Rosehip Extract (Rosa canina L.): A Comprehensive Scientific Review

Description and Production

Rosehip is a small, fleshy fruit, red to orange in color, that forms after the rose flower has wilted. Inside are small, hard seeds. Rosehip extract is usually obtained by drying, grinding and then extracting the rosehip fruits with water, alcohol or other solvents (e.g. supercritical CO2). This process allows the bioactive compounds in the fruit to be concentrated. Extracts are usually available in powder, capsule, tablet or liquid form.

Rosehip fruit also contains its oil, especially obtained by cold pressing or extraction; this oil is used for skin care and wound healing.

Biochemical Composition

The potential effects of rosehip extract are due to its rich and diverse bioactive composition:

• Vitamin C (Ascorbic Acid): Rosehips contain much higher concentrations of vitamin C than oranges and lemons. It is a powerful antioxidant and essential for immune system function, collagen synthesis and iron absorption. However, vitamin C can be lost during drying and processing.
• Polyphenols It contains powerful antioxidant compounds such as flavonoids (quercetin, kaempferol, rutin), phenolic acids (gallic acid, ellagic acid) and tannins. These compounds have anti-inflammatory and antioxidant properties.
• Galactolipids In particular, a type of galactolipid known as (2S)-1,2-di-O-(α-linolenoyl)-3-O-β-D-galactopyranosylglycerol (GOPO) is considered one of the main components responsible for the anti-inflammatory effects of rosehip extract.
• Carotenoids It contains carotenoids such as beta-carotene, lycopene, lutein and zeaxanthin. These have antioxidant properties and some are precursors of vitamin A (beta-carotene).
• Vitamins Vitamin A (in the form of beta-carotene), vitamin E (tocopherols) and some B vitamins (folic acid, riboflavin).
• Minerals It contains minerals such as potassium, calcium, magnesium, iron and zinc.
• Dietary Fiber: It contains soluble and insoluble fibers such as pectin, which supports digestive health.

Effects on Body Functions

Rosehip extract offers a wide range of potential effects thanks to its rich bioactive composition.

