June 29, 2010

High antioxidant diet improves insulin sensitivity in obese men and women

The Endocrine Society's 92nd Annual Meeting held in San Diego was the site of a presentation on June 21, 2010 of the findings of a study involving adults with metabolic syndrome which found an improvement in insulin resistance among participants who received a diet enriched with antioxidant nutrients.

Metabolic syndrome is a cluster of risk factors that includes increases in waist circumference, blood pressure, fasting glucose and triglycerides, and a reduction in high density lipoprotein (HDL) cholesterol. Individuals with three or more of these conditions have a reduced ability to utilize insulin, and are at an increased risk of developing cardiovascular disease and diabetes.

"Oxidative stress could play an important role in metabolic syndrome-related manifestations contributing to insulin resistance," write endocrinology researcher Antonio Mancini, MD and his associates at Rome's Catholic University of the Sacred Heart in the abstract summarizing their research. "The reciprocal influences between oxidative stress and insulin resistance are not clear."

The study included 16 men and 13 women aged 18 to 66 years with insulin resistance and obesity. All participants received a diet that provided 1,500 calories per day for three months. Half of the participants' diets contained fruits and vegetables that provide high amounts of antioxidant nutrients. The subjects were further divided into groups that received or did not receive 1000 milligrams per day of the drug metformin, which improves insulin sensitivity in patients with type 2 diabetes. Body mass index, glucose tolerance and other factors were assessed at the beginning and end of the study.

While all participants experienced similar decreases in body mass index, only those that received the antioxidant-enriched diet had significant reductions in insulin resistance, with the greatest benefits observed in those who also received metformin.

The ability of antioxidants to help reduce oxidative stress may help protect against a number of conditions, including metabolic syndrome. "The beneficial effects of antioxidants are known, but we have revealed for the first time one of their biological bases of action—improving hormonal action in obese subjects with the metabolic syndrome," Dr Mancini stated.

Diabetes

In the early stages of type 2 diabetes, insulin levels are already elevated (hyperinsulinemia). This is because the problem isn’t with insulin production; rather, the underlying defect in type 2 diabetes is a metabolic defect of insulin utilization. The delicate insulin receptors on cell membranes are less responsive to the insulin than are the insulin receptors of people without type 2 diabetes, which means that less glucose is absorbed from the bloodstream than would be normally, and glucose levels slowly rise.

This elevation in glucose upsets the body’s natural balance, prompting the pancreas to discharge copious amounts of insulin to normalize glucose levels. This short-term, biological fix successfully drives glucose into cells, thereby lowering blood glucose levels, but it also hastens the disease’s progress. Eventually, the fragile insulin receptors become less sensitive (insulin resistant), which means that the pancreas must secrete even more insulin to keep clearing the blood of glucose. In later stages of the disease, the pancreas becomes “burned out” and can no longer produce adequate insulin. Insulin levels drop far below normal, allowing blood glucose to rise even higher and inflict greater damage.

The high-carbohydrate, high-plant-fiber (HCF) diet popularized by James Anderson, MD, has substantial support and validation in the scientific literature as the diet of choice in the treatment of diabetes (Anderson JW et al 2004; Hodge AM et al 2004). The HCF diet is high in cereal grains, legumes, and root vegetables and restricts simple sugar and fat intake. The caloric intake consists of 50 to 55 percent complex carbohydrates, 12 to 16 percent protein, and less than 30 percent fat, mostly unsaturated. The total fiber content is between 25 and 50 g daily. The HCF diet produces many positive metabolic effects, including the following: lowered postmeal hyperglycemia and delayed hypoglycemia; increased tissue sensitivity to insulin; reduced low-density lipoprotein (LDL) cholesterol and triglyceride levels and increased high-density lipoprotein (HDL) cholesterol levels; and progressive weight loss.

Life Extension Vacations
Start enjoying life the Caribbean way!

Enjoy our Caribbean Resorts at prices up to 50% off the lowest rates of the year - with lots of fun freebies included!

• Personal Concierge - always at your service!
• Meet and greet orientations
• Welcome cocktail parties
• Water aerobics
• Kids' activities
• Shopping trips
• Beach activities including kayaks, beaching volleyball and more!

This Life Extension special offer is available for booking by July 31, 2010 and travel completed by November 20, 2010.

Offer subject to availability. Limited to new reservations only.

Call 1 888 215 4402 to take advantage of our Sensational Summer Savings. Space is limited. Call today - from 8 a.m. to 8 p.m. CT.

*Please note that Life Extension Vacations is not affiliated with or a part of the Life Extension Foundation®, which supports anti-aging research, or the Life Extension Foundation Buyers Club.
http://www.royalresortscaribbean.com/lef-promotion.php

Life Extension Update

• Vitamin C deficiency linked to metabolic syndrome components in young adults
• Higher plasma vitamin C levels linked with lower diabetes risk
• Alpha and gamma-tocopherol reduce oxidative stress and inflammation markers in metabolic syndrome patients

What's Hot

• Grapes reduce metabolic syndrome in animal study
• Low selenium levels associated with impaired blood glucose in men
• Higher carotenoid levels associated with reduced diabetes risk in nonsmokers

Life Extension Magazine®

• Insulin resistance—a lethal link between metabolic disease and heart attack
• Metabolic syndrome

If you have questions or comments concerning this issue or past issues of Life Extension Update, send them to ddye@lifeextension.com or call 954 202 7716.

www.lef.org
Sign up for Life Extension Update

For Customer Service inquiries, please email customerservice@lifeextension.com or call 1 800 678 8989.

For copyright permission, please refer to Life Extension copyright policy.