Inflammation, exercise, diet, meditation and disease

[Olga]

Jim, I think you raised very interesting questions and they may deserve a separate thread. I have been having similar questions myself especially after I started MSc in Exercise Science and Medicine at Univ of Glasgow this September. I feel that there is a lot of emphasis on research of effects on cardiovascular heath, more than any other function of a human body. Could this be because - I haven't checked the numbers - that the poor CV health is number # reason of premature deaths? At least, in populations serviced by those research facilities where we get the results (such as UK or US).

 

Immune function health is much more difficult to measure than the CVS health (the beloved VO2max - you can get an esimate from submaximal test conducted in your bedroom LOL) so per $1 of research, there is more likelihood to get published and get funding from the CVS/exercise area. And yes I am very cynical.

[Jim Pickles]

"Could this be because ..... poor CV health is number # reason of premature deaths?"

 

Yes, very much so. And moreover it is probably the most easily preventable with current technologies. Once smoking is taken out of the equation, cancers followed by dementias are the next leading causes of death, and they are much more difficult to deal with. I wouldnt be so cynical as to say it is just a matter of ease of funding, but there is a big fashion component in the research that gets supported at any one time.

 

As you get older, and have not already died of anything else, cancer comes further to the forefront (to 50% of deaths, up from 30%). However, one should not forget that in some ways a stroke may be even worse than death, leaving someone very heavily disabled for many years. So cardiovascular health is important at any age.

 

As I said, those reading this board are likely to be leading a cardio-protective lifestyle anyway, and these other factors may be of greater importance to them.

 

I dont know if things have changed recently, but Glasgow where you are doing your degree from, is or was the cardiovascular disease capital of the world (home of the deep-fried Mars bar) and this may influence their local agenda too.

[Nathan]

As inflammation in the body is generally a BAD THING (though it is useful in fighting disease, in many cases it leads to more problems than it solves in individuals in our society).

 

As evidenced by your comment to its potential usefulness I am sure you are aware of this, but I just wanted to point out for clarity's sake that this should probably read something like "too much inflammation in the body..." Like Kit mentions, all things in moderation. Inflammation is absolutely necessary for many beneficial processes in the body, including exercise adaptations. I hesitate to comment because I am what I suppose you would call an "armchair scientist." I like to keep up with a lot of the health/nutrition research via podcasts, etc. but I am certainly no researcher myself, and I am sure I lack much of the basic knowledge to properly read and translate the research itself.

 

This just came through my FB feed and reminded me of this post:

Anti-inflammatory drugs put you at risk of tendon rupture by blocking the normal cross-link formation in response to exercise training - Effect is mediated by TGF-beta which is a common target for anti-rheumatic drugs.
www.suppversity.com | Carroll, C. C., et al. "THE EFFECT OF TGF-Β RECEPTOR INHIBITION AND ACUTE EXERCISE ON RAT ACHILLES TENDON COLLAGEN." Bone & Joint Journal Orthopaedic Proceedings Supplement 97.SUPP 11 (2015): 14-14.

As for cardiovascular exercise, it is most likely another case of the middle road (as it always seems to be). There is research pointing to possible negative outcomes as a result of both too little and too much, be it high, medium, or low intensity. My hunch is that keeping some kind of balance is the key (once again, as it seems to be with everything). I do a lot of walking (it is my main means of transportation), but I also enjoy sprints and find that they seem to give me a lot of bang for my buck regarding overall cardio fitness.

[Jim Pickles]

Inflammation is of course very important to the body - for fighting infections, for instance. However, the general consensus is that the body tends to produce excessive inflammation, and at times when it is not needed, which becomes damaging. Why it does this, is not known. Reducing the level of background inflammation (not with steroids, though, as they are themselves damaging) is probably a good idea.

[Kit_L]

Sprints (or jumping) is truly excellent bang for the buck for both cardiovascular heath (not just via steady state aerobic improvement, 1970s Ken Cooper-style, but strength/springiness, too), but needs to be worked up to. I am going to write more about my bouncing > jumping protocol soon. 

 

And to Jim and Olga: just how many causes of cardiovascular disease (of the sort that proves fatal, I mean) are there? A great many. And only some of them respond positively to "cardiovascular" exercise, I believe. 

