Study finds avocado damaging to carriers of breast cancer gene

BRCA gene carriers should cut back on avocado, broccoli and asparagus. Photo / Getty Images

By Stephen Matthews

Women with the faulty 'Angelina Jolie' gene should cut back on trendy avocado-based breakfasts to slash their chances of cancer.

Mutated BRCA genes - famously carried by the Hollywood actress - significantly raise the risk of ovarian and breast forms of the disease, reported the Daily Mail.

And new research suggests eating avocado, asparagus and broccoli, which are abundant in folate, could make cancer even more likely.

Folate causes the body to produce a cancer-causing compound that can 'lethally damage' the DNA of mutated cells, early trials show.

This, deemed irreparable, may then trigger deadly tumours to crop up around the body in carriers, British scientists have implied.

It is the first time researchers have revealed a build-up of formaldehyde is caused by a reaction within the body - not just by breathing it in.

Published in the journal Nature, the study showed formaldehyde to be a by-product of a key process called the 'one carbon cycle'.

This cycle uses folate, commonly known as vitamin B9, to create DNA and essential amino acids, which cells need to function and multiply.

Treating laboratory-grown cells with folate lead to the release of formaldehyde, the Government-funded researchers discovered.

They speculated this could lethally damage the DNA of mutated BRCA cancer cells that cannot repair this damage.

Healthy surrounding cells would not be damaged since they have functioning DNA repair mechanisms, they added.

The new study was led by Dr Ketan Petal, from the Medical Research Council Laboratory of Molecular Biology.

He said: "We've known for a while that we must produce formaldehyde in our bodies, but we didn't know where it comes from.

"We've discovered that some of it comes from an unexpected source, a key pathway - that's used to make the building blocks of life, such as DNA and certain amino acids.

"The one-carbon cycle is a fundamental process which is present in all forms of life, right down to bacteria."

Research suggests eating too many leafy green vegetables, abundant in folate, could make cancer even more likely in carriers. Photo / Getty Images

WHAT IS THE TOXIN?

Formaldehyde is described by the US government as a 'known human carcinogen' and branded similar by the World Health Organization.

It is given off by MDF and plywood, building and insulation materials, gas stoves, cigarettes and e-cigarettes.

It is deemed a toxin because it can damage DNA. However, cells have two lines of defence against the danger of formaldehyde.

Firstly, an enzyme converts it into a less dangerous chemical, called formate. And secondly, DNA damage caused by formaldehyde can be fixed by repair enzymes.

HOPE FOR NEW CANCER DRUGS

These findings could provide a new target for developing cancer drugs, as some types of cancer lack the necessary repair enzymes.

Dr Patel added: "The one carbon cycle is already a key target for cancer drugs and this study opens up exciting new opportunities to harness this pathway for cancer research."

The scientists were surprised to find that the toxic formaldehyde also has a positive function in cells, as it paradoxically also fuels the one-carbon cycle.

BENEFICIAL AND 'DANGEROUS'

Dr Patel added: "Folate and formaldehyde have two faces: a beneficial side because they provide the chemical buildings blocks for cells to live and grow, and a dangerous side because formaldehyde can damage DNA."

However, the researchers were keen to point out that the trial was conducted on lab-grown cells, and not humans.

WHAT IS THE 'ANGELINA' GENE?

Hollywood actress Angelina Jolie announced that she had a voluntary double mastectomy in May 2013. Photo / Getty Images

Hollywood actress Angelina Jolie announced that she had a voluntary double mastectomy in May 2013.

Jolie took the decision after discovering she had an 87 per cent chance of developing breast cancer.

This was due to her having inherited the faulty BRCA1 gene, which increases the risk of both breast and ovarian cancer.

This same mutation led to her mother's death at age 56.

Women who inherit the faulty, or mutated, BRCA1 or BRCA2 genes have a 50 to 80 per cent chance of developing breast cancer during their lifetime.

Figures suggest that around one in 400 women have such genetic twists.

FORMALDEHYDE: THE FACTS

Formaldehyde is a colorless, strong-smelling gas used in making building materials and many household products.

It is used in pressed-wood products, such as particleboard, plywood, and fiberboard; glues and adhesives; permanent-press fabrics; paper product coatings; and certain insulation materials. It is also used to make other chemicals.

Formaldehyde is quickly broken down in the air - generally within hours. It dissolves easily in water, but does not last long there, either.

When dissolved in water it is called formalin, which is commonly used as an industrial disinfectant, and as a preservative in funeral homes and medical labs.

It can also be used as a preservative in some foods and in products, such as antiseptics, medicines, and cosmetics.

Sometimes, although formaldehyde is not used, substances that release formaldehyde are. These have been found in cosmetics, soaps, shampoos, lotions and sunscreens, and cleaning products.

Formaldehyde also occurs naturally in the environment. Humans and most other living organisms make small amounts as part of normal metabolic processes.

Source: American Cancer Society