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Our most recent book has answers to the 200 most common questions that readers have asked us over the 19 years since this site began. Get it here: Your Diabetes Questions Answered
Safe and Healthy Blood Sugar Targets
Doctors and organizations like the American Diabetes Association suggest people with diabetes strive to achieve various blood sugar targets, but before you adopt any such target, it is worth remembering that the point of setting and adhering to any blood sugar target is to avoid diabetic complications.
"Complications" is a euphemism for some very ugly outcomes that include blindness, amputation, kidney failure and death. So the obvious question to ask about any blood sugar target is "What evidence suggests that this blood sugar level is low enough to prevent complications."
Research conducted with human patients, mice, and pancreas beta cell cultures all point to a single threshold at which elevated blood sugars cause permanent damage to your body. What is that level?
140 mg/dl (7.8 mmol/L) after meals
You can read in detail about the research that establishes this as the highest level you should allow your blood sugars to rise after meals here:
Research Connecting Blood Sugar Level with Organ Damage
The AACE Recommends A Post-Meal Blood Sugar Target Below 140 mg/dl
In 2007, The American Association of Clinical Endocrinologists, an organization of specialists who treat diabetes, published a White Paper recommending that blood sugar should not be allowed to rise above 140 mg/dl two hours after a meal.
The white paper explained this stating:
... a large number of highly robust cross-sectional and prospective epidemiologic studies have clearly implicated a close association between postchallenge or postprandial hyperglycemia and cardiovascular risk. These studies encompass diverse populations and disparate geographic regions, from Honolulu to Chicago to Islington to Paris. A recent analysis of 25,000 patients in Diabetes Epidemiology:Collaborative Analysis of Diagnostic Criteria in Europe (DECODE)Study supports the concept of an important link between postchallenge glycemia and macrovascular risk. Furthermore, Hanefeld et al showed that moderate postprandial hyperglycemia (148 to 199 mg/dL) not only is more indicative of atherosclerosis than fasting plasma glucose levels but also may exert direct detrimental effects on endothelium. . . . In subjects without diabetes, blood glucose levels typically peak approximately 1 hour after the start of a meal and return to preprandial levels within 2 to 3 hours; 2-hour postprandial blood glucose levels rarely exceed 140 mg/dL. Therefore, the consensus panel recommends a treatment-targeted 2-hour postprandial blood glucose level of 140 mg/dL to facilitate tighter control of glycemia without increasing the risk of hypoglycemia.
Unfortunately, though current AACE guidelines continue to cite the same post-meal blood sugar target, the explanation for the target is no longer available and in their most recent practice recommendations the AACE's emphasis has shifted to managing blood sugar using only the cheaper A1c test.
Unfortunately, the A1c tells you nothing about your post meal blood sugars, which are the only ones you can change directly with dietary changes.
The current AACE blood sugar targets can be found on page 3 of their current position statement which you can read at: AACE "American College of Endocrinology Consensus Statement on Guidelines for Glycemic Control"
This web site strongly recommends that you use the post-meal blood sugar targets rather than the A1c, because many of us find that our A1c test results don't correlate very well with the numbers we see on our blood sugar meters.
A large body of research suggests that the height of your usual post-meal blood sugar peaks predicts your likelihood of developing diabetic complications far better than does the A1c.
In 2007, The International Diabetes Federation Also Adopted the 140 mg/dl (7.8 mmol/L) Post Meal Blood Sugar Target.
Why 140 mg/dl at ONE Hour is A Much Better Target than at TWO Hours
Though the organizations cited above recommend that you keep your blood sugar at 140 mg/dl by 2 hours after eating, there is compelling strong evidence that the risk of heart attack starts to rise dramatically when 1 hour post-meal blood sugars rise over 140 mg/dl (7.7 mmol/L). You can review this data HERE.
Since heart attack is the single most damaging diabetic complications, it makes sense to lower your blood sugar to the level that is more likely to avoid it.
