Do lycopene and tomatoes protect against prostate cancer?

Tomatoes and lycopene have been the subject of research into prostate cancer for decades. In cell and animal studies, lycopene consistently and measurably inhibits the growth of prostate cancer cells. In mouse studies using both implanted and genetically driven tumours, tumour activity declined with higher lycopene intake, although the precise effect varies by dose and model type.

In large-scale population studies and case-control studies, men with higher tomato consumption have, on average, a lower risk of prostate cancer. The same pattern emerges in Mediterranean or plant-based dietary patterns, which are rich in antioxidants including lycopene. That is strong evidence, but not yet proof that tomatoes are the cause of this protection: it is also possible that tomato eaters have other healthy habits.

Why might lycopene be protective? In the laboratory, the molecule actively neutralises free radicals, harmful substances that can damage cells and may contribute to cancer development. Whether this mechanism works just as strongly in the human body as it does in a test tube has not been established with certainty.

The critical point is this: large randomised trials in which people were randomly assigned to receive lycopene or a placebo are still lacking. Existing studies partly contradict one another. As a result, the evidence is insufficient to recommend lycopene supplements purely as a means of preventing prostate cancer. A separate clinical effect has also been observed in men with benign prostate enlargement: a combination preparation of lycopene, selenium and a plant extract reduced inflammation in prostate tissue and relieved urinary problems. But benign prostate enlargement is not the same as cancer.

The most concrete conclusion: two to three portions of tomato products per week fits perfectly into a healthy diet and carries no risks. Anyone considering lycopene supplements purely to prevent prostate cancer is, for now, buying a promise that the clinical evidence does not yet fully deliver.