recommend using these preparations during these periods.

Blackcurrant leaf preparations are also not recommended for children under 18 because of insufficient data. This restriction applies to medicinal products made from the leaves, not to ordinary berries eaten as food.

The EMA does not list any characteristic side effects for leaf preparations. However, one isolated case of an allergic reaction after consuming blackcurrants has been described. One juice study reported temporary digestive upset, loose stools and increased urination.

There is insufficient information about toxicity and overdose. Therefore, the absence of known overdose cases should not be interpreted as proof that large doses or prolonged use of herbal preparations are safe.

When to See a Doctor

When choosing between ordinary berries and a medicinal preparation made from the leaves, it is important to consider your health and any medications you take. You should seek medical advice in the following situations:

• Allergic reaction. If signs of intolerance appear, stop eating the product or using the herbal preparation. A severe reaction requires medical attention.
• Pregnancy and breastfeeding. The EMA does not recommend leaf preparations during these periods because their safety has not been established. Discuss the use of herbal remedies with your doctor.
• Heart or kidney disease. If you have a condition that requires limiting fluid intake, do not take leaf preparations on your own for their diuretic effect.
• Taking anticoagulants or other medications. Before using herbal supplements, tell your doctor what they contain. Particular care is needed if you take warfarin.
• Use in children. Medicinal preparations made from blackcurrant leaves are not recommended for children under 18 because of insufficient safety data.
• Unusual reactions after consumption. If you experience digestive upset, loose stools or other unwanted symptoms, stop using the product and discuss the situation with a healthcare professional.

It is especially important not to try to treat urinary problems on your own with infusions or decoctions. Traditional use of a plant does not replace diagnosis or prescribed treatment. If you have a chronic heart or kidney condition, any remedy that affects urine production must be discussed with your doctor.

Boris Wydoff — naturopath and author, Ph.D. in nutrition. For over fifty years I have helped people restore health through nutrition, cleansing and the power of the mind — in Europe, America and Asia. About the author →

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