Saturated Vs Unsaturated Fat For Cooking

Saturated fats have largely been demonized in the media and scientific community. Often they’re mentioned in studies as being linked to various disease risk factors. One big caveat of many of these studies is that they don’t control the ‘saturated fat’ directly.

I’m not saying that unsaturated fats are unhealthy, I’m just saying that saturated fats aren’t necessarily unhealthy and there’s a good argument for why we should eat more saturated fat and less of the unsaturated fat which is present in the vegetable oils most people cook with. 

Isn't Saturated Fat Unhealthy?

Many studies looking at saturated fat with often correlate saturated fat with increased biomarkers for disease risk. There’s plenty out there suggesting we should be reducing our intake of saturated fat. And perhaps we should, if it’s coming from fast food which has been deep fried in vegetable oil.

However, what many of these studies lack is proper isolation of the ‘saturated fat’ risk factor. In many cases, when vegetarians are compared to the normal population, they tend to be healthier. I’m not saying they’re not healthier – but in these instances, those who eat fast food burgers and don’t pay too much attention to exercise are probably going to be less healthy than a group of vegetarians who are more conscious about their food choices and spend more time exercising, looking after their bodies.

Furthermore, there’s a big difference from obtaining saturated fat from processed foods and obtaining it from a source of meat where it is naturally occurring. And let’s take burgers for example. People think about the saturated fat in burgers, but what about all the other components added to the burgers which could add to the risk? Different additives and synthetic ingredients. What about the vegetable oil the burger is being fried in? Could that play a risk?

Saturated Fat Was Present In The Human Diet

I certainly don’t think we should be trying to remove saturated fat from the human diet. About 60% of the human brain is fat, around 50% of our cell membranes and is found naturally in meat.

Saturated fat intake has been associated with decreased dementia risk. Since dementia is associated with cognitive decline, that tells me it’s important for brain function. Some studies also point to how saturated fat may reduce risk of disease, such as coronary heart disease.

All this information makes me very certain that we’re supposed to eat saturated fat. In fact, I worry to think about raising an infant on a diet without saturated fat. 50% of fatty acids in human breastmilk are made of saturated fatty acids. If that doesn’t tell you it’s essential, I don’t know what will.

Chemical Structure Of Saturated And Unsaturated Fats

Saturated fats and unsaturated fats are both made up of a glycerol molecule attached to anywhere between one and three fatty acid chains. These fatty acids can be saturated or unsaturated. If the fatty acid is saturated, that means it contains no double bonds. In other words, it is rigid and inflexible. Monounsaturated fatty acids contain one double bond whilst polyunsaturated fatty acids contain two double bonds or more.

Generally speaking, the more double bonds a fat has, the lower its melting and boiling point. This is why many unsaturated fats such as vegetable oil, sesame oil, sunflower oil and canola oil are liquid at room temperature. Saturated fats on the other hand such as lard, butter and coconut oil are solid at room temperature.

Problems With Vegetable Oils

Due to the double bonds in unsaturated fats, they tend to be more unstable when cooking. Combined with a lower melting/boiling point, this means they oxidise far more easily during cooking at high temperatures compared to saturated fats.

This generates harmful by-products called free radicals which we can end up inhaling (from vegetable smoke) or ingesting through our food. These free radicals cause damage and inflammation to the body.

Vegetable oils oxidise when exposed to heat, light and other chemical inputs. Some are so unstable that preservatives have to be added to them to make them more stable. When exposed to light and heat, these vegetable oils can actually breakdown to form trans fats and lipid peroxides. These two by-products are linked to development of cardiovascular disease, type 2 diabetes and DNA damage.

Furthermore, if you’re buying fast food, these oils are typically used in large quantities and repeatedly reheated. That means more of these harmful by-products are being generated as the unsaturated fat in vegetable oils gets more and more unstable and becomes further oxidised.

Vegetable oils also contain a large amount of omega 6 fatty acids. It is thought that humans should consume omega 3 and omega 6 fatty acids in a ratio of somewhere between 1:1 and 1:4. The typical person consumes a ratio of 1:20 or higher which is a big evolutionary mismatch. Such large quantities of omega 6 fatty acids can cause inflammation in the body (even counteracting the positive benefits of omega 3 fatty acids) and since vegetable oils contain almost solely omega 6 fatty acids, this makes them a poor choice.

Whilst some vegetable oils will say ‘contains omega 3 fatty acids’ these are usually in the form of ALA or EPA. The body tries to convert these into the form found in fish which is DHA, but the conversion process is largely inefficient, with studies finding the conversion to be generally less than 5%.

Fatty fish and fish oil are your best source of DHA. It’s hard to find a good substitute for these.

What Fat Should You Cook With?

Here’s what makes sense to me. When cooking, if possible, try to limit the addition of fat to your meals. If it’s there e.g. part of your chicken thighs or ribeye steak, then let it be there and eat it, but if it’s not you should limit your addition of the fat to the meal unless perhaps you’re consciously trying to increase your fat intake for bulking or are on a particularly high fat keto diet (note that keto is more about lower carb than it is about high fat).

Where you don’t need to add that to your meal, don’t if possible. It adds extra calories which are generally better spent elsewhere. There are many recipes where you can avoid using fats for cooking such as those involving steaming, baking, poaching and cooking food in a type of sauce.

Use The Fat On Your Meat

If the meal you’re cooking is going to contain some fat, use that fat to cook your meal. If not then, I would try to use a type of saturated fat that complements the meal e.g. coconut oil for a Thai green chicken curry or use very limited amounts of unsaturated fat.

For example, if I’m cooking eggs, I might add a slice of bacon before I cook my eggs. The bacon contains fat on it which leaks onto the frying pan preventing the eggs from sticking to the pan when I cook them straight after the bacon. If I'm cooking some scrambled eggs and I plan on having bacon, I'll make sure to cook the bacon before the eggs so I can use the fat the bacon provides to stop the egg sticking to the pan. It also provides more flavour!

It’s also worth noting that olive, avocado and nut oils tend be different to your typical vegetable oils in the amount of processing they undergo. These tend to be safer to consume and if you’re using olive, avocado or a nut oil as a salad dressing, then you aren’t exposing it to the same heat that it would be subjected to on a frying pan.

Generally, The Less Processed, The Better

As a general rule, the less processed the fat you’re cooking with the better. If you’re using vegetable oils try to keep the stored away from light, in a cool environment, in dark bottles to limit oxidation from occurring.

When it comes to cooking fats, I think it's best to stick to the following:

• Animal fat that comes with your meat

• Lard

• Tallow

• Butter or ghee

• Coconut oil

• Olive oil (primarily for salads)

• Avocado oil (primarily for salads)

Richard Laursen is a contributing writer to Sapien.org. In his free time he likes to run and optimise his diet to fuel his athletic ambitions. You can follow more of his work at runrich.co.uk.

References

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Can adults adequately convert alpha-linolenic acid (18:3n-3) to eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3)?

Dietary Fats and Health: Dietary Recommendations in the Context of Scientific Evidence

Dietary fat intake and the risk of coronary heart disease in women.

Efficiency of conversion of alpha-linolenic acid to long chain n-3 fatty acids in man.

Essential fatty acids and human brain.

Evidence from randomised controlled trials did not support the introduction of dietary fat guidelines in 1977 and 1983: a systematic review and meta-analysis

Health Implications of High Dietary Omega-6 Polyunsaturated Fatty Acids

Omega-6 fatty acids and inflammation.

Saturated Fats: A Perspective from Lactation and Milk Composition

The importance of the ratio of omega-6/omega-3 essential fatty acids.