Despite the long held idea that saturated fat causes artery blockage
by raising blood cholesterol and thus contributes to the risk of having a
heart attack (diet-heart hypothesis), the scientific evidence is just
not there!
1. A recent large study published in the Annals of Nutrition and
Metabolism reported an “Expert Consultation” held jointly by the World
Health Organization (WHO) and Food and Agriculture Organization (FAO) of
the US. The consultation took a comprehensive look at the relationship
between fats, physiology and health.
The experts assessing the relationship between saturated fats and heart disease looked at two lines of evidence: epidemiological studies and intervention studies.
The experts assessing the relationship between saturated fats and heart disease looked at two lines of evidence: epidemiological studies and intervention studies.
Epidemiological studies look at the relationship between factors
(such as smoking and lung cancer, or in this case saturated fat and
heart disease) in populations.
These studies can only show associations between things, but cannot really tell us if one thing is causing another.
However, if saturated fat indeed causes heart disease, 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).
These studies can only show associations between things, but cannot really tell us if one thing is causing another.
However, if saturated fat indeed causes heart disease, 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).
According to this report, there is no association.
The report states:
The report states:
“Intake of SFA (saturated fatty acids) was not significantly associated with CHD mortality”
and
“SFA intake was not significantly associated CHD events (heart attacks)”
In intervention studies, people are subjected to some sort of intervention (such as a medication).
In this case, the intervention was to put people on a low saturated fat diet and see how they compare to individuals who are not subjected to this change.
Unlike epidemiological studies, intervention studies can prove cause-and-effect links between things.
In this case, the intervention was to put people on a low saturated fat diet and see how they compare to individuals who are not subjected to this change.
Unlike epidemiological studies, intervention studies can prove cause-and-effect links between things.
The report found that:
” …fatal CHD was not reduced by the low-fat diets …”
2. Another huge study published last week in the American Journal of
Clinical Nutrition looked at the relationship between saturated fat and
heart disease through a meta-analysis of 21 epidemiological studies.
This review monitored 347,747 people over a period of between 5 and 23 years.
This review monitored 347,747 people over a period of between 5 and 23 years.
The conclusion:
A meta-analysis of prospective epidemiologic studies showed
that there is no significant evidence for concluding that dietary
saturated fat is associated with an increased risk of CHD (coronary
heart disease) or CVD (cardiovascular disease).
More data are needed to elucidate whether CVD risks are likely to be influenced by the specific nutrients used to replace saturated fat.
More data are needed to elucidate whether CVD risks are likely to be influenced by the specific nutrients used to replace saturated fat.
3. A third large study published in the Archives of Internal Medicine
last year looked at a systematic review of the evidence linking a wide
variety of nutritional factors and heart disease.
According to this review, there are no appropriately conducted randomised controlled trials that support the notion that cutting back on saturated fat is good for the prevention of heart disease.
According to this review, there are no appropriately conducted randomised controlled trials that support the notion that cutting back on saturated fat is good for the prevention of heart disease.
The dietary factors which were associated with an increased risk of heart disease were:
A higher intake of trans-fatty acids
A higher intake of foods of high glycemic index or high glycemic load
A higher intake of foods of high glycemic index or high glycemic load
Factors associated with a statistically significant reduced risk of heart disease included:
Higher alcohol consumption
Higher dietary beta-carotene consumption
Higher dietary folate consumption
Higher total folate consumption (from diet and supplements combined)
Higher fibre consumption
Higher fish consumption
Higher marine-derived omega-3 fat consumption
Higher fruit consumption
Higher nut consumption
Higher vegetable consumption
Higher monounsaturated fat consumption
Higher dietary vitamin C consumption
Higher total vitamin C consumption
Higher dietary vitamin E consumption
Higher total vitamin E consumption
Higher wholegrain consumption
Higher dietary beta-carotene consumption
Higher dietary folate consumption
Higher total folate consumption (from diet and supplements combined)
Higher fibre consumption
Higher fish consumption
Higher marine-derived omega-3 fat consumption
Higher fruit consumption
Higher nut consumption
Higher vegetable consumption
Higher monounsaturated fat consumption
Higher dietary vitamin C consumption
Higher total vitamin C consumption
Higher dietary vitamin E consumption
Higher total vitamin E consumption
Higher wholegrain consumption
Saturated fat neither increased nor decreased the risk of heart disease.
Therefore, if saturated fat is truly so scary, then why don’t people who eat more of it have more heart attacks?
Well, the low-fat diet-heart hypothesis has been controversial for
many decades and it looks like it finally ends here. It should!
It’s been kept alive by selective citation of inadequate evidence, wishful thinking, and by powerful agricultural and food companies.
It may well have played an unintended role in the current epidemics of obesity, lipid abnormalities, type II diabetes, and metabolic syndromes.
It’s been kept alive by selective citation of inadequate evidence, wishful thinking, and by powerful agricultural and food companies.
It may well have played an unintended role in the current epidemics of obesity, lipid abnormalities, type II diabetes, and metabolic syndromes.
Indeed, you can safely eat organic meat, such as grass-fed beef, pork, chicken, duck, geese, lamb etc. Together with their fatty parts.
Source: Fats and Fatty Acids in Human Nutrition. Annals of Nutrition and Metabolism, 2009; 55 (1-3).
Siri-Tarino PW, et al. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease Am J Clin Nutr. January 2010
Mente A, et al. A Systematic Review of the Evidence Supporting a Causal Link Between Dietary Factors and Coronary Heart Disease. Arch Intern Med. 2009;169(7):659-669.
Siri-Tarino PW, et al. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease Am J Clin Nutr. January 2010
Mente A, et al. A Systematic Review of the Evidence Supporting a Causal Link Between Dietary Factors and Coronary Heart Disease. Arch Intern Med. 2009;169(7):659-669.
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