Plant-Based Fats vs. Animal-Based Fats: What's Better? (2024)

Written by Emma Symonds, BBSc (Hons), PhD(c)Medically reviewed by Clara Fergus, RD on May 3, 2020 —

Last updated on March 25, 2021 at 12:07 pm

Plant-Based vs. Animal-Based? Diet advice is always a minefield! Is it better to cut down on carbohydrates, or is eating too much fat the cause of our high rates of heart disease? Fortunately, modern nutritional science gives us a great picture of what happens in the body when we eat certain kinds of foods.

In the past, nutritionists advised people to avoid eating fats to avoid heart disease. But now, scientists know that fat can be part of a healthy diet—as long as the fats are the right kind.

Plant-based fats and animal-based fats are very different. While eating too much butter and bacon may increase your risk of heart disease, plant-based fats can help you live a longer and healthier life.

What Are Dietary Fats?

Along with carbohydrates and proteins, fats make up one of the three main classes of macronutrients that provide most of the energy in our diets. Fats contain 9 calories per gram, while protein and carbohydrates have 4 calories per gram, making fats the most calorically dense macronutrient.

Chemically, dietary fat is made up of ‘triglyceride’ which is the backbone of the structure that up to three fatty acids can be attached.

These fatty acids contain most of the chemical energy within fats. The bulk of a fatty acid consists of a hydrocarbon chain. These vary in length and may contain one or more double bonds along its length. These bonds create bends along the chain.

Unsaturated fat molecules take up more physical space and can’t pack together as densely as saturated fats. That’s why unsaturated fats are often liquids at room temperature, such as seed and plant oils like olive oil, unlike saturated fat sources such as butter or coconut oil.

These chemical differences also affect how fats break down in the body, which means that different kinds of fats have different nutritional properties and impact the body in different ways.

Are Fats Bad for Your Health?

Dietary fats are an important part of any healthy diet. Fat helps give your body energy, supports cell growth and fats also help your body absorb certain nutrients, and produce key hormones. That said, too much fat and especially too much of the wrong kind of fat can be harmful.

For decades, nutritional science was dominated by the diet-heart hypothesis. This explains that a high-fat diet elevated serum cholesterol levels, increasing your risk of certain heart diseases.Cholesterol is a type of fat that can be produced by your liver or consumed from certain foods.

While a little cholesterol is essential to your body’s function, too much can lead to an increased risk of coronary heart disease. The European Guidelines on cardiovascular disease prevention refers to a conclusive body of evidence on this (1). However, different fats react to the body in different ways which are where plant-based fats come in.

Healthy Plant-Based Fats

More recently, scientists and nutritionists realized that the diet-heart hypothesis wasn’t entirely accurate. One review reflected on what we now know about dietary fats, showing that, not all fats and cholesterols have negative health impacts (2).

How Do Saturated Fats Affect Cholesterol?

Not all forms of cholesterol are created equal. Cholesterol is transported around the body by lipoproteins, and different kinds of lipoproteins take cholesterol to different places.

High-Density Lipoprotein (HDL) binds cholesterol and takes it to the liver to be processed and removed from the bloodstream. Low-Density Lipoprotein (LDL) takes cholesterol to the arteries, where studies show that it can build up and increase your risk for diseases like atherosclerosis and atherothrombosis (3).

Evidence has shown again and again that saturated fatty acids increase blood concentrations of LDL (4). There are a few reasons for this. LDL is usually removed from the blood by a protein called the LDL receptor.

Starting with a 1996 study, scientists began to realize that saturated fats in the diet led the body to produce less and less of this important protein, making blood levels of LDL go up (5).

Saturated fats also change how your DNA is used to make different enzymes involved in the digestion of fats. A study in the Current Opinion in Lipidology journal showed that saturated fats in the diet change how four families of transcription factors are expressed (6).

These are proteins that affect gene expression, changing the way your DNA is used to manufacture different enzymes involved in the biochemical pathways used to produce LDL and HDL.

Plant-Based Fats vs. Animal-Based Fats

A systematic review in the American Journal of Clinical Nutrition in 2003 compiled a wealth of evidence to conclude that plant-based diets could have a range of health benefits, from a reduction in cardiovascular diseases to improved mood (7).

A large part of this is due to the difference between plant-based fats and animal-based fats. First and foremost, plant-based fats are much more likely to be unsaturated when compared to animal-based fats.

Plant-based foods that contain fats include avocados, nuts and seeds, and nut and seed oils. But that doesn’t mean there aren’t plant-based sources of saturated fats too.

Tropical oils, such as palm and coconut oil, are very high in these fats.Yet overall, a plant-based diet provides more of the kinds of fat you need for good health.

A 2002 review of 147 original clinical and epidemiological studies showed that consuming a greater proportion of your diet from plant-based sources substantially reduces the risk of heart disease (8).

A large part of this effect was attributed to a reduction in trans and saturated fats and an uptick in unsaturated fat intake.

Are All Unsaturated Fats the Same?

Simply saying a fatty acid is saturated or unsaturated does not provide enough information to determine its health effects.

Take monounsaturated fats, for example. As opposed to polyunsaturated fats—those omega-3 and omega-6 fatty acids—monounsaturated fats are found in both plant-based and animal-based sources.

Two major studies, the Nurses’ Health Study and the Health Professionals follow-up study have collected extensive datasets over more than 22 years regarding the link between diet and heart disease (9).

This data has shown that monounsaturated fats from plant-based sources were associated with a lower mortality rate from heart disease, while those from animal-based sources increased the subjects’ risk.

These studies accumulated a large pool of data and used robust methodologies to determine their conclusions.

