Tuesday, April 20, 2021

Maintaining muscle function in to old age

An aside: Public Service announcement. I seem to have a lot of Faceache/book friend requests coming through at the moment. Once upon a time I accepted all friend request and have read some interesting posts as a result. But I don't use Faceache for anything technical. The occasional orchid picture or flat water paddling snap is about it. So now I don't accept friend requests unless I know the person. There's nothing Hyperlipid-ish in my FB posts and the algorisms bury the social stuff I'd like to see if I have too many friends. Sorry if it seems rude, it's not meant to be but there is no way round it. End of Public Service announcement.

Back to the post:

The start of the current gross stupidity of lockdown-2 seems to have vanished in to the haze of the past. I can't remember when I last went bouldering, pre-idiocity. I guess it was some time last December. In the dim and distant past of lockdown-1 the climbing wall was completely reset but during the current period of enforced sarcopaenia only small areas were changed, so I got the chance to see how well I fared on some familiar routes after months of enforced idleness.

Pretty well. Endurance was a bit down and finger strength was laughable but on routes with big chunky handholds going up the main competition wall my bulk muscle seems to cope remarkably well.

On which subject I was interested in this paper put up on Faceache by Jay Wortman

The ketogenic diet preserves skeletal muscle with aging in mice

which is strong in it bias-confirming ability, bearing in mind that the keto mice were not exactly spending hours a day in the gym. It's the same group that produced this study


which is also exactly what you want to hear if you are an old bloke like me with young kids.

But I never blogged about the original paper. It has a certain flaw, common to both papers, which made me slightly cautious. The paper is best described as one of those "think about it" studies. Here are the diets used for both:























and here are the survival curves


The first problem is that there is no mention of gas chromatography. We have no idea of what the PUFA content of the lard was and the lard makes up something over 80% of the calories of the ketogenic diet.

In a deeply ketogenic diet such as F3666 it doesn't matter what the PUFA content is and the lard content is relatively low anyway. But for a rodent diet supplying 10%of calories as protein and maybe 20-25% of calories as PUFA it might matter. It mattered in these papers:

"During this one month [ie the lead-in at 12 months of age] period, food intake was measured to determine the daily food intake required by these animals. At 12 months of age, mice were randomly placed on one of three diets: control, low-carbohydrate diet (LCD), or ketogenic diet (KD). The control diet contained (% of total kcal) 18% protein, 65% carbohydrate, and 17% fat. The LCD contained 20% protein, 10% carbohydrate, and 70% fat. The KD contained 10% protein, <1% carbohydrate, and 89% fat. For the longevity study, food intake was set at 11.9 kcal/day, and decreased to 11.2 kcal/day after weight gain was observed during the first weeks of the study."

The studies combined a ketogenic diet with calorie restriction. Calorie restriction is a known longevity promoter. Duh. And keto didn't maintain a normal weight.

Lard can contain anything from almost no PUFA up to more than 30% PUFA, depending on what the pig was fed on and how adulterated the lard has been with cheap vegetable oils.

So these ketogenic mice had to be on a calorie restricted diet because otherwise they gained weight. They were on a diet containing around 20%-ish of calories from linoleic acid. If they felt a hypo in the middle of the light period they would have eaten to correct the hypo. Pathological insulin sensitivity. Or just the loss calories in to adipocytes without a hypo would generate simple hunger to off set those calories lost in to fat calls, ie weight gain.

Of course it's just a rodent study and maybe people would be different.

Or, more likely, maybe not.



As a more general point it's also worth noting that the improvement is in the median lifespan, not peak longevity. The first mouse to die was in the keto group, the last in the low carb group. Median does not mean an intervention is invariably perfect for all individuals.

But it's as good as we have at the moment.

Peter

Tuesday, April 13, 2021

The ginger paradox (6) Reward

Edit: The capitalisation of Reward is sarcasm. End edit.

