Leptin for laymen
Claire Aslangul - Wednesday, October 10, 2012
I really love the work of Neurosurgeon, Dr Jack Kruse, his blog is completely mind blowing. Unfortunately on an understandability scale of 1-10 where one is "My first ABC book" and 10 "Quantum: Einstein, Borh and the Great Debate About The Nature of Reality", it does sit at about 11 sometimes. So, here is a bit of a rundown of what Leptin is, what it does and why this is probably the single most significant thing you could learn about with regards to your health.Welcome to Leptin for Laymen.
What is Leptin?
Leptin is a hormone that is produced in our white fat cells. The more white fat cells you have, the larger volumes of leptin your body produces. Its major function is give the brain updates on the amount and availability of energy at any given time. It is a hormone that is associated with that lovely "full" feeling after we eat.
The body has 2 major forms of communication, the first being our amazing nervous system, where our spinal cord is an information super highway keeping the brain with millisecond to millisecond accounts of what is happening in every organ in the body. The second form is our endocrine system (hormones). These hormones are released, they go into the blood stream and activate certain processes by connecting with hormone receptors on the membranes of certain cells. A hormone is completely useless without a receptor and likewise a receptor is not activated without contact with its corresponding hormone, think keys and locks.You can't unlock the door with out the right key and if a lock is worn out, the right key might not work well at all.
Both your central nervous system and your hormonal systems have a master switch, something that is so vital that if it is not working optimally it can have major impacts on every aspect of your health. For your central nervous system, this is your spine and for your endocrine system this is Leptin and it's receptors.
Why Leptin is The Master of The Universe.
As I mentioned, leptin lets our brain know when we have eaten enough and gives us that nice full feeling, but that is just a small part of why leptin is important.When leptin enters the brain (remember it is not made in the brain like many of our hormones, but made in our fat cells and crosses over the blood brain barrier via a fairly complicated chain of events) it bonds with the receptors on the hypothalamus. The hypothalamus is one of the key hormonal centres in our brain. Here it let's us know exactly how much energy we have so we know how we can spend it. This process is so important it controls ALL hormonal releases in the brain, which then impacts the release of all hormones in the body. So remembering that hormones are one of the major communication tools in the body, when leptin is not working properly it becomes like a game of Chinese whispers played next to the take off path of a 747 in a thunderstorm while green ants bite your feet and you really need to sneeze.
Leptin also has a major role in how you use the energy present in your body. If you are a healthy metabolically optimal person,when you ate a meal, 40% of the energy would be sent to your peripheral tissues, this being your muscles, ligaments, tendons, bones etc. all the bits that are needed for movement. This energy would enter the cells and stored as glycogen to be used as fuel for these tissues.The other 60% would be packaged up in the liver, to be dished out to fuel the body between meals using a hormone called glucagon.When leptin is the master of the universe, this all works perfectly, your body draws on the stores in your liver when you are sleeping or fasting and any excess calories activate a protein called UCP3. This protein facilitates the burning of fuel as free heat without using what is called Kreb's cycle. (Kreb's cycle is the conversion of ATP to ADP using glucose and oxygen, we are taught in basic biology that this is how the cells convert your food into energy to perform functions such as muscle contraction) When this production of free heat occurs, it means we have nothing to worry about if we overeat, we aren't creating excess fat just burning the extra fuel straight away. Basically you use up all you have eaten, you start to feel hungry and then you eat again.
Leptin is also a major player in immunity and inflammation.
How it can all go horribly wrong.
On the day we are born we have no leptin at all, so no way to signal fullness. Most mothers can attest to the seemingly insatiable appetites of newborn baby. We get our first load of leptin in our first few breastfeeds. It is a component of colostrum. Now remember how I mentioned about hormones have lock and key type components, well one of the most amazing things happens to us in around the first 24 hours of our lives. It is then that we set a base number of hormone receptors (locks) that sets up our endocrine (hormonal) system FOR LIFE.This is incredibly important for a whole range of hormones like oxytocin (hormone of love, bonding, giving and trust among other things) and beta endorphin (the body's natural pain killer) but let's stick to leptin for now.
