Why burned toast gives you wrinkles

Press/Media: Research

Description

AGEs are formed when proteins or fats bind with sugars – a process called glycation. This can happen in foods when they are cooked or in the body when levels of sugar in the bloodstream rise. In small quantities, AGEs we produce or consume get neutralised in the body, but consume or create too many of them and your body can’t tackle them before they do harm.  ‘AGEs cause a process called cross-linking which damages proteins in the body – and this damage is linked to ageing and disease,’ explains Professor Barbora de Courten from Monash University.

The most obvious effect of this is the formation of wrinkles - cross linking causes collagen in the skin to stiffen and lose elasticity which creates the lines and folds we all develop as we age. However, in recent years, evidence of more medical forms of damage from AGEs is emerging. Researchers at Mount Sinai in New York, for example, have linked high intakes of AGEs with bone loss in the spine (osteoporosis) and an increased risk of fractures. High intakes of AGEs have also recently been linked to imbalance in our gut bacteria while a new Australian study says they could even reduce fertility. AGEs are strongly linked to increased levels of inflammation and oxidative stress in the body and if that inflammation occurs in the womb it’s believed to make it harder for an embryo to implant.

Conversely, cutting out AGEs has shown positive effects in the body. In a trial by Professor de Courten, people swapping to a low AGEs diet for just two weeks increased their sensitivity to insulin – which is linked to a lower risk of type 2 diabetes (and better management of the condition in those already diagnosed). A trial at Mount Sinai University is the US also showed lowered insulin levels in response to decreased levels of AGEs in the diet – and also reported weight loss and lowered levels of inflammation. 

Results from our recent systematic review and meta-analyses conducted by professor de Courten which combined results from 17 trials and 560 participants show that low AGE diets improve levels or AGEs in the body, sensitivity to insulin, “bad” cholesterol levels, inflammation and oxidative stress levels. However, there was no effect on some other cardiovascular risk factors such as blood pressure. ‘This is likely because most individuals studied were people who had normal blood pressure and so there wasn’t a measureable change one could see,’ she told us. ‘Our results suggest that cutting out AGEs can prevent type 2 diabetes’ she said ‘but long term studies are needed to confirm this.

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AGEs are found in foods containing fat or protein – particularly, meat, fish or dairy products - but what significantly influences the amount of AGEs in any food is how you cook it – incorrect preparation can turn even foods normally thought of as healthy like chicken, fish, nut or potatoes into AGEs bombs.

 ‘The higher the temperature and the less fluid involved in a cooking process, the more AGEs are formed when an item is cooked ,’ explains Professor de Courten. ‘Grilling, roasting and frying lead to high concentrations while steaming or stewing create fewer AGEs.’ What this means is that swapping to stewing chicken instead of grilling, poaching eggs rather than frying them and eating raw nuts over roasted can all make a noticeable difference in the number of AGEs in your diet without you having to give up your favourite foods completely. 

On top of this, AGEs are produced when a food burns. The more you brown something – like meat or toast – the more AGEs it will have, toasting a slice of bread increases the AGEs it contains by about a quarter for example. Try not to chargill or burn foods and adjust your toaster setting to the lowest level you can stand. Also, cook slowly – scrambled eggs cooked on a low heat contain about half the number of AGEs as those made quickly with high heat.

If you are grilling or BBQing meat, you can also reduce the amount of AGEs formed by marinating meats beforehand. ‘Acidic marinades like those containing lemon juice limit the amount of AGEs formed,’ explains Professor de Courten. In one trial published in the Journal of the American Dietetic Association, marinating beef in lemon juice for an hour before grilling cut the amount of AGEs produced in half.

Period15 Jul 2018

Media contributions

1

Media contributions

  • TitleWhy burned toast gives you wrinkles
    Media name/outletSydney morning herald
    CountryAustralia
    Date15/07/18
    DescriptionAGEs are formed when proteins or fats bind with sugars – a process called glycation. This can happen in foods when they are cooked or in the body when levels of sugar in the bloodstream rise. In small quantities, AGEs we produce or consume get neutralised in the body, but consume or create too many of them and your body can’t tackle them before they do harm. ‘AGEs cause a process called cross-linking which damages proteins in the body – and this damage is linked to ageing and disease,’ explains Professor Barbora de Courten from Monash University.
    The most obvious effect of this is the formation of wrinkles - cross linking causes collagen in the skin to stiffen and lose elasticity which creates the lines and folds we all develop as we age. However, in recent years, evidence of more medical forms of damage from AGEs is emerging. Researchers at Mount Sinai in New York, for example, have linked high intakes of AGEs with bone loss in the spine (osteoporosis) and an increased risk of fractures. High intakes of AGEs have also recently been linked to imbalance in our gut bacteria while a new Australian study says they could even reduce fertility. AGEs are strongly linked to increased levels of inflammation and oxidative stress in the body and if that inflammation occurs in the womb it’s believed to make it harder for an embryo to implant.
    Conversely, cutting out AGEs has shown positive effects in the body. In a trial by Professor de Courten, people swapping to a low AGEs diet for just two weeks increased their sensitivity to insulin – which is linked to a lower risk of type 2 diabetes (and better management of the condition in those already diagnosed). A trial at Mount Sinai University is the US also showed lowered insulin levels in response to decreased levels of AGEs in the diet – and also reported weight loss and lowered levels of inflammation.
    Results from our recent systematic review and meta-analyses conducted by professor de Courten which combined results from 17 trials and 560 participants show that low AGE diets improve levels or AGEs in the body, sensitivity to insulin, “bad” cholesterol levels, inflammation and oxidative stress levels. However, there was no effect on some other cardiovascular risk factors such as blood pressure. ‘This is likely because most individuals studied were people who had normal blood pressure and so there wasn’t a measureable change one could see,’ she told us. ‘Our results suggest that cutting out AGEs can prevent type 2 diabetes’ she said ‘but long term studies are needed to confirm this.
    (Section removed here for space)
    AGEs are found in foods containing fat or protein – particularly, meat, fish or dairy products - but what significantly influences the amount of AGEs in any food is how you cook it – incorrect preparation can turn even foods normally thought of as healthy like chicken, fish, nut or potatoes into AGEs bombs.
    ‘The higher the temperature and the less fluid involved in a cooking process, the more AGEs are formed when an item is cooked ,’ explains Professor de Courten. ‘Grilling, roasting and frying lead to high concentrations while steaming or stewing create fewer AGEs.’ What this means is that swapping to stewing chicken instead of grilling, poaching eggs rather than frying them and eating raw nuts over roasted can all make a noticeable difference in the number of AGEs in your diet without you having to give up your favourite foods completely.
    On top of this, AGEs are produced when a food burns. The more you brown something – like meat or toast – the more AGEs it will have, toasting a slice of bread increases the AGEs it contains by about a quarter for example. Try not to chargill or burn foods and adjust your toaster setting to the lowest level you can stand. Also, cook slowly – scrambled eggs cooked on a low heat contain about half the number of AGEs as those made quickly with high heat.
    If you are grilling or BBQing meat, you can also reduce the amount of AGEs formed by marinating meats beforehand. ‘Acidic marinades like those containing lemon juice limit the amount of AGEs formed,’ explains Professor de Courten. In one trial published in the Journal of the American Dietetic Association, marinating beef in lemon juice for an hour before grilling cut the amount of AGEs produced in half.
    Producer/AuthorHelen Foster
    URLreadnow.isentia.com/Temp/129111/979530563.pdf
    PersonsBarbora de Courten

Keywords

  • AGEs