 

A side note: what exercise is not cardiovascular in its benefits? Only the extent of the improvement response varies as the exercise changes. Even pure strength training confers a cardiovascular benefit—small, but measurable. Running is usually (reflexively?) regarded as the gold standard, but learning to relax, too, confers a benefit (presumably by reducing blood pressure via reducing muscular tension). I am sure there are other beneficial effects to learning how to relax, like reducing cortisol. Life certainly feels better when you are not anxious.

 

And (@Jim) experiencing your life as worrying and/or stressful is the #1 reason for elevated corticosteroids, not inflammation, AFAIK. I have never heard that the healthy body does produce excessive inflammation, BTW; what is your source for that claim, if I may ask? The real fight-or-flight-caused inflammatory response (like a trauma) is short lived (IIRC, 72 hours is typical). Of course, if the trauma is massive, this can become longer, but the low-level elevation you speak of is, IMHO, mostly generated internally, through experiencing one's life as "unsatisfactory" in multiple ways.

 

@Olga/Jim: happy to move to a new thread (can you suggest a decent title?) from post #30, if you wish.

[Jim Pickles]

Kit - just a quickie in response to inflammation, which is a massive topic that I've not read systematically about. From many sources, we know that the body tends to produce excessive inflammation, both in health and disease. Yes, please move to a separate thread, because it is important for many issues discussed in this forum, including the effects of exercise, diet, relaxation, and meditation (all of which affect the levels of inflammation in the body). Suggest "Inflammation, exercise, diet, meditation and disease."

 

Some background systemic inflammation (as measured by the levels of pro-inflammatory cytokines in the bloodstream) comes from food for instance (particularly from sugars). But I will read and bring all the information I have together. It is a relatively new area of research so basic knowledge on inflammation and lifestyle will be quite fluid at the moment.

 

(By the way, cytokines are a type of signalling molecule in the body, some of which are pro-inflammatory, others of which have important other functions).

 

A quick quotation from Wikipedia on cytokines:

 

"Cytokines ...  are crucial for fighting off infections and in other immune responses.^[17] However, they can become dysregulated and pathological in inflammation, trauma, and sepsis.^[17]

Adverse effects of cytokines have been linked to many disease states and conditions ranging from schizophrenia, major depression^[18] and Alzheimer's disease^[19] to cancer.^[20] Normal tissue integrity is preserved by feedback interactions between diverse cell types mediated by adhesion molecules and secreted cytokines; disruption of normal feedback mechanisms in cancer, threatens tissue integrity.^[21] Over-secretion of cytokines can trigger a dangerous syndrome known as a cytokine storm ...... Cytokine storms ... were the main cause of death in the 1918 "Spanish Flu" pandemic. Deaths were weighted more heavily towards people with healthy immune systems, due to its ability to produce stronger immune responses, likely increasing cytokine levels. Another important example of cytokine storm is seen in acute pancreatitis. Cytokines are integral and implicated in all angles of the cascade resulting in the systemic inflammatory response syndrome and multi organ failure associated with this intra-abdominal catastrophe.^[22]"

 

Note that in Spanish flu it was not the disease itself that killed most of the patients, but the body's own inflammatory response to the disease. Likewise, when you get a cold, the stuffed nose, sneezing, headache etc, are not direct results of the virus, but the body's own inflammatory response to the infection. If you have a weak immune system, you may get a cold but be unaware, because you have no symptoms (and be a silent carrier).

 

From memory (not done the reading yet), meditation reduces pro-inflammatory cytokines in the blood, while some foods and stress increase them. It is also thought possible that long-term low levels of inflammation (not otherwise detectable) can contribute to cardiovascular disease, among other things. So lifestyle modifications to reduce systemic inflammation are a good idea (if we can work out what they are).

 

In relation to steroids, corticosteroids (perferably: glucocorticoids) reduce the levels of many cytokines (both pro- and anti-inflammatory cytokines). However steroids and cytokines are in a feedback loop, so it is often not possible to say which is the cause and which is the effect. So elevated glucocorticoids in the bloodstream may not be the underlying issue - they may be reflecting higher levels of inflammatory processes elsewhere.

 

More later. Wife just come home.

 

Jim.

[Jim Pickles]

I've started reading about inflammation and diet. Obviously its a massive topic, but the papers that I've come across all point the same way - we normally have pro-inflammatory molecules circulating in our bloodstream. Some foods are pro-inflammatory, and higher levels of inflammatory markers and/or a pro-inflammatory diet is associated with a higher level of disease, e.g. many different sorts of cancer.

