5 Benefits and Side Effects of Lycopene (The Second One is Often Asked)

Lycopene is the red pigment that gives tomatoes, watermelon, pink grapefruit, and guava their distinctive colour. It belongs to a family of plant pigments called carotenoids, which also includes beta-carotene (the orange pigment in carrots). Unlike beta-carotene, lycopene doesn’t convert to vitamin A in the body, but it does act as a potent antioxidant.

In Western diets, tomatoes and tomato products supply roughly 85% of dietary lycopene 1. A fresh tomato contains about 4-10 mg of lycopene, while a cup of tomato juice provides around 20 mg. Interestingly, cooking actually improves lycopene absorption. The heat breaks down plant cell walls and transforms lycopene into a form your body can use more efficiently. This is why processed tomato products like passata, tomato paste, and even ketchup provide more bioavailable lycopene than raw tomatoes.

Adding some fat further boosts absorption since lycopene is fat-soluble. The traditional Mediterranean combination of tomatoes cooked in olive oil turns out to be nutritionally sensible, not just delicious.

Why the supplement interest?

Lycopene has attracted research attention because populations with higher tomato consumption tend to have lower rates of certain diseases, particularly cardiovascular disease and some cancers. The Mediterranean diet, which features tomatoes prominently, is consistently associated with better health outcomes 2.

But association doesn’t prove causation. People who eat more tomatoes might also exercise more, smoke less, or have other healthy habits. Researchers have tried to isolate lycopene’s specific effects through clinical trials, with mixed results.

1. May support cardiovascular health

Heart disease remains the leading cause of death worldwide, and anything that might reduce risk attracts attention. Men tend to develop cardiovascular disease earlier than women, though after menopause, women’s risk rises sharply.

What the research shows

A 2017 meta-analysis pooled data from 21 controlled studies involving 1,189 participants 3. The authors found that consuming tomato products was associated with improvements in LDL cholesterol, interleukin-6 (an inflammatory marker), and flow-mediated dilation (a measure of blood vessel function). When looking specifically at lycopene supplements, there was a modest reduction in systolic blood pressure.

A more recent Cochrane review examined whether lycopene supplementation prevents cardiovascular disease 4. The reviewers found no completed trials that measured hard endpoints like heart attacks or strokes. The available studies only measured intermediate markers like cholesterol levels and blood pressure, which don’t necessarily translate to fewer heart attacks.

My honest take

The cardiovascular evidence is promising but far from conclusive. Eating more tomatoes is probably beneficial as part of an overall healthy dietary pattern, and it certainly won’t hurt. But I’d be cautious about expecting lycopene supplements to dramatically change your heart disease risk.

If cardiovascular health is your concern, the evidence is much stronger for fish oil (particularly for people with existing heart disease) and for overall dietary patterns like the Mediterranean diet. Lifestyle factors like physical activity, not smoking, and maintaining a healthy weight have far larger effects than any supplement.

2. Prostate cancer prevention (the claim people ask about most)

This is the benefit that generates the most questions, probably because prostate cancer is so common among older men. It’s the second most diagnosed cancer in men worldwide, with about 1.1 million cases annually.

What the research shows

Early observational studies suggested that men who ate more tomatoes had lower prostate cancer rates. This sparked hope that lycopene might be a simple prevention strategy.

However, when researchers conducted actual intervention trials, the results were disappointing. A 2011 Cochrane review examined three randomised controlled trials involving 154 participants 5. The conclusion was stark: there is insufficient evidence to support or refute the use of lycopene to prevent prostate cancer.

A 2017 update of the evidence by the World Cancer Research Fund found that the evidence for lycopene and prostate cancer was limited and inconsistent 6.

Some studies have looked at whether lycopene helps men who already have prostate cancer. The evidence here is similarly thin. Lycopene doesn’t appear to reduce PSA levels or slow disease progression based on current data.

Reality check

I know this isn’t what people want to hear. The early observational data looked promising, and the idea of preventing cancer with a simple supplement is appealing. But the randomised trials haven’t supported the observational findings.

It’s possible that eating whole tomatoes provides benefits that lycopene supplements don’t, since tomatoes contain many other compounds. Or the benefit might be too small to detect in trials. Or perhaps the association in observational studies was confounded by other lifestyle factors.

For evidence-based prostate cancer screening and management, see our prostate cancer condition page. The bottom line is that current evidence doesn’t support taking lycopene supplements specifically for prostate cancer prevention.

3. May help with periodontal disease

Gum disease affects a surprisingly large proportion of adults, some estimates suggest 40-90% of people globally have some degree of periodontal disease. Left untreated, it can lead to tooth loss and has been linked to inflammation elsewhere in the body.

What the research shows

A randomised, double-blind, placebo-controlled trial tested lycopene in 42 patients with chronic periodontal disease 7. Participants received either 8 mg of lycopene daily or placebo for two months, alongside standard dental treatment (scaling and root planing).

The lycopene group showed greater improvements in several measures: plaque index, bleeding on probing, gingival index, probing depth, and tumour necrosis factor levels. However, some of these differences didn’t reach statistical significance.

Worth noting

This is a small study, and the participants were also receiving standard dental treatment, so it’s hard to know how much of the improvement was from lycopene versus just good dental care. The antioxidant and anti-inflammatory properties of lycopene might theoretically help inflamed gum tissue, but we’d need larger trials to be confident.

Don’t skip the dentist and rely on supplements. Professional cleaning, good brushing and flossing habits, and not smoking will do far more for your gums than any supplement.

