- Both too high (over 140 mg/dl) and too low (below 80 mg/dl) blood glucose levels appear to be detrimental to health and lifespan
- Mortality rates rise with a fasting blood glucose level around 100 mg/dl (5.5 mmol/l)
- A significant surge in mortality rates is seen in cases of plasma glucose above 120 mg/dl 2 hours after a glucose tolerance test
- High-carbohydrate diets are generally associated with lower fasting blood glucose levels
- Low-carbohydrate diets are usually accompanied by higher blood fasting glucose levels
- Eating about 20% of one’s daily calories from carbohydrate seems to be the best diet concerning glucose for health. For the average adult, that’s around 400-500 carbohydrate calories per day.
Actions to Consider
- Remember that moderation is a useful guiding first principle, especially with nutrition: eating too many carbohydrates can be as detrimental as not consuming any
- Try to keep your fasting blood glucose level at 90 to 100 mg/dl, as this is the optimal range for health and longevity
- For most people, a diet with 20% of calories from carbohydrate is the healthiest eating regime in terms of carbohydrate consumption for health and longevity
Carbs: good or bad? The age-old debate
Over the last few years, with the lambasting of Ancel Keys’ flawed experiment and the popularization low-carb diets like Keto, Paleo, Whole30 and Mediterranean, dietary carbohydrates have been demonized in both mass media and scientific studies, maybe more than deserved.
Some eating regimes like the Ketogenic diet and Atkin’s diet promote extremely low levels of carbohydrate consumption, often lower than 5% of one’s daily calories. Many scientific studies highlight their potential health benefits, while some point out potential harmful effects on blood glucose levels and nutrient deficiencies.
Other studies report that diets extremely high in carbohydrates lead to severe impairment of the body’s ability to process glucose. The typical outcome is excess weight, metabolic syndrome, diabetes, and a drop in lifespan.
The optimal glucose range seems to be somewhere between these extremes.
What is this article about?
Today’s summary is a condensed discussion between Paul Jaminet, author of the Perfect Health Diet, and Dr. Ron Rosedale. Dr. Rosedale promotes eating regimes with as low glucose consumption as physically possible.
The conversation started on Jimmy Moore’s Living La Vida Low Carb (LLVLC) blog. Although the initial seminar on LLVC seems to have been taken down, Paul Jaminet’s massive post contains extensive quotes both from his and Dr. Rosedale’s replies, so that anyone can keep track of the whole conversation.
The two goals of the review were:
- To identify the best glucose level for human health
- The diet that would lead to the optimal blood glucose level
Blood glucose: how much is too much? How low is too low?
The initial discussion sparked from Dr. Rosedale’s thesis is that glucose is toxic. Thus, low-carb diets are superior to other eating regimes. According to Dr. Rosedale, the optimal glucose level is the lowest compatible with life. Higher blood glucose consumption quickly leads to an accumulation of damage, impairment of the body’s repair mechanisms, and eventually—aging, chronic diseases, and death.
Many studies have confirmed that high glucose consumption is indeed detrimental to health. In most cases, the damage becomes substantial around the blood glucose threshold of 140 mg/dl.
However, too low blood glucose levels (the absolute low being around 0 mg/dl) are incompatible with life. The body needs at least some carbohydrate to support its basic functions. Paul Jaminet, the author of today’s article we’re summarizing, noted that extensive damage starts below 60 mg/dl.
Statistically, the lowest mortality rates are seen with a fasting blood glucose level around 100 mg/dl (5.5 mmol/l).
The best diet for optimal blood glucose
Low-carb diets are usually linked to higher fasting blood glucose levels and higher 2-hr glucose levels after a tolerance test. Conversely, high-carbohydrate diets are associated with lower fasting blood glucose levels.
This effect is seen not only in scientific studies. For example, the Kitavans islanders get over 60% of their daily calories from carbohydrates, and their average fasting blood glucose is about 67 mg/dl.
The best way to maintain optimal blood glucose levels seems to eat it in moderation. Avoiding carbs fiercely has been observed to have similarly detrimental effects as bingeing on them. The optimal level of carbohydrate consumption for the average person seems to be around 20% of their daily calories.
Everything in moderation. It seems this principle is true regarding blood glucose as well.
Too low blood glucose levels severely impair the body’s metabolism and are incompatible with life. Too high levels, on the other hand, lead to progressive glycation of the body’s tissues (glucose-related damage), endocrine disruption, metabolic syndrome, and increased mortality rates.
The best fasting blood glucose level for health and longevity is about 90 to 100 mg/dl.
Most people are likely to achieve this glucose level on a diet with 20% of calories from carbohydrate (400-500 calories for the average adult).