The human body cannot function optimally without dietary fats. In this article, For Life spoke to endocrinologists Dr Daniel Wai from Daniel Wai Diabetes Thyroid & Hormone Clinic and Dr Ben Ng from Arden Endocrinology Specialist Clinic on dietary fats as well as listened to their takes on the latest health fad – coconut oil.

Q: Why do we need to have fat in our diet?

Dr Daniel Wai from Daniel Wai Diabetes Thyroid & Hormone Clinic

Dr Daniel Wai from Daniel Wai Diabetes Thyroid & Hormone Clinic

Dr Wai: Fats perform many essential roles in our bodies. Their primary role is providing energy. Fat has nine calories per gram, more than twice the number of calories in carbohydrates and protein, which only have four calories per gram. During exercise, your body uses energy or calories from carbohydrates but after around 20 minutes it uses up all the carbohydrate energy or glucose stored in the blood and muscle tissues and starts using energy stored as fat.

Fat is essential to maintain the membranes of all the different cells that make up your body. It keeps your skin and hair healthy and helps us absorb vitamins A, D, E, and K, the so-called fat-soluble vitamins. Fat also fills your fat cells and insulates your body to help keep you warm.

The fats your body gets from your food give your body essential fatty acids called linoleic and linolenic acid. They are called “essential” because your body cannot make them itself, or work without them. Your body needs them for brain development, controlling inflammation, and blood clotting.

Q: What would happen to our bodies when we completely eliminate fat from our diets?

Dr Wai: Cutting fat out altogether can do serious harm to your body. Eating no fat can disrupt your hormone levels, weaken your bones, and cause dry skin, eczema and other skin conditions. It can also impair your digestion and kidney function and weaken the immune system. In severe cases of fat deficiency, organ failure and death result.

Without fat you can’t absorb the fat-soluble vitamins A, D, E and K. Lack of vitamin A can lead to poor night vision and eventually blindness. Vitamin K is needed for blood clotting. The severe lack of vitamin D can cause diseases such as rickets in children and weak bones in adults. Vitamin E deficiency can also cause problems with vision and lead to muscle weakness.

Q: What is the latest research on the following types of trendy fat and how should they be included in our diets? What do you think about avocado, olive oil, coconut oil, fish oil?

Dr Wai: I think in general the medical fraternity, and certainly myself as an endocrinologist, now believe that the excessive amounts of sugar in our modern diets combined with our sedentary lifestyles are bigger risk factors than most dietary fats, with the exception of manmade trans fats. In fact a recent paper published in the Lancet (Volume 390, No. 10107, p2050–2062, 4 November 2017) concluded that:

“High carbohydrate intake was associated with higher risk of total mortality, whereas total fat and individual types of fat were related to lower total mortality. Total fat and types of fat were not associated with cardiovascular disease, myocardial infarction, or cardiovascular disease mortality, whereas saturated fat had an inverse association with stroke.”

There is certainly plenty of scientific evidence to support increasing the amounts of healthy oils such as avocado, olive oil, and fish oils and even coconut oil, especially as there are now refined coconut oils available that have removed the SCT and left only the MCT.

I would suggest people worry less about how much fat they eat and more about how much sugar and refines carbohydrates as they consume. Avoid processed foods as much as possible and eat more whole and natural foods including fats and oils. But remember, if you are consuming more calories than you are expending, regardless of how healthy the foods are that you are eating, you will put on weight, and being overweight and obese are linked to practically every major health issue from diabetes to heart disease and even cancer.

Q: How would you advise the public to eat their dietary fat? What is the healthier way of consuming fats that are essential to us?

Dr Wai: Have a healthy, balanced diet; ie, eat a range of natural fats and oils, mainly from fish, nuts seeds and grains but also including some from meat and dairy products. Try not to eat too much fried food and try not to fry food at high temperatures or re-use frying oil. Be sure to use suitable oils with high smoke point temperatures for frying.

For example, MCT and olive oil are great on salads but not suitable for deep-frying, for the latter use something like sunflower oil. You can make salads tastier and healthier by adding oily foods like nuts and avocado and dressing them with a healthy oil such as MCT oil

Q: Recently, coconut oil has become popular as it has been said to have benefits from managing weight loss and diabetes to staving off dementia. What is your take on this?

Dr Ben Ng from Arden Endocrinology Specialist Clinic

Dr Ben Ng from Arden Endocrinology Specialist Clinic

Dr Ng: Coconut oil contains several different kinds which we call triglycerides. We classify triglycerides as either short chain (SCT), medium chain (MCT) or long chain (LCT), depending on the number of carbon bonds in their chemical structure. The different types of triglycerides each work differently in the body. Basically the longer the chemical chain in the triglyceride the harder it is for the body to metabolise and use for fuel, and the more likely it is to be stored as body fat. However MCT fats are much more easily metabolised and there is a growing amount of research to indicate they have potential health benefits.

Most fats like LCTs take a long time to metabolise because they have to pass through the stomach and be processed through several different chemical changes in the intestines and lymphatics before reaching the blood system and being transported to the liver. MCTs are different because they don’t have to pass through the intestines and skip many of those steps. They are absorbed directly from the stomach into portal vein and taken straight to the liver where they are very quickly turned into fuel in the form of ketones.

So, coconut oil will increase your good (HDL) cholesterol levels because of the MCTs it contains but it also increase the (LDL) cholesterol levels because of all the LCTs.  So coconut oil itself is not good for managing cholesterol because the desired objective of cholesterol management is to reduce LDL and increase HDL. A better option for cholesterol control would be a pure MCT oil.

Q: How does MCT oil help with weight loss?

Dr Ng: The science indicates that it is the MCT in coconut oil which helps with weight loss through its thermogenic properties, which allows the body to burn more fat as fuel.

A study in 2016 compared meals containing Medium Chain Triglycerides (MCT) with Long Chain Triglycerides (LCT) and all found a statistically higher thermogenesis with meals containing MCT rather than meals containing LCT. (1.)

The LCT component of coconut oil might actually have the opposite effect because as we saw before it is harder for the body to break down and use for energy, and any LCT not used as fuel is stored as body fat. In comparison, MCT is easier and quicker for the body to burn as fuel and research indicates that it also improves the body’s ability to convert other kinds of fats into fuel as well. Which incidentally also makes it a good source of fuel for athletes or anyone wanting to exercise harder

Q: Another popular claim is that coconut oil can improve mental acuity, boost alertness and maybe even help stave off dementia, is there any truth to that?

Dr Ng: The improvement in mental performance also seems to be because of MCT and not LCT. Research has demonstrated that MCTs can cross the blood-brain barrier (BBB) to be used by the brain as fuel in the form of ketones. The ability of MCT to fuel the brain is currently attracting a lot of attention from researchers working in the fields of dementia and Alzheimer’s disease.

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