It’s common to have a few “senior moments” of memory loss here and there over the age of 50. It’s one of the most frequent complaints I hear from my patients. You forget where you put your glasses, you can’t recall someone’s name, or you forgot about that appointment you had.

But, even though these types of memory glitches are common, they could actually be telling you that your brain may not be getting the nutrition it needs. In addition, recent research has found that a certain ingredient in common foods may actually be contributing to your memory fall outs. Here’s what you should know…

Sweetener Fructose May Be Souring Your Memory

Many people don’t realize that your brain is very sensitive to your nutrition and works best when it gets the nutrients it needs. Many of my patients – and perhaps you – may not get enough brain food. These include good fats like those from fish, nuts, olives, etc. Studies have shown that Omega-3 fats, particularly the DHA portion of them, is particularly beneficial to your brain health.

Your brain is also about 75% water and thrives on you being optimally hydrated. When you’re dehydrated, your thinking becomes fuzzy; you become confused, and can’t seem to connect your thoughts very well.

Your brain also needs glucose (sugar) to function correctly.  If you’ve ever gone on a low carb diet for more than a few days, you may have noticed that your mood and your clear thinking took a nose dive. That’s because your brain needs measured amounts of glucose to power its functions. Your body processes glucose from the foods you eat. On a low carbohydrate diet, it takes your body much longer to break down proteins into glucose.

But that doesn’t mean that eating a high carbohydrate diet will be better for your brain function.  If your brain is bombarded by high levels of sugar in your blood from a high carbohydrate/sugar diet, it has just the opposite effect. Your short term memory (where you put your car keys) becomes impaired, it takes you much longer to retrieve stored information (someone’s name), and it becomes harder to concentrate or learn anything.

In short, all your cognitive functions become impaired with higher blood sugar levels. Lately, researchers have been proving it over and over. For example, German researchers out of Charite-University in Berlin recently looked at mental functioning and brain structure of middle aged and elderly adults. They found that for every point increase in Hemoglobin A1c (measures blood sugar averages over 3 months), there was a corresponding decrease in the participants recall, learning ability and memory consolidation.

They also found that the participants’ brain structure changed as well. MRI brain scans revealed that the brains of those with chronically elevated glucose levels lost volume, specifically in the hippocampus areas. This is the area of the brain associated with cognitive functions like learning and memory. These researchers concluded that lifestyle changes to control blood sugar levels could likely help prevent age-related cognitive decline.

So, every time you go for those high carbohydrate/high refined sugar foods – cakes, cookies, candy bars, sodas, you’re risking both your memory and your future brain size and health. But, like many of my patients, you may feel “safe” because you don’t eat sweets, pastries, sodas or eat them only occasionally.  The truth is, there are many common foods that contain a certain food ingredient that can be doing just as much damage to your blood sugar and memory.

That ingredient is called fructose – literally fruit sugar. Research has shown that consuming fructose in high amounts can lead to insulin resistance – a precursor to diabetes, heart and liver disease and cognitive decline.  A recent study out of Georgia State University has also shown that high levels of fructose impaired the spatial memory of adult lab animals.

And you could be eating common foods every day that may contain high levels of fructose, or high fructose corn syrup. What are these foods? Well, some that you may not suspect as “unhealthy” foods can contain high levels of fructose per serving, like the following:

Fruits:  Grapes, apples, pears, cherries, pomegranate all contain 7, or more, grams of fructose per serving. Dried fruits like raisins and currants top the list at a whopping 37 grams per serving but all dried fruits are very high in fructose.

Packaged/Canned/Bottled Foods: Bottled fruit juices made from concentrates (between 18-25g) mg), ketchup and spaghetti sauce (about 7-10g), canned fruits (unsweetened applesauce has about 28g), non-diet sodas (about 30g), salad dressings (balsamic vinegar contains about 17g), ready-to-eat cereals like Raisin Bran (about 10g). In addition, popular, fruit-sweetened yogurts can have more sugar/fructose than regular ice cream. Condiments like pickle relish and mustard can also contain high levels of fructose.

“Healthy” Sweeteners:  Agave, Karo syrup, honey, molasses, maple syrup, organic cane sugar, palm sugar contain 70% to 90% fructose. Consumed regularly they can lead to insulin resistance.

Fast Foods:  McDonald’s Apple Dippers (21g), McDonald’s Hot Mustard Sauce (about 10g). Even food items that don’t seem like they would have sugar in them – chicken nuggets, burgers, salads, all can contain several grams of fructose. These come mostly from the sauces used and sweetened coatings on chicken.

Achieve Good Blood Sugars and Brain Health

For balanced blood sugars (and brain) health, researchers recommend to limit total sugars (includes fructose) intake to 25g per day. As you can see from just the items listed above, you could well exceed that level just eating a handful of grapes or raisins per day. The best advice I can give you is to always read ingredient labels.  If the product lists fructose or high fructose corn syrup (HFCS), omit it. Try to stick to as little processed foods as possible to avoid this common additive.

Of course, fresh fruits also contain fructose. Now, I’m not going to tell you to stop eating fruit. Fruit contains a lot of nutrients – vitamins, minerals, fiber, and phytochemicals – that your body needs for good health. But, there are much lower fructose containing fruits that you can fit into a 25 gram limit each day.

If you’re trying to lose weight, especially belly fat, you may want to temporarily lower this level to 15-20 grams then increase it gradually upward. If you’re diabetic, this level may differ from what your doctor recommends.  Please consult them first. The following nutrient-dense fruits have less than 3 grams fructose per serving:

Beta carotene:  Apricots, peaches, cantaloupe.

Antioxidant Vitamin C, flavonoids:   Lemons, limes, grapefruit, pineapple, guava, strawberries, oranges, papaya.

Lycopene:  Tomato, red grapefruit.

Resveratrol:  Plums have almost as much resveratrol as higher-fructose grapes.

Potassium:  Banana, figs.

Tests: Start with a hemoglobin A1c blood test. It shouldn’t be higher than 5.6. If it is, you may have pre-diabetes, or you may just need to cut back on simple sugars in your diet and exercise more.  You can further tell if you’re getting too much fructose in your diet.

Ask your doctor for a simple and cheap blood test for uric acid. Uric acid is a byproduct of fructose metabolism in your body. High uric acid levels can result in gout and kidney stones. If your uric acid levels are elevated, over 5.0, cut back on fructose-containing foods until it’s back to normal range.

Exercise:  Regular exercise, 30 minutes a day, 4-5 times a week, helps keep blood sugar levels lower. Exercise has been research proven to protect both your brain and your heart health.  I recommend high-intensity interval training (HIT) form of aerobics a few times a week. Research has shown that it lowers hemoglobin A1c levels.

Just because you’ll need to watch how much fructose you eat, you can still work in an occasional sugary-treat like birthday cake or a few holiday cookies, etc. Just be sure to balance occasional treats with your regular food intake and always strive for the highest nutrition from your foods.  These simple lifestyle adjustments will go a long way in preserving your memory, preventing brain health deterioration, as well as protecting the rest of you against serious disease.

Stay Well,
Mark Rosenberg, M.D.

Eating High Levels of Fructose Impairs Memory, http://www.sciencedaily.com/releases/2009/07/090716113247.htm

Blood Sugar Tied to Cognitive Function, http://www.medpagetoday.com/Neurology/Dementia/42446

List of High Fructose Fruits, http://fitnessprohealth.com/high-fructose-fruit/

Foods High in Fructose, http://fitnessprohealth.com/high-fructose-fruit/

6 Healthy Sugars That Can Kill You, http://authoritynutrition.com/6-healthy-sugars-that-can-kill-you/