Multivitamins don’t cause breast cancer

A new study suggests that taking multivitamins may increase risk for breast cancer.  It should be noted that this is just a suggestion and it’s not hard or conclusive proof.

This study was not a clinical trial, meaning that it has not established any direct causal relationship. Australian experts are treating this study with interest and caution.

The study was led by a world-famous researcher named Susanna C. Larsson Ph.D.  (please note Susanna Larsson is not a medical doctor). The study done at the Karolinska Institute in Stockholm, Sweden found women taking multivitamins were 19 percent more likely to develop breast cancer than those who did not take daily multivitamins. The study is published online in the American Journal of Clinical Nutrition.

The study followed 35,000 Sweden women aged 49 to 83 for 10 years.  Of the participants, 9,017 women reported taking multivitamins. During the follow-up, 974 women were diagnosed with breast cancer – of them, 293 were taking multivitamins.

The results are confusing because the researchers found the increased risk of breast cancer had nothing to do with vitamin E, C and B-6 while calcium was found to provide some protection against breast cancer.

Although the study in itself could not prove taking multivitamins increased risk of breast cancer, the researchers suggested that the possibility is real.

A multivitamin tablet contains more than 20 ingredients (including binders and fillers). So which ingredient causes cancer?  It’s very unscientific to make a statement like multivitamins in general cause cancer.  It’s like saying breathing causes cancer – rather than identifying which air pollutant causes cancer. It was probably a binder or filler in the tablet that causes cancer.

They cited studies linking folic acid to elevated risk of breast cancer and high intake of iron and zinc to increased risk of cancer. Some research shows that folic acid increases the risk of bowel cancer.  Bread is now fortified with folic acid so it could be said that it too causes cancer.  Bread is a double whammy because it contains acrylamide which causes cancer.

Another explanation is that those women who took multivitamins might have had some known underlying condition that put them at higher risk of cancer, which prompted them to take multivitamins in hopes that these nutrients can help reduce the risk. The study did not take all these factors into account.

Many factors can raise the risk of breast cancer including –

• High alcohol consumption
• Smoking
• Prolonged early use of the OCP
• Use of the combined form of hormone replacement therapy for more than 5 years
• Family history of cancer
• Low vitamin D levels
• Excess body weight

I also think that often the people who take multi-vitamins are the ones who don’t always eat properly, don’t cook and don’t eat enough vegetables in general – they take multivitamins to try and make up for this. Those people are at increased risk of cancer.

The prevention of breast cancer requires a holistic approach to a healthy diet and lifestyle and for more information see our well researched book titled The Breast Cancer Prevention Guide.

The Complementary Healthcare Council of Australia also urged women not to panic as there were concerns over limitations of this studies design and completeness.

For example, one serious flaw in the study was that it relied on self administered questionnaires and all too often it has been found that they are often imprecise and incorrectly filled out. The study also failed to look at the bioactivity of the various multi-vitamin ingredients.

Professor John Boyages, director of the Westmead Breast Cancer Institute was quoted as saying he “wouldn’t put any weight” on the study as there were many complicated risk factors involved in breast cancer.

Women should not panic and change their habits over night. Speak to your doctor or naturopath or call the Women’s Health Advisory Service on 02 4655 8855.