Which Decreases Insulin Sensitivity--Food Cooked at High Heat, Low Heat, or Raw and Low Heat?

University of California, Davis studies how foods cooked at high heat may contribute to prostate cancer, especially in African-American men. Check out the article, "Well-done meat may be a culprit in prostate cancer, especially for African-American men." In the ongoing study, the 600 men, ages 50 to 70, may provide answers to a grim mystery: Why do African-American men have the highest prostate cancer rate of any group of men in the world?

The UC Davis team of scientists launched the study to test an intriguing hypothesis: African-American men are at high risk of prostate cancer because they consume very high quantities of carcinogens formed in cooked meats, where the meats are cooked at high-heat, such as grilling, roasting, or deep-frying.

The hypothesis stemmed from decades of research conducted by James Felton, co-leader of UC Davis Cancer Center's Cancer Etiology, Prevention and Control Program and division leader of the Biosciences Directorate at Lawrence Livermore National Laboratory. Felton and Bogen are among the 40 Lawrence Livermore scientists who work as members of UC Davis Cancer Center's Integrated Cancer Research Program, the first formal research partnership uniting a major cancer center and a national laboratory.

Preliminary results from the Oakland, CA study suggest there is indeed a significant dose-response: Not only did the study participants have high PhIP intakes, but the higher their intakes, the higher their PSA levels. PSA, for prostate-specific antigen, is a bloodstream marker for prostate damage and early prostate cancer. The findings were published online in the Jan. 16, 2007 issue of Prostate Cancer and Prostatic Diseases. Now let's skip to October-November 2010 for the latest news in a different study noted this week in the Townsend Letter.

In another recent study published in the American Journal of Clinical Nutrition, of which a summary also is published in the November, 2010 issue of the Townsend Letter(page 37), "Cooking Methods Affect Insulin Sensitivity," 62 young, healthy volunteers (ages 18-24) consumed each of two diets for a month each. One group ate food cooked at high temperatures. The other group ate meals cooked at low temperatures with some raw foods.

The conclusion of that study noted that compared with the low-heat treated diet, the high-heat treated diet significantly decreased insulin sensitivity by 17%. You can read the study's abstract, "A diet based on high-heat treated foods promotes risk factors for diabetes mellitus and cardiovscular diseases." American Journal of Clinical Nutrition, 2010;91:1220-1226. Birlouez-Aragon I, et al. (May 2010).

What this means is that when the participants ate some gently steamed foods and some raw foods, their insulin responses were better than those who ate foods cooked at high temperatures. What happens when food is cooked at high temperatures is that AGE's are formed during the cooking process.

In the food cooked at high heat, a reaction occurs in the heat-treated food. The AGEs are formed during cooking of food by a reaction between a reducing sugar that may be glucose, fructose, or lactose, and a protein or amine-containing lipid. A lipid refers to fat or oil.

Then the AGEs are absorbed from food as they are (intact) and they AGEs stay in your tissues. They persist there, where they start to change the protein structures in your body.

AGEs promote inflammation. And AGEs appear to play a role in developing some cardiovascular diseases, complications of diabetes, and fibromyalgia. The study suggests that AGEs could also cause insulin resistance in some people.

Then again, you may or may not need a predisposition or genetic tendency to develop insulin resistance. So the research goes on. Basically, you don't want to eat AGEs formed in food that was cooked with high heat.

In the study, the high-heat treated diet consisted of foods that were grilled, fried, and roasted. The diet also contained commercial foods known to be cooked with high heat such as various brands of 'extruded' corn flakes, sponge cakes, coffee, dry cookies, and "well-baked" bread with brown crusts.

The low-heat treated diet included raw foods and foods that were steamed, including steamed corn flakes and steamed sponge cakes and 'mildly' baked bread. Then the AGEs in the foods were measured.

Scientists were looking for the 'carboxymethyllysine' content of the diet. In the low-heated diet, that chemical's content measured 59% lower than the high-treated diet.

The scientists compared the low-heated diet with the high-heated diet. And the outcome? The high-heated diet decreased insulin sensitivity by 17%. You don't want your sensitivity to insulin to be decreased. If your sensitivity to insulin is decreased, it means your body keeps pouring out more and more insulin to try and bring down glucose/sugar levels or high sugar spikes in your blood as starches turn to sugar, for example, from eating foods high on the Glycemic Index.