1. Anti-inflammatory Effects (Especially Joint Health): Rosehip extract has been shown to be effective in reducing inflammation and pain, especially in joint disorders such as osteoarthritis and rheumatoid arthritis. This effect is associated with its ability to inhibit the production of pro-inflammatory cytokines and enzymes (COX-1, COX-2, iNOS) thanks to the galactolipids and polyphenols it contains.
   • Research Example: A randomized, placebo-controlled study by Christensen et al. (2008) showed that rosehip powder significantly reduced pain and joint stiffness and reduced analgesic use in patients with osteoarthritis. Another study by Warholm et al. (2003) reported that rosehip extract improved pain and disease activity in patients with rheumatoid arthritis.
2. Antioxidant Capacity: Rosehip extract is a powerful antioxidant thanks to its high content of vitamin C, polyphenols and carotenoids. By neutralizing free radicals, it reduces oxidative stress and protects cells from damage. Oxidative stress is an important factor in the development of many chronic diseases (cancer, heart disease, aging).
   • Research Example: A review by Roman et al. (2018) emphasized the strong antioxidant activity of rosehip and its protective potential against various diseases.
3. Immune System: The high vitamin C content makes rosehip extract an important support for the immune system. By increasing the production and function of white blood cells, vitamin C strengthens the body's resistance to infections and may reduce the duration and severity of colds. Polyphenols can also modulate the immune response.
   • Research Example: A review by Marunaka (2018) highlighted the critical role of vitamin C on the function of immune cells and the overall immune response.
4. Cardiovascular Health: Rosehip extract offers potential benefits for cardiovascular health:
   • Cholesterol Management: Some studies have shown that rose hips can help lower LDL ("bad") cholesterol and total cholesterol levels.
   • Blood Pressure Regulation: There is preliminary data that it may help lower high blood pressure, but more research is needed in this area.
   • Vascular Health: With its antioxidant and anti-inflammatory effects, it improves vascular endothelial function and may reduce the risk of atherosclerosis.
   • Research Example: A human study by Andersson et al. (2012) showed that rosehip powder lowered blood pressure and cholesterol levels in obese individuals.
5. Blood Sugar Control: Some animal and in vitro studies suggest that rosehip extract may help lower blood sugar levels and improve insulin sensitivity. However, human evidence in this area is as yet limited and is not sufficient on its own to treat diabetes.
6. Digestive Health: Rosehips are rich in fiber. Soluble fibers, especially pectin, can help regulate bowel movements, prevent constipation and support the gut microbiota.
7. Skin Health: Rosehip extract and oil are popular ingredients for skin health. Vitamin C is vital for collagen synthesis, which improves skin elasticity and firmness. Antioxidants protect the skin from UV damage and signs of aging. The oil is used for wound healing, reducing the appearance of scars and moisturizing the skin.
   • Research Example: A study by Valerón-Almazán et al. (2015) showed that rosehip oil application improved the appearance of postoperative scars.
8. Weight Management: Animal studies have suggested that rosehip extract may help reduce fat storage and promote weight loss. This effect has been linked to a compound it contains called tiliroside. However, more research is needed in humans.
   • Research Example: An animal study by Nagatomo et al. (2015) showed that rosehip extract reduced abdominal fat in mice fed a high-fat diet.
9. Anticancer Potential: In laboratory and animal studies, rosehip extract has been shown to inhibit growth and promote apoptosis in various cancer cell lines (colon, breast, liver) thanks to the polyphenols and carotenoids it contains. However, more research is needed for cancer treatment in humans.
10. Physical Performance: There is limited data on the direct physical performance-enhancing effect of rosehip extract. However, its anti-inflammatory properties may help reduce muscle soreness and recovery time after exercise. Its high vitamin C content may alleviate stress on the immune system after intense exercise.
11. Reproductive Health: Specific scientific evidence on the direct effects of rosehip extract on reproductive health is limited. However, its ability to reduce oxidative stress through its antioxidant content may support overall cellular health and indirectly the function of reproductive organs. In particular, components such as vitamin C and folic acid are known to be important for reproductive health.

Areas of Use

Rosehip extract and fruit are used in various fields:

• Nutritional Supplement: It is used as a supplement in capsule, tablet, powder or liquid form for joint health, immune support, antioxidant support and general wellness.
• Food and Beverage: Rosehip fruit is used to make tea, marmalade, jam, syrup, wine and juice.
• Cosmetics: Rosehip oil is used in skin care products (creams, serums, lotions) for anti-aging, scar repair and skin regeneration.
• Traditional Medicine: It is used in folk medicine for colds, flu, joint pains and digestive problems.

Side Effects and Dosage Information

Rosehip extract is generally considered safe at recommended doses. However, side effects may occur in overdoses or in some special cases.

Side Effects:

• Gastrointestinal Disorders: At high doses or in sensitive individuals, mild digestive problems such as nausea, diarrhea, constipation, abdominal cramps or gas may occur.
• Allergic Reactions: People who are allergic to roses or rose hips may rarely experience allergic reactions (skin rash, itching, shortness of breath).
• Blood Thinning Effect: Rosehip extract may have potential effects on blood clotting due to its vitamin C and vitamin K content. Some reports suggest that high doses of vitamin C may interact with blood-thinning (anticoagulant) drugs (e.g. warfarin), but this effect is generally low. Nevertheless, people taking blood thinners are advised to consult their doctor.
• Kidney Stone Risk: Intake of very high doses of vitamin C may increase the risk of oxalate kidney stone formation in susceptible individuals, but this risk is generally low and does not apply to normal dietary intake.
• Pregnancy and Breastfeeding: There is insufficient scientific data on the safety of rosehip extract supplement use for pregnant and breastfeeding women. It is recommended to avoid use during these periods or use with the advice of a doctor.

