A heart surgeon’s perspective on animal fat

I’m willing to bet you already have an opinion on this topic — or at least heard opinions from friends and family members. Because the type of fat you cook with has (somehow) become a polarizing health debate. Is animal fat good for you, or will it bring you one step closer to a heart attack?

This is a question I get all the time as a heart surgeon. If you follow me on X, you probably already know my thoughts. But rather than offer my opinions alone, I’ve gathered some research so you could come to your own conclusions. 

Here, I’ll explain the major differences between animal fats and plant fats, plus what studies have to say about their effect on human health.

A quick breakdown of animal fat vs plant fat

Human beings eat two different types of fat: animal fat and plant fat.

These are fairly dense topics with an incredible amount of research behind them. But in the spirit of keeping things brief, let’s take a short look at the relevant highlights.

Animal fats

Animal fat, as you may have guessed, is any cooking fat that comes from an animal. This includes butter, ghee, fish oil, and muscle fats like tallow (from ruminants), lard (from swine), and schmaltz (from poultry).

A few general differences between animal fat and plant fat:

• Animal fats are typically higher in saturated fat, which is why they’re more likely to be solid at room temperature. Just remember all cooking fats contain a unique ratio of saturated, monounsaturated, and polyunsaturated fat. Even tallow, for example, only contains ~50% saturated fat — the remainder is ~45% mono and ~5% poly).
• Animal fat contains fat-soluble vitamins that can be difficult to pull from other sources. For example, tallow may contain vitamins A, D, E, K, and B12, as well as conjugated linoleic acid (CLA), which may help reduce plaque buildup in the arteries. Pasture-raised, grass-finished animals tend to contain higher quantities of both.
• Most animal fat goes ‘rancid’ (is no longer edible) within a shorter period of time. Some fats like tallow and lard can be purified to store at room temp, but they won’t have the same shelf life as processed plant fats. 

Plant fats

Plant fats in this context refer to anything not derived from animals: seed oils like grapeseed and vegetable oils like canola are a few examples. 

Compared to animal fats, they are:

• Nearly always liquid at room temperature, since they’re higher in unsaturated fats. Exceptions here include coconut oil (which is nearly 80% saturated fat), and emulsions like margarine, which is combined with milkfat and aerated with nitrogen so it can stand at room temperature. 
• Typically more difficult to extract than animal fat and may require extreme processing to create a palatable product. This may contribute to oxidation (which we’ll get into later), as well as the destruction of certain vitamins and minerals. 
• Long-lasting at room temperature (much longer than most animal fats). 

Now that we have our terms in order, let’s take a closer look at animal fat and your heart. 

What the research says about animal fat and heart health

For decades, nutritionists proclaimed that eating animal fat was one of the quickest avenues to heart disease. But the more research we’ve done, the less certain this has become. We now have reason to believe that animal fat may be the superior option over so-called ‘heart-healthy’ alternatives — and that highly-processed plant fats could be a leading factor in heart disease. 

To summarize: studies show that plant fats lead to oxidative stress, which is a process that slowly damages the walls of your arteries. This damage ultimately leads to inflammation markers in the body, which disrupts cellular health and worsens metabolic function. 

I’ll let the evidence speak for itself:

• The MARGARIN study found that people eating high quantities of linoleic acid may have higher Fibrinogen levels, which can thicken the blood and increase the risk of clotting.
• Plant-based oils are high in omega six. High ratios of omega six to omega three may increase platelet aggregation (aka coagulation), which is a higher risk factor to the heart than high LDL alone.
• Seed oils may increase inflammation and oxidative stress. They may also lead to insulin resistance and worsen certain chronic diseases.

Speaking of the ‘boogeyman’ called saturated fat, you may have heard it’s a ‘bad’ fat that leads to heart disease. This, however, is a common misconception — the hypothesis that saturated fat is bad for your heart health has many weak correlations, and according to researchers, is not necessarily evidence based. 

And even if you do accept the idea that saturated fat is ‘bad for you,’ most animal-based saturated fat is composed of stearic acid. Studies show stearic acid reduces blood pressure and LDL cholesterol, improves heart function, and possibly reduces the risk of cancer.

I cover this more extensively in my guide to saturated fat. 

So is animal fat good for you?

In my opinion, absolutely. Because the research mostly speaks for itself. 

Plus, you’re more likely to eat animal fat alongside complete proteins like beef, which can help you feel fuller longer, improve blood sugar control, and decrease cravings and the desire to eat (especially when consumed with breakfast). 

You’re also much more likely to avoid highly processed foods that could worsen your metabolic health. It’s certainly possible to eat animal fat alongside or within processed foods, but the odds overall are much lower.

That’s not to say all plant-based fats are bad for you, though — pure olive oil and avocado oil are less processed than other alternatives, plus they offer more antioxidants that contribute to better metabolic health. Even a tablespoon of coconut oil per day could significantly increase HDL (good cholesterol) and balance triglycerides for those with symptoms of metabolic syndrome. If you follow a plant-based or vegan diet, this may be a good way to source less-processed forms of fat.

At the end of the day, we may agree to disagree. That’s something I can live with as long as you’re serious about reclaiming your metabolic health.

Still, I would encourage you to consider your own N = 1. Order some baseline blood panels to benchmark your health, then cut out all seed oil for 30 days. At the end of the month, get your lipids checked again. You might be surprised by what you find. 

Not sure which blood tests to order for this? You can start with my course covering lab work for metabolic health.