Most Doctors are Still Recommending Much Higher, Damaging Blood Sugar Targets
Unfortunately, family doctors don't keep up with what specialists recommend. Instead they follow the recommendations of The American Diabetes Association (ADA). The ADA continues to recommend a much higher, much less safe, blood sugar target--180 mg/dl (10 mmol/L) two hours after a meal.
The ADA is heavily funded by drug manufacturers and junk food companies that sell starchy foods. Many people believe that the ADA drags its feet in updating their recommended blood sugar targets because these targets cannot be reached by people who eat a high carbohydrate diet full of the foods sold by their sponsors, not even if they use the expensive, patented products of the ADA's other big sponsors, the big drug companies.
Whatever the explanation, the research makes it clear that the ADA's blood sugar targets are high enough to permit complications to develop. So if your doctor doesn't stress the importance of maintaining truly safe blood sugar levels, print out the AACE guidelines linked above and bring them with you to your appointment. If that doesn't help, find a new doctor.
Remember: It's your eyes that go blind, your nerves that die, and your kidneys that fail if you develop blood sugar-related complications, not your doctor's. He can afford to have low expectations for you. You cannot. Keep your blood sugar at safe levels!
But My Doctor Says Lowering Blood Sugars is Dangerous
If you are told that lowering your blood sugars is dangerous or can cause a heart attack, the chances are that your doctor read about a study called ACCORD in a newsletter. This was a study that followed a large group of people who attempted to reach an A1c of 6.5. It was reported as concluding that those who achieved the lower A1c had a slightly higher risk of heart attack.
Subsequent analysis of the ACCORD data found two things:
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Those who had heart attacks were those in the group attempting to lower A1c who did not achieve the lower blood sugars, and
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The excess heart attacks occurred in those who took Avandia, a drug now known to raise heart attack risk.
Unfortunately, though the original finding received a great deal of press, the subsequent analyses explaining the result did not.
The only other study that found a problem with lowering A1c was in a group of elderly veterans who were also using the sulfonylurea drugs glipizide and glimepiride, two drugs that, like Avandia and Actos, have also been found to damage the heart over time.
There is not a single piece of research, anywhere, that suggests it's harmful to lower blood sugar by cutting down on carbohydrates. In addition, there's a lot of research suggesting that lowering blood sugars without the use of the drugs known to be harmful to the heart prevents or reverses neuropathy, retinal damage, and heart disease.
For further insight into ACCORD and links to the actual research visit:
Diabetes Update: ACCORD Redux, It's the High Blood Sugars Stupid
Diabetes Update: Avandia is sufficient to explain the excess deaths in ACCORD
You can learn more about this issue by typing "ACCORD" into the Google Search box at the upper left corner of this page.
How to Lower Your Blood Sugar to The Safe Target Level
If you are having trouble reaching healthy, safe blood sugar targets, try the technique described on this page: How To Lower Your Blood Sugar.
You will find tips on how to fine tune the dietary changes that will keep your blood sugar within the healthy range on this page: A Diabetes Diet is Different From--and Easier Than--a Weight Loss Diet.
You can get a better understanding of why post-meal blood sugar targets are so important by reading: How Blood Sugar Control Works--And How It Stops Working.
Why Do I Feel Shaky and "Hypo" When I Achieve Normal Blood Sugars?
If you have had high blood sugars for a while--even only moderately high blood sugars--when you start lowering your post-meal blood sugars you may find that you feel shaky and even downright sick. This can happen even before you bring your blood sugars down into the normal range.
This is because over time, your body has become accustomed to those much higher blood sugars and it interprets the normal blood sugar as being dangerously low. When this happens, the body secretes fight or flight hormones in order to push the blood sugars back up to what it erroneously thinks is the safe zone. This phenomenon is called a "false hypo."
