Reversing Insulin Resistance For Better Health and Mental Sharpness
Insulin Resistance Basics
Insulin is a hormone released from the pancreas that helps the body use glucose or sugar in the blood. Insulin binds to receptors on cells like a key would fit into a lock. Once unlocked, glucose can enter cells to be used as energy or stored for future use. Insulin resistance occurs when the normal amount of insulin secreted is unable to unlock the doors of muscle, fat and liver cells. In order to maintain healthy levels of blood glucose, the pancreas must compensate by making and releasing additional insulin.
Insulin Resistance Leads to Bigger Problems
Eventually the pancreas isn't able to keep up with the demand for more insulin and excess glucose builds up in the bloodstream setting the stage for pre-diabetes. Studies have shown that most people with pre-diabetes go on to develop type 2 diabetes within 10 years if they don't make lifestyle changes.
Insulin resistance and pre-diabetes also raises the risk of heart disease. Many people with insulin resistance have excess weight around the waist (40" for men, 35" for women), low levels of the good HDL cholesterol (below 40 mg/dL for men, 50 mg/dL for women), high triglycerides (150 mg/dL or more), high blood pressure (130/85 mm), and small dense LDL particles (the "bad" cholesterol). This cluster of problems is referred to as the metabolic syndrome or insulin resistance syndrome.
The Insulin and Memory Connection
At the recent 3rd Annual World Congress on Insulin Resistance Syndrome in San Francisco, Dr. Suzanne Craft presented cutting edge research findings on how insulin affects the brain. According to Dr. Craft, how an older person's body processes insulin can also affect their memory.
Normally, the insulin secreted after eating can enhance memory. Researchers theorize that this action of insulin evolved to help primitive people remember where to find food. But while optimal insulin levels may help us remember the location of our favorite restaurant in today's world, too much of a good thing may contribute to brain aging and memory impairment later in life.
The chronically high insulin that occurs when the body is resistant to insulin can decrease glucose metabolism in certain brain circuits and provoke inflammation along with free radical damage. Finally, insulin that is too high may also raise the risk of Alzheimer's by promoting the release of beta-amyloid and slowing its breakdown. Beta-amyloid is the major protein found in the plaque and nerve tangles of Alzheimer's patients.
In a series of studies, Dr. Craft and her colleagues found that an anti-diabetic drug which makes the body more sensitive to insulin can improve mental function and memory recall in older patients with insulin resistance, including those diagnosed with early Alzheimer's. Treatments that can reduce high levels of circulating insulin and improve insulin sensitivity are promising therapeutic avenues for some older people with impaired memory, Dr. Craft concluded.
Can You Reverse Insulin Resistance?
Yes! According to Dr. Gerald Reaven who chaired the World Congress meeting, about 50% of insulin resistance and the metabolic syndrome can be attributed to underlying genetic susceptibility, while inactivity and being overweight contribute about 25% each. Physical activity and weight loss make the body more responsive to insulin. Exercise makes muscle cells more sensitive to insulin because they need it for energy. And reducing extra fat tissue around the middle is especially helpful because the fat distributed there is more metabolically active.
Be Active and Eat Well
Results from the 2001 Diabetes Prevention Program, an NIH-sponsored clinical trial, confirmed that losing weight - even just 5-7% of your body weight - and walking briskly or riding a bike 5 times weekly, can reduce the risk of diabetes by 58% in those with pre-diabetes. An estimated 39% of Americans have some degree of insulin resistance, and it usually has no overt symptoms. So as we set our health goals for 2006, remember that fighting fatness and improving fitness isn't optional. It is absolutely essential.