When a baby has unlimited access to the breast and colostrum in that first 24 hours, the number of leptin receptors that are created is much greater than a baby who is removed for her/his mother or is fed artificially. As I explain more, the weight of this single day and it's impact on health will become more apparent.
So the problem with leptin is not that we don't produce enough of it, the problem that occurs with leptin is with our diet and lifestyle we tend to be on a continuous conveyer belt of leptin production which leads to the breakdown of receptors.Imagine it a bit like a busy highway, if you live in a quiet street in the country and you stayed in a hotel near a busy highway, chances are you would be constantly aware of the noise. Where as if you lived near a highway, you would most likely be totally oblivious to even the noisiest trucks as they went by. In the same light, our leptin receptors under constant bombardment of leptin begin to stop hearing the message of "I am full, we have adequate energy on board to function well".
So as I mentioned earlier, leptin is produced by our White Adipose Tissue (WAT), in other words our fat stores when we have eaten an adequate sized meal. The more fat stores you have the more leptin you produce, because you have acceptable levels of energy stores to function. The problems begin when we stop having breaks from leptin. This can often start with having too short a gap between dinner and breakfast and then followed up by constant grazing through out the day. In this way there is a constant release of leptin to signal fullness for most of the 24 hr period.This flow of leptin becomes the drone of an unnoticed highway the receptors stop responding even though leptin is being produced. The hypothalamus (that part of the brain we spoke about earlier) not longer hears the words "You can stop eating now, I am full".It would be like the petrol gauge on your car not working, you would never know how much fuel you had on board, so you would be continuously filling up just incase you break down. Without energy our body dies, so just in case we are constantly told to "fill up". Unfortunately, the greater your fat stores, the worse this problem becomes.
But the problem doesn't stop there, actually this is just the beginning of a terrible downwards slope into unhealth and disease. This leptin resistance in the brain, leads to an imbalance of all the rest of your hormones. You body does the best it can considering the circumstances, but without knowledge on how much energy is available, it tends to start trying to conserve what it has. There are many ways it does this from lowering basal metabolic rate (the amount of energy you use when you are resting or sleeping), decreasing production of sex hormones, increasing fat stores, stops burning fuel as free heat, slows down thyroid function and stops using fat as fuel in the muscles.
Can you see where this leads? So you increase your fat stores, which increases your leptin levels, which increases your leptin resistance and the whole thing goes around again.
The next step after leptin resistance in the brain, is leptin resistance in the liver and muscles.As we mentioned, 40% of energy from a meal goes to your muscles (and peripheral tissues) to be used for function there. When the muscles become leptin resistant, they stop accepting energy and send it back to the liver to be processed and stores as fat.This means the muscles never get the amount of fuel they require, leaving you tired and making exercise really hard work.This tells your brain " Hey, what are you doing, we are starving down here, go and eat something so we can function."
When the liver is leptin resistant, the amount of available space for energy stored in the liver is reduced so this energy is packaged up as Low Density Lipids (LDL's), unfortunately leptin resistance also reduces the function of LDL receptors, so rather than storing all of this cholesterol, it sends some of it out into the blood stream, where it oxidizes and causes damage. This is the beginning of atherosclerosis or hardening of the arteries.The LDLs that are stored are packed around vital organs such as liver, kidneys, heart and pancreas.
Another effect of high leptin levels is that it attacks a protein called amylin, this protein is required for the production of insulin. Type 2 diabetes is the end result, but leptin resistance is always present 5-7 years earlier than insulin resistance (except in the case of quick dramatic loss of pancreatic tissue, such as could occur in an autoimmune disease).
