What you're not worrying about, but should be

Unless you have diabetes, you probably don't think about your blood glucose levels very often. If you're young, you proabably never think about it. If you're older, you might think about it once a year when you get your annual physical and get your fasting glucose levels checked. Physicians don't make a big deal out of blood sugar, so you probably assume it's no big deal. Sometimes a nutritionist might say something about certain foods being good because they "stabilize blood sugar," but the benefits of that stabilization still probab ly seem a little vague to you. Perhaps you've heard that if you prevent your blood sugar from spiking, you'll also prevent the mood swings, fatigue, and ravenous hunger that can result when you "crash" back down from a glucose peak. If you are particularly well-read you may also have heard something about insulin promoting fat storage when blood sugar is high.

While the term "fat storage" can incite fear well enough on its own, there are even more severe consequences to blood sugar levels that are higher than they should be- even if they are not, by clinical definition, abnormal.

First, a little background information, so we're all on the same page. Below are the fasting blood glucose (FBG) and 2-hour oral glucost tolerance test (OGTT) cut-offs for diabetes mellitus and impaired glucose tolerance (AKA pre-diabetes).

Normal: FBG < or =" 99;">OGTT < or =" 139

Impaired Glucose Tolerance: FBG 100-125; OGTT 140-199

Diabetes: FBG 126 and above; OGTT 200 and above

The problem with these cut-offs is that they are somewhat arbitrary. They seem to give the impression that any blood glucose value in the normal range is, well, normal, and that pre-diabetic levels are only a warning of possible future problems if left uncontrolled. What your physician won't tell you is that even within the normal range, lower is better, and that having impaired glucose tolerance can increase your risk for cardiovascular diseases and death, even if you never become diabetic.

The truth is, even a glucose level of 140 can cause damage to blood vessels and to the cells of the pancreas that produce insulin. Blood vessel damage can lead to artery plaques, which can ultimately cause heart attacks. A glucose level of 140 is not what any doctor would call "high," and yet it appears to be an important threshold. Just to be clear, glucose in the blood is dangerous no matter when it happens. So, if your glucose is high after a meal, but normal when you are fasting, you are still going to be at higher risk than someone who has normal glucose levels all the time. In fact, risk of cardiovascular disease increases with OGTT values as low as 80!! Lower really is (nearly) always better in this case. The problem is, most people have no idea what their blood sugar is after a meal. The average person only receives fasting blood glucose tests regularly, not OGTTs. Unfortunately, FBG will start to rise only after post-meal glucose has been elevated for quite some time. This means that by the time a person has a high FBG, a lot of damage has already been done.

So what are you supposed to about this?? Here are my recommendations:

1. If you have any of the following risk factors, talk to your doctor about whether you should have an OGTT: overweight with mostly belly fat, obese, polycystic ovary syndrome (PCOS), first-degree relative with type 2 diabetes (parent, sibling)

2. Be on the look out for free glucose screenings in your area and plan to go about an 1- 1.5 hours after a meal to catch your peak level.

3. Regardless of what your glucose levels are after eating, virtually everyone could benefit from reducing that level. So, think about making dietary choices that will maintain a stable blood sugar.

Some suggestions:

Reduce your portions of starches

Choose whole grains over refined grains

Increase your portion of vegetables

Choose whole fresh fruits over fruit juices or canned fruits

Eat lean protein and healthy fats (olive oil, canola oil, etc.) with starchy foods

Swap out artificial sweeteners (like Splenda) for sugar wherever you can

Switch from regular to diet soda, or no soda

Snack on nuts and fruit rather than high-carb granola bars or candy

Start your day with eggs and/or a high-fiber cereal

Also, physical activity can help your body to use the glucose in your blood, so if you must have dessert, go for a walk afterwards!

References

Ceriello A. Impaired glucose tolerance and cardiovascular disease: the potential role of post-prandial hyperglycemia. Am Heart J. 2004

MedScape article

Peter R, Okoseime OE, Rees A, Owens DR. Postprandial glucose- a potential therapeutic target to reduce cardiovascular mortality. Curr Vasc Pharmacol. 2009