The nutritional pariah known as Fat has been blamed for everything from heart disease and obesity to type 2 diabetes and arthritis; yet, this often misunderstood nutrient is crucial to our good health and well-being.
Without dietary fat the steroid hormones necessary for the proper functioning of the body could not be manufactured, the fat-soluble vitamins A, D, E and K could not be absorbed, sympathetic and autonomic nervous system functioning, brain health, heart health and overall growth and development would be compromised. Fat is good for us.
There are four distinct categories of fat and, although they contain the same number of calories per gram, each of these categories (and their subcategories) affect the body in decidedly different ways.
Types of Fat
- Trans fats
- Saturated fats
- Monounsaturated fats
- Polyunsaturated fats
Of these four fats, the unsaturated varieties are considered best for improving and maintaining good overall health and well-being. As luck would have it, unsaturated fats are also the most common fats found in whole foods.
Unsaturated Fats and their subcategories
- Monounsaturated fatty acids (MUFAs)
- Oleic acid
- Polyunsaturated fatty acids (PUFAs)
- Omega-3 fatty acids
- Omega-6 fatty acids
What truly separates unsaturated fats from saturated fats are their bonds. Unsaturated fats contain at least one double bond in their fatty acid chain, which is why they are liquid at room temperature. Saturated fats have no double bonds. They are filled, or saturated, with the maximum number of hydrogen atoms. This is why saturated fats are solid at room temperature.
Monounsaturated fatty acids (MUFAs) are named such because they possess a single double bond within their carbon chain, whereas polyunsaturated fats contain at least two. According to the American Heart Association, MUFAs have been shown to reduce bad cholesterol levels in the blood, which lowers the risk of heart disease and stroke. MUFAs also “provide nutrients to help develop and maintain your body's cells.”1
Monounsaturated fats have also been credited with...
- reducing belly fat
- assisting weight loss
- decreasing breast cancer risk
- helping to relieve the pain and stiffness of rheumatoid arthritis
The monounsaturated fat Oleic acid, which is found in Avocados, peanuts corn and sunflower seeds, has been shown to “improve fasting plasma glucose, insulin sensitivity and blood circulation, which improves diabetes control and lowers risk for other diseases.”2
Polyunsaturated fatty acids (PUFAs) are distinctly different from monounsaturated fats. PUFAs don't just increase good cholesterol, they attach to and clear out unhealthy fats in the body (saturated, LDL cholesterol, triglycerides). PUFAs are also credited with reducing blood pressure and improving brain health. However, a rat study published in The British Journal of Nutrition produced results that indicated “that enrichment of the diet with polyunsaturated fatty acids causes changes in adipose tissue metabolism that favors deposition.”3 In other words, a diet rich in PUFAs made the rats pack on fat. So, while PUFAs are obviously good for health, too much could lead to weight issues, which come with their own set of health challenges.
Omega-3 polyunsaturated fatty acids have long been known to normalize and regulate cholesterol, triglyceride levels and decrease risk of cardiovascular disease. Over the years, a plethora of evidence relating to the beneficial effects of Omega-3s, in areas other than heart disease, has emerged. Beyond their cardiovascular benefits, omega-3s may improve a child's learning ability and behavior6, as well as prevent cell mutations.4 According to a study published in Molecular Cancer Therapeutics, “Hepatocellular carcinoma (HCC) is a common human cancer with high mortality, and currently, there is no effective chemopreventative systemic treatment.”5 Yet, omega-3 PUFAs, along with DHA and EPA, were found to inhibit HCC growth through simultaneously inhibiting COX-2 and beta-catenin. “These findings provide important preclinical evidence and molecular insight for utilization of omega-3 PUFAs for the chemoprevention and treatment of human HCC.”5
Omega-6 polyunsaturated fatty acids, which were once believed to inflame and damage the lining of arteries, are now recommended as part of a heart healthy diet by the American Heart Association. In moderation, of course.
Concerning Bad Fats...
