Lycopene Benefits—A Supplement for Human Health

What is Lycopene?

Lycopene is a naturally occurring carotenoid found primarily in tomatoes and tomato products (accounting for >85% of dietary sources), as well as in fruits such as pink grapefruit, papaya, guava, apricot, and watermelon. Lycopene content varies significantly across different fruits and processed foods; for instance, fresh tomatoes contain approximately 0.72–4.2 mg/100 g, tomato paste can contain 5.40–150 mg/100 g, and watermelon contains 2.30–7.20 mg/100 g. Additionally, the presence of beneficial microorganisms in the soil microbiome can increase lycopene content by 36% [1].

Physicochemical Properties

Lycopene is an aliphatic, straight-chain hydrocarbon carotenoid containing two non-conjugated and eleven conjugated double bonds. It has a molecular weight of 536.85 Da and a melting point of 172–175°C. It is soluble in chloroform, hexane, benzene, diethyl ether, and oils, but insoluble in water and ethanol. It is sensitive to light, oxygen, high temperatures, acids, catalysts, and metal ions, making it prone to isomerization and degradation. Lycopene exists in both trans- and cis-isomeric forms; cis-isomers exhibit higher bioavailability, with the 5-cis isomer being the most stable.

Benefits

Lycopene offers protective effects for human bones, organs, and skin, and can help alleviate various pathological symptoms [1]. Specific benefits include:

1. Potent Antioxidant Activity

Lycopene is one of the most powerful antioxidants among carotenoids. Its capacity to quench singlet oxygen is twice that of β-carotene, ten times that of α-tocopherol, and 125 times that of glutathione. It ranks at the top of the list for antioxidant activity: lycopene > γ-tocopherol > astaxanthin > canthaxanthin > α-carotene > β-carotene > zeaxanthin > lutein > α-tocopherol > glutathione. It scavenges reactive oxygen species through mechanisms such as radical addition, electron transfer, and allylic hydrogen abstraction, while enhancing the activity of antioxidant enzymes like catalase and superoxide dismutase (SOD).

2. Anti-obesity effects

In a high-fat diet model using male Wistar rats, lycopene supplementation (25 mg/kg for 4 weeks) reduced plasma levels of IL-6, TNF-α, leptin, VLDL, LDL, and total cholesterol while increasing HDL; it also lowered malondialdehyde levels and boosted hepatic SOD and catalase activity. In a high-fat diet mouse model, lycopene improved glucose and lipid metabolism and reduced weight gain by stimulating the browning of white adipose tissue and activating brown adipose tissue through the regulation of the PPARG signaling pathway.

3. Cardiovascular protection

Lycopene supplementation has been shown to reduce levels of C-reactive protein, IL-6, pulse wave velocity, blood pressure, and intercellular adhesion molecule-1 (ICAM-1), thereby improving vascular health via flow-mediated endothelial dilation. During post-myocardial infarction remodeling, lycopene (10 mg/kg for 4 weeks) attenuated inflammation and apoptosis by inhibiting the NF-κB signaling pathway. In ApoE knockout mice, lycopene (60 mg/kg/day for 14 weeks) significantly reduced total cholesterol and triglyceride levels.

4. Cholesterol-lowering effects

The cholesterol-lowering effect of lycopene is attributed to the inhibition of HMG-CoA reductase expression and activity, as well as the modulation of LDL receptor activity. Experiments involving broiler chickens and Wistar rats demonstrated that lycopene significantly reduced total cholesterol, triglycerides, and LDL, while increasing HDL. Systematic reviews and meta-analyses in humans indicate that lycopene supplementation significantly raises HDL cholesterol levels.

5. Hepatoprotection

In a rat model of NAFLD, lycopene (5, 10, and 20 mg/kg for 6 weeks) reduced the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), as well as levels of malondialdehyde (MDA), free fatty acids, and LDL-cholesterol; simultaneously, it increased hepatic superoxide dismutase (SOD) and glutathione levels while decreasing the expression of CYP2E1 and TNF-α, as well as hepatic fat accumulation.

6. Renoprotection

In a female Wistar rat model fed a high-fat diet, supplementation with lycopene extract (200 ml, twice weekly for 8 weeks) significantly reduced plasma creatinine, urea, serum angiotensin-converting enzyme (ACE), and renal tissue levels of MDA and C-reactive protein (CRP), while increasing total protein and tissue antioxidant enzyme levels. Lycopene also ameliorates diabetic nephropathy and improves renal function by inhibiting the AGE-RAGE pathway.

