Science And Oil. The Whole Truth

Sometimes, in an effort to make things simple, we diminish them. Cooking oil and the simple axioms we’ve built around it are a fine example of this unerring human effort to make the world understandable at a glance. Here’s my own attempt to make a complex issue accessible to all of us. This is science and oil. The whole truth.

I’m a nutritional scientist – and I’d like to show you how I choose the oils that I cook with.

There are a lot of qualities that oil offers when we’re cooking. It has flavor, it lubricates ingredients and creates an anti-stick effect on hot metal surfaces. It conducts heat, traffics the flavor of other ingredients, causes glazing, frying and seals meats.

All of that matters. But what I want to draw your attention to today are the key considerations that I account for when determining the appropriateness and healthiness of cooking oils.

Oil’s Hard Problem

Fats & Flammatories

Refinement & Nutrient Death

Smoke Points & Cooking Temperatures

Oil’s Hard Problem

In science we have ‘Hard Problems’. These are problems that we’ve wrestled with for hundreds of years or more – like “how did the universe get here”.

In the science of nutrition we don’t yet have ‘Hard Problems’ because the field hasn’t been around long enough. But if we did, oil would be the owner of one of them. You see, oil is wonderful (as noted), but you have to be very careful how much of it you eat.

Why? Because oil, regardless of the type, has a Kilo Calorie ratio of 9kcal for every 1g of oil.

Just think about that for a moment. There are 15g of oil in a tablespoon, meaning every tablespoon contains 135 calories. That’s the calorie equivalent of four whole cucumbers, or half a cup of sorbet ice cream.

There’s just no getting around it – no matter how healthy an oil is, they all have the same kcal ratio. So moderation is a must if health is a part of the menu, because they’re such an energy dense material.

The guidance on fat is that the most beneficial health impacts of the substance are found in those who people restrict their intake to roughly 65 grams of fat per day.

For perspective, 65 grams of fat would be achieved in one day if you were to consume

1 Boiled Egg5 grams
half an Avocado9 grams
2 tbsp Peanut Butter14 grams
1 slice of Bread1 gram
Average Fast Food Burger36 grams

Only one of the items on the above list contains unhealthy fats. Can you guess which it is?

Fats & Flammatories

Oil is basically just fat.

But fats are not simple things. They’re macro-nutrients, and vital to our survival. They help in the absorption of certain fat soluble vitamins, like vitamin A, D, E and K. Fats are needed for the construction of cell membranes, blood clotting and even muscle movement.

You can’t live without them. In moderation.

The two main types of fats are the Saturated Fats and the Unsaturated Fats. Most oils contain a mixture of these. For a long time we thought that saturated fats were simply ‘bad’, but in moderated quantities they don’t seem to have a negative effect on health. Animal products, butter, dairy, coconut oil, cocoa butter and palm oil are all high in saturated fats.

Unsaturated fats fall into two broad categories – Monounsaturated Fats and Polyunsaturated Fats. These fats are ‘good fats’, within context. Seeds, nuts, avocados, oily fish like salmon or mackerel, vegetable oils, soya, green leafy vegetables, eggs, milks and yogurts all contain these fats.

Pro & Anti Inflammatories

But there’s something else hidden inside all of that fat – there’s pro-inflammatories and anti-inflammatories. That is, nutrients inside of various fats that cause your cells to experience inflammation or anti-inflammation. Omega 6 Type Fats, for instance, cause inflammation, while Omega 3 Type Fats cause anti-inflammation.

And this is where complexity rears its head – pro-inflammation and anti-inflammation can be thought of like the pH Balance in a swimming pool – the “correct” ratio of chemical acidity to chemical base depends on the situation. If you are having a pool-party with a bunch of kids, you adjust the chemical balance of the pool; if you’re going away on holiday for 3 weeks, you adjust it again. So too with your pro-inflammatory to anti-inflammatory dietary balance. Getting the ratio right is complex, in that there is so much we’re learning about how this balance can be tweaked to benefit various lifestyles.

For instance, you can help ‘tune’ your body to better endure a life with CVD (4 Pro-inflammatories for every 1 Anti-inflammatory), colorectal cancer or breast cancer (2.5 to 1), rheumatoid arthritis (3 to 1), asthma (5 to 1), etc.. What we can say broadly, however, is that the average Western dietary intake is too high, at no less than 16 Pro-inflammatories to every Anti-inflammatory, and that a balancing effect focused on an increase of Anti-inflammatories rather than a simple decrease of Pro-inflammatories will render the best health outcomes (and the most satisfying meals!).

To help simplify this, bear the following in mind

  • A ratio of 10:1 pro-inflammatories to anti-inflammatories is where we begin to see broad negative health effects
  • Pre-industrial populations ranged in their ratios of pro-inflammatory to anti-inflammatory consumption from about 4:1 and 1:4

A huge contributor to this fat-centric public health imbalance is oil, both in cooking and in junk food.

Refinement & Nutrient Death

Oils get refined for the best intentions. It prolong their shelf life, can diminish unpleasant flavors, reduce the rate at which it oxidizes, increase it’s smoke point and even alter the amount of inflammatories naturally present. It can even help to eliminate an oil’s allergens.

But how an oil is refined matters a great deal, for a few reasons.

The first reason is that oils aren’t just refined with heat, they’re refined with chemistry, and traces of the chemicals used in that process remain, and enter your body. Many of those chemicals are poisonous or carcinogenic. In industrial styles of refinement bleaching and deodorizing is all commonplace.

The second reason is that during refinement nutrients are destroyed by both the chemical and heat treatment that refined oils are subject to. So the upsides of consuming an oil diminish as its refined. After all, if there’s no nutrients in it, then its just a bunch of calories and a chemicals. Different nutrients breakdown at different temperatures.

So the simple rule is that the less refined an oil is the better it is for your health.

Oil Smoke Points & Cooking Temperatures

Smoke points are important. Taste, nutritional density and the presence of cancer causing ‘free radicals’ are all the results of heating your oil too much, and smoke points are one measurement of that.

To begin with, though, let’s try to understand what temperatures we’re typically going to be cooking at under different circumstances.

Boiling100 Celsius/212 Fahrenheit
Pan Frying120 Celsius/240 Fahrenheit
Deep Frying180 Celsius/356 Fahrenheit
Baking180 Celsius/356 Fahrenheit

So now that we know what temperatures we’re roughly cooking at, take a look at the table below. Don’t cook your oils above the temperatures listed, but be wary that oils also begin to ‘spoil’ when they are heated for long durations, or if they are heated and cooled repeatedly.

I’ve attempted to get as much of the information we’ve discussed in the previous sections entered into this table – as well as an indication of whether or not it’s an oil that features in my own cupboard (Embrace/Avoid).

Pro Tips

This information doesn’t just apply to the oils we cook with, it applies just as poignantly to the pre-made foods we consume. The potato chips, the hamburgers, the candy bars – they have these oils in their ingredients or they’ve been cooked in them by someone who wasn’t you.

Take back control of your food-chain and learn to love your kitchen. Check out my Recipes if you’re looking for something to put some oil in yourself!

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