Will eating oranges make you orange?

Will eating bread crumbs make you feel crumby?

Will eating chicken make you such a chicken that you run away and hide?

The answer to these questions is obviously no.

So why do so many of us continue to believe that eating fatty foods makes you fat? As I wrote in a recent blog post, the latest nutritional research shows that sugar, not fat, is what causes us to put on weight — and makes it harder to lose it.

But what about cholesterol? Will eating foods that are high in cholesterol raise your cholesterol levels?

This is an important question for me since one of the side effects of the anti-rejection drugs I take to protect my new kidney is that they can increase my bad cholesterol levels and my blood pressure.

My doctor is debating whether to put me on drugs that will lower my bad cholesterol, but in the meantime I wanted to learn whether diet plays a role.

First things first. Not all cholesterol is bad. Low-density lipoproteins (LDLs) are known as “bad” cholesterol because too much in our blood increases the chance of heart disease. High-density lipoproteins (HDLs) are known as “good” cholesterol because the more we have in our blood, the lower our risk for heart disease.

It wasn’t that long ago that doctors believed that eating foods with cholesterol was the most important contributor to high cholesterol levels. We were told to restrict egg yolks because they were so high in cholesterol. But the most recent research suggests that just as eating oranges doesn’t make us orange, eating cholesterol doesn’t have much impact on our cholesterol levels.

But diet does play a major role. And it’s as much about eating  more of the right foods as it is about avoiding the bad ones.

Foods that are high in fibre and omega-3 fatty acids help lower bad cholesterol. If you want to lower your LDL cholesterol, the best thing to do is eat more oatmeal, bran and legumes as well as healthy fatty foods like nuts, salmon and avocados.

You also want to cut trans fats out of your diet as much as possible. The science here is clear. Trans fats raise bad cholesterol levels while lowering good cholesterol.

The science around saturated fat is more controversial, because eating it raises both good and bad cholesterol levels. It’s best not to overdo it with fatty red meats or full-fat dairy, but saturated fat is probably not as bad for us as scientists once thought.

A hat-tip to The Half-Arsed Runner, who left a comment on my blog post about fatty foods quoting one expert who said that believing eating fat makes you fat is like believing eating green foods make you green. This comment was the inspiration for today’s post.