 

A quick search turned up this paper: Caviccia PP et al (2009)* http://www.ncbi.nlm.nih.gov/pubmed/19864399

(the actual paper is free online). It is interesting because it has a list of the pro- and anti-inflammatory foods (as determined by measuring the level of a single inflammatory marker hs-CRP in the blood. The level of hs-CRP is correlated with the level of a lot of other pro-inflammatory molecules as well).

 

This link gives the table of the inflammatory effect of different foods - negative values are pro-inflammatory, positive values are anti-inflammatory: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2777480/table/tbl2/

 

Note that the pro- or anti-inflammatory effect is dose-dependent, and in some cases it is given per gram of food, in other cases per mg or micro-gram - all per day.

 

Some main points from the list:

1. Note that food (as measured by energy intake) is overall pro-inflammatory, at -0.0549 DII (dietary inflammatory index) units/kJ/day. On an average diet of 8700 kJ/day that is -477 DII units.

2. The pro-inflammatory foods are carbohydrate, fat, saturated fat, and cholesterol, plus mono-unsaturated fatty acids and minimally so omega-6 fatty acids and vitamin B-12.

3. All the other foods are anti-inflammatory to varying degrees, including among others tea, alcohol, turmeric (not that we eat a lot of it usually), all the other vitamins measured, many flavenoids (last 6 items on the list), and magnesium. Protein is fairly neutral, though anti-inflammatory on balance.

4. Note that MUFAs (mono-unsaturated fatty acids) are slightly pro-inflammatory (-0.05/g/day). These include olive oil and oils from avocado, nuts and seeds. This is a surprise, because these foods are thought to be healthy (probably therefore by other mechanisms which are operative as well)..

5. The magnesium effect is quite large: +0.905 DII units per mg/day. In my case, as I take a 500 mg capsule per day (to counter muscle cramps at night) that gives me +452 DII units, which nearly undoes the pro-inflammatory effect of my energy intake. [Added later - in fact, the 500 mg capsule contains 100 mg of magnesium - so the positive effect is one-fifth as large, unfortunately].

 

(What do the numbers mean and what is its scaling? In the above study, the overall DII values of the different individuals in the study ranged from -20.9 to +24.9. The mean value for the population was slightly pro-inflammatory (-1.0). A 5-point change was needed for a significant change in the level of the inflammatory marker used, This gives an idea of the scale and its sensitivity.)

 

So cutting down on the pro-inflammatory foods, and eating more of the anti-inflammatory ones (as long as they do not have negative other effects) looks a good idea. Beer, wine, and liquor are all anti-inflammatory, though wine is far more so (but remember, alcohol is itself carcinogenic). Cutting down on fat, saturated fat, carbohydrate, and cholesterol is standard dietary advice anyway.

 

Many papers have shown that higher levels of pro-inflammatory markers as found circulating in the blood, or higher levels of intakes of pro-inflammatory foods as measured on the DII scale above, are associated with increased cancers of many types, cardiovascular disease, being overweight, and some psychiatric diseases (depression; schizophrenia). The direction of cause and effect in these studies is not always clear.

 

Next: effect of exercise and meditation on inflammatory markers as measured in the bloodstream.

 

Jim.

 

*I give the name this way because this is the format used by Pubmed http://www.ncbi.nlm.nih.gov/pubmed- a search with a surname name plus the first two initials without a space will find an author.

 

** Inflammatory markers as commonly measured in studies are IL-6, IL-8, TNF, IL-6R, TNF-R1, and CRP (i.e. interleukin-6, interleukin-8, tumor necrosis factor, interleukin-6R, tumor necrosis factor-R1 and C-reactive protein.) Lots of these are just names to me.

 

*** In later studies they seem to have changed the sign of the DII, so positive DII values are more pro-inflammatory.

[Olga]

That's interesting information, I was not aware that such studies were conducted. I would not (personally) use it as dietary guidance, because it shows correlation between a single nutrient taken in isolation, and a level of one particular blood marker. While in the real world i eat complex meals consisting of many nutrients, and my body is a complex, self-regulating system.

