Sugar affects brain power
By Jeanne Millsap Correspondent October 30, 2012 1:20PM
A recent study from the Mayo Clinic found that people whose diets are high in sugar have a higher likelihood of experiencing declining cognitive abilities as they age. | File photo
At A Glance
Want to cut back on the sugar in your diet? Here are some foods you might not realize are packed with sugar:
A dessert coffee. Example: Starbucks’ Java Chip Frappuccino has 66 grams sugar.
99 percent fat-free strawberry banana yogurt: 27 grams sugar. Suggestion: Use Greek yogurt and add fresh fruit.
Canned peaches and other fruit: 23 grams sugar in a half cup. Choose whole, natural fruit instead.
Baked beans: 14 grams sugar in a half cup.
hOat and honey granola bar: 12 grams sugar per two-bar serving.
Updated: December 1, 2012 6:08AM
If you want to keep your thinking as sharp as it ever was, you might want to make plans for throwing away that leftover Halloween candy.
A recent Mayo Clinic report found that those whose diets are laden with sugar have a much higher chance of experiencing declining cognitive abilities as they age. The October 2012 study published in the Journal of Alzheimer’s Disease looked at people 70 and older, but its author, Dr. Rosebud Roberts, a Mayo Clinic epidemiologist, said studies on younger adults show similar results.
“We see decline in memory and other cognitive domains,” Roberts said.
Those changes included mild cognitive impairment such as problems with memory, language, thinking and judgment.
The study found that people 70 and older who eat food high in carbohydrates have nearly four times the risk of developing mild cognitive impairment, and the danger also rises with a diet heavy in sugar.
Those who reported the highest carbohydrate intake at the beginning of the study were 1.9 times likelier to develop mild cognitive impairment than those with the lowest intake of carbohydrates. Participants with the highest sugar intake were 1.5 times likelier to experience mild cognitive impairment than those with the lowest levels.
“We think that sugar is driving this,” Roberts said.
Good sugars, bad sugars
Sugars are necessary for the body and the brain to function, but the way some sugars we eat enter the blood is worse for us than others. Simple sugars, such as those in most cookies, candies, cakes and other foods and drinks made with sugar, enter the bloodstream fast and can spike blood sugar levels, which damages tissue.
Highly refined grains like white flour and white rice are also easily broken down and can spike our sugars. Fruit juices also have simple sugars, and many physicians recommend no more than 12 ounces a day because of that, but they also contain elements that benefit us, such as vitamins, minerals and antioxidants.
Complex carbohydrates are digested directly into simple sugars, but the process is slow and the blood sugar levels rise more gradually than when we eat simple sugars.
“If sugar in the diet is high,” Roberts said, “we see this bad effect. ... A high carbohydrate intake could be bad for you because carbohydrates impact your glucose and insulin metabolism. Sugar fuels the brain, so moderate intake is good. However, high levels of sugar may actually prevent the brain from using the sugar.”
But Roberts’ team found that if their subjects ate more protein and fats relative to sugars and carbohydrates their brains’ thinking powers remained strong. That could be caused either by a healthful effect of proteins and good fats on the brain, she said, or it could be because people who eat more protein and fats usually eat fewer sugars and carbohydrates.
“Fat and protein are important in the brain,” she said.
Roberts said the biggest thing she wants people to take away from the study is that a well-balanced diet is optimal for good brain health, with not too much sugar.
“A well-rounded diet is important,” she said.
A diet of complex carbohydrates, such as whole grains and fruits, along with enough protein and healthy fats, she said, can help us keep sharp throughout our lives.