Showing posts with label Cortisol. Show all posts
Showing posts with label Cortisol. Show all posts

Wednesday, 9 July 2014

Why you really can't outrun your fork.

Hat-tip to Yoni Freedhoff.
From http://www.blacksheepfitness.co.uk/you-cant-outrun-your-fork.html

See Effect of school-based physical activity interventions on body mass index in children: a meta-analysis.
"Meta-analysis showed that BMI did not improve with physical activity interventions (weighted mean difference -0.05 kg/m2, 95% confidence interval -0.19 to 0.10). We found no consistent changes in other measures of body composition."

Some people believe that if going to the gym isn't making them lose weight, they're not exercising hard enough. Chronically over-exercising can chronically raise serum cortisol, which makes the kidneys retain water, causing a stall in weight-loss, as well as causing raised fasting blood glucose, irritability, poor memory and a slower metabolic rate, due to the reduced conversion of thyroxine into tri-iodothyronine.

Don't over-exercise!

A healthy body weight is made in the kitchen, not the gym. Buy produce, cook it and eat it!

Although I totally support the use of low-carbohydrate/calorie diets for people with insulin resistance or Type 2 diabetes, now that I'm no longer insulin resistant, I can eat natural carbohydrates, without any problems.

A medium-sized (orange-fleshed) Sweet Potato takes only 4 minutes to bake in its jacket in a 700W microwave oven. The flesh is moist & sweet, unlike that of a Yam or potato.

I eat the whole thing, including the jacket. It's very filling and I'm still able to lose weight. For active and insulin sensitive people, a Kitavan-style diet is absolutely fine.

Sunday, 7 July 2013

Sunday Smörgåsbord: liberty, the internet, worry, health & Lyle McDonald.

Five items this time, not necessarily related.
From http://en.wikipedia.org/wiki/Smörgåsbord
By liberty, I mean personal liberty. I believe that individuals should be free to do whatever they want, provided that they don't harm another individual. However, collections of individuals should not be free to do whatever they want, as collections of individuals (i.e. businesses) usually try to profit from individuals, so the welfare of the individual isn't of importance. Businesses obviously don't want to instantly kill their customers, as that's obvious and will probably get them sued. However, "killing them softly" isn't obvious!

In the EC, just about everything has a CE kite-mark in order that it may be sold in the EC. Standards include EMC (Electro-Magnetic Compatibility) to ensure that:-
a) Devices don't emit excessive levels of RF "radiation", which may interfere with other devices.
b) Devices don't respond to excessive levels of RF "radiation", which may interfere with their operation.
I put "radiation" in quotes, as it's TEM (Transverse Electro-Magnetic) radiation i.e. Radio Waves.

In the US, who knows?

This is about "Smart Meters" - again! I've recently seen a surge in Facebook statuses about Smart Meters. I posted a technical article about these devices in Smart meters. Even after I posted a link on Facebook to my article, links to alarmist pages still appeared. The latest one is The Great “Smart Meters” Hoax. Electromagnetic Fields Are Real And Dangerous To Our Health, where Sam Milham, MD, MPH epidemiologist & researcher tells us how things really are.

Unfortunately, he's talking shite. The problem with people talking alarmist shite on the internet is that people who read alarmist internet shite and who are ignorant of the subject, believe it! This causes Fear, Uncertainty & Doubt (FUD), which in turn causes chronic worry. Chronic worry causes chronic hypercortisolaemia, which isn't good. A placebo (e.g. wrapping aluminium foil around your Smart Meter or paying for a "proper" solution to the non-existent problem) alleviates the chronic worry, which improves health.

I don't know about US Smart Meters. For all I know, some eejit has designed them to transmit 1,000W of RF (I'm just being silly), to get an outdoor range of >100miles. As these devices are designed for short-range communication, they probably transmit up to 100mW (about the same power level as WiFi) to get an outdoor range of ~150m. 1mW is one thousandth of a Watt. Transmitting more power than is necessary increases the probability of interference to other electronic devices.

100mW is a lot lower than the power transmitted by mobile phones (up to 2,000mW for the 850/900MHz Vodafone/O2 network), which need to be able to reliably communicate with the nearest mast, which may be miles away. As mobile phones constantly transmit occasional bursts of RF (to let the network know that they are on) and they are either in a pocket or are held against the ear/in front of the face to make/receive calls etc (while transmitting regular bursts of RF) and they are safe to use, how can a Smart Meter which is transmitting a much lower power level at a much greater separation be harmful? It can't.

