Intermittent Fasting and Diabetes:

As many readers will by now be aware, I am a firm believer in the benefits of Intermittent Fasting as a convenient method of enforcing calorie restriction and also for optimizing genetic expression of so-called "survival genes" (often also called "thrifty genes" in scientific literature) which optimize lifespan and also improve the quality of an optimized/extended lifespan.

However, there is an aspect of intermittent fasting which appears to be obvious to most people who have an understanding of the concept but which is never really explored in any scientific depth - the issue of Diabetes (Type I or Type II) and how intermittent fasting affects the condition.

Most commentators and researchers who are familiar with the science around intermittent fasting tend to squeeze in the odd comment about its "potential benefits to diabetic individuals" but this is usually glossed over and mentioned only in passing, so to speak. The main reason for this, of course, is that (correctly) we must stick to scientifically studied principles at all times when discussing any health-related issues or recommending any potential course of action to members of the public.

There is an obvious void when it comes to studies on diabetic people and the possible benefits of people with diabetes following an intermittent fasting regime. However, I believe it is a concept diabetic people and their managing clinicians - especially those using insulin to control their diabetes - need to come to grips with. Could a potentially massive opportunity for successful disease control be going unnoticed?

I will not make any direct recommendations in this article but I will look at the theory around why intermittent fasting may be the way forward for diabetes management and why there is a definite need for further research into this field.

Firstly, I will say that there is a large gathering of anecdotal information (usually on forums around the Internet) relating to diabetic people who claim to have benefited from the use of intermittent fasting to control their diabetes. However, as massive as this anecdotal body of data may have become, we simply cannot rely solely on such information when it comes to making lifestyle decisions intended to affect our health. Proper scientific studies are an absolute necessity now.

Why should the practice of intermittent fasting help a diabetic person, you may ask? I believe a brief explanation of the physiology involved will make this clearer. For a good natural history on why the human physiology is suited to (and designed for) intermittent fasting - especially in combination with regular exercise - please view the following studies published in the Journal of Applied Physiology:

1. Study by Manu V. Chakravarthy and Frank W. Booth (PDF - Please allow a few seconds for it to download if it doesn't appear immediately).
2. Copenhagen Muscle Research Centre

If you don't have the time (or inclination) for reading detailed scientific studies the main points raised in this study are:

- The human body is designed to thrive under conditions of irregular food supply but needs to be adaptable as well. For this reason, 'thrifty genes' are not always expressed and specific lifestyle changes need to be made to trigger these genes (such conditions require periods of fasting interspersed with periods of hearty eating).

- Diabetes prevalence in active rural/agricultural societies with low and intermittent food consumption are below 2% but are approaching 33% in highly sedentary Westernised populations with continuous uninterrupted food supplies and a culture of avoiding the 'unfed' state.

- As a result of certain societies attaining a status where most individuals seldom exercise, are never hungry and have access to food whenever they feel the urge to eat - human beings are now at high risk for at least 35 potentially life-threatening health conditions (which were never a significant problem in past centuries - and this statistic probably accounts for the massive rises in diabetes, cardiovascular disease, metabolic syndrome and cancers now prevalent in such societies).

There is little disagreement within the scientific and medical communities when it comes to the above points made in this study.

In the quest to understand the potential role of intermittent fasting in diabetes management it also helps to understand what diabetes actually is. Diabetes is a condition encompassing the major insulin-related health disorders.

Insulin is a hormone produced by the pancreas which enables glucose/sugar (produced by digestion of food and carried in the bloodstream) to enter the body's cells to provide energy/fuel for all cellular functions and to sustain life. Also, the glucose produced from any food breakdown which exceeds the body's requirements needs to be stored in the liver and the muscles - or turned to fat for longer term storage. Insulin has other metabolic effects (related to increasing fat storage - or, rather, to decreasing fat burning) because insulin is almost a 'mirror-image' hormone to growth hormone with regard to its function (the functions of growth hormone will be explained shortly).

Thus, in summary, insulin makes us fatter. Growth hormone does the opposite and makes us leaner and more muscular (I will explain the intricacies, shortly).

Diabetes can result because the pancreas can't produce insulin any more. It can also result from the pancreas not being able to produce adequate insulin - or it can occur as a result of the body's cells becoming resistant to the effects of insulin (so that sugar does not enter the cells even when high quantities of insulin are present).

The last reason listed above for why diabetes may occur is called "insulin resistance" and is caused by a complex set of metabolic circumstances leading to incorrect hormone production (probably originating from the body fat itself, because fat is a large-scale hormone secretory organ). This insulin resistance is often caused by a sedentary lifestyle, overeating and over-consumption of the incorrect (unhealthy) foods, too often.

Insulin production is regulated by other hormones (not all of which are known to science, currently) which respond to the presence of sugar in the blood through feedback mechanisms - the full nature of which has not yet been fully elucidated. One hormone known to be involved in this regulation process of insulin production is growth hormone.

Basically speaking, high levels of insulin do not co-exist in the body with high levels of growth hormone. If one is high, the other is low.

