Neuroscience & Neurology
Blood Glucose and the Brain: Sugar and Short-Term Memory
Millions of older adults suffer from significant memory loss, despite the lack of a diagnosis of dementia-causing disease. This memory loss can lead to a significant decline in quality of life and often remains undiagnosed and untreated. Recently, however, scientists have begun to study the role of glucose regulation in cognitive enhancement of adults. Cognitive function and short-term memory retrieval in middle-aged and older adults may now be linked to blood sugar levels.
The brain’s primary source of fuel is glucose, unlike other organs that have multiple fuel sources. Research has long shown that ingesting drinks or foods with high glucose content before high-demand short-term memory tasks improves cognitive performance. However, people with better blood-sugar regulation performed better on the tests than those with poor glucose regulation. In other words, the faster people metabolized blood sugar, the better their memory functioned.
Moderate increases in blood glucose are effective in enhancing short-term memory performance and cognitive functioning across an array of domains, but while a little glucose is good, too much can be bad. Sustained elevations in blood sugar levels, as seen in conditions including impaired glucose tolerance and diabetes, lead to a decline in cognitive functioning. Simply, the longer that the glucose remains in the blood, the less fuel the brain has to function and retain memories.
These findings are owed, at least in part, to the fact that glucose affects the hippocampus — the part of the brain responsible for short-term memory. In one small study, people with high blood sugar levels actually had a smaller hippocampus than those with normal glucose regulation. Any type of insult or injury to the brain, including high blood sugar, easily damages the hippocampus. Fortunately, it is also a resilient part of the brain and its function can be recovered when blood sugar levels are controlled.
Recently, elevated blood sugar levels were found to be significant predictors of poor cognitive performance or mild cognitive impairment among middle-aged and elderly subjects. Adults with higher fasting blood sugar levels performed worse on memory function tests, whether they received glucose or a placebo prior to the test. These findings are also linked to lifestyle factors. Study participants that had poor glucose regulation, leading to high blood sugar levels, had more risk factors for poor overall health, diet, and lifestyle. People with known risk factors for diabetes or impaired glucose tolerance are at risk for elevated blood sugar levels, in addition to any person who is overweight or has a sedentary lifestyle.
The research requires more investigation before glucose-regulation becomes a mainstay of memory loss treatments, but it provides more incentive for adults to maintain healthy blood sugar levels. Not only does a healthy, active lifestyle prevent heart disease, diabetes, joint ailments, and a plethora of other conditions, but it also improves memory and cognitive functioning.
References
Roozendaal, B. (2003). The hippocampus mediates glucocorticoid-induced impairment of spatial memory retrieval: Dependence on the basolateral amygdala. Proceedings of the National Academy of Sciences, 100(3), 1328-1333. DOI: 10.1073/pnas.0337480100
Meikle, A., Riby, L.M., Stollery, B. (2004). The impact of glucose ingestion and gluco-regulatory control on cognitive performance: a comparison of younger and middle aged adults. Human Psychopharmacology: Clinical and Experimental, 19(8), 523-535. DOI: 10.1002/hup.643
Riby, L.M., McLaughlin, J., Riby, D.M. (2008). Lifestyle, glucose regulation and the cognitive effects of glucose load in middle-aged adults. British Journal of Nutrition DOI: 10.1017/S0007114508971324
Riby, L.M., Marriott, A., Bullock, R., Hancock, J., Smallwood, J., McLaughlin, J. (2008). The effects of glucose ingestion and glucose regulation on memory performance in older adults with mild cognitive impairment. European Journal of Clinical Nutrition DOI: 10.1038/sj.ejcn.1602981
Related Articles
5 Comments
Julie
I read about the effects of glucose & many more things that people should pay attention to in their diet to help their memory and general well being. The book is called “7 Steps to a Healthy Brain” by Dr. Paul Winner.
Great article.
I continue to be impressed with the huge impact of life’s little steps. Eating right, maintaining a healthy weight level, exercising on a consistent basis - these are truly the hallmarks of healthy living.
I appreciate your highlighting the issue of blood sugar levels among the elderly. As you know, many studies support the benefits of active exercise for this group. Personally, I always favor a non-medical intervention when possible - things like natural foods, fresh air, maybe a walk through the park…
Thanks again for the article,
tim
This is a very interesting and well written article about short term memory loss - thank you for that.
There are many reasons for an apparent decline in memory performance and certainly what we ingest will have an impact. This appears to be a well researched article and brings the issue of the effect of blood sugar levels to a level that we lay people can understand.
I suppose the only challenge with this knowledge is how do we know what our blood sugar levels are and whether they are too high or too low? And what of our glucose regulation performance - is mine at the optimum level? If it isn’t how will I know?
If there are tests to give us this information then perhaps we can modify our eating habits to adjust the blood sugar level accordingly in light of that knowledge.
Perhaps the ordinary person isn’t going to go to these lengths to improve their short term memory and so it is here that commonsense should prevail.
Clearly what we eat will affect all aspects of our bodily functions, not least the cognative ones. So a good healthy balanced diet - plenty of fresh stuff, lots of green stuff, good hydration and the right mix of carbohydrates and proteins should be a great place to start.
Seeking nutritional advice is always a good idea too but plenty of greens and fresh “alive looking” food will get you going until the professionals can guide you properly.
If you do begin to have short term memory problems then maybe then is the time to get the blood sugar levels tested.
However before you do, make sure that you have fully explored the other possible causes too.
As someone who helps people understand how to use their memory more effectively through a variety of techniques (mnemonic devices and the like), there are other reasons why the short term memory may appear to fail us but actually are caused by other factors which are well within our control.
