Saturated Fat: What’s The Truth?

We asked you for your health-related opinion of saturated fat, and got the above-pictured, below-described, set of results.

• Most recorded votes were for “Saturated fat is good, but only some sources, and/or in moderation”
  • This is an easy one to vote for, because of the “and/or in moderation” part, which tends to be a “safe bet” for most things.
• Next most popular was “Saturated fat is terrible for the health and should be avoided”
• About half as many recorded votes were for “I’m not actually sure what makes saturated fat different”, which is a very laudable option to click. Admitting when we don’t know things (and none of us know everything) is a very good first step to learning about them!
• Fewest recorded votes were for “Saturated fat is the best source of energy; we should get plenty”.

So, what does the science say?

First, a bit of physics, chemistry, and biology

You may be wondering what, exactly, saturated fats are “saturated” with. That’s a fair question, so…

All fats have a molecular structure made up of carbon, hydrogen, and oxygen atoms. Saturated fats are saturated with hydrogen, and thus have only single bonds between carbon atoms (unsaturated fats have at least one double-bond between carbon atoms).

The observable effect this has on them, is that fats that are saturated with hydrogen are solid at room temperature, whereas unsaturated fats are liquid at room temperature. Their different properties also make for different interactions inside the human body, including how likely or not they are to (for example) clog arteries.

See also: Could fat in your bloodstream cause blood clots?

Saturated fat is the best source of energy; we should get plenty: True or False?

False, in any reasonable interpretation, anyway. That is to say, if your idea of “plenty” is under 13g (e.g: two tablespoons of butter, and no saturated fat from other sources, e.g. meat) per day, then yes, by all means feel free to eat plenty. More than that, though, and you might want to consider trimming it down a bit.

The American Heart Association has this to say:

❝When you hear about the latest “diet of the day” or a new or odd-sounding theory about food, consider the source.

The American Heart Association recommends limiting saturated fats, which are found in butter, cheese, red meat and other animal-based foods, and tropical oils.

Decades of sound science has proven it can raise your “bad” cholesterol and put you at higher risk for heart disease.❞

Source: The American Heart Association Diet and Lifestyle Recommendations on Saturated Fat

The British Heart Foundation has a similar statement:

❝Despite what you read in the media, our advice is clear: replace saturated fats with unsaturated fats and avoid trans fats. Saturated fat is the kind of fat found in butter, lard, ghee, fatty meats and cheese. This is linked to an increased risk of heart and circulatory disease❞

Source: British Heart Foundation: What does fat do and what is saturated fat?

As for the World Health Organization:

❝1. WHO strongly recommends that adults and children reduce saturated fatty acid intake to 10% of total energy intake

2. WHO suggests further reducing saturated fatty acid intake to less than 10% of total energy intake

3. WHO strongly recommends replacing saturated fatty acids in the diet with polyunsaturated fatty acids; monounsaturated fatty acids from plant sources; or carbohydrates from foods containing naturally occurring dietary fibre, such as whole grains, vegetables, fruits and pulses.❞

Source: Saturated fatty acid and trans-fatty acid intake for adults and children: WHO guideline

Please note, organizations such as the AHA, the BHF, and the WHO are not trying to sell us anything, and just would like us to not die of heart disease, the world’s #1 killer.

As for “the best source of energy”…

We evolved to eat (much like our nearest primate cousins) a diet consisting mostly of fruits and other edible plants, with a small supplementary amount of animal-source protein and fats.

That’s not to say that because we evolved that way we have to eat that way—we are versatile omnivores. But for example, we are certainly not complete carnivores, and would quickly sicken and die if we tried to live on only meat and animal fat (we need more fiber, more carbohydrates, and many micronutrients that we usually get from plants)

The closest that humans tend to come to doing such is the ketogenic diet, which focuses on a high fat, low carbohydrate imbalance, to promote ketosis, in which the body burns fat for energy.

The ketogenic diet does work, and/but can cause a lot of health problems if a lot of care is not taken to avoid them.

See for example: 7 Keto Risks To Keep In Mind

Saturated fat is terrible for the health and should be avoided: True or False?

False, if we are talking about “completely”.

Firstly, it’s practically impossible to cut out all saturated fats, given that most dietary sources of fat are a mix of saturated, unsaturated (mono- and poly-), and trans fats (which are by far the worst, but beyond the scope of today’s main feature).

