Saturated fat and cardiovascular disease controversy
Encyclopedia
Whether saturated fat
is a risk factor for cardiovascular disease
(CVD) is a question with numerous controversial views. Although there is a scientific consensus in the mainstream heart-health, government, and medical communities that saturated fat is a risk factor for CVD, individual studies produce conflicting results and notable authors have given opposing viewpoints.
"The findings are suggestive of a small but potentially important reduction in cardiovascular risk on modification of dietary fat, but not reduction of total fat, in longer trials. Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups, should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturates. The ideal type of unsaturated fat is unclear". In a summary it goes on to say "there are no clear health benefits of replacing saturated fats with starchy foods".
A 2010 systematic review and meta-analysis of randomized controlled trial
s commissioned by the National Heart, Lung, and Blood Institute found that substitution of poly-unsaturated fat for saturated fat led to a 19% reduction in Coronary Heart Disease
.
In 2010, a meta-analysis
of prospective cohort studies
supported by the National Dairy Council including 348,000 subjects found no statistically significant relationship between cardiovascular disease
and dietary saturated fat.
In a subordinate meta-analysis to a 2009 risk assessment supported by the Centers for Disease Control and Prevention (CDC), an ischemic heart disease mortality residual risk of 1.05 was determined for the 30-44 year age group for each 1% isocaloric reduction in PUFA in favour of SFA. Higher age groups had lower residual risks.
In 2009, a systematic review
supported by the Heart and Stroke Foundation of Canada of prospective cohort studies or randomized trials concluded that there was "insufficient evidence of association" between intake of saturated fatty acids and coronary heart disease, and pointed to strong evidence for protective factors such as vegetables and a Mediterranean diet
and harmful factors such as trans fat
s and foods with a high glycemic index
.
A 2009 meta-analysis supported by the NHBLI focused on the effects of trans-fats also applied the same techniques to studies focused on SFA, MUFA and PUFA, in order to assess the relative risk of substituting trans-fats with other fats. Risks were assessed from two classes of data - risk factors in trials, and disease outcomes in cohort studies. In order of decreasing risk, the fat types were TFA, SFA, MUFA and PUFA. From the trials analysis, it was found that for partially-hydrogenated vegetable oil with 20% trans-fats at consumption rate of 7.5% of daily calories, replacement with butter would decrease risk by 2.7% and replacement with canola oil would reduce risk by 9.9%. From the cohort analysis, butter would have little net effect (0.5% increased risk) while soybean and canola oil would have the largest reduction in risk (19.0 and 21.8%, respectively).
A 2009 meta-analysis of cohort studies and randomized controlled trials from the University of Otago, New Zealand, found that the results of the cohort studies showed no association between coronary heart disease mortality nor total coronary heart disease events when saturated fat was increased in place of carbohydrates. In the randomized controlled trials where the ratio of polyunsaturated fat to saturated fat had been increased, the risk of coronary heart disease fatality was not changed, but the risk of total coronary heart disease events was decreased. The analysis was critical of the limitations of the primary evidence available, considering the evidence from cohort studies to be mostly unreliable.
A 2009 pooled analysis of 11 cohort studies supported by the National Heart, Lung, and Blood Institute, National Institutes of Health, the Danish Heart Foundation and the Danish Medical Research Council found that substituting polyunsaturated fatty acids in place of saturated fatty acids at a rate of 5% of energy intake led to 13% decrease in coronary events and a 26% decrease in coronary deaths.
The American Dietetic Association's 2008 systematic review found that a diet with 25%-35% total fat but less than 7% saturated fat and trans fat
lowers the risk of coronary heart disease.
A 2003 meta-analysis of prevention dietetic studies found the benefit of a modified fat diet in primary prevention is potentially significant if it is maintained for a sufficient length of time.
A 1999 review found that substitution of the fat from one ounce of nuts for equivalent energy from saturated fat was associated with a 45% reduction in risk of coronary heart disease.
A 1994 meta-analysis from the University of Sydney of the effect on coronary events and total mortality in dietary intervention trials found a 6% reduction in mortality and 13% reduction in events. The dietary advice differed between the trials reviewed, but most prescribed a reduced saturated fat and cholesterol intake with partial replacement by polyunsaturated oils. The review noted that a large controlled trial "may no longer be ethical."
