By Kristen Aline, B.S. Sport & Health Science, NSCA-CPT, CSCS
Functional Exercise Specialist
Integrative Nutrition & Health Coach
Fat plays a vital role in human health. Our bodies depend on fat for energy, for brain development, for nerve function, for insulation, and for maintaining healthy hair and skin. Dietary fats are essential for absorbing certain vitamins, to protect and build cells, for optimal brain function, and for making hormones.
“I believe the shift in our diet that has occurred over the past century – from high-fat to low-carb, to today’s low-fat high-carb diet, fundamentally consisting of grains and other damaging carbohydrates – is the origin of many of our modern scourges linked to the brain, including chronic headaches, insomnia, anxiety, depression, epilepsy, movement disorders, schizophrenia, attention deficit hyperactivity disorder (ADHD), and those senior moments that quite likely herald serious cognitive decline and full-blown, irreversible, untreatable, and incurable brain disease.”
– David Perlmutter, MD
– Author of Grain Brain and The Better Brain Book
Let’s begin by talking about the role of saturated fat and cholesterol since they’ve been labeled “bad” by many doctors, nutritionists and health organizations including the USDA. The idea that saturated fat intake causes high cholesterol in the blood, which causes heart disease is called the diet-heart hypothesis. No solid evidence actually exists that a diet high in saturated fat will raise your blood cholesterol, make you fat or cause heart disease. In fact, eating a low carbohydrate diet with moderate to high amounts of saturated fat has been shown to improve health markers and decrease your chance of getting Alzheimers, diabetes, and cancer. Cholesterol is essential to make vitamin D, to make anti-stress hormones and sex hormones, as an antioxidant, and as protection against autoimmune diseases. Cholesterol is so important that we make most of it inside our body. That’s why decreasing the amount of cholesterol in your diet will do little to nothing to lower your blood cholesterol.
“Cholesterol is the hero, not the villain. Cholesterol is a waxy, fat-like substance found in every cell in your body. Elevated cholesterol is a symptom of inflammation, not the cause. So when cholesterol levels increase, it can mean your body is trying to fight inflammation and cholesterol came to the rescue to heal the damage, as a protective mechanism. What’s promoting heart disease is the inflammation, not the cholesterol. Simply reducing cholesterol numbers does not reduce risk of death from heart disease. Cholesterol is essential for our bodies to function and without cholesterol you would die. In fact, the majority of the cholesterol in your blood comes from your own bodies making it. I don’t think a lot of people understand that concept. People mistakenly think they get most of their cholesterol from their food and that’s not true. Cholesterol is used to make hormones like estrogen and testosterone, is transported into the adrenal gland to aid in hormone synthesis, repair nerves, and make bile for fat digestion, it’s a structural component of of our cells, it synthesizes vitamin D-it plays such a vital role in our body that we genuinely need it. If our cholesterol levels are too low, that can play a negative role in our health, too, as a telltale sign of autoimmune disease or even cancer.”
– Cassie Bjork, Registered, Licensed Dietician
– Founder of Healthy Simple Life
The belief that eating saturated fat raises cholesterol and causes heart disease gained steam in the 50s when a scientist by the name of Dr. Ancel Keys put the diet-heart hypothesis to the test. Keys tested his hypothesis with an analysis of fat intake versus deaths from heart disease. He plotted fat intake against national heart disease mortality for the United States, Japan, Italy, England, Wales, Australia, and Canada. His graph did in fact show a strong correlation between fat intake and heart disease, but two scientists by the names of Yerushalmy and Hilleboe analyzed Keys’ data and found some major flaws. The first problem they found was that Dr. Keys’ excluded data from 16 countries. To be fair, when Yerushalmy and Hilleboe added these countries back in, a correlation still existed. It just wasn’t very strong. One such country excluded from Keys’ data was France, where people consume a lot of fat yet have low rates of heart disease. When analyzing Keys’ data Yerushalmy and Hilleboe also found that “the presumed association is not “specific” for fat in the diet or for diseases of the heart; for example the association for heart disease is stronger when animal protein is substituted for fat, and a strong negative association is found for both animal protein and fat with mortality from non cardiac diseases.”
In summary, Yerushalmy and Hilleboe concluded that, “the suggested association between national death rates from heart disease and percentage of fat in the diet available for consumption cannot at the present time be accepted as valid.”
