Nutrition Myths
Saturated fat - is it really bad for you?

SUMMARY

  • There is no evidence that saturated fat causes atherosclerosis or heart disease.
  • Saturated fat foods provide more health benefits than health risks and should be part of a balanced diet.
  • However, you need to be cautious with some specific foods which are linked to cancer:
    • Processed meats – there is strong evidence that they are harmful;
    • Red meats – may be potentially harmful, but there is still no compelling evidence;
    • Dairy fat – too much can be harmful for men.
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Saturated fats have been part of our diet for hundreds of thousands of years.  They were only vilified 40 years ago for political reasons, rather than evidence based science.

Since 1977, dietary guidelines have been recommending a low-fat diet and the minimal consumption of saturated fat, despite the lack of scientific evidence of its negative impact on human health.

Find out what saturated fat is, why we still think that it is bad and the overall health impacts of consuming saturated fats.

What is saturated fat?

We commonly refer to saturated fats as all foods that contain significant amounts of saturated fatty acids. These foods include eggs, butter, chicken skin, barbecued pork ribs or highly processed smoked bacon.

Understanding the components of saturated fat is important and involves some basic chemistry.

The main types of fat found in foods are triglycerides, which are divided into saturated and unsaturated fatty acids.

Saturated fats, like any other fats, are not soluble in water, but unlike unsaturated fats, are solid or waxy in room temperature. (read more..)

Saturated fats are, for instance, the fatty components of meat, ghee, butter, or coconut butter.

Butter - saturated fat

Structure of Saturated fat

Saturated fats belong to a subcategory of lipids called glycerides, which are composed of a glycerol backbone and between one and three fatty acids.

Although there are molecules with only one or two fatty acids, the most abundant and significant glycerides in food and body tissues are the ones with three fatty acids, also known as triglycerides.

Triglyceride

In saturated fats, although some unsaturated fatty acids may be present, the saturated fatty acids dominate, giving them specific properties.

The saturated fatty acid is a molecular compound consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, arranged as a chain with hydrogen atoms attached to the carbon atoms.

The most commonly occurring chains have between 4 and 18 carbon atoms.

Saturated fatty acidFor comparison purposes, unsaturated fats have at least one double bond between the carbon atoms, making them more unstable.

For more details on the fat chemistry, read the article “Triglycerides – basic chemistry”.

MAIN POINTS

  • Saturated fat is not soluble in water and is solid in room temperature
  • Saturated fat consists of a glycerol backbone and a dominant amount of saturated fatty acids
  • Saturated fatty acids are a molecular compound with no carbon double bonds

Why saturated fat is commonly known as “bad fat”?

Our perception of the negative health effects of saturated fats have been shaped by four decades of dietary recommendations, based on unproven theory, and the ongoing promotion of anti-saturated fat diets.

The following is a brief summary of how we got to this point.

  1. Older studies showed that:
    • Saturated fat consumption increases the blood cholesterol level. (based on animal studies and short term controlled diet trials) (1)
    • High blood cholesterol is associated with atherosclerosis and an increased risk of developing heart disease. (observational studies) (2, 3)

  2. The “Diet-heart hypothesis” was formed

    Based on these findings and on several observational and animal studies, scientists  developed the Diet-heart hypothesis. (4, 5, 6)

    What does this hypothesis state?

    • A diet high in saturated fat increases the cholesterol level in blood. Let’s call it Hypothesis 1 (H1).
    • High levels of blood cholesterol increase the risk of developing heart disease. This is the Lipid Hypothesis. Let’s call it Hypothesis 2 (H2).
    • Conclusion: considering H1 and H2, it is, therefore, assumed that saturated fat increases the risk of developing heart diseases. (7)

    This was a sensible conclusion at the time. However, it was based on assumptions and actual studies that proved the direct cause and effect were not available.

    Not only this hypothesis has never been proven, but the recent, higher quality studies show that it is wrong. (8, 9)

  3. Political decision in the 1977s that changed our dietary habits to this date

    In the 1970s the U.S. government was under pressure to find a solution to the growing obesity and heart disease prevalence. (10)

    Due to the mounting pressure to tackle the increasing health problems and the lack of any solid evidence, the diet-heart hypothesis was considered “sufficient evidence” and accepted as the basis for the dietary guidelines.

    Click here to watch a short clip from Tom Naughton’s “Fat Head” documentary which shows the historical moment where politics took precedence over science.

