Tuesday, November 4, 2014

Cholesterol confusion?

Dr Emma Derbyshire

It was recently National Cholesterol Month and while health campaigns are effective at raising awareness and educating people about particular conditions, cholesterol is one area that can lead people feeling a little confused – especially with differing views on what has an impact on cholesterol levels.

Quite often this advice paints red meat as a villain and more often than not includes guidance on reducing red meat intake.

Firstly, cholesterol is a lipid and a sterol, so is used to make steroid hormones, along with the all-important vitamin D and bile salts that aid the digestion of fat. While there may be concerns over the amount of cholesterol that we ‘eat’, we also actually make cholesterol in the body itself with the liver producing about 1,000mg per day.

There are a multitude of life factors that impact on blood cholesterol levels, such as smoking, which increases levels, while active lifestyles reduce blood cholesterol levels[1]. Also, genetic conditions such as hypercholesterolemia can lead to cholesterol being present in naturally high amounts in the bloodstream.

Foods themselves can be a source of cholesterol with kidneys, eggs and prawns often being named as forerunners. 

In terms of red meat, many studies quoted in advice and the media have include meat pastries within their analysis rather than looking at lean cuts of meat, so it is the saturated fat content of the pastries that could be influencing blood cholesterol levels rather than the meat itself.

Meat and meat products make a significant contribution to intakes of iron, zinc, selenium, vitamin D and B vitamins.  So, cutting out red meat for fear of ingesting cholesterol, could actually be at the detriment of several important nutrients.

Hence, it can be seen that a combination of factors can impact on cholesterol levels.  This is important to bear in mind when interpreting findings from studies looking at trends between foods such as red meat and cholesterol levels, as these factors often act as confounders, skewing results.