 

By way of example, i see that alcohol and wine (why wine is not acohol) are shown as anti-inflammatory (as defined by impact on that blood marker) while research on real life people and their mortality levels showed that alcohol consumption is linked to cancer.

[Jim Pickles]

Olga -

 

1. "it shows correlation between a single nutrient taken in isolation, and a level of one particular blood marker"

 

These were studies looking at different individuals' total diets, knowing how much of each item was in each persons diet, and picking out the effects of the individual factors by correlation.

 

The results were indeed measured in whole bodies which are "complex, self-regulating systems".

 

2. Alcohol - that relates to the alcohol content itself of drink. If the anti-inflammatory effect of a drink is entirely due to its alcohol content, then as alcohol has a DII value of 0.534 d/day, the DII value of the drink would be 0.534x the alcohol content. If wine is 14% alcohol, the DII value due to its alcohol content alone would be expected to be 0.075. In fact its 0.48 - so wine has a lot of extra anti-inflammatory effect, on top of its alcohol content. Same for beer.

 

Yes, alcohol is carcinogenic. It is likely carcinogenic by a separate mechanism. One among many that has been suggested is its metabolism to acetaldehyde, which is a carcinogen. A similar disconnect is shown with mono-unsaturated fatty acids - thought to be healthy overall, but still pro-inflammatory. The inflammatory response does not dominate everything.

 

Jim.

[Olga]

Re #1, I was mistaken then, I thought these were lab tests on a dish. Sorry I did not have time to read the whole doc but I will do so when I am back online properly.

 

I can imagine that this kind of study on real people must be really difficult to conduct, to exclude all confounding factors eg differences in people's lifestyles, environment etc. Again, by way of example, I remember reading (Ben Goldacre, Bad Science) that newspapers are able to find/cherrypick 'moderate alcohol intake is good for health' types of researches because the tee-totallers are usually those who have very good reasons to avoid drinking - other health problems, recovering alcoholics, or religious fanatics :-) - and are not generally a good control group for this kind of study.

 

On a 'single nutrient' point I would still hold my view. A simple example is GI (glycemic index) and how it changes when nutrients are combined (eg some grains are high on GI but, when combined with fats or proteins, go significantly lower).

[Nathan]

It's a very good point Olga. Science can give us little insights into things, but by their very nature the best studies must eliminate as many variables as possible which moves them further and further away from reality. So we have to be careful about how we decide to incorporate those insights back into the much more complex systems of life.

 

For example, since carbs seem to be pro-inflammatory, someone might decide to avoid them completely. After all, they are not necessary for life, as it seems fashionable to say lately. Yet carbs (vegetables, fruits, etc.) also provide so many invaluable nutrients and are our bodies' preferred and most efficient source of fuel. They also provide the fiber that is essential for a healthy and diverse gut flora/microbiota, and this microbiota might be capable of doing far, far more for inflammation than any modification of carb levels could. Not to mention that almost all of the vitamins and minerals in "pro-inflammatory" carbs are "anti-inflammatory". Some of the best sources of magnesium are very carb-heavy.

 

Nature is an incredibly complex and amazing system that we only understand bits and pieces of. Of course trying to increase that understanding can be helpful, but the application of those little insights is tricky!

[Jim Pickles]

Further reading today shows an endorsement of the dietary inflammatory index (DII) approach to understanding diet and health, and the role of inflammation. The results show quite clearly that inflammatory factors via the diet have a major effect on our health.

 

Typing the search string "dietary inflammatory index" into Pubmed shows that there has been an explosion of publications in this area, nearly all within the last 12 months. I have looked at the abstracts of about half of them.

 

In nearly all cases examined, a higher pro-inflammatory diet was associated with a higher disease rate, sometimes markedly so. The biggest effect was for oesophageal cancer (squamous cell type) where those with the highest pro-inflammatory diet had more than 8x the cancer rate of everyone else (oesophageal cancer is a particularly nasty way to go by the way).

 

In most other studies, the risks are higher by about 2 fold (often 1.5 to 2.5 fold) for those in the top quarter of the dietary inflammatory index scores, vs those in the lowest. This was found for endometrial cancer, metabolic syndrome (a predictor of Type II diabetes). cardiovascular disease, depression, death rate (all causes), prostate cancer, colorectal cancer, loss of bone mineral density with age, and pancreatic cancer (more than 3x the risk). Only fairly small effects were found with breast cancer (but still statistically significant)

 

The studies also showed that a anti-inflammatory diet was associated with slower aging, as shown by relatively longer telomeres on the chromosomes, and a lower rate of shortening over time. Shorter telomeres are one of the marks of aging.