With WiFi, Equivalent isotropically radiated power (EIRP) in the EU is limited to 100mW. Dunno about the US. Bluetooth is very-low-power (~1mW for Class 3 devices).

So stop worrying! Chronic worry (also, reading alarmist internet shite) is bad for your health.

Finally, I noticed that Evelyn Kocur "liked" an article that I'd read and completely forgotten about. It's Evidence From the Metabolic Ward: 1.6-2.4g/kg Protein Turn Short Term Weight Loss Intervention into a Fat Loss Diet. Interestingly, the protein intake for optimum body recomposition is 1.6-2.4g/kg LBM. This is equivalent to ~1g/lb LBM, which is the protein recommendation given by Lyle McDonald in his Rapid Fat Loss Handbook. Yup, Lyle was right all along. That amount of protein isn't bad for the kidneys (even 50% more protein than that, isn't bad for the kidneys).

Wednesday, 26 June 2013

Resistance is useless!

...said the Vogon guard. If that means nothing to you, watch this...


You probably know all about Insulin Resistance (IR) if you've read my blog for some time, as I may have mentioned it once or twice ;-) There's also Leptin Resistance (LR) in the brain, which reduces the amount of appetite suppression that leptin is supposed to produce. Robb Wolf's just written about Adrenaline Resistance (AR?) and chronically-high serum cortisol seems to induce Cortisol Resistance (CR?) in the hippocampus, resulting in poor short-term memory.

When the level of "X" in the blood is low most of the time, "X" receptors in the body up-regulate, so when the level of "X" in the blood goes high, it has an effect. When the level of "X" in the blood is high all of the time, "X" receptors in the body down-regulate, so when the level of "X" in the blood goes higher, it has a reduced effect.

The above suggests that regularly "grazing" on food is not a good idea, as this results in a fairly constant slightly elevated serum insulin level. Eating a meal, not eating for a few hours then eating another meal results in high serum insulin while the meal is being absorbed and low serum insulin for the rest of the time.

Friday, 26 April 2013

Hypoglycaemic counter-regulation at normal blood glucose concentrations in patients with well controlled type-2 diabetes.

Hat tip to Graham of the Lowcarb Team. See Hypoglycaemic counter-regulation at normal blood glucose concentrations in patients with well controlled type-2 diabetes.

"Background

Intensive treatment to achieve good glycaemic control in diabetic patients is limited by a high frequency of hypoglycaemia. The glucose concentrations at which symptoms and release of counter-regulatory hormones takes place have not been studied in patients with well controlled type-2 diabetes.

Methods

We studied seven well controlled, non-insulin treated, type-2 diabetic patients (mean HbA1 [corrected according to Diabetes Control and Complications Trial] 7·4%, SD 1·0) and seven healthy controls matched for age, sex, and body mass index with a stepped hyperinsulinaemic hypoglycaemic glucose clamp. Symptoms, cognitive function, and counter-regulatory hormone concentrations were measured at each glucose plateau, and the glucose value at which there was a significant change from baseline was calculated.

Findings

Symptom response took place at higher whole-blood glucose concentrations in diabetic patients than in controls. Counter-regulatory release of epinephrine, norepinephrine, growth hormone, and cortisol showed a similar pattern—eg, at blood glucose concentrations of 3·8 mmol/L [SD 0·4] vs 2·6 [0·3] for epinephrine.

Interpretation

Glucose thresholds for counter-regulatory hormone secretion are altered in well controlled type-2 diabetic patients, so that both symptoms and counter-regulatory hormone release can take place at normal glucose values. This effect might protect type-2 diabetic patients against episodes of profound hypoglycaemia and make the achievement of normoglycaemia more challenging in clinical practice."

What the above study shows is that, in people with "well controlled" T2DM (mean HbA1c 7·4%, SD 1·0 is poor control. Less than 6% is good control), there is counter-regulatory release of adrenaline, noradrenaline, growth hormone and cortisol at normal blood glucose levels. This is bad, as it's unhealthy to have release of counter-regulatory hormones under normal living conditions.

EDIT: Graham posted this study in support of his belief that there is low/no cortisol etc secretion due to blood glucose not falling low enough. This study actually counters his belief, as blood glucose doesn't fall low enough due to excessive cortisol etc secretion!

