Research on Saturated Fat vs. Fish Oil and an Editorial Rant

Your body makes all of the saturated fats you need. Also, certain fats are necessary to have in your diet (these are the so-called "essential fatty acids") and thus it is not suggested that you cut all fat out of your diet, only that you lower your intake of fat to a certain proportion of your daily caloric intake (around 30%) and that you eat certain fats (such as PUFAs, which include the essential fatty acids) while limiting your intake of others (saturated fats, trans fats). Also, I just did a Pubmed search using the words "saturated fat" and "heart disease" and got back 1000 articles on the subject. Just scanning the first few pages, it is clear that many of these articles are research that links saturated fat intake to heart disease, obesity, high cholesterol, etc...You did not cite any scientific articles regarding your anecdotal evidence stating that people used to eat lots of saturated fats and live longer. I'm pretty sure that the link between saturated fats and CVD was not studied 100 years ago, and I'm also fairly certain that people had a lower lifespan back then, and that they ate less food in general because super WalMarts did not exist back then and acquiring food was slightly more difficult than it is currently for the average American. Also, I'm sure portion sizes were smaller than "supersize." Thus, it is pretty much impossible to link one factor of lifestyle (saturated fat intake) with a clear outcome (healthier lives), and anyone who claims that is reporting bad science.

Furthermore, there HAVE been clinical research studies published that link the intake of saturated fat to a greater risk of CVD. For instance, this study:

http://www.ncbi.nlm.nih.gov/pubmed/2127037

Who came up with the brazen, highly flawed, and thoughtless statement that scientists do not base recommendations on scientific research? Do you think we just make stuff up because we think it sounds right?

Two major studies conclude that saturated fat does NOT cause heart disease

Posted By Dr John Briffa On 15 January 2010 @ 12:59 pm In Cholesterol and Statins,Food and Medical Politics,Healthy Eating,Unhealthy Eating! | 67 Comments


One of things I try and do on this blog is right what I see as nutritional wrongs. So, if there’s a common perception that artificial sweeteners are better than sugar for weight loss, but there’s really no evidence for that, then I’m inclined to write about it. If the evidence suggests that margarine is likely to be unhealthier than butter, I’ll write about that too. Similarly, I’ve been keen to point out that it appears that saturated fat, widely taken as to be artery-clogging and heart disease-provoking, is nothing of the sort.

I have written more than once about this, most recently here [1]. This review of the literature found no evidence that saturated fat causes heart disease. And it’s a shame (in my opinion, anyway), that this study got no mainstream publicity.

The same, appears to be true, of a recent report published in the Annals of Nutrition and Metabolism [1]. You can read a complete version of this report here [2]. The whole edition of this journal was dedicated to reporting an ‘Expert Consultation’ held jointly by the World Health Organization (WHO) and Food and Agriculture Organization (FAO) of the US. The consultation took a wide, sweeping look at the relationship between fats, physiology and health, and took place in late 2008. One of the things that was inevitably a focus of the consultation was the link between saturated fat and heart disease.

The ‘experts’ responsible for assessing this relationship looked at two lines of evidence: epidemiological studies and intervention studies. Let’s look at both in turn.

Epidemiological studies look at the relationship between factors (such as smoking and lung cancer, exercise and dementia, saturated fat and heart disease) in populations. These studies can only really tell us about associations between things, but can’t generally be used to inform us if one thing is causing another. Nevertheless, if saturated fat does truly cause heart disease (like we’ve been told for the last few decades), then the epidemiological evidence should show that higher levels of saturated fat are associated with a higher risk of heart disease (also known as ‘coronary heart disease’ or ‘CHD’ for short).

Well, according to the WHO/FAO report, there is no association. Here’s what the report states:

“Intake of SFA [saturated fatty acids] was not significantly associated with CHD mortality…

and also

SFA intake was not significantly associated CHD events [e.g. heart attacks]…”

And now on to intervention studies�

In such studies, individuals a subjected to some sort of intervention (such as a medication, increased exercise or dietary change). The relevant intervention in this area is to put people on a low saturated fat diet diet, and see how they fare compared to individuals who are not subjected to this change. Unlike epidemiological studies, intervention studies can prove ‘causal’ links between things. For example, if eating less saturated fat leads to a reduced risk of heart disease, then it’s a pretty good bet that saturated fat causes heart disease (all other things being equal).

So, what did the WHO/FAO report find with regard to relevant intervention studies? Here’s what:

“…fatal CHD was not reduced by…the low-fat diets…”

Just this week saw the publication of another huge study which assessed the relationship between saturated fat and heart disease [2]. This study was actually an amalgamation (meta-analysis) of 21 epidemiological studies. Taken all together, this review monitored almost 350,000 people over between 5 and 23 years. And here’s what it found:

1. No association between saturated fat and risk of heart disease

2. No association between saturated fat and risk of stroke

You know what this all means, don’t you? That there really is no evidence that saturated fat causes heart disease or cardiovascular disease generally.