Corn oil is very Rewarding for rodents. These people are working hard at the mechanism:


so let's not assume that Reward is some airy fairy concept, it's fully physiological. How Rewarding corn oil is in rodents is beautifully illustrated by the paper I  discussed recently in which mice, when given the choice, voluntarily consumed pure corn oil until it comprised roughly 84% of the total calories in their diet. Of pure fat.  Without training of any sort. This is the paper:


So of course the mice became obese. Okay, I'm making that bit up. Massive consumption of Rewarding corn oil does not make mice obese. They eat a little extra, admittedly, but that is because the metabolic effect of an 84% corn oil diet is to instigate uncoupling. A quirk of the biochemistry of linoleic acid, uncoupling proteins and rodent brown adipose tissue means that a certain amount of energy is wasted as heat, so the mice have to consume a little more corn oil to make up for this loss. A few extra total calories were consumed without any extra weight gain.

Metabolism + extra heat production = an extra amount of food has to be is eaten to maintain normal weight.

Simple.

Going on to look at mechanisms of Reward, this study 


found that the Reward of corn oil is neuronal, it comes from local metabolism of the oil on the tongue using a lingual lipase so that a tiny concentration of FFAs is sensed by receptors in the mouth and nerve signalling from here drives the dopamine release in the brain. You can bypass the lipase on the tongue by adding as little as 1% unesterified linoleic acid to mineral oil which mimics the approximate amount of FFAs provided as a stimulus from the more normal corn oil/lipase process.

To make it absolutely clear:

Mineral oil carrying 1% of free linoliec acid is as Rewarding as 100% neat corn oil because both provide roughly the same FFA drive to the sensory cells. You can measure the dopamine release in the rodent brain. It's the same because the sensory cells on the tongue see the same concentration of FFAs.

I have a thought experiment.

What if one group of mice/rats were given chow plus access to neat corn oil and another group of mice were given chow plus access to mineral oil with 1% free linoleic acid added?

The oils are equally Rewarding.

Would the mice consume the oils in equal amounts because both are equally Rewarding?

If the oils were consumed in equal amounts would the mineral oil mice lose weight?

Or would they eat extra chow?

My bet is that if you ran such a study for eight weeks the mice with access to the mineral oil wouldn't touch it with a barge pole. It might release dopamine in the nucleus accumbens but it's not going to do much to fuel metabolism. That would need chow. Maybe there might be some recreational flavoured mineral oil consumption but I think that would pale quite rapidly.

Oooooooh! They might develop Reward Resistance! Like leptin resistance but dumber.

Reward is the refuge of researchers who consider obesity is caused by eating in excess of your metabolic needs.

A more sensible view of obesity is that it results from a metabolically mediated loss of calories in to adipocytes which then requires more calories to be eaten to meet normal metabolic needs. In the same way as orlistat requires over eating to compensate for fat loss via faeces, so "fake" corn oil (1% linoleic acid in mineral oil) would require extra chow to make up for the lack of calories in that highly Rewarding fake oil. And why feeding D12492 means rodents have to consume extra D12492 because they lose calories in their adipocytes.


Just to summarise: high Reward food makes you fat only if its metabolism result in energy sequestration in to adipocytes. 

Real corn oil at 84% of calories is not obesogenic because it does't sequester calories in to fat cells. I don't care how Rewarding it is. Nor does metabolism care.

Peter

Surwit diet and derivatives (4)

I've been interested in the Surwit diet for years. It's a fascinating diet, high in saturated fat, low in PUFA yet undoubtedly obesogenic.

It's an interesting paradox to think about. As occasionally happens I found a non related paper which gives some suggestion of the mechanism. Here it is:

Characterizing the effects of saturated fatty acids on insulin signaling and ceramide and diacylglycerol accumulation in 3T3-L1 adipocytes and C2C12 myotubes

The paper uses adipocyte-like 3T3-L1 cells or muscle-like C2C12 myotubes. The 3T3-L1 cells might be worth another post in future, today is about the myotubes.