Some meta-analyses have found a significant relationship between saturated fat and serum cholesterol levels, and serum cholesterol levels and cardiovascular disease. However, the ratio of total to high density lipoprotein
cholesterol is considered a better indicator and some saturated fats (lauric acid
and stearic acid
) improve the ratio.
2007's Cardiovascular Prevention and Rehabilitation states that large epidemiological studies have shown consistent associations between the intake of saturated fatty acids and CHD mortality.
According to the 2007 Critical Pathways in Cardiovascular Medicine, substituting unsaturated fat for saturated fat may lower LDL cholesterol without simultaneously lowering HDL cholesterol. This dietary principle partly underlies the Mediterranean style of diet, which has been associated with reduced cardiovascular event rates in two randomized controlled trials.
The 2003 second edition of Evidence-based Cardiology in 'PartII: Prevention of cardiovascular diseases' recommends a low intake of SFA, less than 7% of daily calories, and intake of foods rich in myristic and palmitic acids should be especially reduced. The recommendation was evaluated to be supported by the best grade of available evidence.
In 2003 a World Health Organization
(WHO) and Food and Agricultural Organization (FAO) expert consultation report concluded that "intake of saturated fatty acids is directly related
to cardiovascular risk. The traditional target is to restrict the intake of
saturated fatty acids to less than 10%, of daily energy intake and less
than 7% for high-risk groups. If populations are consuming less than
10%, they should not increase that level of intake. Within these limits,
intake of foods rich in myristic and palmitic acids should be replaced by
fats with a lower content of these particular fatty acids. In developing
countries, however, where energy intake for some population groups
may be inadequate, energy expenditure is high and body fat stores are
low (BMI <18.5 kg/m2). The amount and quality of fat supply has to be
considered keeping in mind the need to meet energy requirements.
Specific sources of saturated fat, such as coconut and palm oil, provide
low-cost energy and may be an important source of energy for the poor."
In its 2007 guidelines, the European Society of Cardiology
states that there are strong, consistent, and graded relationships between saturated fat intake, blood cholesterol levels, and the mass occurrence of cardiovascular disease. The relationships are accepted as causal.
The Mayo Clinic
considers saturated fats potentially harmful and monounsaturated and polyunsaturated fats potentially helpful. It references the Dietary Guidelines for Americans, 2010 and recommends reducing foods rich in saturated fat and emphasizing options with more monounsaturated and polyunsaturated fats.
The British Dietetic Association
guidelines found good evidence in systematic reviews of randomized controlled trials that reducing saturated fat reduces morbidity in patients with CVD.
The 2007 position statement of the American Dietetic Association and the Dieticians of Canada holds that epidemiological studies have shown a positive association between the intake of saturated fatty acid and the incidence of coronary heart disease.
Consumption of saturated fat is a risk factor for cardiovascular disease in the view of the Canadian Heart and Stroke Foundation, the American Heart Association, the British Heart Foundation, the National Heart Foundation of Australia, the National Heart Foundation of New Zealand and the World Heart Federation. The Irish Heart Foundation states that saturated fats can raise your LDL cholesterol and increase your chances of getting heart disease.
The Dietary Guidelines for Americans, 2010 produced by the U.S. Department of Agriculture (USDA) and U.S. Department of Health and Human Services says the human body makes more than enough saturated fats to meet its needs and does not require more from dietary sources. It says higher levels of saturated fats are associated with higher levels of total cholesterol and low-density lipoprotein "bad" cholesterol and recommends reduced saturated fat intake. The guidelines are based on the recommendations of the Dietary Guidelines Advisory Committee (DGAC) report that incorporated the results of the review of 12 studies from 2004 to 2009 conducted by the Nutrition Evidence Library (NEL) part of the Evidence Analysis Library Division of the USDA's Center for Nutrition Policy and Promotion. The NEL concluded that there was "strong" evidence that dietary saturated fats increased serum total cholesterol and LDL cholesterol and increased risk of cardiovascular disease.
at large was that "Researchers agree that replacing saturated fat with healthy PUFAs is beneficial for health and [cardiovascular disease]." Recommendations for dieticians emphasized using mono- and poly-unsaturated fats whenever possible, avoiding trans fats, that while "The evidence against saturated fat may not be as strong as dietary guidelines have interpreted [it is clear] that PUFAs (especially) and MUFAs are healthy fats", and that while there is room for saturated fats within the diet but "[they] should not be viewed as good for you".
