Science That You Should Know You must have heard Dr.
Oz and other health professionals say a zillion times that you have to avoid saturated fat because it ruins your cardiovascular health.
Research supposedly supports that advice.
However, a recent meta-analysis of the best studies in the medical literature that specifically examined the possible relationship between dietary saturated fat and cardiovascular disease show...
well, they show no relationship.
A meta-analysis identifies the best studies on a topic, culling out those that have unacceptable weaknesses or are not applicable, and compares their results.
This comparison of the best of the best studies, ideally, shows consistent trends.
Comparing high-quality studies is a way to find out what good research tells us about the subject of interest.
The Meta-Analysis This 2010 meta-analysis, titled, 'Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease', appeared in volume 91, pages 535-546, of the American Journal of Clinical Nutrition.
This meta-analysis specifically set out to compare dietary saturated fat with incidences of cardiovascular disease, including coronary heart disease and stroke.
A surprisingly small number of studies (i.
e.
, 21) qualified for comparisons.
Nevertheless, the breadth of comparisons was phenomenal.
Timeframes for follow-up ranged from 5 to 23 years and included nearly 350,000 subjects.
This type of correlation study is often the basis for implying cause and effect (even though it is scientifically invalid to do so).
The 21 studies compared in this meta-analysis showed no correlation between dietary saturated fat and cardiovascular disease.
None.
What does it mean when there is no correlation? It means that there is no cause and effect relationship in the first place - that is, saturated fat does not cause cardiovascular disease.
Intervention Studies Nevertheless, the authors of this meta-analysis cited intervention studies (i.
e.
, designed experiments) that were supposed to show that reducing dietary saturated fat leads to reduced cardiovascular disease.
As in all dietary experiments, such studies have to account for a reduction of one thing by an increase in something else.
In this case, intervention studies replaced saturated fat with either high-glycemic carbohydrates or with unsaturated fats.
Such intervention studies do show a decrease in cardiovascular disease with a reduction in dietary saturated fat, depending on what is substituted for it.
Substituting with carbs doesn't do it.
Substituting with omega-6 fatty acids doesn't do it.
Substituting with omega-3 fatty acids does.
This is no surprise to biochemists.
We already know that carbs and omega-6 fatty acids drive up inflammation.
And we already know that omega-3 fatty acids are powerful anti-inflammatories.
Inflammation is the only consistent indicator of cardiovascular disease.
Eating Fat Saturated fat has no link to cardiovascular disease, so eating it is not a problem.
Omega-3 fatty acids are anti-inflammatory and are therefore important as energy sources and as a prevention for heart and vascular damage.
So consume plenty of extra virgin olive oil, oily fish and fish oil supplements, walnuts, flax seeds, and omega-3 fortified eggs.
Carbs are big problem.
Refined carbs, including sugar, drive up blood triglyceride levels, which are one of the culprits associated with arterial damage.
Oh, and glycemic index may not always be helpful.
One of the most common sugars in processed foods is fructose, which has a low glycemic index.
However, it elevates triglycerides faster than any other carb.
Omega-6 fatty acids may be a big problem.
Some are essential in our diet, but consuming too much of them is highly inflammatory.
Cut way down by reducing your intake of most cooking oils (corn, sunflower, safflower, soy, and cottonseed) and the processed and fast foods that are made with them.
Julia Child Had It Right She advocated butter, butter, and more butter.
Her attitude was that there could never be too much butter.
Now we know that we can say the same for all sources of saturated fat, including those from animals (cream, cheese, ghee, suet, tallow, lard, and fatty meats) as well as those from plants (coconut oil, cottonseed oil, palm kernel oil and chocolate).
Hopefully someday the low-fat diet craze, especially the diatribe against saturated fat, will simply die away in the wake of sensible science.
We can already say that this was perhaps one of the worst pieces of nutritional advice ever foisted on an unsuspecting public.
Eat saturated fat.