They looked at many things, but most interesting are the data on the ability of insulin to promote the storage of glucose in glycogen granules. I, being me, would look at this as a surrogate for un-measured lipid storage as lipid droplets in muscle cells. One of the cardinal rules of ectopic lipid deposition research is to never, ever suggest that myocyte lipid droplets might be enlarged by insulin signalling. They will be. Just like glycogen granules are enlarged by insulin.

So, practicalities. The myotubes were prepared in "low glucose" DMEM which is probably code for 5mmol/l, ie a normal physiological glucose concentration. To this medium was added a fatty acid at 0.75mmol/l, ie moderate fasting levels. Cells were incubated for 16 hours and then treated with supra-maximal insulin.

They noted that elevated pure palmitate is utterly harmless to cells in culture with normal glucose levels:

"Under these conditions, no signs of cell death were observed"

which certainly is not the case using 25mmol/l of glucose!

Here are the gels they obtained:















The top row, highlighted in red, is demonstrating the presence of phosphorylated (activated) Akt, a core insulin signalling step. We are comparing P-Akt under insulin and 5mmol/l glucose with that under insulin and 5mmol/l glucose plus 0.75mmol/l palmitate. It's clear that insulin signalling is markedly blunted by palmitate. If we look at the dashed oval we can see that the P-Akt band under oleate is comparable to that of the control.

The same applies to the level of phosphorylated glycogen synthase kinase 3 beta, a key enzyme in activating glycogen formation and outlined in blue. P-MAPK is irrelevant today but, again, might be interesting in the future.

Convincingly, palmitate causes insulin resistance and oleate doesn't. Bear in mind that this is a highly constrained experiment to make a specific point. These is no mention of ROS generation but it is worth looking at this from the Protons/ROS viewpoint.

Palmitate has an FADH2:NADH ratio of 0.484

Oleate has an F:N ratio of 0.457

In this experiment conditions are carefully controlled to give us an all or nothing response, almost like switch. The switch trips somewhere between an F:N of 0.484 and 0.457. Insulin resistant vs insulin sensitive. No double bonds vs one double bond.

It is possible to adjust the F:N ratio by smaller amounts than by adding a double bond simply by altering the length of a saturated fat. If we consider myristic acid the F:N ratio is 0.482 and for lauric acid it is 0.478.

The paper went on to look at insulin signalling using these fats and here are the gels they obtained:












At the extreme left is the control without insulin, next is control with supra-maximal insulin but no fatty acid, then rest of the bands have the indicated fatty acids added, all at 0.75mmol/l. I've put in the red line to divide insulin sensitive from insulin resistant results. Everything to the left of the line causes no insulin resistance, to the right significant insulin resistance. The switch is between myritic acid and palmitic acid, F:N 0.482 and 0.484.

I would expect C10 capric acid to be insulin signal facilitating and probably C8 caprylic acid too, although its strongly ketogenic effect and partial conversion to palmitate might make that less predictable.

Coconut oil is primarily medium chain triglycerides with F:N ratios on the insulin sensitising side of the switch. Formulating a high fat diet out of insulin sensitising fats combined with an insulogenic carbohydrate load seems like a good recipe for obesity.

It's always worth reiterating that there is no "switch" as such, there is a general integration of information about energy status and demand using ROS which can be pushed towards lipid storage or use depending on particular inputs. The F:N ratio looks like a switch in a very simple model asking a very simple yes-no question. But that's still useful information for understanding the Surwit diet.

Peter

Saturday, April 10, 2021

The complete and unifying explanation of human evolution

Miki Ben-dor has a new post on his blog

The complete and unifying explanation of human evolution

If you've not read his blog before, now would be a good time to start.

Peter

The ginger paradox (5) and some speculation

TLDR: If resisting insulin is rendered impossible due to very, very high PUFA diets then mitochondria resort to uncoupling.


reiterated the well known essentiality of FFAs for the activation of UCP-1 and added in the significant role of reactive alkenyl species. In more common parlance that would be lipid peroxides, primarily those derived from linoleic acid. I thought about it in this post.

This is the next step, which I specifically went looking for because this is how I think life should be organised. It is a perfect example of me having a huge bias, knowing what I want, and going looking for it. You have been warned.