 

The studies also confirmed that a higher dietary pro-inflammatory scores were indeed associated with higher levels of circulating pro-inflammatory molecules in the bloodstream. All the work was done in human beings.

 

In these papers, the results were corrected for possible confounding factors (total energy intake, smoking status, age, income, etc), and the dietary inflammatory index was a better predictor of the outcomes than anything else. In other words, it does look as though systemic inflammation has a major effect on many diseases, and that inflammation via the diet is a major factor. Diet is of course modifiable - one of the most modifiable factors we have (unlike our genetics, for instance).

 

As pointed out previously, carbohydrates are pro-inflammatory, and we need carbohydrate. We need energy to live, and total energy intake is also pro-inflammatory. It is not therefore possible to cut out all inflammatory factors - we need to balance them with anti-inflammatory factors where possible. Also I would point out that even if you have an anti-inflammatory diet, the risks do not fall to zero - they are still substantial (though often about half compared with the most pro-inflammatory diet). Therefore inflammation while describing some of the picture, does not account for everything. Life is a risk: one cannot remove all risk by adopting even the best strategies. Eventually we all die of something. However, with an anti-inflammatory diet one might ON AVERAGE last a few years longer before dying. (You could say, that the greatest predictor for death is being born in the first place.) Life is about accepting risk, and managing risk to get the best outcomes.

[Jim Pickles]

As I've not yet got round to continuing the saga on inflammation and (the next stages) exercise and meditation, I thought I'd respond to a few earlier points:

 

@Kit: "And (@Jim) ....I have never heard that the healthy body does produce excessive inflammation, BTW; what is your source for that claim, if I may ask?"

 

The bloodstream of a "normal" healthy person contains inflammatory molecules, albeit at a low level. These molecules go up markedly in disease, as part of the response to infection

 

But what do we mean by "excessive" in your question? In other words, do the inflammatory molecules that are found in "normal" people carry any risk? And the answer is yes. The information comes from the studies quoted - normal people who have higher levels of inflammatory markers (but still within the normal range) have a higher chance of LATER ON getting a number of diseases (cardiovascular, cancers, etc). This shows that the inflammatory molecules in the bloodstream of those otherwise normal people can have a pathological effect. The results show that it is the case for those at the upper end of the normal range; it is therefore quite possible that the molecules can have a similar effect when present at lower concentrations, though the effects will be smaller (it is not certain if the pathological effect is roughly proportional to the concentration of the inflammatory markers, or if there is a threshold below which there is little effect - the data at the moment are too variable to be certain). Does this answer the question?

 

@Olga. "I can imagine that this kind of study on real people must be really difficult to conduct, to exclude all confounding factors eg differences in people's lifestyles, environment etc"

They are. Ideally, they need a very large number of people to be able to have all the comparisons needed (studies are now being published with a million participants). They also need to have a low drop-out rate (because those who drop out may be iller or healthier than the rest), and often need to go on for a long time (if you are interested in effects over a couple of decades, as we are in health and lifestyle.) These are very demanding conditions, and only a few studies meet them, so we also get preliminary evidence from lesser studies, to assemble a picture. Another issue with studies that last 20 years, is that you are testing hypotheses that are 20 years old, which may be out of touch with current thinking.

 

In relation to alcohol intake - this is known as "reverse causation" - where people with a greater chance of disease have adopted a healthier lifestyle. Often, issues like this only emerge over time, as more and more studies are done. However, if you waited until everything was perfect, you would never come to any conclusions at all. Instead, we assemble a picture over time, as evidence accumulates, and modify our conclusions on the way.

 

"I would not (personally) use it as dietary guidance," - it is not meant for actual dietary guidance, because it shows the effects on only one type of variable, i.e. inflammation. Something that is anti-inflammatory may be overall unhealthy (as with alcohol). Combinations of foods is another whole level of complexity, though I'd imagine that the effects are less likely than with GI because of the nature of the process. Also, these measures were obtained in whole people with real-world diets.