Because your body no longer is sensitive to insulin or responds as well to it, the high level of insulin in your blood may lead to health problems such as cardiovasular disease, metabolic syndrome, hypertension, hardened arteries, high triglycerides, type 2 diabetes, inflammation, and possibly some types of dementia or vascular problems.

Also check out this other study that showed that consumption of a number of grains and grain extracts has beenreported to control or improve glucose tolerance and reduceinsulin resistance. See the study's abstract, "Mechanisms of the Effects of Grains on Insulin and Glucose Responses," Journal of the American College of Nutrition, Vol. 19, No. 90003, 320S-325S (2000). Published by the American College of Nutrition.

According to the study's abstract, the inability of the body to maintain normalglucose levels or to require excessive levels of insulin todo so has been called glucose intolerance, impaired glucose tolerance and insulin resistance. These conditions are associated with obesity and may be preliminary steps in the progressionto type 2 diabetes mellitus.

Although dietary goals recommendthe consumption of three servings of whole grains per day, averageconsumption in the United States is less than one serving perday. There are a number of mechanisms by which grains may improveglucose metabolism and delay or prevent the progression of impairedglucose tolerance to insulin resistance and diabetes.

Thesemechanisms are related to the physical properties and structureof grains. The composition of the grain, including particlesize, amount and type of fiber, viscosity, amylose and amylopectincontent all affect the metabolism of carbohydrates from grains. Increasing whole grain intake in the population can result in improved glucose metabolism and delay or reduce the risk of developing type 2 diabetes mellitus.

Whole grains can providea substantial contribution to the improvement of the diets ofAmericans. A number of whole grain foods and grain fiber sourcesare beneficial in reduction of insulin resistance and improvementin glucose tolerance.

Form, amount and method of cooking ofthese foods as well as the health characteristics, age and genderof the group of subjects studied are all important factors inthe effectiveness of the foods in altering these responses.

Dietary recommendations of health organizations suggest consumptionof three servings a day of whole grain foods; however, Americansgenerally fall below this standard. Recent research using variousgrains and grain products effective in improving insulin resistanceor lowering glycemic index are discussed in the study.

The problem with this study is that it doesn't suggest in the abstract, what people who can't eat grains can do to improve insulin resistance. Common sense would tell those who can't eat grains to generally eat low on the Glycemic Index, choosing foods they can eat without discomfort or adverse reactions.

Examples might be gluten-free foods, bean, chick-pea, green pea, or legume flours, sweet potato flours, or some nut meals or flours. Better yet, get a good dry grinder and grind your own flours or meals from foods that work best for you, when you need flours.

On another note, you might look at the site, Medical Myths that Even Doctors Believe. Also check your public or local area university library to see if it has the November 2010 issue of the Townsend Letter (The Examiner of Alternative Medicine).

Another area of research you might look into is how many people, including doctors, know that most B vitamins are synthetic and typically derived from coal tar? Are your vitamin B supplements derived from a patented probiotic-based process? In such a process, probiotic organism manufacture and suspend high energy (normally unstable) B vitamin forms, including the elusive acetyl coenzyme A and other processes.

Are you taking active, 'living' B vitamins in their end-chain forms? Does your vitamin B hve a cellular resonance? Or are they synthetic? Check out natural source B vitamin complex made from proprietary probiotic fermentation where the end-chain forms of B vitamins are ready for use by each of your cells.

You never know how your vitamins are made. For more information on probiotic vitamins compared to synthetic ones, you might take a look at the website for Premier Research Labs. Then use common sense and make up your own mind if you are interested in learning more about where your vitamins may come from and where they are headed.

If you're really serious about studying nutrition for personal use by reading a textbook just to give yourself the benefit of learning all about nutritional medicine so you can discuss your diet with health care professionals, you might also benefit from reading the more than 1,300 pages and 15,000 reference citations of the textbook, Nutritional Medicine, by Alan R. Gaby, M.D. The textbook also is geared to teach healthcare practitioners nutritional therapy as an alternative or adjunct to conventional medicine. Maybe there's something you'd like to know that your own doctor hasn't had the time to read yet.