Saturated Fat is not the major issue | Hacker News Reader

Saturated Fat is not the major issue

bmj.com

66 pointshiroaki61 comments

Saturated fat has been demonised since the 1970s when a landmark study concluded that there was a correlation between incidence of coronary heart disease and total cholesterol, which then correlated with the percentage of calories provided by saturated fat, explains Malhotra. “But correlation is not causation,” he says. Nevertheless, we were advised to “reduce fat intake to 30% of total energy and a fall in saturated fat intake to 10%.”

It is frightening to think that such a fundamental piece of public policy is based on the "correlation is not causation" fallacious thinking.

Is there no one in power who is in the habit of actually thinking before approving actions?

And as the quote states, not just one correlation:

heart disease correlated with total cholesterol

then

total cholesterol correlated with saturated fat consumption

Most things in the biological sciences are correlations, to be as precise as we are in the sciences, you have to point out that some relationship is correlational unless you specifically test for causation (which is unfeasible in most cases)...if you assume causation, even when there seems to be very little doubt as to the causative agent, your paper is going to get sent back to you by the reviewers (in most cases).

Add to that the fact that recommendations are based on erring on the side of caution, and that tight correlations do become predictors of an outcome, then you have a recipe for these recommendations. Nothing bad is going to happen by reducing saturated fat intake, for the most part, but there is a chance of it if intake is excessive, and in fact saturated fat intake is a fairly strong predictor of future heart incidents.

> Nothing bad is going to happen by reducing saturated fat intake

From what I've read, it depends on what you eat instead. For example, as the article says:

"a JAMA study revealed that a 'low fat' diet showed the greatest decrease in energy expenditure, an unhealthy lipid pattern, and increased insulin resistance (a precursor to diabetes) compared with a low carbohydrate and low glycaemic index (GI) diet."

Insulin resistance is caused by sugar intake (completely unrelated to cholesterol)... Arguing that in order to lower cholesterol you have to consume more sugar seems rather strange.

Although individuals did not consciously decide to replace fat with sugar in their diets, the reality is that this policy advisement lead food producers to reduce fat in their products and replace that fat with sugar -- so the practical result was indeed this. Most products that advertise low-fat have accomplished this with sugar. Sure, it didn't have to happen this way, but thats irrelevant because it did happen this way: their was public policy that labeled fat as the bad guy, fat was reduced (sugar increased), and these actions were applauded.

But I've seen no evidence that, that is what happened. There doesn't seem to be a logical reason as to why you'd need to increase sugar in order to lower cholesterol, so why would companies do that?

Can you point to an example food(s) that had high fat, and low sugar, and then after this policy, low fat, and high sugar... ?

Yogurt is one. I don't know about the previous sugar levels, but it is extremely difficult to find anything other than low or no fat yogurt, and they typically have what I consider to be very high sugar levels, even many brands of plain yogurt.

We've had good luck with Brown Cow, if you can find that in your market. However, it still pales in comparison to the full-fat yogurts you get in Europe.

Maybe to make the food still tasty. Go to your local store - check all low-fat, 2%-enters, etc. and then full milk - check the sugar content percentage. That's all... At least here in US, Los Angeles - usually it's the normal yogurt/milk (e.g. hihg-fat) that has lower sugary content (percentage-wise) than the rest. Sometimes it's quite significantly lower.

And I don't know how the whole craze about non-plain yogurt came. I'm bulgarian native, and it's "foreign" to me that yogurt is mixed with any sugar at all.

It's still yummy - you can mix it equal portions with water, shake it well - and you get a very good drink. Or make this cold soup - http://en.wikipedia.org/wiki/Tarator

Or just eat it like this. No need for sugar...

I'm American and it took me until last year to learn that yogurt isn't sweet by default. 95% of the grocery store offerings are the sugary kind, and that's all I was ever exposed to as a kid, so I never noticed it. I spent years thinking I hated yogurt only to eventually discover that the unsweetened kind is really delicious. D:

...so why would companies do that?

Because flavor. It turns out that when you remove fat from a foodstuff, it tends not to taste nearly as good.

Read the ingredients list for a simple salad dressing: basically oil, vinegar, seasonings. Now look a the "lite" version of the same dressing: oil is replaced with high fructose corn syrup, thickeners (probably starches), etc.

