​Nutrition - Cooking methods

Tuesday 08 May 2018

When I do my cooking demonstrations I frequently get asked about which cooking methods are best to use in order to keep as much nutrition in the food as possible. I also get asked about BBQ’d food because people have heard that it is bad for us. So I thought that it would be worthwhile spending some time looking at different foods and cooking methods and which are the best to use and which are best to avoid using, or at least keeping to a minimum.

After all, it is all well and good trying to source really good quality foods if we are not sure how to get the best out of them. Funnily enough it is not a subject that is really covered in books relating to diet and cancer yet, even though the way we cook our food can have a profound impact on its health potential. There is a lot of research on the subject which is interesting.

Some foods of course need to be cooked to make them safe to eat. As the cooking will kill any potential bacteria on the food. This of course relates to meat and fish although I do know that sushi, some smoked fish and beef tartare are eaten raw. This is not a good idea especially if your immune system is at all compromised simply because we may not be strong enough to deal with the potential bacteria that will be present. Most people with cancer have a lowered immune system and certainly going through chemo the immune system will be depleted, in this case all meat should be well cooked.

Which is the best methods to use and which methods should be avoided or only used occasionally. Generally it is best to use moist methods of cooking meat and fish .i.e., steaming, poaching, casseroles and stews. I quite often take a chicken piece or fish portion and wrap it in a foil parcel with mushrooms, onions and fresh tomato added with a little seasoning. This cooks by a steaming method and all the juices of the food are kept. Quite simple and very tasty. The dry methods of cooking have been shown to carry potential health hazards. i.e. grilling, frying, dry roasting and BBQ’ing. Let’s have a look at why.

Keeping dry cooking to a minimum
There are a several well researched studies which have been published on lab experiments showing why we are recommended to keep dry methods of cooking to a minimum. These are mainly because the food cooked by these methods have been shown to become mutagenic, that is they cause changes to the DNA of the cell that may increase the risk of cancer and other chronic diseases. As we know the DNA gives the cell its characteristic and is like the brain of the cell telling it how to function, whether it be a kidney cell or immune cell or skin cell etc. The DNA is affected because of the development of compounds during the cooking process. These are Hetrocyclic amines (HCA’S) and Polycyclic Aromatic Hydrocarbons (PAH’S). As a result of these lab studies there is currently ongoing research into the risks to humans by the American cancer prevention society, studies at the Havard University and some European studies started in 2009/10. I am sure there must be many more. It seems to be that when we ingest these compounds we have enzymes in our bodies that activate them into these mutagenic compounds. This however can differ between individuals making some people more susceptible than others.

HCA’s and PAH’s are chemicals formed when muscle meat, including beef, lamb, pork, fish and poultry is cooked using high temperatures such as frying, grilling, dry roasting or BBQ’ing.  Basically HCA’s are formed when amino acids (building blocks of protein).sugars and creatine (a substance found in muscle) react at a high temperature. PAH’s are formed when fat and juices from the meat drip and the PAH’s formed stick to the food giving it its characteristic charcoal look. PAH’s are also formed when food is smoked. The more well done the meat the higher the levels of these compounds.

So what can we do to minimize our risk and still enjoy the occasional grilled or roasted food.

  • Select leaner cuts of meat as they are less likely to drip fat and produce PAHs.
  • Marinade meat before cooking. Researchers have demonstrated that marinating meat prior to grilling, even for just a few minutes can reduce HCA formation by 90%. It seems that the marinate forms a protective barrier for the meat juices that prevents HCA reaction from occurring.
  • Grilling normally takes place at temperatures of 500’F plus, but under 325’F the formation of these compounds is lower, so grill at a lower temperature.
  • Do not overcook the meat or cut any charcoal pieces off before eating.
  • It is worth noting that meat does not contain the health protective elements that we get from fresh fruits and vegetables like fibre, antioxidants and phytochemicals. So always make sure that your diet includes large quantities of these fresh foods which will help counterbalance the fact that the meat may contain HCA’s and PAH’s.
  • There are certain antioxidant rich foods such as rosemary, citrus fruits and green tea which have been found to reduce HCA levels so these could be included in marinades.


Below I have included a few simple marinades that you may like to try. These are a good idea for people who have lost their sense of taste or smell as they raise the flavour of the food. Remember that the meat only needs marinating for a minute or 2 to have a protective effect.

The methods are all the same you simply mix the ingredients together and then rub into the meat or fish and leave for up to 5 minutes or longer. If you do not use all the marinade it will keep in a screw top jar in the fridge for 3 or 4 days.

  • 2 tablespoons soya sauce, 1 tbsp lemon juice, 1 clove garlic crushed, A hint of brown sugar.
  • 6 tbsps soya sauce or tamari, 2 tsps sesame oil, 1 tbsp thai sweet chilli sauce, zest of 2 limes, 3 cloves garlic crushed.
  • 3 tbsp fish sauce, 1 tsp sesame oil, clove garlic crushed, 1 tbsp honey, 1 tsp grated root ginger.
  • 4 tbsps olive oil, juice of ½ lemon, ½ tsp tomato puree, ½ white onion finely chopped, ¼ pt of natural yogurt.
  • 1 tbsp of tomato ketchup, 1 tbsp Worcestershire sauce, 1 tsp mustard, 3 cloves of garlic crushed.

 You may also be interested in my blog on Microwave and nutrition 

Blog originally written by Caroline (April 2013)

Sign up for our newsletter

Stay up to date with our news and fundraising by signing up for our newsletter.

Sign up