It also noted "dietary patterns are more important than single dietary components" and recommended dietitians "to talk food, not chemicals".
A 2010 perspective in the American Journal of Clinical Nutrition found that the risk of coronary heart disease
(CHD) is reduced when saturated fatty acids are replaced with polyunsaturated fatty acids but no clear benefit in replacing saturated fatty acids with carbohydrates or monounsaturated fatty acids.
In an October 2010 article in the journal Nutrition, the 2010 Dietary Guidelines Advisory Committee (DGAC) report was criticized for the "use of an incomplete body of relevant science; inaccurately representing, interpreting, or summarizing the literature; and drawing conclusions and/or making recommendations that do not reflect the limitations or controversies in the science" stating rather that the evidence associating dietary SFA with increased risk of CVD is inconclusive.
A response by Jeremiah Stamler to the 2010 meta-analysis by Siri-Tarino et al. was point-by-point critical of the analysis, stating "The authors are inaccurate in concluding that 'there are few epidemiologic or clinical trial data to support a benefit of replacing saturated fat with carbohydrate.'" and questioned if it was the intent to dissociate themselves from prevailing recommendations, "A vast array of concordant multidisiplinary research evidence is the sound foundation for these recommendations."
A 2009 review from the University of São Paulo found that the best evidence showed reduced intake of saturated fat decreased risk for coronary heart disease.
A 2009 review from King's College London found that epidemiological evidence suggested a negative influence on vascular function from saturated fat, but that the experimental evidence did not support this convincingly.
A 2009 scientific conference hosted by the University of Reading (UK) and organized and facilitated by the International Dairy Federation’s Standing Committee on Nutrition and Health found that despite the contribution of dairy products to the saturated fatty acid intake of the diet, there was no clear evidence that dairy food consumption is consistently associated with a higher risk of CVD.
A 2004 commentary from the Nestle Research Center stated that no randomized clinical trials of low-fat diets or low-saturated fat diets of sufficient duration had been carried out. The influence of varying saturated fatty acid intakes against a background of different individual lifestyles and genetic backgrounds were recommended as the focus in future studies.
Saturated fat intakes may be monitored more closely than were total fat intakes, therefore ignoring the possibility that simply a larger fat intake may lead to a higher risk of coronary diseases. It also suggests that other parameters may be overlooked, such as carbohydrates intakes.
A 2000 consensus statement appearing in The American Journal of Medicine listed in factors important to prevent heart disease a substantial reduction of saturated fat and partially hydrogenated oils, and the substitution of saturated fats by unsaturated fats.
, a science writer specializing in controversy and three-time winner of the Science in Society Award
of the National Association of Science Writers
concludes "Dietary fat, whether saturated or not, is not a cause of obesity, heart disease, or any other chronic disease of civilization."
Author and journalist Michael Pollan
, a two-time James Beard Foundation Award
winner, in his book In Defense of Food – An Eater's Manifesto states "The amount of saturated fat in the diet probably may have little if any bearing on the risk of heart disease, and evidence that increasing polyunsaturated fats in the diet will reduce risk is slim to nil."
Mary G. Enig
a biochemist and nutritionist who is a member of the International Network of Cholesterol Skeptics
states "there is very little evidence to support the contention that a diet low in cholesterol and saturated fat actually reduces death from heart disease."
Saturated fat
Saturated fat is fat that consists of triglycerides containing only saturated fatty acids. Saturated fatty acids have no double bonds between the individual carbon atoms of the fatty acid chain. That is, the chain of carbon atoms is fully "saturated" with hydrogen atoms...
is a risk factor for cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
(CVD) is a question with numerous controversial views. Although there is a scientific consensus in the mainstream heart-health, government, and medical communities that saturated fat is a risk factor for CVD, individual studies produce conflicting results and notable authors have given opposing viewpoints.
