Tuesday May 20, 2014 (foodconsumer.org) -- A new study published this year in the International Journal of Cancer suggests high consumption of dairy products, particularly milk and cheese may increase the risk of liver cancer or otherwise called hepatocellular carcinoma.

Previous studies have established associations between intake of dairy products and risk of some cancers.  The current study led by Mazda Jenab and colleagues yielded some evidence to suggest that eating too much cheese and drinking too much milk may increase risk of liver cancer.

The study was intended to associate the "consumption of total and specific dairy products (milk/cheese/yogurt) and their components (calcium/vitamin D/fats/protein), with first incident HCC (liver cancer)" in the EPICN cohort (the European Prospective Investigation into Cancer and Nutrition cohort).

For the study, 477,206 men and women were followed up for an average of 11 years.  The cohort study showed that those who ate highest amounts of dairy products, milk, and cheese were 66%, 51% and 56% more likely to develop liver cancer, respectively, compared with those who ate the lowest amounts.  

However, consumption of yogurt was not associated with risk of liver cancer.

Looking at the dairy components, the researchers found dietary calcium, vitamin D, fat and protein from dairy sources all were correlated with increased liver cancer risk.

On the other hand, the researchers found the same nutrients from nondairy sources were not associated with the risk or inversely associated with the risk of liver cancer.  That is, calcium, vitamin D, fat and protein from a plant-based diet does not increase risk of liver cancer.

The nested case–control study revealed similar observations among hepatitis-free individuals.

The researchers concluded "Results from this large prospective cohort study suggest that higher consumption of dairy products, particularly milk and cheese, may be associated with increased HCC (liver cancer) risk."

In early studies, Dr. T. Colin Campbell, a Cornell University nutrition professor and colleagues have found that high consumption of dairy protein or milk protein or specifically casein makes the liver vulnerable to the toxicity of carcinogens.  They found animals that ate high amount of casein were more likely to develop liver cancer or other diseases and more likely to die early, compared with those that consumed soy protein. (David Liu)