Palm oil under fire as a carcinogen

 

Controversy has raged over the carcinogenic potential of palm oil since May 2016 when the European Food Safety Authority (EFSA) claimed in a statement that palm oil “generated more of a potentially carcinogenic contaminant than other vegetable oils”

“In risk assessments of such compounds, evidence from human epidemiological studies are not needed in order to conclude on the human health risk.”

Hellen Knutzen, EFSA

In January, Nature published the results of a study which showed that palmitic acid (major part of palm oil) boosts metastases (spread of cancer) through CD36 — a specific protein found in cancer cells that is responsible for taking up fatty acids.

The EFSA statement said palm oil generates glycidyl fatty acid ester (GE), 3-monochloropropanediol (3-MCPD), and 2-monochloropropanediol (2-MCPD) and their fatty acid esters. when the refining process reaches temperatures above 200 degrees Celsius.

The substances are carcinogenic and damage DNA as well as organs such as the liver, kidneys and testes. They can be found in high concentrations in palm oil and products made with it. While small amounts can also be found in other vegetable oils, the concentration of carcinogenic glycidol in palm oil is 264 times higher than in olive oil, 24 times higher than in rapeseed oil and 15 times higher than in sunflower oil. The ratios are similar for 2-MCPD and 3-MCPD, as the graphs show.

Glycidol in vegetable oils

Mean Middle Bound (in μg/kg)

palm oil/palm fat 3955 

sunflower oil: 269 

rapeseed oil: 166 

olive oil: 15

Palm oil contains more glycidol than other oils by a factor of: 

olive oil: 264 

rapeseed oil: 24 

sunflower oil: 15

3-MCPD in vegetable oils

Mean Middle Bound (in μg/kg)

palm oil/palm fat 2912 

sunflower oil: 521 

rapeseed oil: 232 

olive oil: 48

2-MCPD in vegetable oils

Mean Middle Bound (in μg/kg)

palm oil/palm fat 1565 

sunflower oil: 218 

rapeseed oil: 109 

olive oil: 86

Hellen Knutzen, chair of the Contaminants in the Food Chain panel of the EFSA that investigated palm oil, says there is enough evidence to conclude that glycidol is genotoxic and carcinogenic.

“In risk assessments of such compounds, evidence from human epidemiological studies are not needed in order to conclude on the human health risk,” Knutzen explains .

Knutzen says that assessors investigate the margin between the dose that causes cancer in experimental animals and the dose that humans are exposed to. If the margin is not sufficiently large, it is concluded that there is a potential human health concern.

 

While EFSA is not empowered to make regulations, the European Commission is contemplating steps that may include setting permissible levels of GE in food items.

The agency’s panel concluded that average exposures are a concern for younger age groups, and high exposures are a concern for all age groups. The report does not include recommendations for "safe" levels. However, the panel concluded that an infant receiving only formula (which can contain palm oil) would be below the level of concern. The panel also said levels of the harmful substances in palm oils and fats fell by half between 2010 and 2015, due to voluntary measures by producers to improve processing techniques.

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