Mineral found in Brazil nuts could be key to preventing the spread of cancer

Kate Ng
·Trending Lifestyle Reporter
Tue 22 October 2024 

Brazil nuts are packed with the mineral selenium, which is essential for maintaining body functions. (Getty Images)


A common food supplement that’s mainly found in Brazil nuts could hold the key to preventing the spread of cancer, new research has found.

Selenium is an essential mineral that helps support thyroid function, boosts the immune system, and protects cells from damage. It can also be found in seafood and cereals, as well as in many multivitamins on the market.

However, researchers have found that selenium is necessary for cancer cells to keep them functioning and spreading through the body - so depriving these cells of selenium could be the answer to a new type of cancer treatment.


Cells in the body are more likely to die from a lack of selenium via a process called ferroptosis, which is a sort of "self-destruct" button that goes off when cells are in danger of causing damage or becoming cancerous. But, the research, funded by Cancer Research UK, found that when triple negative breast cancer cells cluster together, they are able to protect themselves from ferroptosis by producing a type of fat molecule that is triggered by a lack of selenium.

The bypassing of the "self-destruct" process means cancer cells are able to grow and spread, becoming deadlier. Although when cancer cells move away from these clusters, which happens when they start moving to other parts of the body, they become more vulnerable to ferroptosis.

Cancer cells benefit from a lack of selenium when clustered together - but when they move away from these clusters, the lack of selenium can become the thing that destroys them. (Getty Images)

Dr Saverio Tardito, who led the research, explained that selenium is necessary for our body to continue normal function, so removing it from our diet is not an option.

"However, if we can find a treatment that interferes with the uptake of this mineral by triple negative breast cancer cells, we could potentially prevent this cancer spreading to other parts of the body."

He added that breast cancer itself is not usually fatal when treated successfully through medication or surgery - but when the cancer spreads, it becomes harder to control.

Interfering with the metabolism of selenium in sparse cancer cells was an effective way to kill them, Dr Tardito and his team found. It is hoped that this could lead to a solution that turns triple negative breast cancer from a potentially fatal disease into a manageable one.


Triple negative breast cancers can be harder to treat than other types of breast cancer because of a lack of receptors for the hormones oestrogen and progesterone, or a protein called Human Epidermal Growth Factor Receptor 2 (HER2).

Doctors are unable to use hormone therapies or targeted cancer drugs to treat this type of breast cancer, which affects around 15% of the 56,800 people in the UK who are diagnosed with breast cancer each year.

Explaining why studies like Dr Tardito’s can be cause for hope, Dr Sam Godfrey, director of research at Cancer Research UK, said that it "could be the key to preventing this type of cancer spreading, and that would have a transformative effect on how this disease is treated".

While you shouldn’t stop eating foods or taking multivitamins that contain selenium - because the mineral is important to keep your body functioning well - there is such a thing as too much selenium.

Eating too many Brazil nuts can result in selenium toxicity, because they contain highly concentrated amounts of the mineral. People are advised to eat no more than one or two Brazil nuts a day, as just one ounce of these nuts contains 544mg of selenium - 777% of the recommended daily allowance.

Selenium toxicity can lead to symptoms such as nausea and vomiting, nail discoloration, brittleness and loss, hair loss, fatigue, irritability, and bad breath. The British Nutrition Foundation warns against the use of selenium supplements, as these could increase the risk of selenium toxicity at high doses.