Discussion of low carb diets and cholesterol

[Westley]

** Mod edit to say that this post (and 6 others in this thread) have been moved from a T2 thread on weight loss here https://www.diabetes.co.uk/forum/threads/weight-loss.209977/#post-2774512 so as to keep that thread on track for the OPs question. **

The strong mainstream consensus among medical professionals is that a very low carb diet rich in saturated fat from full fat dairy, eggs and red meat causes elevated LDL cholesterol, which is an established causal factor for heart disease, which we are already at higher risk of as diabetics.

Dramatic elevation of LDL cholesterol from ketogenic-dieting: A Case Series - PMC

High-fat, low carb dieting, also known as the “ketogenic diet,” has increased in popularity as a rapid weight-loss tool. Previous studies describe a modest elevation in cholesterol in the average keto-diet participant without specific cardiovascular ...

pmc.ncbi.nlm.nih.gov

https://www.sciencedirect.com/science/article/pii/S0146280624000410#sec0003

Lipid hypothesis - Wikipedia

en.wikipedia.org

This forum has quite a strong lean towards some alternative ideas. I don't see anything wrong with sharing these theories, and it is possible that some very widely held and evidence supported scientific beliefs somehow turn out to be misguided, but it is irresponsible to present them as something more than fringe thinking.

I have done a keto diet for periods in the past, and it makes keeping good blood glucose control amazingly easy, as well as causing rapid fat loss. However, after learning more, I no longer think these benefits are worth the dangers.

What works for me now is cutting out most refined carbs like bread, pasta and rice, as well as full fat dairy, and instead eating mainly beans and pulses, lots of veg and fruit, fish, nuts and seeds, whey isolate and some chicken. I also eat a lot of oats, though as a T1 I do find they need a fair amount of insulin to counter, so would understand why some T2s avoid them.
I'm feeling great, happy digestion, getting leaner, performance in the gym is good, and my glucose control is the best it has ever been, plus my LDL is going down.

(and of course it should go without saying that the central thing in weight loss is always consuming less energy than you use)

 

[lovinglife]

but it is irresponsible to present them as something more than fringe thinking.

I don’t agree that it’s fringe thinking, I think it’s taken a long while for the NHS to catch on but the tide is turning, and so is the advice from some forward thinking HCPs. My own particular GP surgery are very much pro low carb/keto and encourage it. I’m lucky that our practice has a part time DSN attached to them (not just a nurse who does the diabetic clinics)

She has said a couple of times that all the patients in the 3 practices she is attached to, those doing the best as regards to T2 management & their results across the board, use a low carb or keto as a lifestyle.

This is our main site low carb programme that is approved by the NHS,

Low Carb Program - Sustainable Weight Loss and Blood Glucose Control

Low Carb Program is a digital solution for obesity, prediabetes, type 2 diabetes, NAFLD and PCOS that supports weight loss and blood glucose control.

www.lowcarbprogram.com

(My reply is as a member & my own views I just happen to volunteer as a moderator)

 

[KennyA]

There is plenty of good robust scientific evidence to support low-carb diets - see below. After getting on six years on a very low carb diet, my cholesterol levels haven't changed at all.

I'd suggest having a look at some of the recent research attached below, and the 2019 paper from the American College of Cardiology in particular. And then make an informed decision.

https://www.sciencedirect.com/scien...tm_medium=referral&utm_campaign=the-arrow-188

Journal of the American College of Cardiology:
•Several foods relatively rich in SFAs, such as whole-fat dairy, dark chocolate, and unprocessed meat, are not associated with increased CVD or diabetes risk.
•There is no robust evidence that current population-wide arbitrary upper limits on saturated fat consumption in the United States will prevent CVD or reduce mortality.

