Hot topic - Is folic acid linked to breast cancer?
23 December 2004 - written by Bupa's Health information team
Mothers who take folic acid supplements during pregnancy may be more likely to die from breast cancer in later life than those who don't take folic acid, according to new research published in the 11 December 2004 edition of the British Medical Journal.1
What did the research show?
The research suggests that mothers who take high doses of folic acid supplements throughout pregnancy are twice as likely to die from breast cancer. It suggests that the risk of these mothers dying from other causes is also higher.1
What is folic acid?
Folic acid (folate) is a B vitamin that is needed to make new cells in the body.2
What do we know already about folic acid?
We know that during pregnancy, the baby needs a regular supply of folic acid to help the development of its spinal cord. Taking folic acid supplements when planning to get pregnant and during the first 12 weeks of pregnancy reduces the risk of the baby being born with spinal problems, such as spina bifida.1,2,3
What is spina bifida?
Spina bifida is a condition caused by the neural tube failing to develop properly. The neural tube is formed within the first few weeks of pregnancy. From the neural tube, the spinal cord and the brain develop.
The most common feature of spina bifida is an incorrectly shaped spine - the small bones that make up the spine will not have formed correctly and may have gaps in them. In severe cases, one or more bones of the spine may be missing.4,5
Should I stop taking folic acid if I'm pregnant or planning to become pregnant?
No. The Department of Health recommends that all women take daily folic acid supplements (0.4mg) for the first 12 weeks of pregnancy, while the baby's spine develops.
If you are planning to become pregnant, you are also advised to take folic acid supplements. If the pregnancy is unplanned, then folic acid supplements should be taken as soon as you find out that you are expecting a baby.
Taking folic acid supplements guarantees that the developing baby will get a regular amount of folic acid.2,3
But if I keep taking folic acid supplements will I get breast cancer?
This is a preliminary study suggesting that women who take folic acid supplements throughout pregnancy may have a greater risk of developing breast cancer in later life.1
Breast cancer is the most common cancer among women. One in nine women will develop the disease at some time in her life.6
More research is needed to show whether there is a definite link between taking folic acid supplements and developing breast cancer.1
For more information about breast cancer, please see our factsheet:
Factsheet: Breast cancer
The researchers still say that when planning to become pregnant and during early pregnancy, women should take folic acid supplements as recommended.1
How was the study carried out?
Between June 1966 and June 1967, 2928 pregnant women took part in trial that looked at folic acid supplementation. Women were either given tablets which contained 0.2mg or 5mg of folic acid or a dummy pill throughout their pregnancy. The women and their doctors didn't know which tablets the women were given.
In September 2002, the researchers looked at what had happened to the women who took part in the trial.1
What happened to women who took folic acid supplements?
Of the 2928 women who took part in the trial, 210 women had died by September 2002. In total, 112 women had died from cancer. Of these deaths, 31 were due to breast cancer.
The other 40 deaths were due to cardiovascular disease.1
How did the different doses of folic acid affect the women?
The research suggests that the women who were given a higher dose (5mg) of folic acid throughout their pregnancy were twice as likely to die from breast cancer. One in every five of these women was also more likely to die from other causes, including cancer.1
Why may folic acid be linked to the development of breast cancer?
It is not known why taking folic acid may increase the risk of a woman developing breast cancer in later life. It is most likely that the link suggested by this research is a chance finding.
More research is needed to see whether there is actually a link between taking folic acid supplements and developing breast cancer in later life.1
How much folic acid do I need before and during pregnancy?
Very little folic acid is stored in the body, so you need a regular fresh supply to stay healthy.
For most women (before and during the first 12 weeks of pregnancy), 0.4mg of folic acid a day is the recommended dose.
If you are known to be at increased risk of giving birth to a baby with spinal problems, then you may need a higher dose of folic acid. A higher dose will need to be prescribed by your doctor.2,3
What puts some women at a greater risk of having a baby with spinal problems?
You may be at greater risk if:
- you have previously given birth to a baby with spinal problems
- your partner or a first-degree relative (mother, father, brother, sister) has a spinal cord problem
- you have coeliac disease - a condition that stops the body from absorbing as many nutrients, including folic acid
- you are taking medicines for epilepsy
- you have sickle cell anaemia or thalassaemia (inherited blood disorders)2
Are folic acid supplements enough to prevent a baby being born with spinal problems?
Taking folic acid supplements before and during pregnancy will not guarantee that your baby won't be born with spinal problems. But it will greatly reduce the risk of this happening.
As well as taking supplements, you can make sure that your diet includes plenty of foods that are rich in folic acid.5
How can I get folic acid from my diet?
Folic acid is found in many foods. These include:
- green leafy vegetables
- breakfast cereals
- bread
- rice
- oranges and orange juice
- lentils and chickpeas2,3,5
Where can I get folic acid supplements from?
Folic acid tablets can be bought from pharmacies, large supermarkets and health food shops. If you need more folic acid than is recommended, then you will need to get your supplements on prescription from a doctor.
If you are taking any medicines, you should check with your doctor first before you start taking folic acid supplements.3
What else can I do to stay healthy before and during pregnancy?
- eat a nutritious and well-balanced diet, including at least five portions of fruit and vegetables every day
- avoid eating foods that are high in vitamin A during the first few weeks of pregnancy, eg liver, liver sausage and cod liver oil - vitamin A found in fruits and vegetables is safe
- keep active - walking and swimming are ideal as they can be continued throughout pregnancy
- don't smoke - smoking may reduce fertility and has been linked to premature and low birth weight babies
- avoid drinking alcohol - alcohol may reduce fertility and can cause problems for a developing baby
- minimise your stress levels - eating well and getting plenty of exercise and sleep will help7
Further information
Bupa resources:
- Factsheet: Breast cancer
- Factsheet: Breast awareness and screening
- Factsheet: Planning for pregnancy
- Factsheet: Healthy eating
- Factsheet: Giving up smoking
External resources:
- Association for Spina Bifida and Hydrocephalus (ASBAH)
www.asbah.org - Department of Health
www.dh.gov.uk
References
- Charles D, Ness AR, Campbell D et al. Taking folate in pregnancy and risk of maternal breast cancer. BMJ 2004;3291375-1376.
- Patient UK. Pregnancy and folic acid.
http://www.patient.co.uk - NHS Direct Online Health Encyclopaedia. Pregnancy and childbirth: What is folic acid?
http://www.nhsdirect.nhs.uk - NHS Direct Online Health Encyclopaedia. Spina bifida.
http://www.nhsdirect.nhs.uk - Association for Spina Bifida and Hydrocephalus (ASBAH). Folic acid and the prevention of neural tube defects.
http://www.asbah.org - CancerBACUP. Breast cancer.
http://www.cancerbacup.org.uk - Bandolier knowledge library. A healthy pregnancy.
http://www.jr2.ox.ac.uk/bandolier/index.html
All websites accessed on 15-16 December 2004
