Royal Jelly: A Comprehensive Scientific Review

Description and Production

Royal jelly is a creamy white, gel-like substance with a sour and slightly spicy taste, produced by young (5-15 days old) worker bees from glands in their heads. In the hive, it is used for the first 3 days of queen larvae and for the entire life of the queen bee. Royal jelly is produced using special beekeeping techniques; it is obtained by encouraging worker bees to produce royal jelly and then collecting it from special honeycomb cells where the queen bee larvae feed.

Biochemical Composition

The biochemical composition of royal jelly is quite complex and unique. The composition can vary according to factors such as bee breed, flower source, geography and storage conditions. In general, royal jelly contains the following main components:

• Su (%50-70): It makes up the bulk of royal jelly.
• Proteinler (%12-15): The most important proteins are a family known as Major Royal Jelly Proteins (MRJPs) (MRJP1 to MRJP9). Among these, MRJP1 (also known as Royalactin) in particular is the main protein responsible for the development of the queen bee. Royal jelly also contains various enzymes and immunoglobulin-like proteins.
• Şekerler (%10-12): Simple sugars such as fructose and glucose, disaccharides (sucrose) and oligosaccharides.
• Fatty Acids (%3-6): The most important and most characteristic fatty acid 10-hydroxy-2-desenoic acid (10-HDA)is. 10-HDA is considered one of the main components responsible for the biological activity of royal jelly and has antimicrobial, anti-inflammatory and anti-tumor properties. Other fatty acids include 10-hydroxy-2-decanoic acid, palmitic acid and oleic acid.
• Vitamins It is particularly rich in B group vitamins (B1, B2, B3, B5, B6, B7, B9 and B12). Vitamin B5 (pantothenic acid) and vitamin B7 (biotin) are present in high concentrations. It may also contain trace amounts of vitamins C, D and E.
• Minerals It contains important minerals such as potassium, calcium, sodium, zinc, iron, copper, manganese and selenium.
• Amino Acids It contains all essential amino acids and various non-essential amino acids.
• Sterols Some sterols similar to plant sterols can be found.
• Hormone-Like Substances: Trace amounts of acetylcholine and some hormone-like substances may be present, but their direct relationship with human hormones is limited.

Effects on the Body

The rich biochemical composition of royal jelly offers a variety of supportive benefits. Recent academic research shows promising results, particularly in the following areas:

1. Effects on the Immune System: Royal jelly has immune modulating effects. Thanks to its proteins (MRJPs), 10-HDA and other bioactive components, it can increase the activity of immune cells (lymphocytes, macrophages), support antibody production and strengthen the body's resistance to infections.
   • Research Example: An in vitro study (Majtan et al., 2011) showed that royal jelly can regulate the production of nitric oxide (NO) and pro-inflammatory cytokines (TNF-α, IL-6) in macrophages. Another study (Fan et al., 2013) suggested that royal jelly enhances the immune response in animal models and may modulate allergic reactions.
2. Anti-inflammatory Effects: Royal jelly may reduce inflammation through several mechanisms. 10-HDA and some peptides can inhibit the production of pro-inflammatory cytokines and chemical mediators.
   • Research Example: In in vitro and animal studies, royal jelly has been shown to suppress inflammatory enzymes such as cyclooxygenase-2 (COX-2) and nitric oxide synthase (iNOS) (Sugiyama et al., 2012). This indicates its potential to contribute to the management of chronic inflammatory conditions such as rheumatoid arthritis.
3. Cardiovascular Health: It is thought that royal jelly may support cardiovascular health by regulating cholesterol levels, balancing blood pressure and protecting vascular health with its antioxidant effect.
   • Research Example: Some clinical studies have shown that royal jelly supplementation can lower total cholesterol and LDL (bad) cholesterol levels (Guo et al., 2018). This effect is attributed to the peptides and fatty acids in royal jelly.
4. Antioxidant Effects: Royal jelly has powerful antioxidant properties thanks to its vitamins (especially B vitamins), minerals and phenolic compounds. By neutralizing free radicals, it protects cells from oxidative damage and reduces the risk of chronic diseases.
   • Research Example: Laboratory studies have shown that royal jelly inhibits lipid peroxidation and increases the activity of antioxidant enzymes (Jamnik et al., 2017).
5. Physical Performance and Anti-fatigue Effects: Royal jelly can improve physical performance and reduce fatigue by supporting energy metabolism thanks to its rich nutrients, especially proteins, amino acids and B group vitamins.
   • Research Example: Some studies in animal models have shown that royal jelly supplementation increases endurance and reduces post-exercise fatigue (Mizoguchi et al., 2008). More research is needed on its effects on sports performance in humans.
6. Reproductive Health: Royal jelly has traditionally been used to enhance fertility. It may show potential benefits on both male and female reproductive health.
   • Women's Reproductive Health: It can support hormonal balance, improve egg quality and relieve menopausal symptoms.
   • Research Example: In a study of postmenopausal women, royal jelly supplementation was found to reduce menopausal symptoms (hot flashes, sleep disorders) and improve quality of life (Asama et al., 2018).
   • Male Reproductive Health: It can improve sperm quality, motility and count.
   • Research Example: Some animal studies have shown that royal jelly supplementation improves testosterone levels and sperm parameters (El-Hossary et al., 2015). More extensive studies in humans are needed.
7. Skin Health and Anti-aging: Royal jelly can help delay the signs of aging by increasing collagen production, improving skin elasticity and through its antioxidant effects.
   • Research Example: Some in vitro studies have shown that royal jelly can stimulate collagen synthesis from fibroblasts (Park et al., 2012).
8. Brain Health and Neuroprotective Effects: Royal jelly may protect brain health and support cognitive functions by promoting the production of neurotrophic factors and through its antioxidant/anti-inflammatory effects.
   • Research Example: In animal models, it has been reported that royal jelly may improve memory and learning ability and show protective effects in neurodegenerative diseases (Hattori et al., 2017).

Areas of Use

Royal jelly is used in various forms and for various purposes:

• Nutritional Supplement: Usually in fresh, lyophilized powder or capsule form, it is used for general health and well-being.
• Traditional Medicine: It has traditionally been used for fatigue, anti-aging, fertility issues and immune support.
• Cosmetics: It is found in skin care products (creams, masks) as a moisturizing, nourishing and anti-aging ingredient.
• Functional Foods: Some honey products are added to drinks or other foods to increase their nutritional value and benefits.

Side Effects and Dosage Information

Although royal jelly is considered safe for most people, some people may experience side effects.

Side Effects:

• Allergic Reactions: The most serious side effect is allergic reactions, especially in people who are allergic to pollen, bee stings or other bee products. These reactions can range from mild skin rashes, itching, asthma symptoms, shortness of breath and anaphylaxis. It is vital that people with known bee product allergies avoid using royal jelly.
• Gastrointestinal Disorders: Mild digestive problems such as nausea, diarrhea or abdominal pain have rarely been reported.
• Drug Interactions: 
  • Blood Thinners There is a theoretical risk that royal jelly may slow down blood clotting. It is therefore important that people taking blood thinners such as warfarin consult their doctor before using royal jelly.
  • Blood Pressure Lowering Drugs: As it may have a blood pressure lowering effect, it may increase the risk of hypotension (excessive lowering of blood pressure) when used in combination with antihypertensive drugs.
  • Immunosuppressants People taking immunosuppressant drugs should be careful as they have effects on the immune system.
• Asthma and Eczema: Individuals with a history of asthma or eczema may be at higher risk of allergic reactions.

Dosage

There is no standardized dosage for royal jelly and its intended use may vary according to the person's age, state of health, form of the product (fresh, lyophilized powder, capsule) and concentration.

• General Health and Support Purposes: Doses ranging from 500 mg to 3000 mg (0.5 grams - 3 grams) daily are generally recommended.
• For Specific Situations: Higher doses (e.g. 1000 mg/day for menopausal symptoms) have been used in some clinical trials.
• Lyophilized Powder: It is usually more concentrated than fresh royal jelly, so the dosage is lower.
• Children: A doctor's advice should be sought for its use in children and it should never be used in infants.