Thursday, 25 April 2013

Music AND lights.

What else but...

Not only can I now tolerate loud music but also I can now tolerate bright lights. Misaligned car headlamps no longer annoy me like they used to.

Wednesday, 24 April 2013

Can very-low-carb diets impair your mental faculties?

I wanna tell you a story...

In 2006, I had a test done on my pituitary gland*, called an Insulin Shock Test. It was pretty much what it said on the tin. I laid on a hospital bed, I was injected with an overdose of insulin and I was monitored for blood glucose and growth hormone levels every 30 minutes.

My blood glucose fell and fell and fell and fell until it reached ~1.5mmol/L (~27mg/dL). What happened was interesting. I came out in a cold sweat and developed a tremor. Apart from that, I felt fine. The consultant in charge was chatting to me and I was chatting to him. Eventually, I was given a sandwich, a yoghurt and a banana to eat.

Some time later, when I had stopped sweating and shaking, the consultant returned and told me that I had become confused. My brain had ceased to function correctly due to a lack of blood glucose (the insulin had totally suppressed serum FFAs and ketones, so there were no other brain fuels available), but I was too mentally-impaired to know that I was mentally-impaired. As far as I was concerned, everything was fine & dandy. This is like the Dunning-Kruger effect.

Referring to Blood Glucose, Insulin & Diabetes, as blood glucose falls due to either starvation or a lack of dietary carbohydrate, insulin falls and glucagon rises, stimulating the liver to convert liver glycogen into glucose for export to the blood. Eventually, liver glycogen becomes depleted and blood glucose falls again. The pituitary gland notices this and secretes AdrenoCorticoTropic Hormone (ACTH) which stimulates the adrenal cortex to secrete cortisol. The adrenal glands are also stimulated to secrete adrenaline (a.k.a. epinephrine). Cortisol increases the conversion of amino acids and other substrates into glucose by the liver and kidneys. If blood glucose continues to fall, the pituitary gland secretes growth hormone (GH), which has an anti-insulin effect.

From http://anthonycolpo.com/boosting-growth-hormone-with-diet-training-fact-or-fiction-part-2/:-
"after the zero-carb phase, subjects reported symptoms of hypoglycemia that included weakness, irritability, mental confusion, nausea, hunger, cold sweating and disturbed co-ordination. GH levels were higher during exercise after the low-carb phase, but so too were levels of other fuel mobilizing hormones such as epinephrine, glucagon, and cortisol." Epinephrine, glucagon, and cortisol are stress hormones. Chronically-high blood levels of stress hormones disrupt sleep and cause irritable, aggressive behaviour.

Ethanol inhibits gluconeogenesis in the liver (possibly also in the kidneys) resulting in worse hypoglycaemia. Worse hypoglycaemia results in more ACTH & adrenaline secretion and worse hypercortisolaemia, which can adversely affect the hippocampus, impairing memory.

In conclusion, if you want to eat a very-low-carb diet, long-term:-1) Don't do much high-intensity exercise. See "Funny turns": What they aren't and what they might be.
2) Don't drink much (if any) booze.

*My pituitary gland failed the test by secreting only 40% the amount of GH that it was supposed to. For six months, I was given GH to inject using a special pen with a 8mm x 0.3mm needle. By the end of the six month trial, I had perfected the art of painless injection. The trial was discontinued due to lack of any noticeable benefit (17 days supply of GH @0.3mg/day cost £120!).

Friday, 23 January 2009

Why exercise may or may not help you to lose weight.

Exercise. I hate it! I'm about as active as a Brazilian 2-toed Sloth. The problem that I had with exercise is that it made me hungry and I ended up eating more Calories than I burned by exercising. This was due to me doing it wrong! See Move More: Solutions to problems and Exercise decreases appetite.

The thing about exercise in moderation, is that it's good for health & fitness. The problem is that some people think that doing lots more is better. It ain't necessarily so. The 38 year old lady sitting near me at karaoke last night used to run a lot when she was at school. She now needs a replacement knee joint due to damaged cartilage and she had her knee wired up to a TENS machine. See A little moderate to vigorous physical activity does more than you think.

Too much early morning exercise can also make you ill, by raising serum cortisol level. High cortisol level is immunosuppressive. See Early morning exercise could make you ill. High cortisol level also causes water retention, so people who over-exercise can gain water weight. Chronically-high cortisol levels can also cause muscle loss, thin skin and osteoporosis.