The stress hormones associated with this counter-regulatory response can make you feel dreadful. However, if you test your blood sugar during a false hypo, you will see that it is not below the 70 mg/dl (3.8 mmol/L) level that defines the beginning of the mild hypo range. That is why it is very important to test your blood sugar when you feel hypo. If you are not using insulin or one of the pills that stimulate insulin secretion you should only treat a hypo when it is a true hypo below 70 mg/dl. With higher "lows" your body will recover on its own.
The symptoms you feel during a false hypo may include a pounding pulse, shakiness, a raised blood pressure and other symptoms very similar to those of a panic attack. (NOTE: If you are using insulin or an oral drug that causes increased insulin secretion you should treat hypos below 80 mg/dl (4.4 mmol/L) because it is always possible that the drug will continue to lower your blood sugar to an unsafe level.)
After a experiencing this kind of counter-regulatory response you may feel shaky for another hour or two, because of the changes the stress hormones have made in your body. You may also become a bit more insulin resistant than usual. But after some period of time which varies from person to person, your body will get used to these new, normal blood sugars and you will only develop hypo symptoms when you are having a true hypo, which, if you are controlling using diet alone, should almost never happen.
So no matter what you feel when you first reach normal levels, try to wait it out. Your body is getting all the glucose it needs when your blood sugar is above 70 mg/dl (3.8 mmol/L). Doctors do not consider true hypoglycemia (low blood sugar) to begin until under 70 mg/dl (3.9 mmol/L). It does not become dangerous until it reaches levels like 45 mg/dl (2.5 mmol/L).
If your blood sugar has been very high for a while, you can make the adaptation process a bit easier by proceeding in stages, setting your blood sugar targets progressively lower, a step at a time. But don't stay at higher than normal levels for any longer than is absolutely necessary. Once your body does adapt, you will probably feel much better and much more energetic than before.
So be patient while your body becomes accustomed to new, healthy, blood sugar levels. Don't respond to feeling as if you were having a hypo by eating carbs to push up your blood sugar as long as your blood sugar tests at 70 mg/dl (3.9 mmol/L) or above if controlling with diet alone or 80 mg/dl (4.4 mmol/L) if using insulin or an insulin stimulating drug. Give your body a chance to adapt and eventually you will feel completely normal when you have a normal blood sugar and may feel surprisingly toxic when your blood sugar reaches the dangerously high levels at which you used to feel normal at.
Lower is Better
The 140 mg/dl (7.7 mmol/L) blood sugar target is a good start, but many of us find we feel better and get even more normal health if we shoot for truly normal blood sugars and keep our blood sugar under 120 mg/dl (6.7 mmol/L) at all times. If you can do it, go for it. Now that we know that heart attack risk rises significantly at A1cs in the mid 5% range, getting to true normal is that much more important.
What If You Can't Always Hit Your Target?
Many of us will still occasional see blood sugars higher than we'd like even if we eat reasonably well most of the time and use the safe diabetes drugs available to us. The good news is that it takes many years of exposure to high blood sugars to damage your organs. If you spike occasionally, but maintain good control overall, your risk of complications is far lower than people whose blood sugar is routinely going up over 200 mg/dl for an hour or more after every meal--which is what happens to people who shoot for that 180 mg/dl (10 mmol/L) 2 hour post-meal target that the ADA recommends and most doctors consider "great control."
Obsession and eating disorders are not healthy, and diabetes makes it very easy to become obsessed and develop an eating disorder. A few hours a week over your target blood sugar range are not an emergency. They probably won't make a significant different in your health looking back from the perspective of a decade or more. It's when you are spending a few hours every day over your target range that the damage starts to occur. If that is your situation it is time to get more aggressive about get good control. If you can't do it with diet alone, consider using safe diabetes drugs like metformin, repaglinide or insulin.
Not so surprisingly, it is when you are spending several hours a day over 140 mg/dl (7.7 mmol/L) and when your blood sugars are spiking into the dangerous range over 200 mg/dl (11 mmol/L) that your A1c rises into the middle 6% range where heart attack risk and risk of other complications will start to become very significant.
