Could a key culprit behind many of our life-threatening modern epidemics — such as children’s food allergies, type 2 diabetes, Alzheimer’s, heart disease and cancer — be a class of toxic substances found in everyday processed foods?
These substances are called advanced glycation end products (or AGEs). They occur to some degree in all foods, but are found at dizzyingly high levels in high-protein, high-sugar processed foods, such as pizzas, burgers, bacon and sausages.
They increase when these foods are cooked at very high temperatures — i.e. baked or fried, rather than steamed or boiled.
Over the past decade, scientists have established that AGEs (advanced glycation end products, including bacon sandwiches above) can provoke the body to react defensively, creating dangerous chronic inflammation, particularly in our vital organs [File photo]
The high heat causes their proteins and sugars to react together, making the products look temptingly browned, but also creating extremely high levels of AGEs.
The compounds occur naturally in other foods, but exist at much higher levels in processed foods — so, for example, an average serving of thin-crust pizza will contain hundreds of times more AGEs than a poached egg.
Over the past decade, scientists have established that AGEs can provoke the body to react defensively, creating dangerous chronic inflammation, particularly in our vital organs.
This inflammation is increasingly thought to increase the risk of heart disease and cancer and, more controversially, could be a significant factor in Alzheimer’s disease.
Could a key culprit behind many of our life-threatening modern epidemics — such as children’s food allergies, type 2 diabetes, Alzheimer’s, heart disease and cancer — be a class of toxic substances found in everyday processed foods? [File photo]
Now, new evidence revealed this month at the European Society for Paediatric Gastroenterology, Hepatology and Nutrition conference in Glasgow, has identified the effect AGEs can have specifically on children.
As the Mail reported, the study found that children with food allergies had far higher levels of AGEs in their bodies. They also ate far more junk food.
The paediatricians at Naples University in Italy studied more than 60 children in three groups: those with food allergies, those with respiratory allergies such as asthma, and those with no allergies.
Roberto Berni Canani, a professor of paediatric gastroenterology, who led the study, says it may be no coincidence that children’s food allergies have suddenly risen to around 10 per cent across Europe over the past two decades — and that, over a similar period, processed foods have increased ‘dramatically’ to constitute 50 per cent of European family diets.
‘As of yet, no existing theory adequately explains the dramatic increase that has been observed in children’s food allergies,’ he says. ‘Dietary AGEs in highly processed foods may be the missing link. Our study certainly supports this hypothesis.’
But how might AGEs cause children to develop food allergies?
Researchers are yet to tease out whether high levels of AGEs are a direct cause of cancer or a marker of generally poor lifestyle habits, such as being overweight and eating a bad diet, which can raise the risk of developing the disease [File photo]
Peter Smith, a professor of medicine at Griffith University in Australia has suggested a mechanism he calls the ‘false alarm hypothesis’. AGEs closely resemble specialised ‘warning’ molecules in our bodies called alarmins, which exist to trigger our immune defence systems against dying bodily cells that might otherwise fester and poison us.
So when, for example, we have a bruise or a cut, the body releases alarmin molecules that tell the immune system to expel the damaged cells from the body.
When children eat highly processed foods, the cascade of AGEs they ingest sets off a ‘false alarm’ in their guts, Professor Smith suggested in the Journal Of Allergy And Clinical Immunology in 2017.
This, in turn, triggers their still-developing immune systems to become oversensitive to harmless proteins in common foods such as wheat, eggs and milk.
But it is not only children who may suffer serious harm from AGEs. While adults seem far less susceptible to false alarm syndrome (possibly as their mature immune systems ignore AGE molecules), ageing metabolisms appear to become increasingly susceptible to the chronic inflammation that AGEs spark.
In 2015, a U.S. study in the Journal Of Clinical Biochemistry And Nutrition warned that high-calorie processed diets can overwhelm the body’s regulatory systems with toxic AGEs, precipitating a cascade of cell damage that may ultimately cause the insulin resistance characteristic of type 2 diabetes.
High AGE consumption may also raise the risk of heart attacks and strokes in people who don’t have diabetes. And it is being linked with a raised risk of cancer — another disease associated with chronic inflammation.
Researchers have repeatedly found through blood tests that patients with the disease have more AGEs in their bodies.
However, they are yet to tease out whether high levels of AGEs are a direct cause of cancer or a marker of generally poor lifestyle habits, such as being overweight and eating a bad diet, which can raise the risk of developing the disease.