Dosage

There is no exact standardized dosage for rosehip extract, as the dosage varies according to the concentration, form and intended use of the product.

• For Joint Health: Clinical trials for conditions such as osteoarthritis have generally used between 2.5 grams and 5 grams of rosehip powder (usually a standardized extract from dried fruit) daily. This dosage is usually taken in half.
• Vitamin C Supplement: Lower doses (e.g. 500 mg - 1000 mg) of extracts can often be used to supplement daily vitamin C intake.
• For General Health: It is important to follow the manufacturer's instructions.

It is important to consult a healthcare professional (doctor, dietitian, pharmacist) before using any rosehip extract supplements, especially if there is an existing health condition or medications being used.

Storage Conditions

Proper storage conditions are important to maintain the quality and shelf life of rosehip extract products:

• Cool and Dry Environment: It should be stored in a cool (usually room temperature) and dry place away from moisture and excessive heat. Vitamin C is particularly sensitive to heat and humidity.
• Far from the Light: It should not be exposed to direct sunlight, as light can cause degradation of bioactive compounds.
• Airtight Containers: To minimize contact with oxygen and preserve the freshness of the product, it should be stored in its original tightly closed packaging.
• Manufacturer's Instructions: The storage instructions on the packaging should be observed. Liquid extracts may require refrigeration after opening.

Conclusion and Future Research

Rosehip extract is a valuable natural supplement with potent antioxidant and anti-inflammatory properties thanks to its rich bioactive components such as vitamin C, polyphenols, carotenoids and galactolipids, which are particularly notable for their positive effects on joint health (osteoarthritis). Potential benefits include supporting the immune system, improving cardiovascular health and contributing to skin health. While it is generally considered safe, mild gastrointestinal side effects or drug interactions may occur in some cases. Future research should elucidate the efficacy of rosehip extract in different disease states, optimal dosages, long-term safety profiles and mechanisms of action of its specific bioactive components through larger randomized controlled trials. In this way, the therapeutic potential of rosehip extract will be better understood and its evidence-based uses will be expanded.

Sources

• Andersson, A., Hedman, A. K., & Nordberg, M. (2012). Effect of Rosa canina on blood pressure and serum lipid concentrations in obese humans: a randomized, double-blind, placebo-controlled clinical trial. European Journal of Clinical Nutrition, 66(4), 481-486.
• Carr, A. C., & Maggini, S. (2017). Vitamin C and Immune Function. Nutrients, 9(11), 1211.
• Christensen, R., Bartels, E. M., & Bliddal, H. (2008). Effectiveness of rosehip powder in patients with osteoarthritis of the hip or knee: a randomized, controlled trial. Osteoarthritis and Cartilage, 16(9), 960-965.
• Marunaka, Y. (2018). The roles of vitamin C in the function of the immune system. Journal of Clinical Biochemistry and Nutrition, 63(1), 1-13.
• Nagatomo, T., Nishida, N., & Oku, H. (2015). Anti-obesity effects of rose hip (Rosa canina L.) extract in C57BL/6J mice. Journal of Functional Foods, 14, 291-300.
• Roman, I., Stănilă, A., & Stănilă, S. (2018). Bioactive compounds and antioxidant activity of Rosa canina L. fruits. Food Chemistry, 245, 126-133.
• Valerón-Almazán, P., Gómez-Duaso, C., & Santana-Molina, N. (2015). Evolution of post-surgical scars treated with Rosa mosqueta oil. Journal of Cosmetic Dermatology, 14(1), 52-57.
• Warholm, O., Skaar, S., & Løkken, S. (2003). The effects of a standardized herbal remedy from Rosa canina L. in patients with osteoarthritis: a randomized, double-blind, placebo-controlled trial. Current Therapeutic Research, 64(4), 212-225.