Summary table
| Systematic review | Relationship between cardiovascular disease and saturated fatty acids (SFA) |
|---|---|
| Hooper, 2011 | Reducing saturated fat in diets reduced the risk of having a cardiovascular event by 14 percent (no reduction in mortality). |
| Mozaffarian, 2010 | 19% reduction in Coronary Heart Disease (CHD) events by replacing saturated fatty acids (SFA) with polyunsaturated fatty acids (PUFA). (Note: the study included n-3 fatty acids in the PUFA group). |
| Siri-Tarino, 2010 | insignificant |
| Danaei, 2009 | 1-5% additional IHD mortality risk for each 1% calories exchanging PUFA for SFA |
| Mente, 2009 | insignificant |
| Skeaff, 2009 | reduced events by substituting PUFA |
| Jakobsen, 2009 | 5% exchange of SFA for PUFA: 13% decrease events, 26% decrease deaths |
| Van Horn, 2008 | 25-35% fats but <7% SFA and TFA reduces risk |
| Chanu, 2003 | significant in longer term |
| Hu, 1999 | exchanging SFA for nuts gave 45% reduction |
| Truswell, 1994 | decrease SFA and cholesterol intake, partial replacement with PUFA: 6% reduced deaths, 13% reduced events |
Review details
A 2011 systematic review from The Cochrane Library analyzed 48 studies conducted between 1965 and 2009 and included 65,508 participants. All studies reduced or modified participants’ dietary fat or cholesterol for at least six months by at least 30 percent. It was found that reducing saturated fat by reducing and/or modifying dietary fat reduced the risk of having a cardiovascular event, such as heart attack, stroke and unplanned heart surgery, by 14 percent. Of the 65,508 participants, 7 percent had a cardiovascular event."The findings are suggestive of a small but potentially important reduction in cardiovascular risk on modification of dietary fat, but not reduction of total fat, in longer trials. Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups, should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturates. The ideal type of unsaturated fat is unclear". In a summary it goes on to say "there are no clear health benefits of replacing saturated fats with starchy foods".
A 2010 systematic review and meta-analysis of randomized controlled trial
Randomized controlled trial
A randomized controlled trial is a type of scientific experiment - a form of clinical trial - most commonly used in testing the safety and efficacy or effectiveness of healthcare services or health technologies A randomized controlled trial (RCT) is a type of scientific experiment - a form of...
s commissioned by the National Heart, Lung, and Blood Institute found that substitution of poly-unsaturated fat for saturated fat led to a 19% reduction in Coronary Heart Disease
Coronary heart disease
Coronary artery disease is the end result of the accumulation of atheromatous plaques within the walls of the coronary arteries that supply the myocardium with oxygen and nutrients. It is sometimes also called coronary heart disease...
.
In 2010, a meta-analysis
Meta-analysis
In statistics, a meta-analysis combines the results of several studies that address a set of related research hypotheses. In its simplest form, this is normally by identification of a common measure of effect size, for which a weighted average might be the output of a meta-analyses. Here the...
of prospective cohort studies
Cohort study
A cohort study or panel study is a form of longitudinal study used in medicine, social science, actuarial science, and ecology. It is an analysis of risk factors and follows a group of people who do not have the disease, and uses correlations to determine the absolute risk of subject contraction...
supported by the National Dairy Council including 348,000 subjects found no statistically significant relationship between cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
and dietary saturated fat.
In a subordinate meta-analysis to a 2009 risk assessment supported by the Centers for Disease Control and Prevention (CDC), an ischemic heart disease mortality residual risk of 1.05 was determined for the 30-44 year age group for each 1% isocaloric reduction in PUFA in favour of SFA. Higher age groups had lower residual risks.
In 2009, a systematic review
Systematic review
A systematic review is a literature review focused on a research question that tries to identify, appraise, select and synthesize all high quality research evidence relevant to that question. Systematic reviews of high-quality randomized controlled trials are crucial to evidence-based medicine...
supported by the Heart and Stroke Foundation of Canada of prospective cohort studies or randomized trials concluded that there was "insufficient evidence of association" between intake of saturated fatty acids and coronary heart disease, and pointed to strong evidence for protective factors such as vegetables and a Mediterranean diet
Mediterranean diet
The Mediterranean diet is a modern nutritional recommendation inspired by the traditional dietary patterns of southern Italy, Crete and much of the rest of Greece in the 1960s....
and harmful factors such as trans fat
Trans fat
Trans fat is the common name for unsaturated fat with trans-isomer fatty acid. Because the term refers to the configuration of a double carbon-carbon bond, trans fats are sometimes monounsaturated or polyunsaturated, but never saturated....
s and foods with a high glycemic index
Glycemic index
The glycemic index, glycaemic index, or GI is a measure of the effects of carbohydrates on blood sugar levels. Carbohydrates that break down quickly during digestion and release glucose rapidly into the bloodstream have a high GI; carbohydrates that break down more slowly, releasing glucose more...
