This title may sound surprising I must admit, but fat is essential for the body to optimum functionally and cholesterol is not the ‘bad guy’ everyone thinks he is. Fat, and even saturated fat plays a critical role in maintaining homeostasis (balance) within the body throughout our daily lives, as does cholesterol in preventing damage within our artery lining.
One reason I’m also going into the reasons fat is essential, is that many diets or foods tend to trend towards ‘low fat’ or ‘fat free’. Whilst this isn’t always a bad thing, being obsessed with avoiding fat certainly is due to the benefits fat provides which I will talk about later.
Types of Fats
There are two main types of fat:
- Saturated fats
- Unsaturated fats
- Monounsaturated fats
- Polyunsaturated fats
In addition to this, there are also transfats which are typically produced within the industry via a process known as hydrogenation and have been linked to heart disease.
Saturated fats are full of single bonds and so have a straight chain structure. Because of this, they require more energy to break. Typical examples would be butter and palm oil. These remain solid at a higher temperature than unsaturated fats such as olive oil due to this difference in their structure.
Other sources of saturated fats include:
- Red meat
- Whole-milk dairy products
Saturated fat has often been touted as unhealthy since it has been linked to raised levels of ‘bad’ cholesterol, aka LDLs (low density lipoproteins). This has been linked to cardiovascular disease. However, there is evidence contradicting this:
- The Masaai tribe in Kenya have a diet consisting of around 66% saturated fat (meat, milk and cattle blood).
- Inuit Eskimos in the Arctic have a diet where 75% of their energy intake comes from saturated fat (whale meat and blubber).
- The Rendille tribe in Kenya takes about 63% of their energy from saturated fat (camel meat, milk and blood).
- The Tokelau tribe in New Zealand consumes 60% of their energy from saturated fat (fish and coconuts).
All of these tribes have little mortality from heart disease and considering the huge amount of saturated fat their diet contains, it is hard to believe that high amounts of saturated fat can be linked to heart disease and that rather there is another cause.
In fact, human breast milk contains 54% saturated fat, how can it be bad for you considering breast milk provides the perfect nutrition for developing infants!
Why Cholesterol isn’t the Problem
One reason people avoid eating eggs is because of their cholesterol content. However, what people don’t realise is that 75% of your cholesterol is produced by your body, inside the liver – the other 25% comes from your diet. The body actually regulates cholesterol quite well – when your dietary cholesterol intake increases, the body produces less and when dietary cholesterol intake decreases, the body synthesises more cholesterol.
25% of the population are “hyper-responders” where dietary cholesterol will increase both LDLs and HDLs (bad and good cholesterol). However, the ratio of the two is not affected and the risk of heart disease is not increased.
Whilst some studies have shown that saturated fat raises blood cholesterol, these studies are generally short-term, only lasting a few weeks so not substantial conclusions can really be made.
Longer term studies have not shown an association between saturated fat intake and blood cholesterol levels apart from one, and even then the link was weak. A study in Japan found that after following 58,000 people for 14 years there was no direct causation between saturated fat intake and cardiovascular disease. In fact, an inverse association was found between saturated fat and stroke – those who ate more saturated fat had a lower risk of stroke.
But What about Blood Cholesterol Levels?
For those of you who are still wondering about the whole measurement of blood cholesterol levels well this was developed by a man called Ancel Keys in the late 1940s. In the blood test, you gather all the lipoproteins you can find – good, bad, low density, high density, very low density (whatever you want to call them now), and measured them all. Without knowing which lipoproteins he was measuring exactly, he created an equation to predict the effect of saturated and polyunsaturated fats on serum (blood) cholesterol levels.
Change in serum cholesterol concentration (mmol/l) = 0.031(2Dsf − Dpuf) + 1.5√Dch
[Where Dsf is the change in the percentage of dietary energy from saturated fats, Dpuf is the change in the percentage of dietary energy from polyunsaturated fats, and Dch is the change in intake of dietary cholesterol].
But don’t worry about that. The point is that now it has been accepted that dietary cholesterol intake has no significant impact on blood cholesterol levels. To quote the man, Ancel Keys who came up with this formula cited above:
‘In the adult man the serum cholesterol level is essentially independent of the cholesterol intake over the whole range of human diets.’ – Ancel Keys, paper in 1956
‘There’s no connection whatsoever between cholesterol in food and cholesterol in blood. And we’ve known that all along. Cholesterol in the diet doesn’t matter at all unless you happen to be a chicken or a rabbit.’ – Ancel Keys, Ph.D., professor emeritus at the University of Minnesota 1997.
The fact that the man who created the formula has said this himself shows that there isn’t much information to be gleaned from analysing blood serum levels.
The reason cholesterol has been linked to heart disease is because cholesterol is used when the inner lining of the artery is damaged in forming a blood clot. The body uses cholesterol to cover these lesions within the artery lining. If the inflammation is successfully resolved, the inflammation goes away as does the cholesterol and repair takes place. Most of the time, the inflammation develops and the cholesterol plaque is acted upon by macrophages (white blood cells) that oxidise the cholesterol to the point it takes up more space in the artery, thus slowing down arterial flow so that when it breaks loose it can more easily form a clot!
