Risk Factors

What You Don’t Know About your Blood Sugar

What the safe range of blood sugar really is. Current guidelines state that a person is diabetic if fasting blood glucose levels exceed 126 mg/dL on two consecutive occasions. Fasting glucose levels over 109 are flagged as potential prediabetic (glucose intolerant) states. Life Extension has long argued that optimal glucose ranges are less than 100.

In a new hypothesis that shakes the pillars of conventional wisdom, it now appears that optimal fasting blood glucose levels should probably be under 86 mg/dL. This means that those with high “normal” glucose (86-109) are at an increased risk of premature death. While the medical establishment clearly understands the lethal dangers of hyperglycemia (blood sugar over 126), they have yet to recognize that even high normal glucose levels pose a serious threat to one’s health.

Conventional Medicine’s Interpretation

Of Fasting Glucose Blood Tests

70-109 mg/dL . . . . . . . . .Normal glucose tolerance
110-125 mg/dL. . . . . . . . .Impaired fasting glucose (prediabetes)
126+ mg/dL . . . . . . . . . Probable diabetes

Fasting Glucose Guidelines

70-85 mg/dL . . . . . . . . . Optimal (no glucose intolerance) 86-99 mg/dL . . . . . . . . . Borderline impaired fasting glucose 100+ mg/dL . . . . . . . . . .Probable prediabetes

Why “Normal” Glucose Levels Are Dangerous

To support our hypothesis that higher“normal” ranges of blood glucose represent a health risk, we first investigated the multifaceted toxic effects that sugar inflicts throughout the body. We found many studies showing that sugar damages cells via multiple mechanisms and is a causative factor in common diseases of aging.1-37 It thus appears desirable to maintain the lowest level of blood glucose needed to sustain healthy metabolic function.

We then looked at the effects of caloric restriction, and noted one study in which fasting glucose declined from an average of 92 to 74 mg/dL in a group of adults who reduced their food intake.38 This corresponded to animal studies in which caloric restriction induced significant reductions in blood glucose levels.39-41 It is well established that cutting calorie intake reduces one’s risk of age-related diseases and probably slows aging itself.42-50 One reason for this may be the reduction in blood glucose levels that occurs in response to ingesting fewer calories.

As people age, their fasting glucose levels normally increase as their health declines. Standard laboratory reference ranges show an aging person having a “normal” fasting glucose level of up to 109 mg/dL. Yet the most effective anti-aging therapy—caloric restriction—lowers glucose levels to the low 70s (mg/dL).

Many theories of aging focus on the deleterious effects of glucose itself. Only a few studies have evaluated disease risk in people whose fasting blood glucose levels are in normal ranges. One study of nearly 2,000 men looked at fasting blood glucose levels over a 22-year period. Its startling results showed that men with fasting glucose levels over 85 mg/dL had a 40% increased risk of death from cardiovascular disease. The researchers concluded, “fasting blood glucose values in the upper normal range (appear) to be an important independent predictor of cardiovascular death in nondiabetic apparently healthy middle-aged men.”51

A light micrograph of a human pancreas.

The pancreas is a digestive gland, but also controls blood sugar levels by secreting insulin.

People often have their blood tested through our discounted mail-order blood-testing service. In addition to using the results of these blood tests to improve members’ health, Life Extension is able to use this information to evaluate trends that can lead to better recommendations for extending longevity.

Where Your Pancreas Thinks Glucose Levels Should Be

The pancreas plays a major role in regulating blood glucose levels by secreting insulin to transport sugar out of the blood and into cells for energy production or storage.

Insulin also drives fat into cells, prevents fat from being released from cells, and makes people hungry. High insulin levels contribute to obesity and the disease states associated with being overweight, such as type II diabetes, cardiovascular disease, kidney failure, and certain types of cancers.

In normal health, the pancreas stops secreting insulin when glucose levels drop below 83 mg/dL.52-54 As I noted earlier, healthy aging people typically have fasting glucose levels over 90 mg/dL, and even competent doctors wait until fasting glucose is over 109 before suspecting a pre-diabetic (glucose-intolerant) condition.

But insulin continues to be secreted when blood glucose levels are over 83 mg/dL, which indicates that the pancreas is striving to drive glucose levels down to a range safer than what aging people typically are able to achieve.

An in-depth discussion about the lethal dangers of excess insulin can be found in the chapter on obesity in our Disease Prevention and Treatment reference book (4th edition). In the obesity protocol, we present evidence that excess insulin is a causative factor for body fat accumulation.

In order to assess your fasting blood glucose status, a standard blood chemistry test provides this information at a modest cost.

Overweight and obese people have very high insulin levels.55-56 Chronically elevated insulin contributes to a host of degenerative diseases.57-63 Our new hypothesis suggests that lowering fasting glucose levels results in an even greater reduction in fasting insulin. By secreting insulin when blood sugar levels exceed 83 mg/dL, the pancreas is telling us to keep blood glucose far below the high “normal” reference ranges used by blood test labs. While today’s standard fasting glucose reference range extends to 109 mg/dL before flagging a problem, our new hypothesis suggests that fasting glucose over 85 mg/dL is cause for concern.

Ways to Lower Blood Glucose

The safest, most effective way to lower blood glucose levels is caloric restriction. Few people, however, are able to consistently under-eat. Consuming a lower glycemic index/load diet reduces blood glucose levels somewhat.64-69 (For more information about the “glycemic index/load,” see pages 1151-4 of Disease Prevention and Treatment.)

Chromium supplements have been shown to reduce blood glucose significantly.70-74 The dose used in human studies ranges from 200 to 1000 mcg of elemental chromium a day, with best results occurring when 400 mcg or more of chromium is taken daily.

Of interest is an animal study showing that chromium extended mean and maximum life span.75 This study surprised gerontologists, as chromium had not been considered a particularly promising antiaging nutrient. It may have been chromium’s effect in lowering glucose levels that resulted in the significant prolonging of life span demonstrated in this study.

Magnesium, carnitine, alpha lipoic acid, and biotin also can help maintain glycemic control.76-108 A prescription drug for diabetes called metformin significantly lowers glucose levels in most people, but not everyone can take this medication.109-119

• Alpha Lipoic acid81-94
• Biotin98-108
• Carnitine95-6
• Chromium70-4
• Magnesium76-80
• Vanadium146-50
• Zinc138-45

Regrettably, many aging people will not be able to maintain optimal blood glucose levels of less than 86 mg/dL. In this situation, protecting the body from the toxic effects of glucose becomes paramount. Glycation is a pathological process that occurs when glucose binds to protein molecules, resulting in the formation of non-functioning structures in the body. Higher blood glucose levels mean more-damaging glycation reactions.

Glycation advances slowly and accompanies every fundamental process of cellular metabolism. Glycation accelerates aging and neurodegenerative disorders such as Alzheimer’s disease. Fortunately, a nutrient called carnosine confers significant protection against glycation processes.120-121

Higher blood glucose also causes increased oxidative stress. Consumption of antioxidants has shown beneficial results in type II diabetics.122-150 Based on our hypothetical definition that blood sugar over 85 mg/dL is too high, antioxidants may be more important to healthy people than previously thought.

A new fat-soluble form of vitamin B1 has demonstrated significant protection against sugar toxicity at the cellular level. In Europe, this vitamin B1 derivative called benfotiamine is prescribed for those suffering from disorders related to sugar toxicity, such as peripheral neuropathy.