Addressing Metabolic Syndrome

Multi-functional nutritional ingredients may stop the progression of metabolic syndrome

References

Metabolic syndrome is a convergence of cardiovascular disease (CVD) and diabetes risk factors—including being overweight/obese, high blood pressure, abnormal blood lipids and blood glucose abnormalities—connected by insulin resistance. While a relatively new term, and one that is still not officially recognized in some mainstream medical circles, its profile is rising with mainstream media attention.

Researchers from the University of Minnesota recently reported not only does the Western dietary pattern—high intakes of refined grains, fried foods and red meat—significantly increase the risk of developing the disorder (by 18 percent), but drinking diet soda raised the risk by 34 percent.¹ In their study, 60.5 percent of the population (n=9,514; ages 40 to 64 at baseline) had metabolic syndrome at baseline or developed it during the nine-year followup. It’s not only adults who are facing rising rates of metabolic syndrome; new research suggests about 9 percent of U.S. teenagers have metabolic syndrome, with incidence rising to one in four obese teens.²

A recent study from the Joslins Diabetes Center, Boston, specifically identified insulin resistance in the liver as a key factor in the development of metabolic syndrome and the associated cardiac pathologies.³ Using liver insulin receptor knockout (LIRKO) mice, which have pure hepatic insulin resistance, the researchers found an atherogenic diet caused LIRKO mice to develop severe atherosclerosis, beyond the dyslipidemia developed on a standard chow diet.

In insulin resistance, there is a reduction in the number of insulin receptors sites on the cell wall. The result of this, according to a review of the etiology of metabolic syndrome, produced by Albion Advanced Nutrition, is that glucose cannot be efficiently transferred by insulin through these receptor sites from the bloodstream into the cell to be burned as energy. This causes elevated blood sugar levels. This blood sugar is carried into the liver, where it is converted to fat that can be transferred and stored throughout the body, the end result being weight gain. Additionally, the conversion of these sugars to triglycerides leads to unhealthy blood lipid levels, which can lead to CVD.

The American Heart Association (AHA) and the National Heart, Lung, and Blood Institute (NHLBI) recommend metabolic syndrome be identified as the presence of three or more of the following components: elevated waist circumference; elevated triglycerides; reduced high-density lipoprotein (HDL) cholesterol; elevated blood pressure; and elevated fasting glucose. Lifestyle therapies are considered first-line interventions for managing both long- and short-term risk, including fat loss, increased physical activity, and following a healthy diet with a reduced intake of saturated fat and cholesterol, and an emphasis on whole grains, fruits and vegetables, fish and lean protein, and low-fat dairy.

Obesity appears to be one of the driving forces behind metabolic syndrome. Italian researchers reported a literature review found the most striking resolution of metabolic syndrome based on different approaches was with weight-reduction surgery, in which 93 percent of cases were resolved.⁴ At the same time, the researchers acknowledged it is likely a more Mediterranean-style diet may be a less drastic intervention, while offering a workable dietary pattern: lower content of refined carbs, high fiber, moderate intake of fat (mostly unsaturated), and a moderate-to-high content of vegetable proteins. Spanish researchers seconded the use of a Mediterranean-style diet to address not only fat loss, but also to help control inflammation.⁵

A one-year trial out of Italy supports this suggestion, as adults who followed a lifestyle intervention with diet and exercise (n=169) significantly reduced metabolic syndrome incidence, central obesity and diabetes risk, compared to control subjects who were only given general information.⁶ Data from the Framingham-Offspring study concluded women with higher nutritional risk profiles (more total fats, more alcohol, less fiber, less micronutrients) had a two- to three-fold risk of developing abdominal obesity and metabolic syndrome.⁷

Whole grains and fiber are particularly cited by researchers for health benefits that translate into the area of metabolic syndrome. A review out of the University of Granada, Spain, noted dietary fiber could play a key role in managing metabolic syndrome through multiple mechanisms of action, including aiding weight management, supporting glucose and lipid homeostatus, enhancing insulin control, and regulating inflammatory markers.⁸ Italian researchers found in a cohort of 1,653 adults, prevalence of metabolic syndrome significantly decreased from the lowest to the highest tertile of fiber and magnesium intake, with subjects in the lowest tertiles three- to four-times as likely to have metabolic syndrome.⁹ Further, an intervention study at Pennsylvania State University College of Medicine, Hershey, involving 50 obese adults with metabolic syndrome, concluded a hypocaloric diet with an emphasis on whole grain intake had greater reductions in inflammatory markers and abdominal fat, compared to those consuming refined grains.¹⁰

Researchers have also found benefits of specific types of fibers in addressing different aspects of metabolic syndrome. Oat beta-glucan (as Viscofiber®, from Natraceutical Canada) was the subject of two clinical studies at St. Michael’s Hospital, Toronto. In the first study, Viscofiber was compared to a less-viscous oat betaglucan and found to be more effective at suppressing postprandial glycemia in healthy individuals.¹¹ The second study, which is in preparation for publication, examined the effect of oat and barley Viscofiber on postprandial glycemia and plasma insulin in healthy individuals, and found a dose-dependent reduction in both indices. Studies have further found intervention with Viscofiber can assist in weight loss by increasing satiety;¹² and oat beta-glucan helps reduce serum cholesterol,¹³ and hypertension.¹⁴

A research review out of Pakistan reported guar gum may have a role to play in addressing metabolic syndrome, as its soluble dietary fiber content may improve cholesterol levels, aid in glycemic control and support weight management.¹⁵ Animal research out of Spain found long-term intake of guar by healthy rats improved glucose tolerance and insulin response to glucose absorption.¹⁶

The type of fat in the diet is also an important factor in managing metabolic syndrome. A review out of Cape Breton University, Nova Scotia, noted consumption of the long-chain omega-3 essential fatty acids (EFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) particularly benefits metabolic syndrome by impacting dyslipidemia and platelet aggregation, in addition to possibly reducing conversion of metabolic syndrome to type 2 diabetes.¹⁷ To wit, a population study in Alaska natives found consumption of long-chain omega-3 EFAs from fish were associated with lower blood pressure and triglyceride levels, as well as lower fasting insulin; higher consumption of saturated fat and trans fats increased triglyceride levels and blood pressure, with adverse effects on metabolic syndrome.¹⁸ Researchers from the University of Litoral, Santa Fe, Argentina, examined the impact of fish oil on dyslipidemia, insulin resistance and adiposity in rats.¹⁹

They found fish oil reversed dyslipidemia, improved insulin activity and reduced weight; part of its activity was linked to a reduction in adipocyte cell size, making them more insulin sensitive and reducing the release of fatty acids.

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