It is utterly clear that UCPs in general suppress ROS generation and that some members of the family are not being used for thermogenesis at all, more likely for prevention of the generation of supra-physiological levels of ROS.

We have an interesting situation where PUFAs, the prime pathology of which is their failure to generate adequate ROS, are also extremely effective at facilitating uncoupling, which needs significant ROS generation to happen. Where does this superoxide come from?

This is the core question.  





Warning: I think step f) is the one I have least evidence for. Life is like that sometimes.

Okay. The story so far:

Caloric ingress in to a cell is controlled to an appropriate level while calories are freely available by limiting insulin signalling.

Insulin signalling is curtailed by driving electrons in reverse through complex I to generate superoxide and hydrogen peroxide which disable/limit said insulin signalling.

This reverse electron transport rises in direct proportion of FADH2 supplied compared to the amount of NADH.

The presence of double bonds in fatty acids limits FADH2 generation, limited FADH2 generation limits the control of insulin facilitated caloric ingress and continued insulin signalling diverts calories in to storage.

I have to accept that not all excess calories will be stored, some will continue to enter the electron transport chain as both NADH and FADH2. If electrons enter the electron transport chain when there is a low (relative) demand for ATP then

a) mitochondria membrane potential will rise, a direct consequence of the inability to limit electrons entering the ETC through complex I and multiple FADH2 entrance points. Protons are pumped but not used

b) the cytochrome C pool will become progressively more reduced, limiting it's ability to accept electrons from complex III

c) electrons will be transported through the cytochrome b centre of complex III back on to the CoQ couple

d) these electrons will replace those absent as a result of double bond containing fatty acid oxidation and will restore superoxide production

e) superoxide production, under these circumstances, is being facilitated only at the cost of high membrane potential secondary to low ATP synthase activity in parallel to excess calorie storage

f) if the double bond content of the lipids providing input to the CoQ couple from beta oxidation is very, very high then the need for negative feedback through complex III will be very, very high as well and will be associated with an excessively high membrane potential

g) the answer to excess membrane potential is uncoupling

h) superoxide positively regulates the activity of UCP-1 as do superoxide derivatives of LA

i) uncoupling allows the flow of electrons down the electron transport chain and lowers membrane potential, it immediately stops reverse electron transport/superoxide generation and converts the excess calories entering the cell in to heat, water and carbon dioxide


Summary:

Normally regulated calorie ingress to a cell occurs when linoleic acid is low.

Excess ingress from LA is dealt with by diversion to storage, leading to obesity.

Marked excess is dealt with by uncoupling which does not "require" obesity.

There are no hard boundaries between the above conditions, there simply appears to be an inverse "U" shaped curve in response to the content of linoleic acid in the diet. Such curves are common in nature.

A few last thoughts:

Simply looking at the experimental data the situation appears to be that including linoleic acid at levels between somewhere just under 10% up to somewhere in the high 20%s will facilitate excess insulin action and excess lipid storage. As we increase the supply of linoleic acid through the 30%s and in to the 40% region of calories then uncoupling becomes the primary molecular solution to a progressively more intractable problem.

It is worth pointing out that in a given mitochondrion there are lots of CoQ/CoQH2 molecules, lots of beta oxidation sites and, while the calculation of FADH2:NADH is useful for insight as to how RET works for a single fatty acid molecule, the mitochondria are integrating lots of FADH2 production sources, lots of NADH sources and are continuously monitoring the membrane potential (which is an integration of energy input/need) as well as the redox state of the CoQ couple.

What happens on a whole organism basis is also an integration of all of these effects. The mechanism for weight loss in high PUFA diets is both comprehensible and plausible.

The studies are real, the data are real.

Personally I still wouldn't go there, but understanding them is key. 

Peter

Friday, April 09, 2021

The ginger paradox (4)

Here we go with ad-lib corn oil.

