2012 December 5 by Dr. Randy
A new, eye-opening study has taken the novel approach of examining a country’s high fructose corn syrup (HFCS) consumption and correlated that with the incidence of diabetes. This study examines the long-suspected assumption that corn syrup contributes to the rapidly and consistently increasing rise in diabetes in developed countries. No surprise that in this study a high HFCS use by consumers is associated with a higher incidence of diabetes in that country.
The study published in the journal Global Public Health compared 43 countries (Goran et al, 2012). Half of those countries had little or no corn syrup in their foods or citizens’ diets. Countries that consume none or very little HFCS include India, Ireland, Czech Republic, Austria, France, and China. The highest HFCS consuming countries include the US, Mexico, Canada, and Japan. The United States is by far the greatest consumer and the greatest producer of corn syrup. The average American consumes 55 pounds of HFCS per year. Far more than any other country.
Those countries that consume greater amounts of HFCS have a 20 percent higher incidence of diabetes compared to countries that use none or low amounts. This result was unchanged when the study controlled for possible confounding factors such as body size, carbohydrate consumption, and population size.
Corn syrup (fructose) when eaten in excess causes negative metabolic effects including excess weight gain with accumulation of fat and insulin resistance (Stanhope et al, 2009). Insulin resistance leads to diabetes, and this study shows the clear association between corn syrup and the rise in diabetes rates.
Eliminate corn syrup and HFCS from your diets. Avoid processed foods that contain corn syrup, including highly sweetened electrolyte drinks like Gatorade and other soft drinks. Other processed foods that may contain corn syrup include yogurt, breakfast cereals, salad dressing, ketchup, and protein bars.
Goran MI, et al. High fructose corn syrup and diabetes prevalence: A global perspective. Journal of Global Health, 2012, Nov. 28, published online ahead of print.
Stanhope KL, et al. Consuming fructose-sweetened, not glucose-sweetened, beverages increases visceral adiposity and lipids and decreases insulin sensitivity in overweight/obese humans. Journal of Clinical Investigation, 2009, 119 (5),1322-1334.
2012 May 25 by Dr. Randy
A recent study in rats examined the effect of omega-3 fats (particularly DHA) and fructose on memory. Rats were trained to solve a maze and then given either a diet with omega-3 fats (DHA and flax seed oil) or one deficient in omega-3 fats. Each group was further divided into those also fed high-dose fructose in their drinking water or not. The group that was fed the fructose showed impairment of memory and took a longer time to solve the maze than prior to eating fructose. Those fed an omega-3 deficient diet and fructose fared the worst in the memory task. The rats fed fructose and omega-3 fats did better.
The conclusion of this study was that rats fed fructose had impairment of their ability to solve a maze because of memory deficits. Those given DHA and fructose had an improvement in their memory. The mechanisms involved in the memory impairment seemed to be a direct result of brain insulin resistance induced by fructose and ameliorated by taking DHA.
This study is the first to document insulin resistance and metabolic syndrome effects in the brain. And it suggests that taking DHA improves insulin metabolism, even with a diet containing fructose that induces insulin resistance.
Conclusions from the study
We can derive several take home messages from this simple study. We already know that the epidemic of obesity, insulin resistance, and diabetes is in large part due to the consumption of high fructose corn syrup in the American diet. This study tells us that fructose also results in dysfunction in the brain associated with insulin metabolism. It also confirms the importance of DHA for brain function.
Here are the words of the authors. “These findings expand the concept of metabolic syndrome affecting the brain and provide the mechanistic evidence of how dietary habits can interact to regulate brain functions, which can further alter lifelong susceptibility to the metabolic disorders.”
What you should do
Obesity and metabolic syndrome play a huge part in the epidemic of chronic inflammatory diseases including heart disease, cancer, and diabetes. Now we see that mental impairment is another part of this picture. Studies like this warn us that high fructose corn syrup should not be an ingredient in any foods in our diets. Unfortunately, corn syrup is a primary ingredient in many packaged and processed foods. Read labels and choose products sweetened with other sources of sugar or more natural sweeteners like stevia, sorbitol, or xylitol. It is always better to choose foods sweetened with sugar than corn syrup. Assume that any sweetened drinks from vending machines or restaurants will have corn syrup. Of course, it is best to eat unprocessed whole foods and avoid processed foods and juices. The natural fructose in fruit is not harmful in moderate amounts. And supplements like omega-3 fats along with antioxidants can provide extra benefit for mental functions as well.
Agrawal R and Gomez-Pinilla F. ‘Metabolic syndrome’ in the brain: deficiency in omega-3 fatty acid exacerbates dysfunctions in insulin receptor signalling and cognition. The Journal of Physiology, May 1, 2012, 590, 2485-2499.