However, AGEs seem to have an effect on people’s chances of surviving cancer, as U.S. oncologists warned last year in the journal Breast Cancer Research And Treatment. They found that when breast cancer cells that had stopped growing (thanks to the anti-tumour drug tamoxifen) were then exposed to AGEs in the lab, they began to grow again.
Several recent reports have also suggested that high AGE consumption could help to explain the rising toll of dementia and Alzheimer’s disease. In 2017, these conditions were the leading cause of death in England and Wales, accounting for more than one in eight of all deaths.
One report, in the Proceedings Of The National Academy Of Sciences in 2015, found that when laboratory animals ate diets high in AGEs, their cognitive abilities diminished. Furthermore, protein tangles called amyloid plaques proliferated in their brains. These plaques are characteristic of advancing Alzheimer’s.
The fundamental cause of the damage appeared, once again, to be chronic inflammation caused by the AGEs.
These findings should make us ‘a bit more worried’ about the quality of our diets, Tom Dening, a professor of dementia research at the University of Nottingham, told Good Health.
However, he added: ‘What still isn’t clear is how much AGEs contribute to Alzheimer’s disease compared with other factors [such as drinking, smoking and lack of exercise]. We also don’t know whether cutting back our consumption of AGEs would be helpful in prevention.’
While the jury remains out on how badly AGEs affect our bodies, experts agree cutting our consumption of them can only help.
Last year, a similar study by the German Institute Of Human Nutrition recommended that we incorporate a range of low-AGE foods in our diets, such as fruits and vegetables, butter and milk products including yoghurt.
‘All the available databases agree that the AGE content of fruit and vegetables is negligible,’ it said.
The way we cook is crucial, too, as ‘high-temperature cooking and processing techniques enrich AGEs in foods such as bakery products and processed meat’, added the report in the journal Ageing Research Reviews.
Scientists recommend that we steam or boil our meals, as this involves lower temperatures, and avoid excessively browning foods.
Professor Berni Canani wants to go much further, slapping taxes or bans on convenience foods.
According to Helen Bond, a registered dietitian and spokesperson for the British Dietetic Association, the emerging mass of research on AGEs brings a simple beneficial conclusion: ‘The answer once again is to concentrate on wholefoods and fresh foods that are gently prepared. How can that be a bad thing?’
How much is in your food?
AGEs are present in most raw foods, but some are naturally high in them, and the cooking method makes a difference.
Animal products high in fat and protein, such as meat, contain high levels of AGEs, as do higher-fat and processed cheeses — parmesan, for instance, contains three times as many AGEs as cheddar.
Vegetables, fruit and wholegrains contain quite low levels of AGEs, even after cooking.
Animal products high in fat and protein, such as meat, contain high levels of AGEs, as do higher-fat and processed cheeses — parmesan, for instance, contains three times as many AGEs as cheddar [File photo]
Using dry heat or ‘crispy’ cooking — frying, baking, grilling, barbecuing or roasting — increases AGE content. Adding moisture and cooking at lower temperatures or for a shorter time lower AGE content.
For example, by microwaving bacon for 3 minutes instead of frying it, you could reduce the AGE level by 1,000 per cent. Opt for poached eggs over fried, and raw nuts over roasted.
Processed and ready-made foods are also high in AGEs.
Here are ten of the highest AGE foods (measurements are in kU — kilo units — the number of AGEs per 100g) . . .
Bacon rasher, fried for 5 minutes with no oil: 91,577
Grated parmesan: 16,900
Olive oil: 11,900
Beef steak, pan-fried: 10,058
Chicken breast, breaded and deep-fried for 20 mins: 9,722
Walnuts, roasted: 7,887
Pizza, thin-crust: 6,825
Fried egg: 2,749
Figs, dried: 2,663
Source: Journal of the American Dietetic Association, 2013
Secrets of an A-List body
This week: Jennifer Lopez’s abs
The singer, 49, is fastidious about fitness and works out with different trainers on her travels
On the red carpet recently, Jennifer Lopez showed off an enviably toned midriff.
The singer, 49, is fastidious about fitness and works out with different trainers on her travels.
‘When I’m in New York, I work out with David Kirsch — he’s amazing,’ she has said.
‘In LA, I work with Tracy Anderson. I like the balance they both give me.’
Her exercises include kickboxing, circuit training with push-ups and burpees, and workouts that target her abs.
What to try: The push-up to plank will really work the core muscles.Start in the raised push-up position — legs extended and hands on the floor beneath your shoulders, arms straight and weight on the balls of your feet.
Lower yourself to your forearms one at a time. Push yourself back up to the start position one arm at a time. Repeat until you can do no more. Perform three sets.