    In 1977, dietary goals were established by the Senate Select Committee on Nutrition and Humans Needs.  (10)

    Dietary goals - USDA 1977

    In 1980, Dietary Guidelines for Americans were made public, based on these  recommendations.

    Updated dietary guidelines have been published every five years since 1980.

    All of them, including the latest Dietary Guidelines of 2015-2020, are still based on this unproven theory and continue to recommend limiting saturated fat intake.

  4. What was the result of this low-fat campaign?

    The government-backed anti-fat campaign gave the opportunity for inexpensive food commodities, such as corn (and HFCS), wheat, rice and potatoes, soybeans, industrial vegetable oils or sugar, to grow exponentially.

    Changes started to occur in the food industry, such as : (11, 12)

    • Whole foods, such as those from animals and other plants, became comparatively more expensive
    • The production of GMO (genetically modified organism) products escalated
    • The use of partially hydrogenated oils (high in trans fatty acids) in cooking increased (read more..)
    • Highly processed polyunsaturated oils started to be used more frequently
    • Sales of margarine (most of them high in trans fats) reached its peak in the late 1970s, which continued until the 1990s (read more..)
    • The consumption of refined carbohydrates, including sugars and starches, increased considerably
    • The consumption of unrefined carbohydrates increased significantly

    Overall, there was more focus on saturated fats and less focus on reducing consumption of sugar, which has proven to be the real culprit of heart diseases and the obesity epidemic.

  5. What do recent studies show?

    Recent studies have shown that there is no direct association between saturated fat and the increased risk of developing heart disease. (13, 14, 15, 16)

    Recent studies also show that intake of saturated fats is not associated with: (17, 15, 18, 19)

    – all cause mortality
    – cardiovascular disease related mortality
    – coronary heart disease related mortality
    – ischemic stroke related mortality
    – type 2 diabetes related mortality

    Here are the major findings that may explain this lack of association:

    • LDL (low-density lipoprotein) particles consist of various sizes, small and dense and large and fluffy. While the small and dense LDL particles are responsible for atherosclerotic formation, the large ones are not. (20, 21, 22)  
    • Not all saturated fatty acids increase the concentration of LDL particles. For instance, stearic acid found in chocolate has little effect on LDL and HDL blood cholesterol, while meristic acid found in dairy and beef increases both LDL particles and HDL particles. See saturated fat types table below. (23, 24)
    • Not all saturated fatty acids increase the levels of the large LDL particles. Some types have no impact on it at all. For example myristic and palmitic acid raises total cholesterol including LDL, while stearic acid lowers LDL particles or has neutral effect. See saturated fat types table below. (23, 25)
    • High saturated fat consumption increases the good HDL cholesterol levels. The HDL cholesterol is linked to a reduced risk of atherosclerosis. (1)

    NOTE: current standard lipid profile tests are inconclusive since they show (26, 22, 27):

    • A LDL-c reading which does not distinguish between small (bad) and large (benign) LDL particles
    • A total cholesterol reading which includes both HDL (good) and LDL (a mix of good and bad). (read more..)
  6. Currently, where are we at with the saturated fat controversy?

    The mainstream nutritional scientists still stand strong with their support of the diet-lipid-heart hypothesis. They still seem to be the majority.

    Governments and major health organizations continue to promote a low saturated fat intake and a low-fat diet.

    An increasing number of studies, however, show no association between saturated fat and heart disease. This movement is growing very rapidly and with the quality of the studies improving, we might see some changes in the next dietary guidelines.

    Nevertheless, good science sometimes is not enough. Other factors often play role in the decision-making process. (read more..)

MAIN POINTS

  • Increased levels of obesity and heart disease incidence forced politicians to turn the unproven diet-heart hypothesis into a doctrine.
  • 40 years of anti-saturated fat propaganda impacted our food choices and saturated fat officially remains a villain, even today
  • New developments in science have shown that the lipid-heart hypothesis was incorrect
  • More higher quality recent studies show no association between saturated fat and heart disease

Bad side of saturated fats

There is no evidence that saturated fat on its own causes health issues in healthy individuals.

Some foods rich in saturated fats, however, are linked with negative health effects. However, there is no evidence that these health impacts are necessarily related to the saturated fat component

The strength of the available evidence varies. Some studies show that these foods are a direct cause of cancers, while others only show an association still to be proven.

The following are the most researched foods containing saturated fats. These studies are mostly observational and epidemiological.