As I also mentioned earlier, leptin plays a major role in immune function as it controls and modulates the immune system. Leptin itself is chemically similar to an inflammatory immunity molecule called interleukin 6 (IL-6). So with high levels of leptin, you increase the levels of inflammation in your body dramatically. This inflammation can cause chronic pain as well as chronic diseases. It puts pressure on all the major organs in your body and is a major contributor to diseases such as osteoporosis, high blood pressure, degenerative disc disease and arthritis.
But wait, there is still more. Eventually once you are severely leptin resistant and then insulin resistant the next step is you become adrenalin resistant and have cortisol issues.When high insulin meets high cortisol, you end up with the perfect recipe for cancer.
Did I mention that this was big? We are talking diabetes, heart disease and cancer. These are our biggest killers today and they all have one root cause.
What about my skinny friend that eats loads Maccas and never gets fat?
If you are overweight or obese, you no doubt have some level of leptin resistance, there is no doubt about that.As for your skinny friend, she is just as likely to have a decent level of leptin resistance too and is not necessarily any healthier than you are.The way it is manifesting is just different. Your skinny friends thyroid is working over time to cope with the excess, where as yours has slowed right down.Both paths lead to the same place though, that is why there are just as many average sized people in oncology wards as there are overweight or obese. The reason we are seeing more obese people with heart disease and cancer is because we have a higher percentage of the population that are obese.
If your skinny friend had a great relationship with food and ate an amazing diet and was metabolically optimal, the story would be very different though.But understanding that obesity is NOT caused by over eating and under exercising, but is a disease of inflammation which can also be found in skinny or average weight people is of paramount importance.Firstly understanding, your size does not determine your health and to help remove the insidious horrible plague of society that is fat-hatred.
How do I know if I am leptin resistant?
Your first port of call is to look in the mirror. Are you overweight, obese or decidedly underweight? If the answer is yes, you have a leptin issue.
Do you get cravings or find it difficult to eat only at meal times? Does you body do poorly if you fast?
Do your muscle fatigue quickly when you start exercising?
Do you suffer from any sort of chronic illness, including eczema, asthma, chronic fatigue syndrome, depression, anxiety, high blood pressure, high cholesterol, diabetes?
Do you have problems with sleep?
Do you suffer from infertility or have difficulty maintaining pregnancies (miscarriages or threatened miscarriages)?
Getting a blood test to check your levels of reverse T3 is another way to check, but finding a doctor who will both order the test for you and understand the results may prove difficult.
So, what do I do now?
Ok, here is one of Dr Jack Kruse's blog posts that is easy to understand, his leptin reset prescription:
The basics are:
- Stop eating at least 4 hrs before bed time and get up first thing in the morning and eat a very low carbohydrate, high protein breakfast. Straight away. Then eat at lunch and again at dinner. No snacks, even be aware of drinks that you are consuming that will stimulate insulin and leptin.
- Add more seafood to your diet, a minimum of 4 meals per week. All meals need to be very low carbohydrate meals, no grains and paleo.
- Make it as dark as possible after sun down.
- Consider Cold Thermogenesis, among other things, this converts white fat to brown fat (which produces free heat and not leptin)
Leptin in a nutshell:
1. Leptin is made in our white fat cells.
2. We are born without leptin, but get a big dose with our first breastfeed which also set our number of receptors.
3. More receptors means reduced risks of resistance
4. Leptin is the master of the universe, it :
Controls All other hormones
Controls Energy metabolism
Controls Thyroid function
Allows fat to be used as fuel in muscles
Stops muscles fatiguing quickly
Increases resting metabolism
Effects immunity and inflammation
Resistance leads to insulin resistance and adrenalin fatigue
Resistance increases visceral fat, choking your vital organs
Resistance leads to high oxidative cholesterol
Resistance leads to heart disease, cancer, arthritis etc...
5. You don't have to be overweight or obese to have a leptin problem, actually underweight is just as big an indication as overweight.
6. Leptin resistance is fixable not just through what you eat but when/how you eat.
As you can imagine, there is much more to this than the simple explanation I have given here. I will be adding more as we go along.