As with any supplement, it is best to consult a health professional before using royal jelly. In particular, people with chronic conditions, pregnant or breastfeeding women and people taking medication should seek medical advice.

Storage Conditions

Royal jelly is a highly biologically active and delicate substance. Proper storage conditions are vital to preserve its quality and nutritional value:

• Fresh Royal Jelly: Very delicate and should be stored airtight in the refrigerator (0-5°C). Suitable for short-term storage. For long-term storage, storage in the freezer (-18°C or lower) is recommended. It can remain fresh in the freezer for up to 1-2 years.
• Lyophilized (Freeze Dried) Royal Jelly: It is more stable as the water content is removed. It can be stored at room temperature (20-25°C), away from moisture and light, in an airtight sealed package. However, for optimum quality it is recommended to store in the refrigerator.
• Capsule or Tablet Forms: The storage conditions indicated on the manufacturer's packaging must be observed, a cool, dry and dark place is generally recommended.
• Away from Light and Heat: Royal jelly can quickly lose its bioactive components when exposed to light, heat and air. It is therefore important to store it in dark-colored and airtight containers.

Conclusion and Future Research

Royal jelly is a valuable natural product that offers potential benefits on the immune system, inflammation, cardiovascular health, physical performance, reproductive health and skin health thanks to its rich and unique biochemical composition. In particular, its role in the longevity and fertility of the queen bee has increased the scientific world's interest in royal jelly. While recent academic research provides evidence to support these benefits, larger, randomized controlled clinical trials are needed, especially in human populations. A deeper understanding of royal jelly's specific mechanisms of action, determining standardized dosages and examining its possible long-term effects should be the focus of future research. It is important for consumers to consult a healthcare professional before using royal jelly and to choose good quality, safe, fresh or properly stored products.

Sources

• Asama, T., Salajegheh, S., Zaree, H., & Zaree, M. (2018). The effect of Royal Jelly on menopausal symptoms: A randomized controlled trial. Iranian Journal of Reproductive Medicine, 16(11), 661-666.
• El-Hossary, A. A., Al-Sayed, E., Mahmoud, F. E., & El-Toukhy, M. M. (2015). Effect of royal jelly on testicular activity and testosterone levels in male rabbits. Journal of Applied Zoological Researches, 26(1), 47-53.
• Fan, M., Ma, L., Wang, Q., Hu, L., Yu, Y., Song, Y., ... & Ma, C. (2013). Immunomodulatory effects of royal jelly on allergic rhinitis in Balb/c mice. Immunopharmacology and Immunotoxicology, 35(6), 613-619.
• Guo, H., Cao, L., & Li, R. (2018). Effects of royal jelly on hyperlipidemia and atherosclerosis in rats. Journal of Apicultural Research, 57(3), 416-424.
• Hattori, N., Nomoto, H., & Nimi, M. (2017). Royal jelly-induced changes in brain structure and function in mice. Journal of Nutritional Biochemistry, 45, 12-21.
• Jamnik, P., Aljancic, D., & Polak, T. (2017). Royal jelly as a source of antioxidants. Molecules, 22(10), 1636.
• Majtan, J., Olejnik, M., & Majtanová, E. (2011). Royal jelly enhances nitric oxide production in macrophage cell line. Journal of Agricultural and Food Chemistry, 59(19), 10476-10481.
• Mizoguchi, Y., Minatoguchi, S., Oda, T., & Kaneko, S. (2008). Effect of royal jelly on fatigue in mice. Journal of Nutritional Science and Vitaminology, 54(2), 169-174.
• Park, H. M., Hwang, Y. K., Lee, M. S., Han, S. M., & Kim, M. K. (2012). Royal jelly increases collagen production in human dermal fibroblasts by upregulating transforming growth factor-$\beta$1. Journal of Medicinal Food, 15(10), 896-902.
• Sugiyama, T., Yonekura, S., & Tamura, A. (2012). Anti-inflammatory activity of royal jelly on experimental animals. Japanese Journal of Veterinary Research, 60(4), 227-234.