Processed meats

Processed meats

The evidence of the carcinogenic effects of processed meats is strong.

These highly processed products include mostly red meats, such as pork, beef, lamb, but also poultry, offal and products made of blood, such as sausages.

The processes include smoking, salting, curing or fermenting, which aim to improve the taste or prolong the life of the products.

We currently know that: (28, 29, 30)

  • Processed meats (high in saturated fat) increase the risk of developing bowel cancer.
  • A daily consumption of a 50 g portion of any processed meat results in an 18% increase in the risk of colorectal cancer risk.
  • Of all yearly cancer-related deaths in the world, it is estimated that 34,000 are due to eating processed meats. For comparison purposes, tobacco smoking causes about one million cancer deaths, alcohol consumption 600,000 and air pollution 200,000.
  • WHO considers the current evidence strong enough to classify processed meats in the same carcinogenic category (Group 1) as tobacco smoking and asbestos.

For all those reasons, it is advisable to limit or even avoid processed meat consumption.

But how does all of this relate to saturated fats?

The answer is that nobody knows. It is not currently known what mechanisms  make processed meats increase the risk of developing cancers. However, a few compounds are on the suspect list, such as N-nitroso and polycyclic aromatic hydrocarbons.

Red meats

Red meat

Unlike processed meats, there is limited scientific evidence that proves that red meat is associated with the risk of cancer.

There is some, although insufficient, evidence showing links between eating red meat and colorectal cancer, and weaker evidence pointing to pancreatic and prostate cancers.

If scientists were to find definite evidence that eating red meats causes colorectal cancer, it is estimated that for every 100g of red meat eaten, the risk of colorectal cancer would increase by 17% and of all cancer-related deaths in the world, 50,000 would be due to eating red meats. (31)

Currently, due to the lack of sufficient evidence, authorities cannot estimate the safe limits for red meat consumption. Therefore, choosing mostly fish and white meat and only eating red meat occasionally is the safest choice. 

Again, what is the role of the saturated fats?

Scientists still don’t know. The compounds suspected to increase the risk of cancer in red meat are heterocyclic aromatic amines and polycyclic aromatic hydrocarbons.

Milk and dairy products

Milk and dairy

Dairy products have both protective and harmful effects on our health. The protective effects are backed by robust evidence, and outweigh the harmful effects, backed by weaker evidence. (read more..)

There is limited evidence showing that high whole milk consumption increases the risk of prostate cancer and cheese intake increases the risk of bowel cancer. (32, 33, 34, 35, 36, 37, 38, 39)

There is no significant association between breast and ovarian cancers and dairy consumption. (40, 41, 42)

Although all the observational studies are not conclusive, these indications cannot be dismissed.

It may be not possible to conduct randomized controlled studies due to ethical reasons.

However, how does this relate to saturated fat?

The mechanism through which dairy products may be causing health effects is not known. It could be a consequence of a number of the different dairy components, not necessarily the saturated fat.

Life-long saturated fat diet

Although the ketogenic diet, when used for a short-term period, is effective in controlling and preventing many diseases, the health consequences of a life-long consumption of high amounts of saturated fat are not known. 

MAIN POINTS

  • There is no evidence that saturated fat necessarily has negative health impacts
  • There is a strong evidence that processed meats cause bowel cancer
  • There is an association between red meat consumption and cancer. However, there is no compelling evidence yet.
  • Dairy fat intake has shown to increase the risk of prostate cancer. Therefore, men are advised to eat less dairy fat.
  • Scientists don’t know which component or components of these products are responsible for the negative health effects.
  • We don’t know the impact of a life-long high saturated fat diet.

Good side of saturated fat

There are several proven benefits of using saturated fat in our diets. Please note that some of these benefits may be due to other constituents of saturated fat foods rather than the saturated fat.