Straight from the article:

Malhotra also points to the United States, where percentage calorie consumption from fat has declined from 40% to 30% in the past 30 years (although absolute fat consumption has remained the same), yet obesity has rocketed. One reason, he says, is that the food industry “compensated by replacing saturated fat with added sugar.”

How is that? My understanding is that lipid oxidation promotes insulin resistance itself.

If anything, and under the right dosage, sugar is protective.

It benefited the wheat farmers and "Big Ag" so there was possibly political pressure to focus on this.

What about "Big Dairy" or "Big Meat", they got the short end of the stick from the push to high carb low fat diets.

Industry lobbying as a theory lacks predictive power.

Perhaps their lobbyists aren't as convincing.

This is the second time I've encountered the phrase "lacks predictive power on HN tonight" by the way. Is a theory without predictive power now considered wrong?

IMHO if it doesn't have predictive power it cannot be a theory:

the·o·ry noun \ˈthē-ə-rē, ˈthir-ē\ : an idea or set of ideas that is intended to explain facts or events

Explanation and prediction are two different things.

Your definition doesn't even require explanation - it just requires intent to explain.

So for example, "the moon is made of cheese" is a theory according to the definition you just quoted. It's an idea that is intended to explain the composition of the moon.

I think it's more a matter of different beliefs arising from complicated, hard to interpret evidence. It's very comforting to believe in good guys and bad guys, but the real world of research is more complex than that.

There have been a lot of people saying this for quite awhile. Malcolm Kendrick wrote an entire book about the poor science behind our current belief that cholesterol causes heart disease. There are many others. But in the current medical environment where doctors want to prescribe a pill to fix everything and the biogen companies have enormous influence over public policy, dissent never rises above the level of a whisper.

Smoking, cocaine, stress, these things cause heart disease. Saturated fat probably isn't even a minor issue as it relates to heart disease. Every day, millions of Americans take a pill to reduce cholesterol when it's not even an issue. But don't expect that to ever change no matter how many doctors start saying saturated fat isn't the major issue.

You are ignoring the medical researchers who advocate for a diet low in saturated fat, and ridiculously characterizing mainstream doctors as not caring about prevention, and perhaps even wanting to cause disease so that they can treat it.

I'm on the fence on saturated fat, but it is an issue that is being debated by people who on both sides want to discover the best diet for preventing disease and lengthening life.

I'm not ignoring them, I'm specifically speaking to that population who advocate a diet low in saturated fat as a preventative measure for heart disease when there is NO causal evidence linking the two.

Also, I said nothing about them wanting to cause disease, I said they wanted to prescribe a pill to fix it, glossing over the known issues with the pill (statins in this case) in populations with no elevated risk of cardiovascular disease. I don't have any hard evidence of this other than the fact that in 2005, 29.7 million people in America purchased statins.

Why are you on the fence? What evidence have you seen that causes you doubt that saturated fats are unrelated to heart disease?

http://meps.ahrq.gov/mepsweb/data_files/publications/st205/s...

First, I'm still not clear on your logic.

On the one hand, there is a debate about whether consuming saturated fats cause heart disease.

On the other hand, there is the issue of whether statins prevent heart disease.

To me these are logically separate issues, yet you seem to think they are related, and my best guess at what you were hinting at seems to be wrong. So can you tell me: how would whether a doctor wants to prescribe a pill for X instead of preventing X, have anything to do with whether Y causes X.

On the evidence of saturated fat and heart disease, I will as usual defer to Wikipedia:

"Whether saturated fat is a risk factor for cardiovascular disease (CVD) is a question with numerous controversial views. Although most in the mainstream heart-health, government, and medical communities hold that saturated fat is a risk factor for CVD, some recent studies have produced conflicting results."

http://en.wikipedia.org/wiki/Saturated_fat_and_cardiovascula...

Read the article. It fairly clearly demonstrates that it is not nearly the risk factor it has been made out to be. Controversy is not science, and just because there is controversy does not make scientific results less valid.

On your second point, they are very much linked issues if X is something that does not need to be treated or prevented. That's what the article is really getting at: high cholesterol is not the primary risk factor for heart disease. They are correlated, sure, but there's not a causal link.

He points out that recent studies “have not supported any significant association between saturated fat intake and risk of CVD.” Instead, saturated fat has been found to be protective.

Seriously, read the whole article.

The wikipedia article I linked references about a dozen studies or meta-analyses, most of which establish a link between dietary saturated fat, and heart disease.