.
A 2009 meta-analysis supported by the NHBLI focused on the effects of trans-fats also applied the same techniques to studies focused on SFA, MUFA and PUFA, in order to assess the relative risk of substituting trans-fats with other fats. Risks were assessed from two classes of data - risk factors in trials, and disease outcomes in cohort studies. In order of decreasing risk, the fat types were TFA, SFA, MUFA and PUFA. From the trials analysis, it was found that for partially-hydrogenated vegetable oil with 20% trans-fats at consumption rate of 7.5% of daily calories, replacement with butter would decrease risk by 2.7% and replacement with canola oil would reduce risk by 9.9%. From the cohort analysis, butter would have little net effect (0.5% increased risk) while soybean and canola oil would have the largest reduction in risk (19.0 and 21.8%, respectively).
A 2009 meta-analysis of cohort studies and randomized controlled trials from the University of Otago, New Zealand, found that the results of the cohort studies showed no association between coronary heart disease mortality nor total coronary heart disease events when saturated fat was increased in place of carbohydrates. In the randomized controlled trials where the ratio of polyunsaturated fat to saturated fat had been increased, the risk of coronary heart disease fatality was not changed, but the risk of total coronary heart disease events was decreased. The analysis was critical of the limitations of the primary evidence available, considering the evidence from cohort studies to be mostly unreliable.
A 2009 pooled analysis of 11 cohort studies supported by the National Heart, Lung, and Blood Institute, National Institutes of Health, the Danish Heart Foundation and the Danish Medical Research Council found that substituting polyunsaturated fatty acids in place of saturated fatty acids at a rate of 5% of energy intake led to 13% decrease in coronary events and a 26% decrease in coronary deaths.
The American Dietetic Association's 2008 systematic review found that a diet with 25%-35% total fat but less than 7% saturated fat and trans fat
Trans fat
Trans fat is the common name for unsaturated fat with trans-isomer fatty acid. Because the term refers to the configuration of a double carbon-carbon bond, trans fats are sometimes monounsaturated or polyunsaturated, but never saturated....
lowers the risk of coronary heart disease.
A 2003 meta-analysis of prevention dietetic studies found the benefit of a modified fat diet in primary prevention is potentially significant if it is maintained for a sufficient length of time.
A 1999 review found that substitution of the fat from one ounce of nuts for equivalent energy from saturated fat was associated with a 45% reduction in risk of coronary heart disease.
A 1994 meta-analysis from the University of Sydney of the effect on coronary events and total mortality in dietary intervention trials found a 6% reduction in mortality and 13% reduction in events. The dietary advice differed between the trials reviewed, but most prescribed a reduced saturated fat and cholesterol intake with partial replacement by polyunsaturated oils. The review noted that a large controlled trial "may no longer be ethical."
Some meta-analyses have found a significant relationship between saturated fat and serum cholesterol levels, and serum cholesterol levels and cardiovascular disease. However, the ratio of total to high density lipoprotein
High density lipoprotein
High-density lipoprotein is one of the five major groups of lipoproteins, which, in order of sizes, largest to smallest, are chylomicrons, VLDL, IDL, LDL, and HDL, which enable lipids like cholesterol and triglycerides to be transported within the water-based bloodstream...
cholesterol is considered a better indicator and some saturated fats (lauric acid
Lauric acid
Lauric acid , the saturated fatty acid with a 12-carbon atom chain, is a white, powdery solid with a faint odor of bay oil or soap.-Occurrence:...
and stearic acid
Stearic acid
Stearic acid is the saturated fatty acid with an 18 carbon chain and has the IUPAC name octadecanoic acid. It is a waxy solid, and its chemical formula is CH316CO2H. Its name comes from the Greek word στέαρ "stéatos", which means tallow. The salts and esters of stearic acid are called stearates...
) improve the ratio.
Specialist/professional textbooks
The 2009 European Society of Cardiology Textbook of Cardiovascular Medicine states that in cohort studies the positive relationship between fat intake and CVDs was linked to their saturated fatty acid content.2007's Cardiovascular Prevention and Rehabilitation states that large epidemiological studies have shown consistent associations between the intake of saturated fatty acids and CHD mortality.
