Variety of fruits and vegetables
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Prostate cancer rates were lower in men who regularly consumed “colorful fruits and vegetables,” according to new research from the University of South Australia. Nutrients from such a diet were also potentially linked to recovery among men who underwent radiation treatment for the disease.

In prostate cancer cases, verses controls, the researchers found plasma concentrations of lutein, lycopene, α-carotene, β-carotene and selenium were significantly reduced. Levels of iron, sulfur, and calcium, meanwhile, were increased.

A second study found that white blood cells of prostate patients had more DNA damage than those of healthy controls and were more prone to DNA damage induced by ionizing radiation. The researchers linked this effect to low levels of lycopene and selenium.

Co-author Permal Deo, Ph.D., told Inside Precision Medicine that eating foods that are naturally rich in lycopene and selenium is preferable to taking supplements, because “Current evidence suggests benefits of supplements are limited.”

This team’s findings were published in two papers featured in Cancers. One looked at diet and prostate cancer risk, the other examined levels of lycopene and selenium in such patients undergoing radiation therapy. Both studies involved controls.

Their first study included 116 white men with histologically confirmed prostate cancer who had a suspicious finding on digital rectal examination and/or elevated serum levels of prostate-specific antigen. The aggressiveness of their tumor was defined by the Gleason score. All patients who were part of this study were deemed to need radiotherapy for cancer control.

The results showed, the researchers wrote, “That the plasma nutriome could be a useful diagnostic of prostate cancer risk.”

Their second study involved 103 prostate cancer patients who had not yet been treated. Blood samples from these patients were exposed to radiation. The team reported that radiation-induced micronucleus and nuclear buds frequencies, both dangerous signs, were significantly higher in prostate cancer patients with low selenium or low lycopene levels compared to the controls.

Asked whether the team’s findings could be extended to other cancers, Deo said, “There are research studies reinforcing the role of selenium and lycopene in prostate cancer, but limited evidence in other cancers.”

Prostate cancer is the fourth most commonly diagnosed malignancy worldwide, according to the World Cancer Research Fund International. Men of African descent have a higher risk of this disease than others, research suggests.

The authors note that, “Many epidemiological and laboratory studies provided persuasive evidence that diet, genetic factors, and lifestyle were the major contributory factors of prostate cancer.”

“Our recommendation is to adopt a Mediterranean diet enlisting the help of a dietician because people absorb nutrients in different ways, depending on the food, the digestive system, the person’s genotype and possibly their microbiome,” Deo added.

The best way to pursue this diet, he said is to, “Have a variety of fruits and vegetables and include those high in lycopene, such as tomatoes, melons, papayas, grapes, and cranberries.  Also, food high in selenium, such as white meats, fish, shellfish, eggs and nuts.”

Other risk factors, such as ethnicity, family history and age have previously been linked to prostate cancer. Recently, the gut microbiome has been implicated in aggressive prostate cancer.

In addition, “There is strong evidence that being overweight and tall increases the risk of prostate cancer. Diets high in dairy products and low in vitamin E may also increase the risk but the evidence is less clear,” said Deo.

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