Starving yourself and over-exercising makes things even worse. From WHY is the combination of high intensity and/or long duration activity a mistake when calories are being severely restricted?

"Water retention: cortisol binds to the mineralocorticoid receptor (the receptor involved in water retention, well one of them). And although cortisol has 1/100th of the effect on water balance of the primary hormones (aldosterone and a couple of others), since there is like 8000 times as much of it, it can cause a major effect."

"Excessive cortisol, especially chronic elevations cause other problems not the least of which is leptin resistance. Which only magnifies the drop in leptin from dieting. This could be another mechanism behind the greater drop in metabolic rate for the study I mentioned above."

So, what's the best thing to do for maximum fat loss with minimum muscle loss? A mixture of high-intensity exercise (resistance training with weights, or sprinting) and medium-intensity exercise (jogging) (a.k.a. High-Intensity Interval Training, or HIIT) is better than just medium-intensity exercise. See Resistance Weight Training With Endurance Training Enhances Fat Loss, Impact of Exercise Intensity on Body Fatness and Skeletal Muscle Metabolism and HIIT & Run.

One theory to try and explain the improved fat loss of HIIT is that Calories are burned after the high-intensity exercise is finished. However, the Excess Post-exercise Oxygen Consumption (EPOC) only amounts to ~35kcals, so it isn't significant. It's almost certainly the appetite-suppressive effect of exercise that makes you glow, that results in reduced Calories in.

Sunday, 4 January 2009

Everybody knows.........Part 2

.........that ketogenic diets like the Atkins diet destroy your kidneys and rot your bones, right? Wrong!
.........that the Atkins diet causes ketoacidosis which is a very dangerous condition requiring urgent hospital treatment, right? Wrong!

There's a lot of nonsense spoken about ketogenic diets by people who really should know better. I suspect that they have been taught wrongly at uni or med school as per the quote in Everybody knows.........Part 1.

Benign Dietary Ketosis is NOT Ketoacidosis.

Consider the following four cases:- Note: Figures are from "Introduction to Nutrition and Metabolism" By David A Bender (Senior Lecturer in Biochemistry, UCL)

1) Healthy human, fed state: Glycogen stores are replete. Serum glucose = ~5.5mmol/L. Serum fatty acids = ~0.3mmol/L. Serum ketones = 0mmol/L. No gluconeogenesis is taking place. Amino acid pool is replete. Cortisol level is normal so there is no loss of muscle mass.

2) Healthy human, fasting for 7 days: Glycogen stores are depleted. Serum glucose falls to ~3.5mmol/L. Serum fatty acids rise to ~1.2mmol/L. Serum ketones (mainly D-3-hydroxybutyrate) rise to ~4.5mmol/L (not high enough to cause acidosis). Gluconeogenesis is occurring. Amino acid pool is depleted. Cortisol level is high, causing slow loss of muscle mass. This is bad ketosis.

3) Healthy human, low-carbohydrate diet: Glycogen stores are depleted. Serum glucose falls to ~5mmol/L.
Serum fatty acids rise to ~1.2mmol/L. Serum ketones (mainly D-3-hydroxybutyrate) rise to ~4.5mmol/L (not high enough to cause acidosis). Gluconeogenesis is occurring. Amino acid pool is replete (due to protein intake). Cortisol level is normal so there is no loss of muscle mass. This is good ketosis.

4) Human with untreated type 1 diabetes: Glycogen stores are depleted. Due to lack of insulin, the Glu-T4 transporters in cells cannot move to the surface so glucose cannot enter cells. Serum glucose = >20mmol/L. This causes major damage to kidneys, arteries, eyes, nerves etc by cross-linking with proteins (glycation) resulting in major disability and eventual death. As the body is forced to run on fatty acids & ketones, metabolic processes are out of control and ketones rise to much higher levels than in 2) or 3) (I don't know how high exactly) resulting in acidosis and eventual death. This is ketoacidosis.

Conclusion: Low-carbohydrate, very-low-carbohydrate & ketogenic dieting is similar to fasting in that serum glucose levels are lower than normal and glycogen stores are depleted. The body is encouraged to burn less glucose and more fatty acids & ketones, but the metabolic processes are all under control. The big difference between low-carbohydrate dieting and fasting is in the amino acid pool and cortisol levels.