Voluntary corn oil ingestion increases energy expenditure and interscapular UCP1 expression through the sympathetic nerve in C57BL/6 mice

Mice were either offered chow from a hopper or chow from a hopper with the option of corn oil from a drinker bottle in addition. They like corn oil.

The mice with access to corn oil ate more calories than those without:



but most calories weren't from chow, top line is grams of chow only, bottom line the weight of chow eaten when there is access to ad lib corn oil:


We can look at the total amount of corn oil consumed:






















Assuming 9kcal/g we can now reverse engineer that to 16kcal of corn oil a day as part of a total daily intake of 19kcal. So that's 84% of calories from corn oil. As 55% of this 84% is linoleic acid that gives 46% of calories as LA. Well in to the weight loss range of intake noted for high LA safflower oil, in fact that's verging on a self selected ketogenic diet, which complicates matters a little.  With 16% of calories from chow this will also be rather low in protein, though far from zero carb. Just look at the RER if they have access to corn oil, the black circles. Yes, these mice really are oxidising lipid and very little else, but also bear in mind that exactly the same effect could be obtained with safflower oil under far from ketogenic/low protein conditions. Here are the RERs:








Anyhoo. What was the end result? These are the body weights at the end of the eight week trial:























More calories, more oxygen consumption, same body weight.

This looks like a generic property of linoleic acid in exactly the same way as weight gain is at lower levels. The Jacobs study rats were around 24%, on the border between obesogenic and weight limiting effects, on the obesity side.

To get weight loss you need to go higher with the LA.

Just before I finish and post some speculation about mechanisms it's clear from the rest of this study that uncoupling is the answer to the paradox. In modern mice this is mediated through UCP-1 within the interscapular brown adipose tissue, as the paper went to considerable lengths to demonstrate.

This is the current level of development in the modern evolutionary terms of rodents. It's a sophisticaled high level system which will overlay the insulin system which will overlay the ROS system. It is perfectly possible to make a case for why this high level system is advantageous by thinking about the underlying ROS system.

I'll have a discuss about that in the next post.

This series is looking at body weight. Using an approach to normalise body weight which involves the incorporation of markedly unsaturated lipids in to the inner mitochondrial membrane does not strike me as a sensible thing to do. Might be a technique for looking good in your coffin.

Peter

The ginger paradox (3)

Here is the next step. Mice this time.

Prevention of diet-induced obesity by safflower oil: insights at the levels of PPARa, Orexin, and Ghrelin gene expression of adipocytes in mice

The basic study design was that mice were fed a control diet, a safflower oil based diet or a lard based diet for an initial 10 weeks. At 10 weeks half of the lard fed mice were switched to the safflower oil based diet and feeding continued for another 10 weeks.

Here are the diets























They measured the linoleic acid content by gas chromatography. That is very, very good. We can rough out the LA content of the control diet at around 5% of calories as LA, the lard diet at 11% of calories as LA and the high safflower oil diet at around 38% LA.

Here's what happened to the weights









As expected the lard mice became overweight by 10 weeks. Putting them on to 38% of calories as LA returned their weight to that of control mice or that of mice fed 38% LA safflower throughout the full 20 weeks.

This is not an isolated study showing the benefits of safflower oil, but it's one of the better ones. I find it impressive. It has to be understood.

Towards the end of the discussion in this paper the authors cite another gem which completely contradicts their own findings while providing more insight:

"These results are different to the study that the rats fed on 30% safflower oil and mice fed with 20% safflower oil showed significantly higher body weight, white adipose tissue weight, serum leptin, and hepatic PPARa mRNA expression [28]."

The paper they cite is this one:

Changes in liver PPARa mRNA expression in response to two levels of high-safflower-oil diets correlate with changes in adiposity and serum leptin in rats and mice

Here are the diets



















Wow! Have you spotted it? Thats right. More excellent gas chromatography and suddenly you find out that "safflower oil" and "safflower oil" can be very, very different oils. This batch of safflower oil was 24.1% LA. In the highest fat diet we are looking at 24.1% of the 53.68% of fat calories as LA. That's 13% of calories as LA, bang in the middle of the obesogenic range. That's very different from the 38% which corrects obesity...