Secondly, a lot of research has been conducted and found insignificant or inconclusive results, in cases where saturated fat intake was already within acceptable levels (per the recommendations we mentioned earlier), and then cut down further.

Rather than fill up the newsletter with individual studies of this kind here’s a high-quality research review, looking at 19 meta-analyses, each of those meta-analyses having looked at many studies:

Dietary saturated fat and heart disease: a narrative review

Saturated fat is good, but only some sources, and/or in moderation: True or False?

True! The moderation part is easy to guess, so let’s take a look at the “but only some sources”.

We were not able to find any convincing science to argue for health-based reasons to favor plant- or animal-sourced saturated fat. However…

Not all saturated fats are created equal (there are many kinds), and also many of the foods containing them have additional nutrients, or harmful compounds, that make a big difference to overall health, when compared gram-for-gram in terms of containing the same amount of saturated fat.

For example:

1. Palm oil’s saturated fat contains a disproportionate amount of palmitic acid, which raises LDL (“bad” cholesterol) without affecting HDL (“good” cholesterol), thus having an overall heart-harmful effect.
2. Most animal fats contain a disproportionate amount of stearic acid, which has statistically insignificant effects on LDL and HDL levels, and thus is broadly considered “heart neutral” (in moderation!)
3. Coconut oil’s saturated fat contains a disproportionate amount of lauric acid, which raises total cholesterol, but mostly HDL without affecting LDL, thus having an overall heart-beneficial effect (in moderation!)

Do you know what’s in the food you eat?

Test your knowledge with the BHF’s saturated fat quiz!

Enjoy!

We asked you for your (health-related) view of ice baths, and got the above-depicted, below-described, set of responses:

• About 31% said “ice baths are great for the health; we should take them”
• About 29% said “ice baths’ risks outweigh their few benefits”
• About 26% said “ice baths’ benefits outweigh their few risks”
• About 14% said “ice baths are dangerous and can kill you; best avoided”

So what does the science say?

Freezing water is very dangerous: True or False?

True! Water close to freezing point is indeed very dangerous, and can most certainly kill you.

Fun fact, though: many such people are still saveable with timely medical intervention, in part because the same hypothermia that is killing them also slows down the process* of death

Source (and science) for both parts of that:

Cold water immersion: sudden death and prolonged survival

*and biologically speaking, death is a process, not an event, by the way. But we don’t have room for that today!

^{(unless you die in some sudden violent way, such as a powerful explosion that destroys your brain instantly; then it’s an event)}

Ice baths are thus also very dangerous: True or False?

False! Assuming that they are undertaken responsibly and you have no chronic diseases that make it more dangerous for you.

What does “undertaken responsibly” mean?

Firstly, the temperature should not be near freezing. It should be 10–15℃, which for Americans is 50–59℉.

You can get a bath thermometer to check this, by the way. Here’s an example product on Amazon.

Secondly, your ice bath should last no more than 10–15 minutes. This is not a place to go to sleep.

What chronic diseases would make it dangerous?

Do check with your doctor if you have any doubts, as no list we make can be exhaustive and we don’t know your personal medical history, but the main culprits are:

• Cardiovascular disease
• Hypertension
• Diabetes (any type)

The first two are for heart attack risk; the latter is because diabetes can affect core temperature regulation.

Ice baths are good for the heart: True or False?

True or False depending on how they’re done, and your health before starting.

For most people, undertaking ice baths responsibly, repeated ice bath use causes the cardiovascular system to adapt to better maintain homeostasis when subjected to thermal shock (i.e. sudden rapid changes in temperature).

For example: Respiratory and cardiovascular responses to cold stress following repeated cold water immersion

And because that was a small study, here’s a big research review with a lot of data; just scroll to where it has the heading“Specific thermoregulative adaptations to regular exposure to cold air and/or cold water exposure“ for many examples and much discussion:

Health effects of voluntary exposure to cold water: a continuing subject of debate

Ice baths are good against inflammation: True or False?

True! Here’s one example:

Winter-swimming as a building-up body resistance factor inducing adaptive changes in the oxidant/antioxidant status

Uric acid and glutathione levels (important markers of chronic inflammation) are also significantly affected:

Uric acid and glutathione levels during short-term whole body cold exposure

Want to know more?

That’s all we have room for today, but check out our previous “Expert Insights” main feature looking at Wim Hof’s work in cryotherapy:

A Cold Shower A Day Keeps The Doctor Away?

Enjoy!