Try talking to any painfully body conscious teenage girl, or bodybuilding male about fat, and you might find they run away screaming. This is because fat is typically associated with big bellies and clogged arteries. But what if I told you the right types of fat can have entirely healthful purposes? In fact, a diet high in the right types of fat could improve longevity and significantly decrease risk of heart attack and stroke. A higher fat diet might be the solution to your health problems.
Now, don’t get me wrong, I am by no means advising you to stock up on potato chips and streaky bacon because a blog on Ideal Nutrition informed you that fat will make you live longer. What I am suggesting, is to educate yourself on the different types of fat and understand how the right type of fat (evidently, not that found in potato chips and streaky bacon) can have positive effects on health.
Before delving into the world of fats, it is important to understand the structure and most basic categories of fat. Fatty acids are the central component of fat and can be thought of as a chain (long, medium or short) of bonded carbon atoms. Fats have a lot more going on than this but this explanation will suffice for this article. The bonds that connect carbon atoms within the chain can either be single (C-C) or double (C=C). The existence of these bonds, determine if the fatty acid is saturated or unsaturated. If all bonds are single, the fat is classified as saturated. Saturated fats are linear, straight molecules. If one or more double bonds are present, the fat is classified as unsaturated and the molecule is bent where the double bond occurs.
Now that the housekeeping is out of the way, we can move on to the interesting stuff!
The current link between fat and poor health is largely due to trans fat. This type of fat, truly is evil. It is the sort of fat you should run away from screaming. While this might seem a bit dramatic, all in seriousness, it should be avoided. Completely. It is the only type of fat that does nothing but damage.
Ironically enough, trans fat, the worst type of fat, is formed from unsaturated fat, the best type of fat. The conversion of unsaturated fat to trans fat occurs when it is exposed to heat at either at very high temperatures or for very long durations. Heating turns the unsaturated fats’ characteristic double bond kink, straight. The fat now more closely resembles a saturated fat (only with a double bond), and is known as trans.
Trans fats are largely unnatural and only small quantities occur in nature. For this reason, our body doesn’t really understand how to process them, and it most certainly can’t do anything useful with them. Instead, trans fat acts to relocate cholesterol stored in the liver to the blood vessels. It does this through up regulating the production of LDL (low-density lipoprotein) which picks up cholesterol at the liver and deposits it at the periphery. Circulating cholesterol, in concentrations that exceed normal, undergoes oxidation. Oxidised cholesterol buries itself in the endothelial wall of the blood vessel where is forms a foam cell. This foam cell can grow with the addition of more oxidised cholesterol until it forms atherosclerotic plaque, which is basically just a fancy term for an artery clogger. The plaque can continue to grow until it completely blocks blood flow through the vessel causing either heart attack or stroke. And death. See… Evil!
Trans fats are found in deep fried, baked or processed foods. Beware of processed products that incorporate healthy oil (for example, sunflower oil) to their products. They boast the healthful properties of such oils on the packaging, however, often the product has been subject to baking or frying which means most of the fat has become trans and the healthful qualities of the original oil are no longer relevant.
Let’s move away from bad fat and start talking about how we can use fat to our advantage.
Unsaturated fats have an opposing function to trans fats. That is, they up regulate the production of HDL (high-density lipoprotein) which takes cholesterol out of the blood and bring it back to the liver for healthful purposes. Effectively, unsaturated fat reduces the risk of cardiovascular disease through this mechanism. See, told you not all fat was evil.
The wonders of unsaturated fat don’t stop here! The unsaturated fat, DHA (docosahexaenoic acid) is essential to the diet. This means we need it in our food to achieve wellbeing. During foetal life and infancy, it is necessary to normal development and function of the retina and nervous system. Throughout life, it helps regulate nerve transmission and communication. DHA is found in cold water-fish such as salmon. Vegan sources include seaweed.
Furthermore, unsaturated fats are used by the body to produce eicosanoids. Eicosanoids participate in over 100 metabolic functions! Just some of these include regulating cell division and movements of substances in to and out of the cell, maintaining normal kidney and hormone function, regulation of ovulation, body temperature and immune function. The type of eicosanoid produced is dependent on the unsaturated fatty acid from which it is derived. Omega-6 fatty acids produce what are known as pro-inflammatory eicosanoids and omega-3 fatty acids produce anti-inflammatory eicosanoids. While the pro-inflammatory eicosanoids are essential to our health, they do not make as large a contribution to wellbeing as their anti-inflammatory counterparts. Anti-inflammatory eicosanoids are associated with decreased blood clotting, blood pressure and generally healthier vasculature. It is recommended we consume more omega-3 than omega-6 fatty acids to achieve a more healthful state. This means consuming foods such as flaxseed, cold water fish and avocado.
An excellent real life example of the work of super hero unsaturated fat is the Mediterranean diet. Research shows that those who closely follow the Mediterranean diet are at lowest risk of cardiovascular disease. This isn’t because they don’t eat any fat. In fact, they eat quite a lot of it. What is important, is that the type of fat consumed is predominately unsaturated. Their diet is high in nuts, sardines, olive oil and low in red meat and fried foods. If it’s a long healthy life you’re after, this might be the type of diet for you.
This brings us to the last type of fat. Saturated. This is the sort of fat you find in pork belly or a T-bone steak. It’s delicious, I’ll give it that. But our insides aren’t such fans. Like trans fat it up-regulates the production of LDL and increases the risk of cardiovascular disease. However, it is only fractionally as evil as trans-fat because it doesn’t up-regulate LDL to quite the same extent. Furthermore, unlike trans fat, saturated fat has some healthful purposes. For example, it is needed to provide rigidity to cell membranes and is necessary for storing energy. For the most part, however, we consume far more saturated fat than we require and the excess contributes solely to unhealthy, vascular damaging functions. Most westerner’s need to cut back on saturated fat and this can be achieved by swapping bacon for tuna. Or pork crackling for avocado on wholegrain toast. Your insides will thank you.
Hopefully this article has shifted your opinion on fat. Basic things to take away is say yes to unsaturated and no to trans. This translates to dietary choices that move away from streaky bacon and potato chips and towards avocado, salmon and some nuts. Fat can have profound effects on health and wellbeing so it is important to choose wisely.
Renae Earle is a Masters of Dietetics student at the University of Queensland. Having achieved her Bachelor of Exercise and Nutrition Science with distinction, she is motivated to complete her studies and become an accredited practicing dietitian.
Renae is passionate about evidence-based practice and debunking nutrition myths. She believes that in today’s fad celebrity diet culture, it is increasingly important to deliver the facts. She aims to help people achieve a sustainable and healthful lifestyle by combating the flurry of misinformation offered by tabloids and social media.
In order to achieve this goal, Renae has dedicated herself to the field of nutrition. She is well educated on a wide range of nutrition topics such as supplementation, chronic disease, restrictive diets and metabolism.
Renae has a keen interest in offering personalised nutrition plans that suit the specific needs of her future clients.