Salmon, olive oil and avocado have been ruling the health game for years now, but why? The truth is that they are full of healthy fats called unsaturated fatty acids. Do any of us truly know the benefits of the ‘healthy fats’ that lie within our foods?
What is unsaturated fat?
Unsaturated fats are divided into monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs). Fatty acids are long chains of carbons and hydrogens. The reason why they have been given this name is that they have carbon-carbon double bonds in their structure, unlike saturated fats which have no carbon-carbon double bonds. Monorefers to having one carbon-carbon double bond, whereas poly- refers to having multiple carbon-carbon double bonds. This unsaturated bond typically makes them more fluid at room temperature such as with oils.
The way they are written tells you about their structure. For example with the following:
● Palmitoleic acid - 16:1 is a MUFA. The 16:1 denotes that it has 16 carbons and a carbon-carbon double bond.
● α-Linolenic acid - 18:3 is a PUFA. The 18:3 denotes that it has 18 carbons with 3 carbon-carbon double bonds.Image source: https://dlc.dcccd.edu/biology1-3/lipids
Examples of unsaturated fats
These include the following:
● Myristoleic acid (14:1)
● Palmitoleic acid (16:1)
● Oleic acid (18:1)
● α-Linolenic acid (18:3)
● Arachidonic acid (20:4)
● Docosahexaenoic acid (22:6)
● Eicosapentaenoic acid (20:5)
● Linoleic acid (18:2)
● Linoelaidic acid (18:2)
Omega 3 oils are by far the most prominent and well known of the unsaturated fatty acids. The reason why they are called omega 3 fatty acids is that they have a double carbon-carbon bond between the 3rd and 4th carbon. The most well known of these being Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA).Omega 3 oils have approved health claims from the European food safety authority.
(EFSA), these include the following:
● Docosahexaenoic acid (DHA) maternal intake contributes to the normal brain development of the foetus and breastfed infants.
● EPA and DHA contribute to the normal function of the heart
● DHA contributes to the maintenance of normal vision
● DHA contributes to the maintenance of normal blood triglyceride levels
● Docosahexaenoic acid (DHA) intake contributes to the normal visual development of infants up to 12 months of age.
● DHA and EPA contribute to the maintenance of normal blood pressure. We will discuss the health benefits of all unsaturated fats below. Foods rich in unsaturated fats
● Nuts-Almonds cashews, peanuts
● Oils - Sesame, peanut, canola, soybean, olive and sunflower oil
● Fish - Salmon, mackerel, trout.
● Seeds - Linseed, flaxseed, chia seed
● Nuts- Pine, walnuts, brazil nuts
Health benefits of unsaturated fats
According to the world health organisation (WHO) cardiovascular diseases (CVDs) are the leading killer in the world today. These include diseases such as deep vein thrombosis, peripheral arterial disease, coronary heart disease, and cerebrovascular disease. One 2016 study looked at dietary factors contributing to coronary heart disease (CHD). The results found that there were lower incidents of CHD in those with greater intake of polyunsaturated fatty acids and wholegrain carbohydrates. Other research found that DHA and EPA have been associated with reduced risk of heart disease and can have positive effects on blood lipid profile.
Cognitive health relates to diseases including dementia/Alzheimer’s disease and Parkinson’s disease. The WHO recognises that there are around 50 million people living with dementia worldwide. Cognitive disorders have varied biological causes between each disease. That being said, it’s thought to be due to the degradation of neurological material that helps with communication within our brain and body. This can lead to loss of memory and functional skills.
One study looked at dietary intake and cognitive decline. They found no association between trans fatty acids, saturated fatty acids and dietary cholesterol and cognitive decline.However, they did find an association (not a causation) between monounsaturated fatty acids
(MUFAs) and cognitive decline. Increased dietary intake of MUFAs has been found to slow the
decline of cognitive functions. Another study found that increased fish intake (supplying Omega
3 PUFAs) was linked to protective effects against Alzheimer’s disease. This supports the ideathat lower intake of quality fatty acids (MUFAs and PUFAs) have possible links to decrease cognitive performance.
According to the WHO (2016), 1.6 million yearly deaths are attributed to diabetes and a further 2.2 million deaths were related to high blood glucose (hyperglycaemia). Recent research supports the idea that type 2 diabetes can be reversed by improving insulin sensitivity. Evidence suggests that the quality of fat intake can be associated with diabetes symptoms. One study suggested that trans fats were positively associated with the incidence of type 2 diabetes. Moreover, Omega 6 ( linoleic acid) intake has been shown to improve the incidence of diabetes. That being said the same relationship has not been found between omega 3, insulin resistance and type 2 Diabetes Mellitus. There is no conclusive evidence to state the correct ratio of Omega 3/6 to reduce the incidence of type 2 diabetes. Practical ways to increase unsaturated fats in your diet
● Increase fish consumption to at least twice a week.
● Take a fish oil supplement
● If you are vegan/vegetarian try an algae supplement.
● Add an oil drizzle on salad/vegetables - olive oil, avocado oil or sesame oil.
● Cook in unsaturated oils.
● Add nuts/seeds to porridge and salads
● Try a handful of nuts as a snack.
● Add natural nut butter to your snack or breakfast.
No need to fear fat, embrace it and enrich your life.
WRITTEN BY HARRIET HUNTER, ANUTR. NUTRITIONIST