Fat – what is it and which functions does it have in our bodies?
Fats are divided into tree groups: saturated fatty acids, polyunsaturated fatty acids, monounsaturated fatty acids. All fatty acids contain of carbon atoms that are connected in chains in various lengths from 4 to 22 carbon atoms. All of them also contains hydrogen and some also contains oxygen.
The saturated fats contain the maximum amount of hydrogen which makes the chain stiff and straight. Unsaturated fats are a term that includes both polyunsaturated fats and monounsaturated fats. Monounsaturated fats contain two less hydrogen atoms and has instead a double bond. This double-bond bends the chain and the fat gets a what is called a cis-form. All fatty acids that has more than one double bond is called polyunsaturated fats. Long fatty acids can have up to six double bonds, and the more double bonds a fatty acid has, the more crocked will the acid be, this also affects its functions in our bodies.
Some saturated fats are straight even though they have double binds, this is when the double binds have a transformation, with other words, it’s a transfat acid. Transfats can be formed chemically by adding more hydrogen to the molecule. In natural fats are unsaturated fats almost always in cis-form, with the one exception of ruminants, in milk there is a few percentage of the fats are transfat.
Fats are often considered something negative today, but it’s actually an energizing substance that is essential for many vital functions in out bodies. Fat functions as fuel and has is the macro that has the highest energy content per gram, one gram of fat translates to 9 kcal. Access fat are stored in adipose tissue and can later be used when our bodies lack energy. The adipose tissue provides protection, support and heat isolation for our inner organs and help keep our body temperature stable. Fat is also needed for our body to be able to build and repair cells, manufacture hormones and hormone-like substances and to be able to take up the fat-soluble vitamins A, D, E and K.
Some fats are even completely vital for our survival, the so called essential fats, these are the so called polyunsaturated fats. We need to get these fats via the food we eat. The essential fats affect our bodies in different ways, among other things they affect our brain function, blood pressure, the bloods clotting ability, our immune system, regulation of the cell’s protein production and our skins functions.
Even though fats are important for us, too much fat can have negative consequences like overweight and obesity, therefor its important to not eat to much fat either. Read more about how much fat we should eat here: https://elifestyle-se.myshopify.com/blogs/nyheter/how-much-fat-do-we-need
The different shapes of fat molecules have different effects in our bodies:
Monounsaturated fats consist of a bent chain. This inflection means that the fatty acid takes up more room in the cells membranes and makes it more porous. When the membrane is more porous, this makes it easier for substances to move in and out of the cell. Monounsaturated fats affect our cellmembrane and our blood vessels in a positive way by being resistant against oxidation, which lowers the production of harmful free radicals.
Polyunsaturated fats are more crooked, which means that it takes up even more room in the cells membranes. This results in the membranes being even airy and porous and that substances passes even easier in and out of the cell. Polyunsaturated fats, the essential fats, are the fats that our body cannot produce on it’s own and that we need to obtain though the food we eat. The most important essential fats are alpha-linoleic acid, also known as omega-3 and linoleic acid, also know as omega-6.
Saturated fats consist of more hydrogen, which makes the molecule straighter and less limber. The saturated fats, straight and stiff chains, are closer together in our cells membranes and makes it harder for substances to move in and out of the cell. Our brain consists to a big part of fat and about half of it is saturated fats, which is critical for some important functions. Our kidneys also need saturated fats for their cells to be able to communicate. However, saturated fats in bigger quantities that what is recommended, has negative effect on out health. Too high intake increases the bodies production of cholesterol, which results in our blood fats rising. High blood fats increases the odds for heart- and vascular diseases and overweight. Overweight increases the odds for diabetes typ-2 and some forms of cancer.
Transfats are formed when oils are hardened, this means that unsaturated fats become saturated by chemically adding more hydrogen to the molecule. Transfats affects out bodies in a negative way by rising the level of LDL-cholesterol in the blood, also called the bad cholesterol and lowers the lever of HDL-cholesterol. This increases the risk of being affected by heart- and vascular diseases. According to WHO 2009, small intake of transfats, less than 1 E%, does not lead to an increased risk to be affected.