Rosemary fights off free radical damage in the brain, protecting it from stroke and ageing stress. Now the herb can help prevent cancer by adding it to hamburgers.

The compounds in rosemary – rosmarinic acid, carnosol and carnosic acid – play an important role in protecting the brain from damage by free radicals, reducing the risk of stroke, neurodegenerative conditions, and the stressful effects of ageing.

This was shown by studies from the Burnham Institute for Medical Research in La Jolla, California and in Japan, which were reported in 2007 in The Journal of Neurochemistry.

Now food researchers have discovered that these same compounds prevent carcinogenic compounds known as HCAs (heterocyclic amines) from forming when meat is cooked at high temperatures.

Dr J. Scott Smith, food science professor at Kansas State University, found out about rosemary’s strength against the compounds while researching ways to reduce HCAs as part of a long-term Food Safety Consortium project.

HCAs a Potential Problem In Cooked Beef

The presence of HCAs is a potential problem in cooked beef as their production is influenced by cooking time and temperature.

Previous studies showed that meat products cooked below 352 degrees Fahrenheit for less than four minutes had low or undetectable levels of HCAs.

The HCAs would increase as temperature and cooking time increased.

Although lower temperatures and shorter cooking times can reduce the risk of HCA formation, those alternatives have their own problems, Dr Smith explained.

Lower temperatures can affect the taste adversely, so commercial steak houses generally cook at temperatures above 400 degrees F.

“Some use real high temperatures quick on the surface (to brown it), then they pull it out and put it in an oven to finish it,” he said.

Commercial Rosemary Defeats HCAs

Dr Smith began researching the effect of commercial rosemary extracts on stopping HCAs from forming in cooked beef patties.

His research group found that adding the rosemary extract reduced the HCAs levels, ranging from 30-100 percent reduction.

He said using rosemary extracts allows cooking temperatures to be kept high without HCAs developing.

Rosemary’s antioxidant content makes this method possible thanks to the presence of phenolic compounds.

Those compounds – rosmarinic acid, carnosol and carnosic acid – block the HCAs before they can form during high temperatures.

“Put a little bit (of the extract) on the surface,” Dr Smith advises grillers.

“Rosemary extracts shouldn’t have much of an aroma to them. Most people don’t want a rosemary-flavored burger.

So if you get the extract you don’t really know it’s there.”

Rosemary extracts can be found for sale on the Internet.

Of course if you like the flavour of rosemary – which is very good with chicken, lamb and fish – you can marinate your steak or beef patties with fresh or powdered rosemary.

Rosemary and Other Herbs Rich in Antixodants

The results of the rosemary research tie in with previous findings from Dr Smith’s group.

Those studies showed that marinating steaks with certain herbs also reduces HCAs. As well as rosemary, the herbs basil, mint, sage, savory, marjoram, oregano and thyme are all rich in antioxidants.

Marinating with any of these herbs in either dry or fresh form adds a healthy boost to grilling steaks, just as rubbing rosemary extracts onto burger patties is beneficial, Dr Smith said.

“The industry is moving toward an extract that you can rub onto the surface, or a rub that you can mix into the power to get better flavor to the hamburger,” he said.

In Australia there are already commercial spice and herb mixes available containing rosemary, thyme and basil for rubbing into meat before cooking to add flavour.

Now we know they can prevent HCAs as well.

That may not be all. Antioxidants can have other benefits besides curtailing HCAs, Dr Smith said.

“There is some indication that they protect the pancreas. If you can get that from burgers, then that’s great.”

See also: Rosemary Herb Helps Memory