What does growth hormone do? Apart from the well known functions of aiding growth and development, another major function of growth hormone is the liberation of free fatty acids from the adipose tissues, leading to the suppression of insulin production (because the burning of sugar is not necessary in the presence of a more efficient fuel). These free fatty acids are the usable form of energy derived from the body fat stores and they can also be absorbed by the body's cells to be used as fuel - much like glucose can. So growth hormone relates to fatty acids in a similar way to how insulin relates to glucose/sugar. It serves to allow the fuel to become available for use in the cells.

Fatty acids provide energy in a different way to glucose because glucose provides energy more quickly. Fat fuels the less vigorous activities because the fatty acids can only be availed at a relatively slow pace. So there is a place in the human metabolism for both energy forms. However, vigorous physical activities are seldom sustained for extremely long periods, so there is a greater need for the sort of energy supply provided by free fatty acids than there is for the energy provided by glucose.

However, if people regularly eat a 'reasonable' quantity of food the digestion of this food will require constant (and high) production of insulin to clear the bloodstream of the glucose which will result from this digestion. High glucose levels, if not addressed, are life-threatening, so the body does not wait around for glucose levels to build up - insulin is produced on a sliding-scale basis to ensure glucose levels never remain raised for very long. Insulin production is only ever held back to prevent glucose levels from becoming too low (which is also life-threatening).

As previously stated, high insulin and growth hormone levels don't occur simultaneously. So as long as insulin demand is high, growth hormone levels will be low. This is why most people following Westernised eating patterns tend to experience growth hormone elevations when asleep - that's the only time their insulin levels are low because they are not eating during sleep!

However, insulin levels can be kept low (and growth hormone levels elevated) for most of the day, if an intermittent fasting routine is adopted - especially if the daily fasting method is applied. The same thing happens when calories are restricted by any other method - but it is considerably more pronounced when there is a genuine fasting period of some sort.

As most people are aware, growth hormone has a number of other functions - related to aging, growth and development. So high levels of growth hormone will help with better maintenance, performance and repair of the body; as well as higher energy levels, better brain function, increased longevity and increased resistance to illness. High general growth hormone levels will also lead to an increase in muscle bulk and better responses to exercise or physical training.

Remember that, in addition to the above benefits of high growth hormone levels, growth hormone is also directly involved in implementing the fat burning metabolism (at the expense of the effects of insulin). Insulin and growth hormone affect parallel (and almost mutually exclusive) body systems - and do not exist at high levels simultaneously. Another important consequence of the liberation of free fatty acids caused by growth hormone secretion during intermittent fasting is the detoxification of the body. Most toxins in animals generally tend to accumulate in the body fat because the fat tissue remains static (in-situ) as long as it is not needed for energy. If you never lose weight you will carry the same fat throughout your life, even over decades. The toxins in this stored fat will increase over time and may eventually threaten your life through the development of metabolic diseases and/or cancers. By metabolizing fat during fasting you release stored toxins into the bloodstream for excretion. This 'cleansing' is aided by high water consumption so always drink lots of water when you fast, to assist the process of detoxification.

So, apart from triggering 'thrifty genes' and causing detoxification, intermittent fasting leads to a higher reliance on the fat burning metabolismand it lowers the demand for insulin (something of key significance - especially to diabetic people).

Because you are not eating much during a fast, digestion ceases and very little glucose enters the bloodstream, as a result. Thus, the damage caused by high glucose levels is potentially avoided for a diabetic person and the negative effects of insulin on fat burning are circumvented.

In addition, higher levels of growth hormone are necessitated by the need to run on free fatty acids for energy, instead of glucose, when fasting. This leads (over a period of time) to an increased percentage of lean body mass (something regularly observed in numerous clinical studies on intermittent fasting) and much higher levels of fat burning - as the percentage of overall energy derived from fat is increased significantly, while the energy derived from sugar is reduced dramatically.

Note that growth hormone increases muscle mass but it also decreases fat levels (at the same time). Isn't that what all people need to be doing - not just people with diabetes?

This leads on to my conclusion:

If intermittent fasting is known to do all these things to the metabolism - and is likely to reduce the risk for diabetes and many other 'lifestyle diseases' - is it not likely that people with diabetes (and on medication) will require less medication if their bodies were to adapt to burning fat (and using very little glucose) and if their growth hormone levels were to be raised for most of the time - in conjunction with long, regular periods of negligible energy intake (intermittent fasting)?

If your body does not produce high amounts of glucose for most of the day it follows that it will require less insulin for most of the day. This means that people in this state are less likely to be affected by the harmful effects of insulin supplementation (as used to control diabetes) because they will need less insulin to achieve suitable control of blood sugar levels. Other medications needed to clear sugar out of the blood will also be less needed - following this line of reasoning.

Less medication and easier control of sugar levels. These are the main goals of diabetes management...

In a future article I will discus the implications of this concept on insulin injection regimes (basal/bolus insulin regimes) and how this can also have potential implications on diabetes treatment regimes involving oral medication only (or combinations of both oral medications and insulin, simultaneously). This is all theoretical, of course, but I feel it's research urgently required by society.

Food for thought...

Remember never to attempt to modify your treatment of diabetes - or any other disease - without the support and advice of your managing clinician(s).