Confused about fats and oils…...which are the healthiest?

Fats and oils play a very important role in our health, contrary to popular belief. Understanding the different types of fats and oils available to us and their health benefits or risks is key to preventing metabolic diseases such as obesity, high blood pressure, type 2 diabetes and heart disease. We look at the roles that saturated and unsaturated fats and oils play in our health and the different types of fats and oils that fall into each category.

Why we need fats and oils in our diet

Dietary fats and oils are important to include in a healthy eating pattern, as they play an essential role in our health and in the optimal functioning of our body. Fats are one of the three macronutrients we need to provide energy (37kJ/g), along with carbohydrates and protein. Aside from the importance of providing energy, dietary fats also:

Are essential for growth and development
Carry and help absorb the fat soluble vitamins A, D, E and K, and fat soluble antioxidants such as beta carotene and lycopene
Structurally important for our cells – every cell membrane in our body is made of a few types of fat called phospholipids, triglycerides and cholesterol
Cholesterol is involved in making hormones and bile salts and is a precursor to making Vitamin D
Fats provide omega-3 and omega-6, the essential fatty acids

Dietary fat is divided into four types and knowing and understanding the differences and impacts on our health, helps us to make informed decisions about the choices we make in terms of which oils to use and consume.

Monounsaturated Fats

Monounsaturated fats are found mainly in plant based foods such as avocados, nuts, olives and olive oil, canola oil and peanuts and peanut oil. They are heart healthy and help to decrease LDL (bad) cholesterol in the blood, they are sometimes known as good or healthy fats.

Polyunsaturated Fats

Polyunsaturated fats are mainly from plant sources such as sunflower, safflower, soybean, corn and sesame oil. They are more effective at lowering LDL (bad) cholesterol than monounsaturated fats, and for this reason, are also known as good or healthy fats, and heart healthy for their action at reducing LDL cholesterol.

There are 2 subgroups of polyunsaturated fats, omega-3 and omega-6, otherwise known as essential fatty acids, as our bodies cannot make them and we must get them from our diet.

Omega-3 Fatty acids

There are three main types of omega-3 fatty acids:

EPA (Eicosapentonoic acid)
DHA (Docosahexaenoic acid)
ALA (Alpha-linolenic acid)

EPA and DHA can be made from ALA, but it is better to get them from the diet or supplements as the conversion rate is low.

Omega-3 fatty acids are important as they:

Form part of cell membranes
Involved in making hormones that regulate blood clotting, thinning the blood
Involved in contraction and relaxation of artery walls
Reduce blood pressure and lower the amount of fat in the blood
Anti inflammatory
Supports the immune system

Dietary sources of omega-3 fatty acids include oily fish such as salmon, herring, tuna, mackerel and sardines, vegetables oils (canola and canola based margarine), walnuts, and flaxseeds.

Saturated Fats

Saturated fats are solid at room temperature and are mostly found in animal products such as butter, cream, lard, ghee and meat. There are two plant based types of saturated fat – coconut oil (90% saturated fat) and palm oil (50% saturated fat). Palm oil, among other saturated fats, are commonly used in the manufacturing of discretionary foods such as biscuits, pastries, cakes, confectionery and fast food. Palm oil and coconut oil have been linked to Type 2 Diabetes, bowel and breast cancer. Saturated fats are also found in wholefoods such as full fat dairy – cheese, yoghurt and milk.

The health risks with consuming too much saturated fats is that it increases LDL (bad) cholesterol, increasing the risk for heart disease and obesity. For this reason, saturated fats are sometimes known as bad or unhealthy fats.

Trans Fats

Trans fats are monounsaturated and polyunsaturated fats that behave like saturated fats. They both increase LDL (bad) cholesterol and decrease HDL (good) cholesterol, so their effect on health is likely to be more damaging. They also increase inflammation, with the effect on cholesterol levels and inflammation, there is an increased risk of heart disease, stroke, type 2 diabetes and insulin resistance when consuming trans fats. They occur naturally in milk, cheese, beef and lamb in small amounts. The types of trans fats to be concerned about are the ones manufactured industrially. They are formed during the manufacturing process of turning liquid unsaturated vegetable fats by hydrogenation, into semi solid fats and spreads. There are no known health benefits in consuming trans fats. They can be found in processed foods such as cakes, biscuits, pastries and deep fried foods.

How much fat should I have in my diet?

The issue is not only how much fat you should have in your diet, but also the type of fat you consume and whether you are at risk of heart disease, high cholesterol or type 2 diabetes. Generally speaking, 1-2 tablespoons of mono- or polyunsaturated oils is enough to get the nutritional benefits. The problem is that we are getting much more than that due to consuming foods high in saturated fats in processed and take away foods.

The Australian Dietary Guidelines recommend limiting your intake of foods high in saturated fats such as biscuits, cakes, pastries, pies, processed meats, commercial burgers, pizza, fired foods, potato chips, crisps and other savoury snacks, and replacing them with foods that predominantly contain monounsaturated and polyunsaturated fats. Total fat intake should be between 20-35% of the total kilojoules (energy) consumed per day with no more than 10% of kilojoules coming from saturated/trans fats.

If you are concerned that you may be consuming too much or the wrong type of fat in your diet and need some guidance connect with me to make an appointment for a consultation.

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