However, it is important to note that the dietary percentages of plant-based and animal-based monounsaturated fatty acids were calculated from the subjects’ responses to questionnaires by mail, and as such, were subject to certain biases.

Omega-3 and Omega-6 Fatty Acids

Plant-based foods, along with fish, are also the major source of polyunsaturated fats in a diet.Two of these fatty acids, alpha-linolenic acid, and linoleic acid, are unable to be synthesized within the body.

As a result, they are considered essential dietary nutrients. Polyunsaturated fatty acids are often classified by the position of the first double bond, which is where the familiar terms omega-3 and omega-6 originate.

You’ve probably heard that omega-3 fats have health benefits, but omega-6 fatty acids are also important. A major review found that diets high in all kinds of polyunsaturated fats are strongly correlated with a reduced risk for coronary heart disease and strokes (10).

While omega-6 fatty acids are important, most people consume far more omega-6 than omega-3 in their diets, which is not good for your health and may promote inflammation. That’s why it’s important to consume a balance of omega-3 and omega-6 fatty acids.

Omega-3 fatty acids can be found in plant-based foods too. One of the best sources of these fats is chia seeds. A 2007 study showed that a diet high in chia seeds both increased omega-3 levels in the blood and improved the ratio of HDL cholesterol to LDL (11), a cholesterol ratio associated with a lower risk of heart disease.

Fat Consumption Around the World and Heart Disease

In 1970, an epidemiological study compared the prevalence of coronary heart disease in seven countries (12). Countries on the Mediterranean sea were found to have a lower rate of heart-related conditions, and the difference couldn’t be explained by other known risk factors such as smoking.

In retrospect, this makes sense. Traditionally, people living near the Mediterranean Sea consume the majority of their fat calories from plant oils, particularly olive oil, and from fish. These oils are high in monounsaturated fats, and fish contain healthy omega-3 polyunsaturated fatty acids.

In contrast, studies of the average American diet show that Americans consume a majority of their fat calories as trans-saturated fats from hydrogenated vegetable oils and other saturated fats from meat and other animal products (13). This results in a higher rate of heart disease, cancer, and other health conditions.

Plant-Based Foods with Healthy Fats

If you’re looking to include some plant-based foods, here are some options:

Avocados
Nuts, including peanuts, cashews, almonds, and macadamia nuts
Seeds, including flax, chia, hemp, pumpkin, and sesame seeds
Vegetable and seed oils, especially olive oil

As shown by the Mediterranean diet, a healthy-fat diet doesn’t mean that you need to avoid all animal products, either. Seafood such as salmon is a great option to supplement a plant-based diet since it contains a high proportion of omega-3 polyunsaturated fats.

Are All Plant-Based Fats Healthy?

It is not true that all plant-based fat sources are healthy, or that all animal-based sources are not. French fries are a plant-based source of fats but aren’t great for your heart.

There are also plenty of plant-based sources of saturated fat. Coconut oil contains around 87% saturated fat, according to the USDA (14). Palm and palm kernel oils are also plant-based sources of saturated fats.

It is important to be aware of how plant-based fats have been processed.

Vegetable oils are commonly hydrogenated to produce margarine. In this process, unsaturated fats are saturated by pumping hydrogen gas through them in the presence of a catalyst. This results in double bonds along the fatty acid chain being saturated by the addition of hydrogen.

When unsaturated fats are partially hydrogenated, some of the remaining double bonds are converted into a configuration known as trans.

Trans and cis refer to the placement of the atoms surrounding double bonds: on the same side for trans, and the opposite side for cis. Given that most fatty acids in nature are in the cis configuration, trans fats create significant problems for our bodies during fat metabolism.

A comprehensive review in 2011 found that along with being the class of fats most associated with increased risk for heart disease, trans fat consumption was also correlated with nervous system diseases, cancer, diabetes, allergies, and other health conditions (15).

The Best Way to Eat Healthy Fats

A plant-based diet is a great way to consume more of the healthy kinds of fats. Nuts, seeds, and their oils are a great way to start.

Plenty of fresh fruits and vegetables can also provide these fats, while also contributing many other kinds of macro and micronutrients needed to protect against cardiovascular diseases and other health conditions.

Chia seeds, brussels sprouts, flaxseeds, and walnuts are also great to include in your diet because they all contribute omega-3 fatty acids that are essential for your body.

Of course, animal-based fats can have a role in your diet too. Fish is the best source of omega-3 fatty acids, even when compared to plant sources. Additionally, other meats and dairy products contain plenty of unsaturated fats.Red meats, processed foods, and deep-fried foods are high sources of saturated fats and are best kept to a limited quantity in your diet.

Most importantly, avoid trans fats. Butter may be high in saturated fats, but it doesn’t contain the same kinds of fats as margarine. This is because trans fats seldom occur in nature and are only present in partially hydrogenated fats.

Thankfully, many countries around the world have put into place legislation restricting the use of hydrogenated trans fats in food products such as margarine, but it’s still worthwhile to check the label of the food products you buy to ensure you’re not buying something with trans fats.

You can use a simple piece of common sense: whole, unprocessed foods are almost always a healthier choice than highly processed products.

The Bottom Line

While it isn’t true that all plant-based fats are healthy and all animal-based fats are unhealthy, it’s a good rule of thumb to follow.

Most people can experience better cardiovascular health when replacing animal fats with fats from plant-based sources. But this doesn’t mean that you need to give up animal products altogether. Some animal fats, like those found in seafood, are among the healthiest.

Replacing some of your red meat and dairy with seeds, nuts, vegetables, and plant oils can help you reduce your risk of heart disease, along with a list of other health conditions.

As part of a balanced diet, there’s nothing at all wrong with eating fats as long as they’re the right kind and you do so in moderation.