Many recent studies suggest that it is only when LDLs have oxidised that they pose a threat. What causes oxidation of LDLs? Free radicals – highly reactive molecules. The main cause of free radicals is transfats, cooking oils heated to a high temperature where they then become oxidised and processed foods such as cakes, pies, sausages and more. In the UK transfats aren’t regulated so much in foods products, but there has been a study to show that 7,200 lives could be saved with a transfat ban although in the UK it is thought that people are eating transfat within healthy levels. The main cause is more likely to be fast food, deep fried foods and preservatives found in meat and many processed meals. It’s those transfats and preservatives that allow a happy meal to look normal after being purchased, 6 years later!
The best way to counter free radicals is with antioxidants: eat plenty of vegetables, fruits, nuts, fish (you need those omega 3’s!) and obtain a wide range of nutrients from a variety of sources.
Whilst cholesterol is certainly a factor that people should take into consideration when thinking about their health, I would suggest not being so afraid of consuming sources of HDLs and limiting sources of LDLs.
In short, don’t be afraid to consume these foods as they raise HDL cholesterol whilst lowering LDL cholesterol:
- Fatty fish (we’re talking salmon, tuna, mackerel and the like which have high levels of omega 3 fatty acids).
- Nuts and seeds (packed with healthy unsaturated fats and antioxidants, just be careful not to overeat these as it is very easy to do so).
- Olive oil (and olives).
- Fibre rich fruit.
In order to try and keep cholesterol levels low from a dietary perspective try to limit:
- Processed meat (bacon, sausages, chicken nuggets etc…).
- Deep fried and packaged foods (e.g. chips and burgers).
- Cookies and sugary treats (these have been linked to higher levels of LDL cholesterol).
- Processed vegetable oils (when these undergo hydrogenation, it increases levels of transfats which increases LDL cholesterol levels).
- Refined grain products (the high glycemic index of these products lead to significantly higher risks of cholesterol).
- Alcohol (too much raises your blood pressure and triglyceride levels).
In my opinion, it is highly unlikely that the amount of dietary cholesterol you consume would affect this process considering how your body produces more or less cholesterol in the liver depending on your dietary intake of cholesterol. This means that the real cause of heart disease is inflammation in the arteries. I could go further into this topic of cholesterol, but I’ll save that for potentially another article and we’ll jump back to saturated fats!
Benefits of Saturated Fat
Saturated fats are required for the optimum functioning of your:
- Cell membranes
- Satiety (hunger)
- Bones (to accumulate calcium)
- Genetic Regulation
- Immune System
In addition, saturated fat has been shown to have the following effects:
1) Reduced Risk of Cardiovascular Disease
Saturated fat has been shown to reduce the levels of a compound called lipoprotein (a) that correlates strongly with risk for heart disease.
2) Stronger Bones
In order for calcium to be properly used within the bones, saturated fat is required. According to one of the leading research experts in dietary fats and human health, Dr. Mary Enig, Ph.D., you can justify having as much as 50 percent of the fats in your diet as saturated fats for this reason.
3) Improved Liver Health
Saturated fat has been shown to protect the liver from alcohol and medication such as drugs commonly used as painkillers for conditions like arthritis.
4) Healthy Lungs
To function properly, the lungs must be coated with a thin layer of lung surfactant (a substance which reduces the surface tension of the liquid in which it is dissolved). Ideally, lung surfactant is composed of 100% saturated fatty acids. By not obtaining enough saturated fats, your body is forced to replace saturated fatty acids used for lung surfactant with other types of fat. This makes the surfactant faulty and can potentially cause breathing difficulties.
5) Healthy Brain
Your brain is actually composed of mainly fat and cholesterol and out of the types of fat used in the brain, most of it is saturated fatty acids. Without sufficient saturated fat, your brain cannot function optimally.
6) Proper Nerve Signalling
Certain saturated fats such as those found in butter, lard, palm oil and coconut oil function directly as signalling messengers that influence metabolism. This includes critical roles such as the appropriate release of insulin to match your body’s needs.
7) Strong Immune System
Saturated fats play key roles in your immune system. Without sufficient saturated fatty acids, the ability of your white blood cells to recognise and destroy foreign invaders like viruses, bacteria and fungi is hampered.
My Thoughts on Saturated Fat and Cholesterol
With so much evidence to go against the common idea that saturated fat and cholesterol lead to heart disease, I think it’s quite surprising to find out that this is not the case. I feel there is sufficient evidence to back the idea that we need saturated fats and cholesterol, the biggest point being that human breast milk contains 54% saturated fat which tells me, that it is absolutely essential for optimal development.
Points being made against saturated fat and cholesterol have identified cholesterol as a link to increased risk of heart disease by blocking up the arteries rather than the cause which would be inflammation.
Did these facts and findings surprise you? Let me know what you think down below!