If you have ever put your keys down at home and then are unable to find them again (even if you are the only one at home!) then have a read of my article “Short Term Memory Loss - What Causes It” on my Memory Improvement Blog
Trackbacks
- Jul 10, 2008 | Holistic Healing
Leave a Reply
Friday, September 5, 2008
- The Anti-Psychiatry Movement
- Vaccines - A Two-Edged Sword
- Should Doctors Have Guns?
- Extremist Muslim Doctors Do More Than Heal
- Woman Comparable to Men in Domestic Violence: Stereotypes and their Consequences
- The Bipolar Trend
- The Implications of Implanted Chips
- Anti-Smoking Campaign Doesn't Mess Around
- The Science of Brain Freeze
- The Biopsychosocial Model of Health & Illness
- Unhinging from Theory: Autism and Opinions
- God And Religion: Is It All In Our Heads?
- Encephalon, Thirty-Third Edition
- Is War A Psychosis?
- Meditation for Troubled Minds: Can the Mind Heal the Mind?
- Mind-Body: We Want Evidence, Don't We?
- Usually It's Cheaper to Pay Than to Go To Court
- Acknowledging Vaccination Concerns
- Integrating Schizophrenia Management
- Rabies Virus Helps Deliver Drugs into the Brain
- Life in a Bubble - The Dangers of Triclosan
- The Dark Side of Antibiotics
- Stroke’s Little Known Complication - Pain
- Laughter is the Best - and Possibly Oldest - Medicine
- Epilepsy - Social and Cognitive Considerations
- New Treatment for Alzheimer’s Disease?
- When the Doctor is the Patient
- The Gift of Life - Part 2
- Drugs and Pharmacology, Tenth Edition
- Are Drug Reps Really Necessary?
- Can Drug Therapy Prevent Parkinson’s Disease?
- Medicine and the Law - Part 6: Third Party Liability
- Go For The Gold, It May Prolong Your Life
- When It Comes to Health, Adults Shortchange Kids
- Is Seeing Into the Future More Than an Optical Illusion?
- Malignant Medicine
- Putting an End to Medicare Fraud
- The Gift of Life - Part 1
- Brain Blogging, Thirty-Eight Edition
- The Mental Health of our Military
- It's great to see all those niche blogs out there. Congrats for joining 9rules!...
- Is there really no better translation possible?
“Something which has never occu...
- What an excellent post! Thank you!...
- Laughter Therapy is mentioned in the Bible (Proverbs 17:22) but more recently do...
- i am not sure about this but there is a virus that can "cure",in any form or wha...
- no matter how many times we change nations, government, weapons, peace strategie...
- but still, a little chuckle here and a little laugh there makes everyone feel be...
- is it the same as when you dive into a pool on a winter evening and some water e...
- Are there any trials happening in around the London area?...
- ARE ANY TEST SITES NEAR CENTRAL FLORIDA? TAMPA BAY AREA IN PARTICULAR. IF SO, F...
- Cool opinions,but some doctors are careless.They are just concerned about their ...
- I can't stop the N=1 studies on myself with free Lyrica samples....
- This is really great information. I just recently signed up to be on the regist...
- Thank you! My son recently had a bone marrow transplant and I stand in awe of a...
- Thanks for including my IC Disease site in the blog carnival! I posted a link b...
- Hey thanks for the addition to the carnival - much appreciated!!
Barry B...
- Please reread the article. The chip contains a 16 digit ID number, the equivale...
- Are Drug Reps Really Necessary?
No.
But I sure do miss the great food we u...
- There is certainly a trend in being diagnosed bi-polar. Hollywood underlies tha...
- To respond to your questions...
Q: Are people merely misinformed?
A: Yes...
Advertisement
Sponsored Links
Online Criminal Justice Degrees, Insurance, Home Loans, Free Movies, California DUI Lawyer, Tattoo, Health Insurance, Drug Rehabilitation, Mesothelioma Lawyer, Hydroxycut, Custom Rubber Stamps, Unique Gift Ideas , mesothelioma cancer , Aquarius Personality , vehicle tracking , vasectomy reversal , Richardson Divorce Lawyer , t-shirts , Free Insurance Quotes.
Neuroscience & Neurology
September 02, 2008 | 0 Comments | By RD, MD
Stroke’s Little Known Complication - Pain
More In Neuroscience & Neurology
- Can Drug Therapy Prevent Parkinson’s Disease?
- Is Seeing Into the Future More Than an Optical Illusion?
- When Age Is Just A Number
- Virtual Reality - New Steps in Stroke Rehabilitation
- The Science of Brain Freeze
Neuroscience & Neurology
Opinion
August 27, 2008 | 2 Comments | By Sajid Surve, DO
The Gift of Life - Part 2
More In Opinion
- Are Drug Reps Really Necessary?
- Malignant Medicine
- The Gift of Life - Part 1
- Medical Students Can Make A Difference
- Can this Economic Downturn Lead to Better Psychosocial Health?
Opinion
Psychiatry & Psychology
August 15, 2008 | 2 Comments | By Jennifer Gibson, PharmD
The Mental Health of our Military
More In Psychiatry & Psychology
- Sleep and Consciousness - A Dynamic State of Being
- Finding New Ways to Treat Depression
- Dying To Be A Good Mom - Eating Disorders In Pregnancy
- The State of Mental Healthcare in Prison
- Treating Psychiatric Disorders - Something Smells Fishy


Thank you.
I’ve always been somewhat skeptical of the simplified advice to eat sugar for improved cognitive performance. There’s always more to the story.