May 31, 2011 at 8:27 AM ET
Do you ever forget people's names? Enter a room and forget why you went there? Forget a word mid-sentence? As we get older, these types of "senior moments" happen more often. Many of the people I evaluate worry that these slips mean they are getting Alzheimer's disease. In most cases, they aren't. They're just part of normal, age-related memory decline. Starting at about age 30, our ability to process and remember information declines with age.
But though these cognitive changes are common, cognitive decline is not inevitable. Recent research has identified specific brain alterations that underlie this kind of age-related cognitive decline. And the good news is that many of these brain changes can be prevented with healthy lifestyle practices. A key finding: Elevated blood sugar contributes to cognitive decline.
The details: It has long been known that problems with short-term memory are related to age-related decreases in blood flow in a part of the brain called the hippocampus. Recently, researchers at Columbia University Medical Center discovered that decreased blood flow to the hippocampus is related to elevated blood sugar levels. Scott Small, MD, the lead investigator, said the effects can be seen even when levels of blood sugar, or glucose, are only moderately elevated. This finding may help explain normal age-related cognitive decline, since our body's ability to regulate blood glucose levels worsens with age.
Your brain's primary fuel is glucose. If your blood sugar level drops too low, you'll have trouble paying attention, learning, and remembering information. But if your sugar level is consistently too high, the body pumps out excess insulin, which causes inflammation and oxidative stress that prematurely age your brain. So, a cup of coffee with sugar and a bagel can be just the thing to get you going in the morning: It quickly gets glucose into your brain and enhance your cognitive functioning. But over the long term, consuming a large volume of sugar — and foods that are quickly converted by your body into sugar — will prematurely age your brain.
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What it means: Like so many things, it's about balance. A key to healthy cognitive function as you age is maintaining good blood sugar regulation, preserving your body's ability to keep your blood sugar neither too high nor too low. The primary ways to do this are through exercise and diet. A healthy diet keeps you from overdosing on sugar, and regular aerobic exercise increases insulin sensitivity, enabling the cells of your body to efficiently utilize glucose for energy. This is a big part of why you feel more energetic when you exercise regularly, plus, it means your body doesn't have to produce as much insulin to get the job done.
Here are some ways to keep your sugar levels balanced, overcome sugar addiction and cravings, and keep your cognition in good working order:
Minimize your intake of sugar, and of the refined carbohydrates that your body quickly converts into sugar. When it comes to carbs, stick with fruits, vegetables, and whole grains. The fiber in these foods helps your body maintain consistent blood sugar levels and reduces cravings for more carbs. Avoid highly processed carbs, found in many cakes, cookies, breads, cereals, and pasta products.
Eat healthy carbs with protein, which further enables your body to maintain consistent blood sugar levels. Eating protein stimulates your liver to produce glucagon, which slows down the absorption of glucose and makes it available longer.
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Eat healthy fats like omega-3 fatty acids. These also help to balance your blood sugar.
Get regular aerobic exercise. This is the main way to increase insulin sensitivity and healthy glucose metabolism. Exercise also stimulates production of brain-derived neurotrophic factor (BDNF), a substance that promotes the growth and connectivity of new brain cells.
Be aware of your blood glucose level. If it's creeping up as you age, talk with your doctor about strategies for keeping it lower. With healthy lifestyle modifications, you can prevent type 2 diabetes, and stave off its precursor, insulin resistance, while also keeping your brain sharp.
Manage stress well. Prolonged, excessive stress can damage and impair functioning of the hippocampus. Slow, rhythmic breathing exercises and meditation can help to quiet the mind, relax the body, and reduce the effects of stress.