It must be sad trying to understand your own results and those of rival labs without the Protons/ROS hypothesis to fall back on. Must be awful.

Currently I don't think there is anything special about safflower oil. I think it is an effect the linoleic acid at very high dose rates. You should, theoretically, be able to do the same with corn oil. Sadly most of the corn oil based high fat diets aim to get in to the sweet spot of 10-20% of calories as LA. They want obesity after all.

If we are trying to generate diets with 40% or more of total calories from linoleic acid it will be much easier with safflower oil at 75% LA than using corn oil at 55% LA.

Interestingly mice appear to rather like corn oil. Let's look at a free choice feeding study next. Chow as pellets or corn oil from a liquid feeder bottle. Let the mice decide how much of each... And see if they get fat.

Peter

Thursday, April 08, 2021

The ginger paradox (2)

Here is ref 17 from the previous post

Effect of short-term dietary fat on cell growth in rat gastrointestinal mucosa and pancreas

Here are the diets by weight of ingredients














and here are the relevant weights after four weeks on the diets









I think it's unarguable that the weight gains are only trivially different between the three groups. It becomes clearer when you look at lard in terms of linoleic acid level as opposed to accepting that it is "saturated fat". Modern lard is around 12% linoleic acid. It might have been a little higher or lower in the 1980s depending on how much adulteration with cheap seed oils the manufacture could get away with in those days or what the pigs were fed on 40 years ago. Lets go with 12% to include the splash of corn oil thrown in.

The control diet is reported as 16.8% total calories as fat and both high fat diets as 52% of calories from fat.

That makes the control diet around 9% linoleic acid, the lard diet 12% linoleic acid and the corn oil diet around 28%.

At 9% LA the control diet is already obesogenic. The lard diet is a bit worse but not in a different ball park, much as I would expect. The fascinating one is the lack of excess weight in the corn oil group, the group with the diet used by the Cairo study as their obesogenic one.

The easy part is to assume that all of the diets in the Jacobs paper are obesogeic, as is the corn oil diet used in the Cairo study. All of these rats gained about 150-180g. The control diet in Cairo was unspecified chow. If it contained 4% or less of linoleic acid we have a plausible explanation for the low weight gain in that control group. We just have to explain why the rats in Jacobs' paper on 12% LA weighed about the same as those on 28% LA.

This is very important to me. There are a series of papers using very high LA diets, especially Safflower oil based, which show minimal obesogenic effects and even the ability to partially reverse lard derived obesity. Something I have been thinking about for years.

Peter

The ginger paradox

For odd reasons I was looking for papers on orlistat, in particular for rodent papers about the drug which might demonstrate effects relevant to the Protons/ROS hypothesis.

Rodent reports seem to divide up in to those which use an intermittent oral dosing regime vs those which incorporate the drug in to food as a fixed component of the ration. It became clear that if you mix orlistat with the ration you can exactly titrate the amount of lipase inhibitor to the dose of fat administered and include this with every meal and every snack, whatever the size and whenever consumed. This latter has no bearing on the real life use of the drug where it is given three times daily to establish a background inhibition of enteric lipases and people have to judge their fat intake in relation to how far they are from the nearest toilet and if they are carrying spare underwear. Not the most successful or pleasant drug for weight loss per unit grief and it doesn't seem to work very well.

Of course unpredictable bowel function doesn't matter to a lab rat, it's not wearing underwear and it can pooh whenever it likes, wherever it likes because it lives in a mesh floored cage.

There is remarkably little in the rodent literature on orlistat alone for obesity control and mostly you have to look at drug or supplement trials where orlistat was used as the control/usual care group. In these trials it is usual to use intermittent oral dosing rather than admixture to the food because intermittent oral dosing doesn't work very well. If you have an ineffective but conventionally accepted drug that then provides an ideal comparator to show your intervention does something good.

