New data from the scientific literature is confirming that, which proponents of raw food diets have known for decades: raw food is healthy. The reasons have changed over the years, but the results are ever more clear.
One of the side effects of cooking food is the formation of substances, known as advanced glycation end products (AGEs). AGEs are bad for you; they cause oxidative stress in your body and are implicated in a host of diseases, including:
- Diabetes
- Insulin resistance
- Atherosclerosis
- Kidney damage
- Decreased vasodilation
- Increased vascular stiffness
- Obesity in children and adults
- Premature aging
The evidence shows that diets high in AGEs cause increases in oxidative stress. In fact a vicious cycle is set up between AGEs and oxidative stress, both of which cause increases in each other.
Where do AGEs form?
AGEs are produced in you body as a result of several different reactions. These involve completely different kinds of molecules (such as glucose, lipids and amino acids) but the product is a destructive AGEs molecule. Inflammation, for example, sets up a series of reactions that ends in the oxidation of amino acids and the formation of AGEs.
In food, sugars, amino acids and lipids can combine to form AGEs in a process that depends on the amount and type of:
- Proteins
- Lipids
- Carbohydrates
- Cooking temperature
- Cooking time
Our modern western diet, rich in fats that are broiled or grilled, are very high in AGEs. The following table, adapted from Peppa et al 2008, shows the AGEs values for different foods cooked differently.
Table 1. Thermal Exposure Determines AGEs Content of Common Foods
|
Foods |
AGEs*(U/g) |
|
Frankfurter, boiled x 7 min |
75000 |
|
Frankfurter, broiled x 5 min |
113000 |
|
Pork chop, pan fried x 7 min |
48000 |
|
Beef and pork links, pan fried |
54000 |
|
Chicken breast, skinless cutlet, raw |
8000 |
|
Chicken breast, skinless cutlet, boiled x 1 hr |
11000 |
|
Chicken breast, skinless cutlet, broiled x 15 min |
58000 |
|
Chicken breast, skinless cutlet, fried x 8 min |
74000 |
|
Chicken breast, skinless cutlet, microwave x 5 min |
15000 |
|
Chicken breast, skinless cutlet:-Roasted, barbecue sauce |
48000 |
|
Chicken breast, skinless cutlet:-Roasted, breaded |
46000 |
|
Chicken breast, skinless cutlet:-Roasted, breaded, microwave, 1 min |
57000 |
|
Salmon, raw |
6000 |
|
Salmon, smoked |
6000 |
|
Salmon, breaded, broiled x 10 min |
15000 |
|
Tuna, broiled with soy x 10 min |
51000 |
|
Tuna, broiled with vinegar dressing x 10 min |
51000 |
|
Tuna, roasted x 25 min |
9000 |
|
Tuna, white, canned in oil, Albacore |
17000 |
|
Egg yolk, boiled x 10 min |
12000 |
|
Egg yolk, boiled x 12 min |
19000 |
|
Egg white, boiled x 10 min |
400 |
|
Egg white, boiled x 12 min |
600 |
|
Egg white powder, cooked with margarine |
10000 |
|
Egg, fried with margarine |
27000 |
|
Almonds, roasted |
67000 |
|
Mayonnaise |
94000 |
|
Walnuts, roasted |
79000 |
|
*AGE denotes εN-carboxymethyl-lysine (CML),16 determined by ELISA (4G9). |
|
Notice the differences:
· Broiling a hotdog is a 51% increase over boiling the same dog. Don’t forget that hotdogs have already been thoroughly cooked when you purchase them at the store.
· Boiling a chicken breast has only minor effect on its AGEs
· Broil it, though an you have a 625% increase in AGEs
· Fry it for 8 minutes and the increase jumps to 825%!
· Smoking salmon has no effect but broiling more than doubles the AGEs
· Canned tuna has almost twice the AGEs as roasted fresh (wow!)
· Boil an egg yolk for 2 minutes more and the AGEs content goes up almost 50%.
· No matter what you do to an egg white, it is always low.
What are our defenses?
Besides avoiding high fat foods that are broiled to dryness (actually a very effective measure), there are many defenses available to us:
- Your body has its own mechanisms of detoxifying itself of AGEs. These include enzymatic degradation, proteins that trap and sequester them and urinary excretion.
- Powerful antioxidants in the diet can help to neutralize AGEs and prevent their damage. They can also help block the vicious cycle between AGEs and oxidative stress.
Still, one of the best measures you can take is to poach, steam or stew foods instead of frying, broiling or roasting them. You can also avoid foods high in fats. Changing your diet can have very quick results in your blood profiles and the health of your blood vessels.
Or go raw.
Peppa M, Uribarri J, Vlassara H.2008. Aging and glycoxidant stress. Hormones (Athens). 2008 Apr-Jun;7(2):123-32
Vlassara H, et al. 2009. Protection against Loss of Innate Defenses in Adulthood by Low Advanced Glycation End Products (AGE) Intake: Role of the Antiinflammatory AGE Receptor-1. J Clin Endocrinol Metab. 2009 Nov;94(11):4483-91.