Despite all this evidence to the contrary, I suspect the idea that saturated fat causes heart disease will perpetuate for some time. One reason for this has to do with cholesterol. There is some evidence that saturated fat puts cholesterol levels up, and we all know that cholesterol causes heart disease, right? So, if saturated fat puts cholesterol up, it must increased the risk of heart disease too. Well, this line of argument assumes that cholesterol causes heart disease, and actually the evidence shows this is far from assured. But even if it did, the logic is still faulty. We could use the same logic to claim that if something causes cholesterol to fall it must be good for heart health. So, if arsenic and cyanide reduce cholesterol, should we all be swigging these poisons down every day?

Anyway, while the ‘cholesterol causes heart disease’ paradigm is prevalent, I think saturated fat is going to be in the firing line. Shame, because at worst it appears an innocent bystander.

Another reason that saturated fat is likely to get a hard time for some time yet has to do with the fact that paradigms do tend to change very slowly. And at least some of this has to do with a reluctance some of us have to changing our minds about things we ‘know’. Some of us feel we ‘know’ saturated fat causes heart disease, because we’ve been told it so often and consistently we’re not even inclined to challenge this notion. And if we happen to be health professionals or academics who, at least in part, define ourselves by our ‘knowledge’ and ‘intelligence’, it can be mightily difficult to admit that we were wrong.

Not being a literary type, I’m not really a quote person either. But I do know at least one. It is British economist’s John Maynard Keynes’ assertion that When the facts change, I change my mind. What do you do, sir?� How I would like to see health professionals and Government departments take a leaf out of Keynes’ book, and make pronouncements regarding saturated fat and other dietary factors based on science fact (not fiction).

References:

1. Fats and Fatty Acids in Human Nutrition. Annals of Nutrition and Metabolism, 2009; 55 (1-3).

2. Siri-Tarino PW, et al. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease Am J Clin Nutr 13 January 2010 [epub ahead of print].

There is plenty of scientific evidence that PROVES that saturated fats are not bad for us and that they are completely necessary in very moderate amounts for proper brain function and also down to the cellular level.

There are well known research scientists and doctors that are proving this day by day.

Also, breast milk is compromised of mostly saturated fats. If saturated fat were so bad for us, then why would the thing we eat from the day we are born be bad for us??????????

Yes, infants need more fats then adults, that's why there is more fat in breastmilk and why whole milk is recommended for children up to age 2. Fat is the primary source of fuel for metabolism at rest and babies aren't born with a lot of body fat and need dietary intake to fuel their bodies as well as the need for development of all sorts of cells. After age 2, however, we don't need that much fat because most of the central nervous system is fully functional and locomotion allows the anaerobic metabolism to work burning more carbohydrates then fat so less is needed for fuel. Any basic lifecycle nutrition class will teach that. But if you need a reference, I like the book Nutrition Across the Lifespan by Mary Kay Mitchell. She lists lots of references for studies that have been done over the years.

Also, saturated fat is NATURAL occurring and that is what I eat. All natural foods.

Arsenic is also natural. Doesn't mean I'm stupid enough to eat it.

I refuse to believe that we are supposed to eat "low fat" when for generations before us ate higher fat foods and lived to be ripe old ages without the health problems that we see today. And there are tribal people around the world that eat about 90% saturated fat with no heart disease.

The generations before us actually died of acute diseases like the common cold and nutrient deficiencies such as scurvy and rickets before they lived long enough for their cardiovascular disease to be evident. That's why when we started curing those issues, heart disease and cancer started being the predominant killers in about the mid-1900's. Also, I never stated that we should eat low fat. I stated that we should eat healthy fats like fish oil and other unsaturated fatty acids, some of which are vital to optimal human performance, instead of saturated fats that are scientifically linked to cardiovascular disease and are proving to be linked to diabetes and cancers.

The proof is there.

I also find it very odd that since I have went back to eating a high fat, moderate protein, low carb eating plan that my cholesterol and triglyceride levels have dropped to the point that my doctor has asked me to raise them a bit.

I had high cholesterol and high triglyceride levels before embarking on that journey.

This is merely anecdotal evidence. And quite honestly, expected if you started an exercise program, regardless of what you eat. Exercise lowers total cholesterol and triglyceride levels. That has been proven. Sorry, I don't have the the studies in front of me but look for the book Clinical Exercise Physiology and I'm sure it will list them. As for telling you to raise your cholesterol, your doctor was probably referring to your HDL levels, which are cardioprotective. We tell all our patients to raise their HDL levels. But you can't raise HDL levels with saturated fat. You have to consume unsaturated fatty acids, particularly Omega 3's such as fish oil, and exercise more in order to raise HDL levels.

I don't read the latest magazine articles or what have you. I do read scientific sites, books, articles, etc..............

Really? Then why are you posting links to MSNBC and a blog in your later posts? Neither of those are scientific journals. Which is the whole point of me posting a real research article. I want to make sure that people don't listen to blogs that can be written by any Joe Blow regardless of actual credentials or popular media articles that take one small section of a study and quote it out of context to meet the sensational headline they want to sell. It takes a little more work to search Pubmed and click through to find the full text of the study and actually read it, but the information is much higher quality then MSNBC, Yahoo, Google, Wikipedia, or some random persons blog.