Aside: Just think of metaclopramide. It was/is a standard antinausea/antiemetic for post op use. It is ineffective, dreadful stuff but it's licensed. Which makes it ideal as a "standard therapy" against which to compare a lovely modern drug such as maropitant or ondansetron. You know the latter are going to beat metaclopramide  hands down because metaclopramide is little better than placebo and makes you feel crap. Study design is important and this shows in the methods section. End aside.

However some trials do use the effective food admixture method. I found an innocent little study from 2013 which did just this:

Comparative evaluation of the efficacy of ginger and orlistat on obesity management, pancreatic lipase and liver peroxisomal catalase enzyme in male albino rats

It feels like a throwback to the 1950s. They generated their intervention (ground ginger, 5% by weight of the diet) by going to the local market in Cairo and buying some ginger, peeling it, washing it, mincing it and air drying it before milling it in to a fine flour to incorporate in to the diet. The comparator intervention was orlistat which they bought as capsules to be opened and incorporated in to the ration in a similar manner to the ginger.

The bottom line is that their ginger worked rather well compared to an unmodified high fat diet but sadly (for the ginger) the orlistat was incredibly effective, far more so than the ginger. This is why I got interested in the study. Not only did the rats on orlistat fail to grow, they had a marked increase in food intake. They ate a ton of high fat food yet put on remarkably little weight. There is no information provided about bowel function but I guess the rats on orlistat didn't wear underwear and they lived their lives metaphorically sitting on the loo. Certainly whenever they ate anything. Which was as often as possible.

The basic premise to orlistat is that if you take a drug which blocks fat absorption you decrease the functional "calories-in" so lose weight. Which is, of course, bollocks. What would actually happen is that you would eat more. You cannot fool your metabolism. You either eat more to meet your needs or you slow your metabolism to match your available calories. You feel cold, move as little as possible and dream about food. Most people would eat more.

This is what happened






Chow rats gained 60g, high fat fed rats gained 130g, orlistat treated high fat fed rats gained 7g. Seven grams. These rats did not want to be slim. They are not heading for the beach in a bikini. That low weight gain is malabsorption in action.

It causes hyperphagia because that is the only way the rats can even try to meet their caloric needs.

The implication of this study is that malabsorption makes you thin. That could be CICO. But orlistat malabsorption might also block linoleic acid absorption. That this might actually be true in real live people to facilitate a little genuine fat loss is where I was heading, but I lost interest when I tracked back through ref 17 to find that the high fat diet cited in this study is not obesogenic! Ref 17 as mentioned in:

"Group (2) G2: (High fat diet), rats of this group fed high fat diet (The diet contain 30% corn oil) according to Jacobs17"

A diet composed of 30% corn oil by weight, around 26% of calories from linoleic acid, is not obesogenic, in rats under the supervision of Jacobs.

Yet it clearly is obesogenic in Cairo.

Now that is interesting. These are thing which fascinate me. Ref 17 is next.

Peter

Monday, April 05, 2021

Butter vs peanut butter


It was specifically designed to show that fat raised insulin and that saturated fat was particularly bad in this role.

It produced this graph:

















Let's imagine the group leader has sketched out in advance the above graph or something like it which he wants the PhD student to aim for as their results.

Group Leader: How are you going to generate these graphs?

PhD student: Well, seems like a pot of yogurt, a slice of bread, some plain pasta and a dose of each type of fat might work...

Sadly life is not quite that simple. The insulinogenic components would need to be chosen to produce a small but measurable insulin response. Not so small as to be undetectable but not so large as to tax the pancreas or overwhelm the effect sought. Then there had to be enough fat to augment insulin secretion and generate the appropriate resistance to that signal, within the normal physiological range of pancreatic function. So the amount of fat would have to be very carefully adjusted to give an ideal amplification of the carbohydrate/protein insulin signal. In the end it turned out to be necessary to adjust the quantities of food directly to the body surface area of the participants, not a fixed meal and not even calories merely adjusted to bodyweight. The use of body surface area is normal for calculating doses for various highly toxic treatments such as chemotherapy because dosing has to be as precise as possible in this instance. Turns out this dose/surface area was needed to correctly dose the fat (50g/m2) and pasta (30g/m2) to illustrate the double bond/ROS effect. The yogurt and plain bread got a free pass.