  • They are a major source of energy (fat, including saturated fat is denser in energy per gram than carbohydrates and protein).
  • Dietary saturated fat provides the structural components of the cell membranes. (43)
  • Foods high in saturated fat, such as eggs, dairy, white meat, dark chocolate or coconuts, are very nutritious (rich in micronutrients, especially fat-soluble vitamins: A, D, E and K). Dairy and meat fat from ruminant animals fed on grass contain potentially beneficial type of trans fatty acids and high amount of omega-3 fatty acids.  (44, 45, 46, 47
  • Many saturated fat foods, such as meat and dairy, are a great source of good quality protein (containing the full range of essential amino acids). (48)
  • Due to its chemical structure, saturated fat is resistant to high heat and, therefore, the best choice in high heat cooking methods. (49). Please note that a diet based in high-heat cooking increases a risk of diabetes mellitus and cardiovascular diseases (50)
  • It is highly regarded from a culinary perspective – adds fantastic taste and texture to the food.
  • A high fat diet, including saturated fat, such as the Ketogenic diet is associated with weight loss and healthy weight maintenance. (51)

MAIN POINTS

  • Many saturated fat foods, such as eggs, dairy, white meat, coconuts and cocoa, are very nutritious and including them in our diet promotes good health.
  • These foods have great culinary properties, making our foods more palatable and improving their texture.

List of saturated fat foods

 The following is a list of the most common foods rich in saturated fats.

  • Biscuits/cookies
  • Cacao and chocolate
  • Cakes
  • Many crackers
  • Cooking margarine
  • Dairy foods, such as ghee, butter, cream, full fat milk, yogurt, ice-cream, and cheese
  • Eggs
  • Coconut oil, coconut meat, cream and milk, and shredded coconut
  • Lard and shortening
  • Meats – especially the fatty cuts of any meats, such as pork, beef, lamb, goat, chicken with skin and duck
  • Palm oil and palm kernel oil
  • Pastries
  • Pies
  • Potato chips
  • Take-out foods, such as deep fried and high fat foods

A comprehensive list of over 900 foods showing the saturated fat contents can be found in here: “List of foods and their fatty acid composition”

Foods that contribute to the highest saturated fat intake in the U.S. NHANES (52)

Food itemContribution to intake (%)
Regular cheese8.5
Pizza5.9
Grain-based desserts5.8
Dairy desserts5.6
Chicken and chicken mixed dishes5.5
Sausage, franks, bacon, and ribs4.9
Burgers4.4
Mexican mixed dishes4.1
Beef and beef mixed dishes4.1
Reduced fat milk3.9
Pasta and pasta dishes3.7
Whole milk3.4
Eggs and egg mixed dishes3.2
Candy3.1
Butter2.9
Potato/corn/other chips2.4
Nuts/seeds and nut/seed mixed dishes2.1
Fried white potatoes2

List of saturated fatty acid types

Foods containing the types of saturated fats that raise the LDL particles in blood, also contain other fats that offset these effects. The effects on LDL or HDL are compared to carbohydrates and unsaturated fat intake. (53, 54, 55, 56, 57, 58, 59)

Saturated fatty acid (no. of carbon atoms)Consumption as a % of all saturated fatsEffect on LDLEffect on HDLFood sources
Palmitic acid55%raises (predominantly large benign LDL)negligentpalm kernel oil, butter, red meat, salmon, cocoa butter, lard, egg yolks, cashews, coconut oil
Stearic acid25%lowers slightlystudies show inconclusive resultscocoa oil, meat and butter, egg yolks, palm kernel oil
Myristic acid9%raises more than other saturated fat types (predominantly large benign LDL).negligentcoconut oil, Palm kernel oil, butter, red meat
Lauric acid3%negligentraises considerably, more than other staturated fatty acidspalm kernel oil, coconut oil
Butyric acid2%negligentnegligentbutter, cheese
Capric acid2%negligentnegligentgoat's milk, palm kernel oil, coconut oil
Caproic acid1%negligentnegligentgoat's milk, coconut oil
Caprylic acid1%negligentnegligentgoat's milk, coconut oil
Other3%negligentnegligent

Final note

Foods containing saturated fats are very nutritious and have a great culinary value. Their saturated fat component generally doesn’t pose health risks. However, specific foods have shown to increase the risk of some diseases.

To insure optimal health, avoid processed meats, reduce red meat consumption, and for men reduce  dairy fat intake.

The saturated fat foods that are safe to consume are eggs, white meat, cocoa, coconuts and dairy (in moderation for men).

While a high saturated ketogenic diet has shown to be effective in weight loss, type 2 diabetes and the blood lipid profile, its long-term health consequences are still unknown.

If you need to improve you heart health eat more omega-3 fatty acid foods in place of saturated fats. There is plenty of evidence that Omega-3 fatty acids have heart protective properties.

Replacing saturated fats with refined carbohydrates may increase the risk of heart disease. Low fat/high carbohydrate diet reduces HDL and increases triglycerides in blood increasing risk of cardiovascular disease. (60, 5)

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