Eat plenty of it.
Oz and other health professionals say a zillion times that you have to avoid saturated fat because it ruins your cardiovascular health.
Research supposedly supports that advice.
However, a recent meta-analysis of the best studies in the medical literature that specifically examined the possible relationship between dietary saturated fat and cardiovascular disease show...
well, they show no relationship.
A meta-analysis identifies the best studies on a topic, culling out those that have unacceptable weaknesses or are not applicable, and compares their results.
This comparison of the best of the best studies, ideally, shows consistent trends.
Comparing high-quality studies is a way to find out what good research tells us about the subject of interest.
The Meta-Analysis This 2010 meta-analysis, titled, 'Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease', appeared in volume 91, pages 535-546, of the American Journal of Clinical Nutrition.
This meta-analysis specifically set out to compare dietary saturated fat with incidences of cardiovascular disease, including coronary heart disease and stroke.
A surprisingly small number of studies (i.
e.
, 21) qualified for comparisons.
Nevertheless, the breadth of comparisons was phenomenal.
Timeframes for follow-up ranged from 5 to 23 years and included nearly 350,000 subjects.
This type of correlation study is often the basis for implying cause and effect (even though it is scientifically invalid to do so).
The 21 studies compared in this meta-analysis showed no correlation between dietary saturated fat and cardiovascular disease.
None.
What does it mean when there is no correlation? It means that there is no cause and effect relationship in the first place - that is, saturated fat does not cause cardiovascular disease.
Intervention Studies Nevertheless, the authors of this meta-analysis cited intervention studies (i.
e.
, designed experiments) that were supposed to show that reducing dietary saturated fat leads to reduced cardiovascular disease.
As in all dietary experiments, such studies have to account for a reduction of one thing by an increase in something else.
In this case, intervention studies replaced saturated fat with either high-glycemic carbohydrates or with unsaturated fats.
Such intervention studies do show a decrease in cardiovascular disease with a reduction in dietary saturated fat, depending on what is substituted for it.
Substituting with carbs doesn't do it.
Substituting with omega-6 fatty acids doesn't do it.
Substituting with omega-3 fatty acids does.
This is no surprise to biochemists.
We already know that carbs and omega-6 fatty acids drive up inflammation.
And we already know that omega-3 fatty acids are powerful anti-inflammatories.
Inflammation is the only consistent indicator of cardiovascular disease.
Eating Fat Saturated fat has no link to cardiovascular disease, so eating it is not a problem.
Omega-3 fatty acids are anti-inflammatory and are therefore important as energy sources and as a prevention for heart and vascular damage.
So consume plenty of extra virgin olive oil, oily fish and fish oil supplements, walnuts, flax seeds, and omega-3 fortified eggs.
Carbs are big problem.
Refined carbs, including sugar, drive up blood triglyceride levels, which are one of the culprits associated with arterial damage.
Oh, and glycemic index may not always be helpful.
One of the most common sugars in processed foods is fructose, which has a low glycemic index.
However, it elevates triglycerides faster than any other carb.
Omega-6 fatty acids may be a big problem.
Some are essential in our diet, but consuming too much of them is highly inflammatory.
Cut way down by reducing your intake of most cooking oils (corn, sunflower, safflower, soy, and cottonseed) and the processed and fast foods that are made with them.
Julia Child Had It Right She advocated butter, butter, and more butter.
Her attitude was that there could never be too much butter.
Now we know that we can say the same for all sources of saturated fat, including those from animals (cream, cheese, ghee, suet, tallow, lard, and fatty meats) as well as those from plants (coconut oil, cottonseed oil, palm kernel oil and chocolate).
Hopefully someday the low-fat diet craze, especially the diatribe against saturated fat, will simply die away in the wake of sensible science.
We can already say that this was perhaps one of the worst pieces of nutritional advice ever foisted on an unsuspecting public.
Eat saturated fat.
Eat plenty of it.