7. Skeletal protection

Lycopene protects postmenopausal women against bone loss by upregulating alkaline phosphatase, type I collagen, and RUNX2; activating the Wnt/β-catenin and ERK1/2 pathways; and downregulating RANKL. In a rat model of glucocorticoid-induced osteoporosis, lycopene (30 mg/kg/day for 8 weeks) alleviated osteoporosis.

8. Anti-inflammatory effects

Lycopene alleviates palmitic acid-induced neuroinflammation and inhibits the TLR4 and NF-κB p65 signaling pathways. In a C57BL/6 mouse model of chronic cigarette smoke exposure, lycopene restored redox status and alleviated hepatic inflammation. In rats with acetic acid-induced colitis, lycopene (10 mg/kg for 21 days) effectively protected the colonic epithelial mucosa.

9. Anti-diabetic effects

In a streptozotocin-induced diabetes model, dietary supplementation with lycopene increased serum insulin concentrations, reduced urinary and blood glucose levels, and alleviated diabetes-induced pancreatic damage. In diabetic Wistar rats, oral administration of lycopene (40 mg/kg) significantly reduced serum MDA, cortisol, and blood glucose levels, while increasing the activities of SOD, CAT, and GSH-Px.

10. Anticancer effects

Lycopene inhibits the growth and proliferation of prostate cancer cells, arrests the cell cycle, and induces apoptosis. Dietary lycopene supplementation attenuates breast cancer cell growth by inhibiting the IGF-1R signaling pathway. In animal models of liver cancer, lycopene suppresses cancer initiation and progression.

11. Gastrointestinal protection

In male albino rats, lycopene (200 mg/kg for 10 days) prevents ethanol-induced mucosal injury. Lycopene also inhibits gastric acid secretion and combats *Helicobacter pylori* infection. However, it is noteworthy that high doses (150 mg/kg) of lycopene can exacerbate ethanol-induced acute gastric mucosal injury.

12. Neuroprotection

Lycopene alleviates age-related memory loss, cognitive impairment, neuronal damage, and synaptic dysfunction. It mitigates age-related oxidative stress by inhibiting lipid peroxidation and enhancing the activities of GSH, SOD, and CAT. In a mouse model of Alzheimer's disease induced by β-amyloid, lycopene reduces oxidative stress and neuronal loss, improves synaptic plasticity, and inhibits neuroinflammation. It also reduces the accumulation of amyloid-β 1-42 in the brains of aged CD-1 mice.

13. Pulmonary protection

In male C57BL/6 mice, dietary lycopene (25 or 50 mg/kg) attenuates cigarette smoke-induced emphysema. In a ferret model, lycopene (90 mg/kg for 22 weeks) effectively inhibits emphysema, chronic bronchitis, and precancerous lesions induced by tobacco carcinogens.

14. Sperm Quality and Fertility Enhancement

In rats with varicocele, lycopene protects sperm from DNA damage by upregulating antioxidant responses, thereby improving sperm motility, membrane integrity, and Johnson scores. In men with oligospermia, lycopene supplementation (25 mg/kg for 12 weeks) alleviates oxidative stress and improves sperm quality. Among infertile men, daily consumption of tomato juice containing 30 mg of lycopene for 12 weeks increased sperm motility and reduced seminal plasma leukocyte counts.

15. Skin Protection

Lycopene is widely used as a cosmetic ingredient, protecting the skin against aging and photodamage. As a dietary supplement, lycopene improves skin appearance and pigmentation while reducing erythema. It also helps prevent and/or treat sunburn and photoaging, and may be effective against UV-induced skin cancer.

Safety

Epidemiological studies recommend a daily lycopene intake of 2–20 mg. Daily intakes of up to 100 mg do not cause adverse effects. In rat toxicology studies, a diet fortified with 1% (w/w) lycopene caused no side effects, and a dosage of 200 mg/kg/day produced no negative impact on the animals.

Lycopene is generally considered safe as a dietary supplement during pregnancy and lactation. However, excessive long-term consumption of lycopene-rich tomato juice can lead to lycopenemia; therefore, excessive intake should be avoided.

References

[1] Shafe, M. O., Gumede, N. M., Nyakudya, T. T., Chivandi, E. (2024). Lycopene: A Potent Antioxidant with Multiple Health Benefits. Journal of Nutrition and Metabolism, 2024, 6252426. https://doi.org/10.1155/2024/6252426