 

"Newspapers are able to cherry-pick....." Never go by newspaper reports. They are useful in alerting you to new and important results, but it is important to always go to the original paper (which may be behind a paywall, though as a student you should get access; also the abstracts are usually free). Newspapers want a dramatic headline to attract attention, so sometimes blow small effects out of proportion. A typical one might be "XYZ doubles the risk of cancer". But you need to know the background rate. If it is 0.1%, that means it goes up to 0.2% - still very small. Also, is it lifetime risk, risk/year, or what?

 

@Nathan: "but by their very nature the best studies must eliminate as many variables as possible which moves them further and further away from reality." These demographic studies often include people of all types, ages, etc, to get as full a picture as possible, and make all the comparisons needed by having a very large number of participants.

 

"For example, since carbs seem to be pro-inflammatory, someone might decide to avoid them completely." Not a good idea - if you go for a low-carb (and high-protein) diet, you seem to have a higher death rate than the rest. There is no simple solution.

[Kit_L]

So: after reading these some-thousands of words here: moderation in all things, and make sure you have a drink or two with your heavy-on-the-tumeric curry.

 

I am still waiting for some kind of confirmation that the body does produce excessive inflammation: if the blood assayed was taken from "average" white folk selected from an industrial society, I can think of many lifestyle factors that are giving rise to the markers that are associated with excessive inflammation. Just a thought.

[Jim Pickles]

"if the blood assayed was taken from "average" white folk selected from an industrial society, I can think of many lifestyle factors that are giving rise to the markers that are associated with excessive inflammation."

 

Very likely it was - because that is the average. And of course the average do have many pro-inflammatory lifestyle factors, and (as I said earlier) it is likely that many people reading this discussion board are untypical and have a relatively low-inflammatory lifestyle anyway. At what point "average" levels of inflammatory factors turn dangerous, is as yet uncertain (whether there is a threshold, with only the upper end being dangerous, or whether it is more evenly graded over all levels).

 

So far, it looks as though it is going to turn out to be the usual suspects - dont eat excessively - cut down on the carbs and fat, and make sure you have your (non-starchy) vegetables and fruit. Drink tea. Take exercise. Dont hold excessive tension, meditate if you can. But there are some unexpected points in there as well.

 

When I've done the reading on exercise it may show which types of exercise are best - though at the moment the data seem so variable that it may be difficult to decide.

 

This thread may turn into an explanation of the mechanisms that underlie some of what we already know (by experience) about lifestyle and health. As a scientist, I find that interesting in itself. And it would be surprising (and in fact, a reason to think there was something wrong), if the recommendations that come out were radically different from what is known already by experience.

 

There are some further positive points that can potentially come out: (1) it may reveal certain aspects of lifestyle or exercise that affect health, that were not previously suspected by experience. (2) It clarifies and emphasises how to live a healthy lifestyle. (3) It will show ways to monitor potential ill-health before disease actually shows itself (hence could be used to prevent disease, as well as opening up new avenues for medical intervention if necessary). And it satisfies intellectual curiosity.

 

Jim.

[Frederik]

I have had six years of undergraduate and graduate level training in Physiology and Medical Science. Further, I have spend more time reading articles, papers and listening to podcasts about diet and its relationship to health, than any sane human being should in a lifetime. This is the first time I am hearing about the "Dietary Inflammatory Index!

 

To me it sounds both a little contrived and simplistic. Once you get down into the nitty gritty of inflammation it is extremely complex: A number of interleukins and other cytokines interacting upon a number of different cells, both locally and distant—which again release other cytokines, and so it goes. There is a number of feedback loops, most of them are negative feedback loops, if memory serves me right.

 

Also, consider the fact that we almost never eat any one food in isolation, and I think it is reasonable to assume that there is an interaction between the various food we eat and their constituent parts: what this interaction means in the context of human nutrition and health I think is still years from being elucidated (and likely will remain so in 10 years time.)

 

A few years back all the hype was the Glycaemic Index. Now this is increasingly being abandoned. We tend to make up new concepts and then contribute whatever we cannot explain to it, only to be humbled a few years later.

 

My take away, and why I do not tend to read such articles any longer, is simply because they are engaged in research that needs another 5,10 or 20 years to get into the larger context. Speaking about signal to noise ratio, reading "the recent findings" will skew you highly towards the noise end of the spectrum.

