Life Extension Magazine May 2003
As We See It
Eating Food Cooked At High
A new study published in the Proceedings of the National Academy of Sciences1 reveals that eating foods cooked at high temperature may increase the rate at which we age. According to this study, the ingestion of high temperature cooked foods causes chronic inflammation and the formation of advanced glycation end products.
Life Extension members have been frequently warned about the dangers of chronic inflammation and glycation. For the benefit of new members, I will succinctly explain these two lethal processes.
As humans age, there is a systemic increase in inflammatory cytokines (destructive cell-signaling chemicals) that contribute to many degenerative diseases. Rheumatoid arthritis is a classic disorder where excess levels of cytokines cause or contribute to the destructive inflammatory syndrome. While inflammatory cytokines can cause agonizing pain, they also disrupt the linings of our arteries, mutate DNA and degrade brain cells. Chronic inflammation is directly involved in diseases as diverse as cancer, atherosclerosis, diabetes, aortic valve stenosis, congestive heart failure, Alzheimer's disease and kidney impairment.
In aging people with multiple degenerative diseases, we often find elevated blood levels of C-reactive protein, indicating the presence of an inflammatory disorder. When a cytokine blood profile is conducted in these individuals, we usually discover excess levels of one or more of the pro-inflammatory cytokines. The most common pro-inflammatory cytokines are tumor necrosis factor-alpha, interleukin-6, interleukin-1(b) and/or interleukin-8.
Chronic inflammation inflicts devastating effects, especially as humans grow older. The lethal consequences of inflammation are clearly established in the medical literature.2-14 The good news is that many of the nutrients, hormones and drugs being taken by Life Extension members suppress the production of these deadly inflammatory cytokines. As you will soon read, avoiding foods cooked at very high temperatures can also reduce production of inflammatory cytokines.
Age-accelerating effects of glycation
The other pathological aging mechanism exacerbated by eating high temperature cooked food is the formation of advanced glycation end products (A.G.E.'s). Glycation can be described as the binding of a protein molecule to a glucose molecule resulting in the formation of damaged protein structures. Many age-related diseases such as arterial stiffening, cataract and neurological impairment are at least partially attributable to glycation. These destructive glycation reactions render proteins in the body crosslinked and barely functional. As these degraded proteins accumulate, they cause cells to emit signals that induce the production of inflammatory cytokines.
The glycation process is presently irreversible, though a recent study indicates a drug in clinical trials may be partially effective. Life Extension members take supplements to help protect against glycation. According to the Proceedings of the National Academy of Sciences study, consuming foods cooked at high temperature accelerates the glycation process, and the subsequent formation of A.G.E.'s.
A more succinct descriptive term for "advanced glycation end products" is "glycotoxin", since "advanced glycation end products" are toxic to the body. We will use the word "glycotoxin" from here on to describe the term "advanced glycation end products".
Cooking and aging have similar biological properties
Cooking foods at high temperatures results in a "browning" effect, where sugars and certain oxidized fats react with proteins to form glycotoxins in the food. Normal aging can also be regarded as a slow cooking process, since these same glycotoxins form in the skin, arteries, eye lenses, joints, cartilage, etc. of our body.
The Proceedings of the National Academy of Sciences study shows that consuming foods high in glycotoxins might be responsible for the induction of a low-grade, but chronic state of inflammation. In addition, the glycotoxins in food cooked at high temperatures also promote the formation of glycotoxins in our living tissues. The implication of these findings is profound.
Feeding foods rich in glycotoxins to diabetics
The presence of glycotoxins in the blood of individuals with diabetes has been known for quite some time.15 To ascertain reasons for this, a group of diabetics were studied to assess the difference between consuming a diet high in glycotoxins compared to diet low in glycotoxins. The high glycotoxin diet was induced by heating food for a longer period at higher temperatures compared to the lower glycotoxin diet. Using a variety of foods, the scientists were able to increase the glycotoxin content five-fold by cooking the food at high temperatures.
After only two weeks, diabetics on the high glycotoxin diet showed a 50% to 100% increase of glycotoxins in their blood and urine compared to the group consuming the low glycotoxin diet. The group eating the high glycotoxin food also showed increased levels of inflammatory blood markers such C-reactive protein and pro-inflammatory cytokines such as tumor necrosis factor alpha.
The researchers also found that eating diets low in glycotoxins reduced the level of other potentially harmful substances in the blood, including LDL cholesterol ("bad cholesterol"). During the two-week, low-glycotoxin diet, diabetics had lower LDL levels than those on a high-glycotoxin diet. A six-week, low-glycotoxin diet caused a 33% reduction of LDL, while a high-glycotoxin diet increased LDL by 32%.
Aging control and weight loss
This study on human diabetics raises intriguing possibilities of preventing disease and slowing aging via proper food preparation. First of all, previous studies have shown that caloric restriction prolongs life span in rodents while simultaneously decreasing glycotoxin formation in body tissues.16 There is now considerable evidence that the same glycotoxin formation that occurs during cooking also occurs inside the body during normal aging17 and at an accelerated rate in diabetics.18 For example, glycotoxins accumulate faster in the skin collagen of diabetics compared to non-diabetics.19 We also know that glycotoxins engage cell receptors in such as way as to promote tumor growth and metastasis (via mechanisms that stimulate cell migration, tumor cell growth factors and enzymes that digest the extracellular matrix).20
While this study on human diabetics is preliminary and needs confirmatory results in healthy populations, there were other benefits associated with consuming a low glycotoxin diet. Not only did the diabetics consuming the low glycotoxin diet lose weight, but their blood glucose levels also dropped. In the group eating the high glycotoxin diet, blood glucose levels increased. Elevated glucose levels can trigger production of deadly inflammatory cytokines.
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