According to the 2007 Critical Pathways in Cardiovascular Medicine, substituting unsaturated fat for saturated fat may lower LDL cholesterol without simultaneously lowering HDL cholesterol. This dietary principle partly underlies the Mediterranean style of diet, which has been associated with reduced cardiovascular event rates in two randomized controlled trials.
The 2003 second edition of Evidence-based Cardiology in 'PartII: Prevention of cardiovascular diseases' recommends a low intake of SFA, less than 7% of daily calories, and intake of foods rich in myristic and palmitic acids should be especially reduced. The recommendation was evaluated to be supported by the best grade of available evidence.
Medical establishments
In 2003 a World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
(WHO) and Food and Agricultural Organization (FAO) expert consultation report concluded that "intake of saturated fatty acids is directly related
to cardiovascular risk. The traditional target is to restrict the intake of
saturated fatty acids to less than 10%, of daily energy intake and less
than 7% for high-risk groups. If populations are consuming less than
10%, they should not increase that level of intake. Within these limits,
intake of foods rich in myristic and palmitic acids should be replaced by
fats with a lower content of these particular fatty acids. In developing
countries, however, where energy intake for some population groups
may be inadequate, energy expenditure is high and body fat stores are
low (BMI <18.5 kg/m2). The amount and quality of fat supply has to be
considered keeping in mind the need to meet energy requirements.
Specific sources of saturated fat, such as coconut and palm oil, provide
low-cost energy and may be an important source of energy for the poor."
In its 2007 guidelines, the European Society of Cardiology
European Society of Cardiology
The European Society of Cardiology is a membership organisation of more than 70,000 cardiology professionals across Europe and the Mediterranean. It is involved in scientific and educational activities for cardiology professionals and also promotes cardiovascular disease prevention messages to the...
states that there are strong, consistent, and graded relationships between saturated fat intake, blood cholesterol levels, and the mass occurrence of cardiovascular disease. The relationships are accepted as causal.
The Mayo Clinic
Mayo Clinic
Mayo Clinic is a not-for-profit medical practice and medical research group specializing in treating difficult patients . Patients are referred to Mayo Clinic from across the U.S. and the world, and it is known for innovative and effective treatments. Mayo Clinic is known for being at the top of...
considers saturated fats potentially harmful and monounsaturated and polyunsaturated fats potentially helpful. It references the Dietary Guidelines for Americans, 2010 and recommends reducing foods rich in saturated fat and emphasizing options with more monounsaturated and polyunsaturated fats.
The British Dietetic Association
British Dietetic Association
The British Dietetic Association is a professional association and trade union for dieticians in the United Kingdom. It was founded in 1936 and became a certified union in 1982; it is affiliated to the Trades Union Congress and the Scottish Trades Union Congress.The BDA was established in 1936...
guidelines found good evidence in systematic reviews of randomized controlled trials that reducing saturated fat reduces morbidity in patients with CVD.
The 2007 position statement of the American Dietetic Association and the Dieticians of Canada holds that epidemiological studies have shown a positive association between the intake of saturated fatty acid and the incidence of coronary heart disease.
Heart-health organizations
Consumption of saturated fat is a risk factor for cardiovascular disease in the view of the Canadian Heart and Stroke Foundation, the American Heart Association, the British Heart Foundation, the National Heart Foundation of Australia, the National Heart Foundation of New Zealand and the World Heart Federation. The Irish Heart Foundation states that saturated fats can raise your LDL cholesterol and increase your chances of getting heart disease.
Governmental guidelines
The Dietary Guidelines for Americans, 2010 produced by the U.S. Department of Agriculture (USDA) and U.S. Department of Health and Human Services says the human body makes more than enough saturated fats to meet its needs and does not require more from dietary sources. It says higher levels of saturated fats are associated with higher levels of total cholesterol and low-density lipoprotein "bad" cholesterol and recommends reduced saturated fat intake. The guidelines are based on the recommendations of the Dietary Guidelines Advisory Committee (DGAC) report that incorporated the results of the review of 12 studies from 2004 to 2009 conducted by the Nutrition Evidence Library (NEL) part of the Evidence Analysis Library Division of the USDA's Center for Nutrition Policy and Promotion. The NEL concluded that there was "strong" evidence that dietary saturated fats increased serum total cholesterol and LDL cholesterol and increased risk of cardiovascular disease.