Total cholesterol and all-cause mortality by sex and age: a prospective cohort study among 12.8 million adults - Scientific Reports

It is unclear whether associations between total cholesterol (TC) levels and all-cause mortality and the optimal TC ranges for lowest mortality vary by sex and age. 12,815,006 Korean adults underwent routine health examinations during 2001–2004, and were followed until 2013. During follow-up...

www.nature.com

No simple conclusion from this huge Korean study but - U-curve associations between TC levels and mortality were found in both men and women. The TC range associated with the lowest mortality was 210–249 mg/dL (5.4- 6.4mmol/l). When age was further considered, U-curve associations were observed regardless of sex or age, and the optimal TC range for survival was 210–249 mg/dL (5.4- 6.4mmol/l) for each age-sex group, except for men at 18–34 years (180–219 mg/dL or 4.6-5.6 mmol/l ) and for women at 18–34 years (160–199 mg/dL or 4.1-5.1 mmol/l) and at 35–44 years (180–219 mg/dL or 4.6-5.6 mmol/l)

Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73)

Objective To examine the traditional diet-heart hypothesis through recovery and analysis of previously unpublished data from the Minnesota Coronary Experiment (MCE) and to put findings in the context of existing diet-heart randomized controlled trials through a systematic review and...

www.bmj.com

Conclusion: Available evidence from randomized controlled trials shows that replacement of saturated fat in the diet with linoleic acid effectively lowers serum cholesterol but does not support the hypothesis that this translates to a lower risk of death from coronary heart disease or all causes. Findings from the Minnesota Coronary Experiment add to growing evidence that incomplete publication has contributed to overestimation of the benefits of replacing saturated fat with vegetable oils rich in linoleic acid.

Is the use of cholesterol in mortality risk algorithms in clinical guidelines valid? Ten years prospective data from the Norwegian HUNT 2 study

Many clinical guidelines for cardiovascular disease (CVD) prevention contain risk estimation charts/calculators. These have shown a tendency to overestimate risk, which indicates that there might be theoretical flaws in the algorithms. Total cholesterol ...

www.ncbi.nlm.nih.gov


Conclusion: ".....If our findings are generalizable, clinical and public health recommendations regarding the ‘dangers’ of cholesterol should be revised. This is especially true for women, for whom moderately elevated cholesterol (by current standards) may prove to be not only harmless but even beneficial."

The Cholesterol Paradox in Long-Livers from a Sardinia Longevity Hot Spot (Blue Zone) - PubMed

<span><b>Background/Objectives</b>: Hypercholesterolemia is commonly viewed as a risk factor for coronary heart disease; however, several studies have reported an inverse relationship between cholesterol levels and cardiovascular mortality, particularly in older adults. This "cholesterol...

pubmed.ncbi.nlm.nih.gov

Conclusion: “… In the long-lived population examined, the cholesterol paradox was unlikely to be a reflection of reverse causality. Our results challenge the common view that longevity is invariably associated with low cholesterol levels. Furthermore, moderate hypercholesterolemia does not preclude the oldest adult from attaining advanced ages, contrary to common belief.”

 

[Antje77]

the strong mainstream consensus among medical professionals is that a very low carb diet rich in saturated fat from full fat dairy, eggs and red meat causes elevated LDL cholesterol

My lipid levels were out of whack upon diagnosis, almost 9 years ago. They quickly normalised on LCHF and insulin. And we have more members who have seen the exact same thing.
So maybe the consensus is incorrect, and HF doesn't cause elevated LDL in everybody.
Here are my lab results on a 'normal' diet versus LCHF: https://www.diabetes.co.uk/forum/th...tion-book-recommendations.201616/post-2674018

As far as I understand, high LDL and NAFLD are connected as well. If you want to create a fatty liver in birds to sell foie gras, you dont feed them sat fats, you feed them grains.

 

[Lakeslover]

My NHS GP surgery in England has started recommending a low carb diet in the last year. Perhaps the tide is slowly changing.

 

[zand]

My NHS GP surgery in England has started recommending a low carb diet in the last year. Perhaps the tide is slowly changing.

Yes, mine too.

My cholesterol figures greatly improved on a low carb high fat diet.

 

[Melgar]

I don't follow a low carb diet, I use exercise , and a lot of it, to control my blood sugars. I have to say that my Dr's clinic here in BC , Canada recommends a low carb diet to control blood sugars. So it may have been a fringe diet a decade or so ago, but it's now no longer fringe.

 

[Westley]

I fully expected some pushback, as I'm familiar with how prevalent these views are within this particular forum. I'll try and respond to some, but as you see, in a short space of time, we have 7 responses in support of these views, with a mix of personal 'anecdata' and links to multiple studies, each of which will take some time to look at. I'm clearly in a minority here (and not by coincidence, diabetes.co.uk sells low carb programs), but I repeat, what I am sharing is the consensus view in mainstream science. This forum is very far from representative.