Everyone knows, by now, that trans fats are very unhealthy. They don't just elevate LDL (low density lipoproteins)/“bad” cholesterol, they decrease HDL (high density lipoproteins)/“good” cholesterol as well. So, any benefit one may have expected from eating unsaturated fat foods along with trans fat foods will be diminished by the trans fats. That particular quirk is what makes trans fats the most harmful of all fats. Fortunately, if you're a raw vegan, you will not have to worry about trans fats in your diet. Trans fats only occur naturally in some meats and dairy products, and unnaturally in processed foods.
Saturated fats, while not in the same league as unsaturated fats, because they also raise LDL cholesterol, are not as bad for us as previously believed. Recent studies have shown that saturated fats raise a variety of LDL cholesterol called “Large LDL cholesterol” – the particles of which are too large and fluffy to penetrate the arterial wall and become a problem.8 In addition, saturated fats don't decrease heart healthy HDL cholesterol as trans fats do. Still, getting too much saturated fat is a bad idea. Most nuts and even coconuts contain a small percentage of saturated fat, but since we understand that moderation must be exercised in all things, particularly fat consumption, that won't be a problem.
Any healthy diet, whether it contains animal products or not, must include fats. We need fats to achieve and maintain overall good health and well-being. Does this mean that we should eat heaping cups full of coconut meat, avocado, nuts, seeds and other foods rich in good fats every day? No. All fats, even the “good”, unsaturated varieties, should be consumed in moderation, to avert the many health problems attributed to high-fat diets.
1 “Monounsaturated Fats”. American Heart Association, August 5, 2015. Web. July 21, 2015
2 Richardson, Alicia. “What is Oleic Acid?” Livestrong, June 18, 2015. Web. July 21, 2015
3 Gaira MH, Couto RC, et al. “Polyunsaturated fatty acid-rich diets: effect on adipose tissue metabolism in rats”. The British Journal of Nutrition, September 2001. Web. July 20, 2015
4 Ruxton, C.H.S., Reed, S.C., Simpson, et al. “The health benefits of omega-3 polyunsaturated fatty acids: a review of the evidence”. Journal of Human Nutrition and Dietetics, October 2004. Web. July 21, 2015
5 Lim, Kyu, Han, Chang, et al. “Omega-3 polyunsaturated fatty acids inhibit hepatocellular carcinoma cell growth through blocking β-catenin and cyclooxygenase-2”. Molecular Cancer Therapeutics, November 2009. Web. July 21, 2015
6 Stevens, Laura J., Zentall, Sydney S., et al. “Omega-3 fatty acids in boys with behavior, learning, and health problems”. Physiology & Behavior, April – May 1996. Web. July 21, 2015
7 “Trans Fats”. American Heart Association. August 5, 2014. Web. July 21, 2015
8 Gunnars, Kris. “Top 8 Reasons Not to Fear Saturated Fats”. Authority Nutrition – An Evidence Based Approach. n.d.. Web. July 21, 2015
Glick, David. Methods of Biochemical Analysis, Volume 4. September 24, 2009. Web. July 19, 2015.
“Saturated vs Unsaturated Fats – Structure in Relation to Room Temperature State?” Chemistry Stack Exchange. n.d. Web. July 19, 2015
“Dietary Fats: know which types to choose”. Mayo Clinic. n.d. Web. July 19, 2015
“Frequently Asked Questions About Fats”. American Heart Association, May 19, 2014. Web. July 21, 2015
Christensen JH, Schmidt EB. “Autonomic nervous system, heart rate variability and n-3 fatty acids”. Journal of Cardiovascular Medicine (Hagerstown, Md.), September 2007. Web. July 21, 2015
Schwartz JH, Young JB, and Landsberg L. “Effect of dietary fat on sympathetic nervous system activity in the rat”. The Journal of Clinical Investigation, July 1983. Web. July 21, 2015
A guest blog post by holistic writer Andrea Lewis. Consult with your doctor before making any medical or health changes.