 

If you are engaged in nutritional science as a researcher then it makes sense to follow the literature, but if you are wanting to improve your health or take preemptive steps, then energy is much better focused elsewhere.

[Kit_L]

http://www.newyorker.com/magazine/2015/11/30/inflamed

 

A good read, I feel.

[Jim Pickles]

@Kit  - yes!

 

(except for the focus on Hyman; I know journalists like to personalise things, but anecdotal evidence should have no place in this debate - only large-scale properly-controlled studies. Also "belief" implies believing beyond the evidence....).

 

@Frederik - the reason you didnt hear about the Dietary Inflammatory Index is because it has only recently been devised. As I said, research using it has appeared "nearly all within the last 12 months". Is it a fad which will disappear? We dont know yet. However, contrary to your statement that the glycaemic index is increasingly being abandoned - you will see from a Pubmed search that although its rate of use has gone down a bit in the last year or so, it is still very substantially being used in the medical literature. I cannot comment on the popular literature though.

 

Finally, I suggest people read what I wrote in Getting up off the floor about scatter in the results, and what these types of results might mean for you personally, vs health policy or health research generally.

 

Jim.

[Nathan]

I think (I am sure he will correct me if I am wrong) Fred was probably referring to not simply using the glycemic index within research as much as focusing on it, both as a subject of research and within popular literature (diet books, etc.). It seems that the trend has moved from the glycemic index to glycemic load, and just recently new research emerged that shows individuals have very different responses to different types of carbohydrates and even fats, which has called the whole idea of a general glycemic index into question.

 

The study: http://www.cell.com/cell/pdfExtended/S0092-8674(15)01481-6

One of the many write-ups floating around: http://sciencedrivennutrition.com/personalized-nutrition/

[Jim Pickles]

A news report today, on a just-published paper on how loneliness can produce a chronic inflammatory response, affect our immune system, and increase our vulnerability to disease: popular article at http://www.npr.org/sections/health-shots/2015/11/29/457255876/loneliness-may-warp-our-genes-and-our-immune-systems?utm_campaign=storyshare&utm_source=facebook.com&utm_medium=social

 

Full scientific article at http://www.pnas.org/content/early/2015/11/18/1514249112.long(I've not read the full article yet).

 

So loneliness is one of the many stressors that seems to work in the same way as many of the other chronic stressors.

 

Jim.

 

@Nathan - I have no doubt that you are right. However, it seems to me that using published values of the GIs for individual foods is a good start, given that a proper investigation as described in the paper you cited is not practical for most people. Better something approximate, than nothing at all. After all, science is always provisional, very rarely has the last word on a topic been said, and most analyses evolve over time as further research is undertaken.

[Nathan]

Yes, Jim, that is certainly true! I saw an article about that loneliness study a couple of days ago. Very interesting but not at all surprising.

[Jim Pickles]

More on the long arm of inflammation (not suggesting that the levels of inflammation seen in "normal" people do this, or that these levels of inflammation can be manipulated by diet or exercise; rather, it is likely that something unknown triggers a vicious cycle of inflammation and degeneration):

 

"Scientists have fresh hopes for an Alzheimer’s treatment after experiments to reduce inflammation in diseased mouse brains prevented memory and behavioural problems in the animals. Alzheimer’s disease has long been linked to disruption in the brain’s immune system, but the latest research adds to evidence that inflammation in the brain is not so much caused by the disease, but is a driver of the disorder."

 

See http://www.theguardian.com/science/2016/jan/08/alzheimers-treatment-closer-as-brain-inflammation-shown-to-be-key

 

Jim.

[Jim Pickles]

Just come across a Facebook link which led me to look at Pubmed where I found this article (PDF attached), part of a big and thriving field which I wasnt aware existed. It seems that there is an interaction between microglia in the brain (which can cause inflammation) and pruning of less-used synapses which then allows new memories to be formed. I havent read the scientific article yet (it looks full-on, and its after 1 am now), but there is a general summary of some of the issues at http://prepareforchange.net/2017/03/02/your-brain-has-a-delete-button-and-heres-how-to-use-it/ (which is what led me to it).

The scientific article suggests that excessive inflammation in the brain promotes memory loss, degeneration, and dementia. I think (at least till Ive read it properly). Another reason to avoid excessive inflammation, although low levels have a biologically useful function.

Lui_et_al_2016_Progranulin_synaptic_pruning.pdf