My own views on this have shifted - I actually used to be quite pro keto, and liked using it myself. My change in thinking is relatively recent, so I welcome the chance to refine it through some debate, but don't present myself as an expert on these matters.

Anyway, to try and address a few of the points-
The paper supporting the low carb program in lovinglife's link (of which one of the authors is incidentally employed by this site), reports the results of the diet, and cites another meta-study mentioning positive changes in HDL and trigs, but omits any mention of LDL (and it is specifically LDL I'm talking about here as the CVD risk factor).
I haven't dug down into the individual studies cited by that metastudy, but one thing to watch out for in some studies which show little change is that they use patients starting with high LDL. There's a big difference between starting in a bad place and not getting much worse and a diet which actually improves the bad ones and doesn't worsen the good ones.

As for anecdotes - results from one person are are not always indicative of overall patterns - individual responses to cholesterol are widely variable. It's not surprising that some people get lucky and don't follow the trends. If your LDL is good (I know <70 is the target for diabetics now), I can understand why you might be less bothered. The statistical data looks pretty clear to me though.

Also, I think with all this anecdata users are sharing, it's worth distinguishing between the variants of low carb diet different people are following re the sources of fats. I'd expect a big difference between those eating high dairy, red meat and eggs, compared to one more based on things like olive oil, avocados and nuts.

What I actually referred to in my post was "a very low carb diet rich in saturated fat from full fat dairy, eggs and red meat"
I see the question of whether some low carb diets could be healthy for some people as more open.

Bird digestion functions very differently to humans'. Cows build muscle while eating grass. I'd be cautious of thinking goose rearing is too relevant to human diet (also - I would say the defining feature of foie gras production is the force feeding of vastly more food than they need, grain just happens to be cheap).

The papers from Kenny will take more time to respond to properly, and at this rate I'm unlikely to keep up with everything, but a few quick thoughts from a skim:

The first paper seems to focus on the whole LDL-particle-size-matters-quantity-doesn't idea, when it comes to the lipids discussion, which I don't believe is well supported now. From what I've read, particle size does matter a bit in terms of how likely they are to cause heart disease, but not enough to ignore elevated levels.

The Nature paper actually gives evidence supporting the consensus view that high LDL causes greater all cause mortality and heart disease. That U-curve they talk about goes up sharply to the right!
I know there is some data linking very low LDL with mortality - though if I recall correctly (I'll have a look at some point for the studies), this correlation can be largely explained by people dying of other things having their levels drop as internal systems fail, rather than the low LDL causing death.

The BMJ paper re-examining an old study gives supporting evidence that saturated fat intake raises LDL. It compares it to a diet where saturated fat is just replaced with large quantities of vegetable oil(!) and finds that patients died at around the same rate. I'm unconvinced that provides any meaningful support for the meat+cheese vs olive oil+avocados question.

The NCBI Norwegian study again shows the U-curve, reinforcing the evidence that too high total cholesterol is harmful. It does not appear to address the effect of LDL levels specifically at all.

I only very briefly looked at the 'blue zones' Sardinia paper, but it looks like it's about a group of old people in a specific location who live to an old age despite some of them having elevated cholesterol.
It seems reasonable that a generally healthy lifestyle in good climate, with good social life, good quality food etc, could lead to longer life despite some raised LDL.

I think Gil also goes into it a bit here:

I'm not keen on providing youtube links as supporting evidence in general, but Gil Carvalho (https://www.youtube.com/@NutritionMadeSimple) is a medical doctor(in contrast with say Dave Feldman, a popular proponent of alternative lipid theories, who is a software engineer) who I think does evaluate the science in a fair and balanced way and with an open mind.

 

[Antje77]

Also, I think with all this anecdata users are sharing, it's worth distinguishing between the variants of low carb diet different people are following re the sources of fats. I'd expect a big difference between those eating high dairy, red meat and eggs, compared to one more based on things like olive oil, avocados and nuts.