Editorial, commentary and conference findings in reputable medical journals
A May 2011 extended feature in the Journal of the American Dietetic Association published an edited summary of a debate at the American Dietetic Association's 93rd conference. Regarding saturated fat, the key point agreed upon by the panel and scientific communityScientific community
The scientific community consists of the total body of scientists, its relationships and interactions. It is normally divided into "sub-communities" each working on a particular field within science. Objectivity is expected to be achieved by the scientific method...
at large was that "Researchers agree that replacing saturated fat with healthy PUFAs is beneficial for health and [cardiovascular disease]." Recommendations for dieticians emphasized using mono- and poly-unsaturated fats whenever possible, avoiding trans fats, that while "The evidence against saturated fat may not be as strong as dietary guidelines have interpreted [it is clear] that PUFAs (especially) and MUFAs are healthy fats", and that while there is room for saturated fats within the diet but "[they] should not be viewed as good for you".
It also noted "dietary patterns are more important than single dietary components" and recommended dietitians "to talk food, not chemicals".
A 2010 perspective in the American Journal of Clinical Nutrition found that the risk of coronary heart disease
Coronary heart disease
Coronary artery disease is the end result of the accumulation of atheromatous plaques within the walls of the coronary arteries that supply the myocardium with oxygen and nutrients. It is sometimes also called coronary heart disease...
(CHD) is reduced when saturated fatty acids are replaced with polyunsaturated fatty acids but no clear benefit in replacing saturated fatty acids with carbohydrates or monounsaturated fatty acids.
In an October 2010 article in the journal Nutrition, the 2010 Dietary Guidelines Advisory Committee (DGAC) report was criticized for the "use of an incomplete body of relevant science; inaccurately representing, interpreting, or summarizing the literature; and drawing conclusions and/or making recommendations that do not reflect the limitations or controversies in the science" stating rather that the evidence associating dietary SFA with increased risk of CVD is inconclusive.
A response by Jeremiah Stamler to the 2010 meta-analysis by Siri-Tarino et al. was point-by-point critical of the analysis, stating "The authors are inaccurate in concluding that 'there are few epidemiologic or clinical trial data to support a benefit of replacing saturated fat with carbohydrate.'" and questioned if it was the intent to dissociate themselves from prevailing recommendations, "A vast array of concordant multidisiplinary research evidence is the sound foundation for these recommendations."
A 2009 review from the University of São Paulo found that the best evidence showed reduced intake of saturated fat decreased risk for coronary heart disease.
A 2009 review from King's College London found that epidemiological evidence suggested a negative influence on vascular function from saturated fat, but that the experimental evidence did not support this convincingly.
A 2009 scientific conference hosted by the University of Reading (UK) and organized and facilitated by the International Dairy Federation’s Standing Committee on Nutrition and Health found that despite the contribution of dairy products to the saturated fatty acid intake of the diet, there was no clear evidence that dairy food consumption is consistently associated with a higher risk of CVD.
A 2004 commentary from the Nestle Research Center stated that no randomized clinical trials of low-fat diets or low-saturated fat diets of sufficient duration had been carried out. The influence of varying saturated fatty acid intakes against a background of different individual lifestyles and genetic backgrounds were recommended as the focus in future studies.
Saturated fat intakes may be monitored more closely than were total fat intakes, therefore ignoring the possibility that simply a larger fat intake may lead to a higher risk of coronary diseases. It also suggests that other parameters may be overlooked, such as carbohydrates intakes.
A 2000 consensus statement appearing in The American Journal of Medicine listed in factors important to prevent heart disease a substantial reduction of saturated fat and partially hydrogenated oils, and the substitution of saturated fats by unsaturated fats.
Lay scientific books
Gary TaubesGary Taubes
Gary Taubes is an American science writer.He is the author of Nobel Dreams , Bad Science: The Short Life and Weird Times of Cold Fusion , and Good Calories, Bad Calories , titled The Diet Delusion in the UK and Australia. His book Why We Get Fat: And What to Do About It was released in December...