But they did all of this successfully, got the "down" on saturated fat and polished the halo of olive oil. 

I'm both impressed and grateful.

Now let's go back in time to the 1980s and look at this study:


The agenda in this study is to show that fat blunts insulin response to carbohydrate ingestion but causes delayed insulin resistance during the following meal. They threw in a butter group and a peanut butter group. Here are their results, I've chopped off the right hand end about the follow on meal as it's not relevant here:




















We can also ignore the 2 X WB line which was just 480kcal of bread with a smear of cottage cheese. The lower two lines are bread alone  vs the same dose of bread with some fat. Both fat sources produced results which were indistinguishable so were combined. The insulin response is exactly the same with or without fat, saturated or unsaturated.. 

How do you reconcile the two studies?

This second one used a fixed calorie meal with 50g of carbohydrate and 25g of protein. Fat provided around 25g for each meal.

The dose of insulinogenic substrate was well over half of the calories in the meal, the fat well under half. The total gross insulin response was to the bread, not the fat. The amount of fat was insufficient to make any detectable difference to that insulin response.

Just compare the insulin values achieved in each study, the Spanish study use a fat-free insulinogenic stimulus raising insulin from 50pmol/l up to about 70pmol/l. The bread meal raised insulin from around 70pmol/l (10mU/l) to around 400pmol/l (60mU/l), even without any added fat! There is no scope for picking up any effect of the fat, let alone from the nature of the fat. The bread effect was approaching maximal, even though it didn't quite max out the pancreas as much as the double bread meal did.

Ultimately you design your study around the result you want to generate. Sometimes it's easier than others.

The Spanish study was remarkably cleverly done but looks like they had to work hard to get the results they wanted. I still like it, even though I markedly disagree with their interpretation of the findings.

Peter

Saturday, April 03, 2021

Israel is doing really well for COVID-19 vaccination

Israel has missed out on submitting data to EUROMOMO for week 13 of this year. During week 12 they recorded a marked, unique, increase in all cause mortality in their over 65 year olds, almost all of whom are now fully vaccinated against COVID-19 with the Pfizer vaccine.

These people do not appear to have died of COVID. It seems to be mostly cardiac problems which don't seem to be particularly well defined. Translated from a Hebrew newspaper via Google as a specialist saying "We are now witnessing a murky wave of heart attacks."

The now-outdated week 12 data are presented on-line by a group called Swiss Policy Research. I have no idea of their affiliations, politics or agenda and, frankly, I don't care. The graph certainly looks like a EUROMOMO graph and Israel has not, as of today, submitted their week 13 data.








Of course these data are provisional and, of course, numbers of deaths in week 13 might be really low but the Israelis just haven't gotten around to submitting the numbers yet. Maybe they're too busy partying in celebration of their vaccine success. EDIT Or Passover! END EDIT

I'm uncomfortable about ADE with these vaccines. I'm concerned about triggering auto-immune diseases. I've not really considered the thrombogenic/disseminated intravascular coagulation potential but it's also there to worry about.

The European Medicines Agency is responsible for the authorisation of SARS-CoV-2 vaccines in Europe.

Doctors For COVID Ethics are currently in discussion with the head of the EMA with a view to starting a prosecution of EMA for crimes against humanity relating to these vaccines. The physiology and immunology which they cite as being relevant (and as yet un-assessed by the EMA) make a very interesting case.

I personally am very, very cautious about yielding to the coercive pressure to accept such a vaccine here. Coercion is becoming a part of reality in the UK. These vaccines are absolutely experimental in their technology, have never before been licensed anywhere in the world and will provide no benefit for the vast majority of the recipients. The sooner the legal cases actually begin the better. Sadly a victory in Europe would not get we folks in the UK out from under the Boris Johnson jackboot.

As always: If you are at risk of dying from COVID-19, take the vaccine. If you are not, think hard about it.

Peter