All of them were done after the 1970's.

Seriously, get back to me when you have read all of them.

A causal link, or a correlation? Because it matters, and that's what the article is making clear. Those correlation links lead to bad guidelines because the cause is not understood.

Those with higher cholesterol have a higher percentage of heart attacks.

Doctors (in Australia at least) prescribe when your risk (calculated on your cholesterol, smoking, stress, exercise, etc) is lowered by reducing your cholesterol, and dietary restriction hasn't worked (i.e. your liver just isn't as good as it used to be). Is that not how its done in the U.S?

It's the HDL/Cholesterol and triglyceride/HDL ratios that predict risk. Check it out.

Not usually, no. Here, doctors usually reach for the script pad as soon as an issue with blood pressure, cholesterol, or such is detected, THEN work on the dietary and lifestyle changes to get the patient off the drugs.

Just want to add for any 'seekers' in the audience, some new hallucinogens probably do too.

http://en.wikipedia.org/wiki/5-HT2B_receptor

A related pet peeve:

It's becoming difficult to find products with "all" the fat (vs "low/reduced" fat). Prime example for me: chocolate milk. It's pretty rare nowadays that I ever see anything over 1% milk used in it -- and of course the label touts the low fat formulation, but doesn't mention there's more sugar pumped in it than a can of soda.

Even if this was healthier than full-fat/less sugar chocolate milk, I'd still resent it. Chocolate milk is a treat, not a dietary staple. People should know that. Make it that way, market it that way.

But it's starting to look like it isn't healthier. Which makes the marketing more misleading and the formulation pretty ironic.

I think the biggest issue is that high (saturated) fat is often combined with high carb (refined sugars, starchy foods etc). My diet consists of high fat / low carb foods and it simply works (for me...). I've lost weight (without trying) and my energy levels are much more predictable and stable. I never watch how much I eat because my body will naturally stop be from overeating.

I found that "mentally" what worked for me was focusing on increasing fibre intake, rather than reducing sugar intake.

The effect is basically the same but I find it easier from a discipline perspective to focus on including more high fibre foods (even in "treats" and dessert foods) thank I do to "cut out" things that I enjoy.

I agree, I lost a load of weight doing this. I still eat treats but I make them with whole wheat flour and I typically reduce the sugar content as well.

They need to sell you skimmed milk so they can also sell the fat as ice cream, butter, and cream.

I can let you have the recipe for chocolate milk.

I HATE 1% MILK. gdsgnf,dhjghld

I also really dislike sweet things, so I'm with you 100% on the rest of the content too. I'd probably like chocolate milk if it weren't so nauseatingly sugary.

About 10 years ago the journal "Science" ran a cover story called "The soft Science of Dietary fat". If you have access to back issues through a library (sadly it's paywalled), go pull it and read it. Your mind will be blown at how thin the evidence is for many dietary recommendations. We know shockingly little about how our bodies actually work.

Is this what you're talking about?

http://garytaubes.com/wp-content/uploads/2011/08/Science-The...

Yes, that's it. If I recall there were multiple pieces in that issue about various aspects, but this was the primary one.

I'm confused by the reference towards the Mediterranean diet being protective against heart disease, because it seems tangential to the argument presented in the rest of the article.

The clinical Mediterranean diet is low in saturated fat. In one of the landmark papers measuring the effects of the Mediterranean diet on CVD risk, the "prudent" Western-style diet used as a control has 11.7% of calories from saturated fat, while the experimental Mediterranean diet has 8.0% of calories from saturated fat [1]. This diet is actually within the 10% limit the article references as out-of-date advice from the 1970s.

Another large intervention study has the calories from saturated fat on a Mediterranean-style diet falling from 13.7% before intervention to 8.0% after intervention [2], again below the 10% limit.

I am not at all suggesting that the Mediterranean lowers the risk of CVD because it is low in saturated fat. It just seems odd to use it as an example of saturated fat not being linked with CVD risk without addressing the fact that the Mediterranean diet is relatively low in saturated fat, and that intervention studies using the Mediterranean diet typically reduce the % calories from saturated fat in the intervention group.

