Named useful foods that cause cancer

Not all healthy foods are the same. It turns out that not only fried potatoes, smoked meats, chips or trans fats are carcinogens. Some traditionally healthy vegetables and fruits can also become stimulants of malignant processes in the body. Among them are many “positions” beloved by modern healthy lifestyle fans, for example, citrus fruits. Recently, several large scientific studies have appeared at once, linking furocoumarins, which are found in “healthy plant foods” with an increased risk of cancer.

According to the famous American scientist, geneticist Dmitry Prus, plants do not have an adaptive immune system to fight infections. Instead, they use bioactive molecules that kill pathogens and sometimes harm humans as well. In 2015, a Journal of Clinical Oncology article that followed the diet and health of 100,000 people over 25 years found a link between natural citrus fungicides and skin cancer.

The work showed an increase in the risk of developing melanoma with an increase in … consumption of orange juice and grapefruit. The association was stronger in people with a stronger history of sunburn with blisters and with more severe sun exposure, as well as for parts of the body exposed to sunlight (head, neck and limbs). Researchers blame this on furocoumarins (psoralens), which are produced by plants to protect against infections. They, under the influence of ultraviolet light, cause “cross-links” between DNA strands. Previously, they were even added to “sunburn” creams, but they have been banned for 30 years because of the obvious connection with melanoma.

In citrus fruits, psoralens are mainly found in the peel, which typically contains hundreds of micrograms per gram (as opposed to a few micrograms in the flesh). The essential oils further concentrate the psoralens in the peel. For example, bergamot essential oil, which contains a few percent of psoralens, and studies have shown that perfumes containing bergamot oil cause sunburn. A similar story is with lime oil, which is often used to flavor drinks.

But in grapefruits, furocoumarins are found not only in the peel, but also in the white film between the slices, and even in fresh juice! “Oranges seem to be an exception in the sense that their skin is not as rich in psoralens (and the pulp contains 2 to 33 mcg/g), but “not from concentrate” orange juice is usually flavored with blends of orange essence and essential oils from peels and thus enriched with psoralens.This is a relatively recent phenomenon; orange juice began to be so flavored after 2007, and grapefruit even more recently.It is not easy to determine exactly which citrus products are at risk due to changes in their spectrum and composition over time. years of study.Attitudes towards tanning have also changed.People have become more sun-protected, more sunscreen used.However, the scale of cancer nutritional research continues to grow, and in recent years, several studies have been added confirming the risk of skin cancer, and not only melanoma, but also more common basal cell carcinoma,” notes Dmitry Prus.

For example, the AARP Diet and Health Study, which included 400,000 older Americans, found that the risk of melanoma increased with citrus consumption. But! This was true only for people actively taking sunbaths.

A 2021 study of 50,000 women found that eating citrus fruits was associated with a higher risk of all types of skin cancer. The same results were demonstrated by the European study of the EPIC project among 500,000 people.

But the most impressive results came from a British Biobank study of 200,000 people. Those who consumed citrus fruits at least 2 times a week developed melanoma 1.5 times more often; and among the fairest-skinned participants, the effect was nearly double!

Similar risks may be fraught with other plant foods, such as the traditionally beloved celery. In Russia, many who dream of losing weight even sincerely believe that this product has a negative calorie content, so they try to include it in the diet more often. From this point of view, other representatives of the umbrella family are also dangerous: parsley, dill, parsnip, fennel and even carrots. As Dmitry Prus explains, these plants naturally produce psoralens and a number of other bioactive molecules on the surface to fight fungal infections. And the production of psoralen increases with the growth of the fungal population.

This theory is supported by outbreaks of photodermatitis not only among workers on a celery farm, but even among workers at a greengrocer’s shop that sold celery due to direct skin contact. Plant-related photodermatitis has also been reported among carrot processing workers. “Celery that was left in the field longer than usual (as in Israel during the Iraq War) or exposed to fungi has significantly higher levels of psoralen, but interestingly, these levels were even much higher when refrigerated for extended periods. , presumably due to the cold and moisture favoring the fungus (young fresh celeriac may contain as little as a few micrograms per gram of psoralen, while older, long-stored plants may have as high as 300 micrograms per gram). fungal disease was found in parsnips, where the total psoralen content increased from 40 to 1740 mcg/g. Carrots usually contain only traces of psoralens, but fungal infections also increase their levels to several micrograms per gram. In any case, Umbelliferae roots usually contain psoralens in the skin so they are largely lost when peeling. marketed as a “health food” ostensibly for longevity) has an even higher psoralen content, up to 6000 mcg/g. But that’s still nothing compared to the 12,000 mcg/g found in hogweed leaves. These giant umbrella plants, up to 15 feet high, were brought to Russia from the Caucasus for silage, but caused sun-related morbidity in spotted and fair-skinned cattle (and common sunburn in unsuspecting people who touched it). Hog parsnip Heracleum sosnowskyi still thrives in Eastern Europe even decades after its cultivation for silage ceased and it became fashionable to call the “Caucasian migrant” the “Stalin’s curse”. But still, Stalin was not the first distributor of hogweed in Europe; it was first introduced as a botanical curiosity to Kew Botanical Gardens in London in 1817. In recent decades, hogweed has also invaded the United States and Canada,” says Dmitry Prus.

The good news is that among citrus fruits, the least psoralens in Russians’ favorite tangerines. “I would not call citrus juice really dangerous for most, although for those who consume a lot of it and spend a lot of time in the sun without protection, it can be serious,” the expert reassures. If we talk about umbrella plants, then most of all psoralens are in their green parts, and least of all in root crops hidden from sunlight.