Good point.
Seeing as my own anecdata included my lab results, it makes sense to also include a bit more on my diet. I've been using the same bottle of olive oil for 2 years, don't like avocados, do eat nuts, salted or with chilli flavour or such.
I love butter and use it in good amounts on LC crackers/toast, and with cooking. I eat lots of cheese, my go to meat products are usually pork. Pork scratchings with aioli before bed happen a lot. About 4 eggs a week. So the exact opposite of your expectations.

Before diabetes I ate pretty standard, a little less meat and veg than I eat now, more bread, usually wholemeal, more fruit the occasional portion of chips (with mayo because I'm Dutch), and admittedly crisps too often.

My drinking habits haven't changed, still drink more than is advised.

For me, it doesn't really matter what the medical mainstream consensus is, my lab results tell me that this works for me. It's no different than using a glucose meter. Lab results and blood glucose are unbiased, they tell you what is, not what the current science says should be.

Anecdata like this proves that the blanket statement "the strong mainstream consensus among medical professionals is that a very low carb diet rich in saturated fat from full fat dairy, eggs and red meat causes elevated LDL cholesterol" cannot be correct, or it would be true for all.

This should make medical professionals and scientists curious as to what is going on, not make them shout louder!
Remember how long it took before it was accepted that stomach ulcers were caused by a bacterial infection and not by stress?
The first signs were there in 1951, less than 10 years after penicillin became available. It was only generally accepted in the 1990's.
Just to illustrate that consensus in the medical field doesn't prove it is correct.

 

[Westley]

I doubt anyone would have an issue with saying that there is a strong medical consensus that smoking causes lung cancer, yet it's easy to find many cases of individuals who smoked heavily yet lived long healthy lives.

Likewise, high intake of saturated fat from animal sources doesn't necessarily elevate LDL in absolutely every single individual, just most of them. In a pro-low-carb setting like here, I think we maybe there is a skew towards people presenting their labs more when they support the forum view, but there are copious studies with large numbers of participants painting a statistical picture.

When presenting data, it's also important to consider all the factors that accompanied the change. Losing a significant amount of body fat could lead to a long term reduction in LDL, as a different thing from the other cholesterol effects of the diet that lead to that fat loss. In some people one effect might be bigger than the other and in others vice-versa.

For those considering high animal fat keto diets based on recommendations here, I'd urge them to take advice found here with a pinch of salt (or should that be a pinch of fibre?), consider a wider range of information sources outside the bubble, keep a close eye on their labs (and maybe check other things like ApoB, LipoA, calcium score to assess your individual risk level), and run from those that tell you LDL doesn't matter at all.

 

[debs248]

The strong mainstream consensus among medical professionals is that a very low carb diet rich in saturated fat from full fat dairy, eggs and red meat causes elevated LDL cholesterol, which is an established causal factor for heart disease.

It hasn't elevated mine. Unfortunately I wasn't given results for all the subcategories but my total cholesterol changed by 0.1 mmol/l and LDL is currently 1.6 mmol/l after nearly 10 years of LCHF. Admittedly I don't eat as low as keto levels of carbs most days, but I love my saturated animal fats. If it's elevated my LDL to 1.6, what on earth must it have been before?

This forum has quite a strong lean towards some alternative ideas. I don't see anything wrong with sharing these theories, and it is possible that some very widely held and evidence supported scientific beliefs somehow turn out to be misguided, but it is irresponsible to present them as something more than fringe thinking.

I've not noticed any lean towards fringe ideas. What I have seen is people challenging dogma and sharing what has worked for them. Sometimes that refutes "received wisdom", but as scientific knowledge improves, outdated or wrong ideas get replaced.

I have done a keto diet for periods in the past, and it makes keeping good blood glucose control amazingly easy, as well as causing rapid fat loss. However, after learning more, I no longer think these benefits are worth the dangers.

That's your personal choice, it doesn't make those who prioritise good blood glucose control and fat loss now over a potential risk of heart disease later wrong, just different.

my glucose control is the best it has ever been, plus my LDL is going down.

I'm glad that works for you. Others have achieved the same results while eating keto with saturated animal fats. Did your LDL go up when you tried keto, or was it high already and keto just didn't bring it down?

One day, hopefully, there'll be enough decent evidence confirming what many have experienced for themselves, ie

a very low carb diet rich in saturated fat from full fat dairy, eggs and red meat causes elevated LDL cholesterol

isn't true for a significant percentage of the population.