It also seems odd to use the Mediterranean diet as an example in an article that paints refined carbohydrates as a major CVD risk factor. While the Mediterranean diet is relatively higher in whole-grain carbohydrates [2], it still includes lots of refined-carbohydrate foods (think pasta), and it introduces so many other dietary changes, particularly a vast increase in consumption of fruits and vegetables [2], that one can't assume that the increase in whole grains particularly is the source of the diet's protective effects against CVD risk.

[1] http://www.drhirani.com/Assets/lyonfinalreport.pdf

[2] http://jama.jamanetwork.com/article.aspx?articleid=199488

Good response to this article with, like, facts and that..

http://theconversation.com/its-not-even-debatable-saturated-...

Such a shame that the author apparently didn't read all of the linked "facts".

eg. "This cause and effect is now beyond reasonable doubt; science shows (http://www.ncbi.nlm.nih.gov/pubmed/8043072) that high levels of cholesterol cause arterial damage and this, in turn, causes coronary heart disease."

The linked paper and the comments to that paper disputing the findings completely contradicts the author's "beyond reasonable doubt" argument.

I don't have a "team" in this debate, personally I wish scientists would put their pride aside, stop the furious debating and find a definitive answer. I'm just pointing out an obvious flaw in this response.

Excellent point. It sounds like a conspiracy theory, but I find the anti-fat crowd to be chronically intellectually dishonest.

The problem with the 'science' is that the main study done on this topic cherry picked the countries it included in the results and excluded some 20 countries. If you only is d data from the excluded countries you would find the reverse correlation. One has to be very careful to look out for confirmation bias in research.

What about the fact that there are different kinds of saturated fats and different kinds of cholesterol?

The current post links to the BMJ press release on this topic. These links are to the full article:

http://www.bmj.com/content/347/bmj.f6340

https://news.ycombinator.com/item?id=6599460

"Catalyst", the ABC's weekly science show, had an interesting investigation into this last Thursday [1]. Last week was Part I, which presumably means this week will be Part II.

[1] http://www.abc.net.au/catalyst/stories/3876219.htm

---

Edit: Wed->Thu

Followup: Last week's program is generating some heat, with calls for the next installment not to be shown. The ABC plans on showing it.

http://www.abc.net.au/news/2013-10-28/professor-says-abc-cat...

They had me right until the end, with the quote from Timothy Noakes, who is not a cardiologist, and makes plenty of data-unsupported mistakes in his own writing, e.g. about barefoot running. It's like having Malcolm Gladwell back up your research findings.

Was this piece supposed to be science or it is entertainment-journalism? The latter, I think. (I.e. it is not the abstract of any particular research study.)

I'm not saying the anti-anti-saturated fat recommendation is wrong. I'm saying this piece is just another opinion, which adds nothing to my understanding. Obviously the vast majority of educated and well-intentioned physicians disagree with their recommendation.

Here is a transcript from a show that has cardiologists on the panel :http://www.abc.net.au/catalyst/stories/3876219.htm

Am I the only one to see a trend in the increasing number of articles like these?

Traditionally for centuries people in India have been consuming coconut oil, ghee, etc which are supposed to be high in saturated fats and never had problems. After globalization (1992), the food industry in here changed a lot as well. The business promotion and the usage of refined oils increased which is good for business, nevertheless not for health. These days, diabetes, heart attacks and other such illness are very common even among 20+ and 30+. The Indian food industry is one in which India (as a society) failed to nurture and preserve its rich, diverse and healthy food culture.

Diabetes and heart disease were widespread in India long before 1992. A simpler explanation, over the last century, is that Indians are eating more, and exercising less (i.e. not in the fields).

Aloo curry over white rice - nothing healthy about that, whatever oil you use to cook it in.

For what it's worth, my GP told me that old studies didn't distinguish regular fats from trans fats, so saturated fats got the blame for what's wrong with trans fats (which do mess up your cholesterol badly).

Trusting nutritionists is like having surgery in the 19th century. Deadly.

This show was quite interesting. Makes a very similar case: http://www.abc.net.au/catalyst/stories/3876219.htm

...refined carbohydrates and sugar in particular are actually the culprits

Adopting a Mediterranean diet after a heart attack is almost three times as powerful in reducing mortality as taking a statin, writes Malhotra.

Coconut oil is perhaps the best with its anti oxidant and microbicide properties. More often than not, it is the lifestyle that causes health issues.

or better yet, "saturated fat is not an issue"

carbs + saturated fat = cholesterol

choose one

Reply on news.ycombinator.com