, a science writer specializing in controversy and three-time winner of the Science in Society Award
Science in Society Journalism Awards
The National Association of Science Writers created the Science in Society Journalism Awards to honor and encourage "outstanding investigative and interpretive reporting about the sciences and their impact for good and ill." Each year the NASW recognizes work in these categories: books,...
of the National Association of Science Writers
National Association of Science Writers
The National Association of Science Writers was created in 1934 by a dozen science journalists and reporters in New York City. The aim of the organization was to improve the craft of science journalism and to promote good science reportage....
concludes "Dietary fat, whether saturated or not, is not a cause of obesity, heart disease, or any other chronic disease of civilization."
Author and journalist Michael Pollan
Michael Pollan
Michael Pollan is an American author, journalist, activist, and professor of journalism at the UC Berkeley Graduate School of Journalism. A 2006 New York Times book review describes him as a "liberal foodie intellectual."...
, a two-time James Beard Foundation Award
James Beard Foundation Award
The James Beard Foundation Awards were established in 1990 and are often called "The Oscars of Food." Held on the first weekend in May, the Awards honor the finest chefs, restaurants, wine professionals, journalists, cookbook authors, restaurant designers, and other food professionals in the...
winner, in his book In Defense of Food – An Eater's Manifesto states "The amount of saturated fat in the diet probably may have little if any bearing on the risk of heart disease, and evidence that increasing polyunsaturated fats in the diet will reduce risk is slim to nil."
Mary G. Enig
Mary G. Enig
Mary Gertrude Enig, PhD is a nutritionist and early trans fat researcher known for her unconventional positions on the role fats play in diet and health...
a biochemist and nutritionist who is a member of the International Network of Cholesterol Skeptics
The International Network of Cholesterol Skeptics
The International Network of Cholesterol Skeptics is a group of scientists, physicians, and other academicians from around the world who dispute the widely accepted lipid hypothesis of atherosclerosis...
states "there is very little evidence to support the contention that a diet low in cholesterol and saturated fat actually reduces death from heart disease."
Popular press
Writing in Men's Health Magazine, Nina Teicholz proposed that intake of saturated fat is only correlated with heart disease, "not a clear, causal link."Dairy producers
The Dairy Farmers of Canada quote Andrew Mente, PhD (Assistant Professor, Department of Clinical Epidemiology and Biostatistics, McMaster University) that "In light of new scientific data, it appears that saturated fat is not associated with an increased risk of cardiovascular disease."Canola producers
The Canola Council of Canada states that research studies have shown a link between saturated fat and increased serum cholesterol that, in turn, is associated with increased coronary heart disease risk.Pork producers
Pork Marketing Canada states that the fat in pork is trans-fat free and mostly mono-and poly-unsaturated, so trimmed pork is suitable for even cholesterol-lowering or "heart-healthy" diets.See also
- Diet and heart disease
- Fast foodFast foodFast food is the term given to food that can be prepared and served very quickly. While any meal with low preparation time can be considered to be fast food, typically the term refers to food sold in a restaurant or store with preheated or precooked ingredients, and served to the customer in a...
- Healthy dietHealthy dietA healthy diet is one that helps maintain or improve general health. It is important for lowering many chronic health risks, such as obesity, heart disease, diabetes, hypertension and cancer. A healthy diet involves consuming appropriate amounts of all essential nutrients and an adequate amount of...
- Junk foodJunk foodJunk food is an informal term applied to some foods that are perceived to have little or no nutritional value ; to products with nutritional value, but which also have ingredients considered unhealthy when regularly eaten; or to those considered unhealthy to consume at all...
- Lipid hypothesisLipid hypothesisThe lipid hypothesis was one of two hypotheses developed in the 1850s to explain the pathogenesis of atherosclerosis...
- Medical research related to low-carbohydrate dietsMedical research related to low-carbohydrate dietsLow-carbohydrate diets became a major weight loss and health maintenance trend during the late 1990s and early 2000s. While their popularity has waned recently from its peak, they remain popular. This diet trend has stirred major controversies in the medical and nutritional sciences communities...
Further reading
- Ravnskov, UffeUffe RavnskovUffe Ravnskov is a Danish independent researcher, a member of various international scientific organisations, and a former private medical practitioner in Sweden...
. (October 1, 2000). The Cholesterol Myths – Exposing the Fallacy that Saturated Fat and Cholesterol Cause Heart Disease. Newtrends. ISBN 978-0967089706. - Steinberg, Daniel. (September 24, 2007). The Cholesterol Wars – The Skeptics vs. the Preponderance of Evidence. Academic Press. ISBN 978-0123739797.