4. Possible association with lower stomach cancer risk

Stomach cancer ranks fourth among common cancers globally, with men affected about two to three times more often than women. The main risk factors are Helicobacter pylori infection, smoking, and dietary factors including high salt intake and low fruit and vegetable consumption.

What the research shows

A 2013 meta-analysis combined data from 17 epidemiological studies and found that higher intake of tomato-related products was associated with a lower risk of stomach cancer 8. This fits with broader evidence that diets high in fruits and vegetables are protective against stomach cancer.

The mechanism isn’t entirely clear. It could be lycopene’s antioxidant effects, or it could be other compounds in tomatoes (they also contain vitamin C, potassium, folate, and various other phytochemicals), or it could simply reflect that people who eat more tomatoes tend to have healthier overall diets.

My assessment

This is observational evidence, which means we can’t be certain that tomatoes themselves prevent stomach cancer rather than being a marker of other healthy behaviours. No clinical trials have tested whether lycopene supplementation specifically prevents stomach cancer.

Eating tomatoes as part of a diet rich in vegetables and fruits makes sense for many reasons. Whether taking lycopene pills adds any protection remains unproven.

5. May benefit male fertility

Male factors contribute to about half of all infertility cases, and many men turn to supplements hoping to improve their sperm parameters. Oxidative stress can damage sperm cells, so antioxidants like lycopene have attracted research interest.

What the research shows

A 2019 randomised, double-blind, placebo-controlled trial gave 44 men with low sperm counts either 25 mg of lycopene daily or placebo for 12 weeks 9. The lycopene group showed improvements in sperm count, concentration, motility, and total antioxidant capacity.

Another trial in 60 healthy men tested a lower dose (14 mg daily) for 12 weeks and found improvements in sperm motility and morphology 10.

The catch

These studies measured semen parameters, not pregnancy rates. Improving numbers on a semen analysis doesn’t necessarily mean more pregnancies. The studies were also relatively short and small.

For men struggling with fertility, lycopene is one of several supplements with some supporting evidence. Zinc and CoQ10 have similar levels of evidence. Our article on supplements for male fertility covers this topic in more detail.

But supplements aren’t a substitute for addressing underlying issues. Conditions like chronic prostatitis can affect fertility, and lifestyle factors like smoking, excessive alcohol, obesity, and heat exposure matter too.

Side effects and safety

Lycopene from food is very safe. The main concern with excessive tomato or lycopene intake is a harmless condition called lycopenodermia, where the skin takes on an orange-yellow tinge. This reverses once you reduce your intake.

Lycopene supplements are generally well tolerated, but possible side effects include:

• Gastrointestinal upset, including nausea, diarrhoea, and stomach cramps
• Allergic reactions (more common in people allergic to tomatoes or related plants)

Safety precautions

Blood pressure medications: Lycopene may have mild blood pressure-lowering effects. If you’re on antihypertensive medication or have naturally low blood pressure, monitor your blood pressure when starting supplementation.

Anticoagulant medications: There’s theoretical concern about increased bleeding risk when combining lycopene with blood thinners like warfarin, though this isn’t well documented. If you’re on anticoagulants, mention any supplements to your doctor.

Hormone therapy: Lycopene might interact with oestrogen or other hormone therapies in unpredictable ways. Caution is warranted if you’re on hormone replacement therapy.

Prostate cancer patients: If you have prostate cancer, be aware that lycopene supplements might affect PSA test results. This doesn’t mean lycopene is harmful, but it could complicate monitoring.

Pregnancy and breastfeeding: There isn’t enough safety data to recommend lycopene supplements during pregnancy or breastfeeding. Eating tomatoes as part of a normal diet is fine.

Children and people with liver or kidney disease: Safety hasn’t been established in these groups, so supplementation isn’t recommended.

Dosage

Most clinical studies have used doses between 8-25 mg daily. Food sources provide varying amounts:

• One medium raw tomato: 4-10 mg
• 1 cup tomato juice: 20-25 mg
• 2 tablespoons tomato paste: 13-15 mg
• 1 cup watermelon: 6-8 mg
• 1 pink grapefruit: 2-4 mg

For many people, simply eating more cooked tomato products may be more practical than taking supplements.

References

1. Rao AV, Agarwal S. Role of antioxidant lycopene in cancer and heart disease. J Am Coll Nutr. 2000;19(5):563-569.
2. Martínez-González MA, et al. The Mediterranean diet and cardiovascular health. Circ Res. 2019;124(5):779-798.
3. Cheng HM, et al. Tomato and lycopene supplementation and cardiovascular risk factors: A systematic review and meta-analysis. Atherosclerosis. 2017;257:100-108.
4. Rees K, et al. Mediterranean-style diet for the primary and secondary prevention of cardiovascular disease. Cochrane Database Syst Rev. 2019;3:CD009825.
5. Ilic D, et al. Lycopene for the prevention and treatment of prostate disease. Cochrane Database Syst Rev. 2011;(11):CD008007.
6. World Cancer Research Fund. Diet, Nutrition, Physical Activity and Prostate Cancer. Revised 2018.
7. Chandra RV, et al. Efficacy of lycopene as a locally delivered gel in the treatment of chronic periodontitis. J Clin Diagn Res. 2012;6(7):1241-1244.
8. Yang T, et al. Tomato product and tomato-based food consumption and gastric cancer risk. J Cancer Res Clin Oncol. 2013;139(8):1297-1304.
9. Gupta NP, Kumar R. Lycopene therapy in idiopathic male infertility: a preliminary report. Int Urol Nephrol. 2002;34(3):369-372.
10. Williams EA, et al. The effect of a high-lycopene diet on prostate-specific antigen and sperm DNA damage. Eur J Clin Nutr. 2019;73(12):1652-1659.