Based mostly on Keys’ flawed research, the USDA began recommending that Americans lower their saturated fat intake and replace those calories with carbohydrates. The public responded and so did the food industry by replacing saturated fat with sugar and/or trans fat. Ironically, many experts now believe it’s sugar, trans fats, and an excess of polyunsaturated fats that increase your risk for heart disease, obesity and a plethora of other illnesses.
A number of studies that do not support Keys’ findings have been published since, but mostly ignored by the USDA and mainstream media.
A 2010 study published in The American Journal of Clinical Nutrition analyzed 21 different studies and combined their results. They found no evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD.
A 2014 study published in The Annals of Internal Medicine analyzed 72 separate studies and came to the same conclusion. They found no evidence to support guidelines that people should restrict saturated fat in order to prevent heart disease.
A 2013 study published by the Swedish Council on Health Technology Assessment reviewed 16,000 studies and concluded that a high-fat low-carb diet improved health markers like HDL to LDL ratio, glucose levels and triglycerides. They also concluded that a low-carb high-fat diet is the best treatment for weight loss.
The mainstream media in the United Sates is now reporting some of this, but the USDA has not reacted. Their My Plate guidelines that replaced the Food Guide Pyramid still advocate a high-carb low-fat diet.
If you’re thinking about adding more healthy fat to your diet, here are a few points to consider.
1. Omega 6 to Omega 3 Ratio: Anthropologists believe that our hunter-gatherer ancestors consumed these fats in a ratio of about 1:1. With the introduction of vegetable oils and grains into our own diet and the diet of the animals we consume, we now eat 10-30x more Omega 6 fats than Omega 3s. Research indicates that this imbalance in omega fats causes chronic inflammation which is the root of just about all medical problems from heart disease to cancer to depression. Omega 6 fats are highly concentrated in vegetable oils like soybean oil, corn oil and safflower oil. By Replacing these oils with fats like coconut oil, palm oil, pastured animal fats, olive oil, and avocado oil you’ll begin to bring this ratio back into balance. You may also want to consider increasing your Omega 3 consumption by adding plenty of Omega 3 containing foods to your diet and/or supplementing with omega 3 fish, krill or flax oil. Additionally, think about cutting way back on grain fed meat and eggs and replacing them with meat and eggs raised on pasture.
“The more omega-3 fat you eat, the less omega-6 will be available to the tissues to produce inflammation. Omega-6 is pro-inflammatory, while omega-3 is neutral. A diet with a lot of omega-6 and not much omega-3 will increase inflammation. A diet of a lot of omega-3 and not much omega-6 will reduce inflammation. Big Pharma is well aware of the effect of n-6 on inflammation. In fact, the way over-the-counter and prescription NSAIDs (ibuprofen, aspirin, Celebres, etc.) work is by reducing the formation of inflammatory compounds derived from n-6 fatty acids. (The same effect could be achieved by simply limiting dietary intake of n-6, but of course the drug companies don’t want you to know that. Less profit for them.)”
– Chris Kresser M.S, L.A.c
– Author of Your Personal Paleo Code
“The pro-inflammtory mechanism in our body is driven by omega-6 fats and the tamping down of inflammation is driven by omega-3 fats. By consuming an overload of omega-6 fats, we are pushing our system toward a pro inflammatory state, which is why omega-6 consumption is now implicated in autoimmune disorders, allergic reactions, and rheumatoid arthritis.
– David Gillespie
– Author of Toxic Oil
2. Oxidized Fats: The second thing to consider when consuming fats is their level of stability or likelihood to become rancid. Rancid fats have been oxidized and cause free radical damage that can lead to disease. The fats that are most resistant to oxidation are saturated fats found in animal fats, coconut oil and palm oil. This is important because when fats oxidize they cause free radical damage which can lead to disease. Saturated fats are saturated with hydrogen atoms which makes them compact, stable and solid at room temperature. These fats are best for cooking because they can withstand higher temperatures.
Monounsaturated fats are not as densely packed as saturated fats because they are missing two hydrogen atoms making them a little more prone to oxidation, especially when exposed to heat. Olive oil, avocado oil and nuts fall into this category. They will not last as long as saturated fats so buy them in smaller quantities and use them up quickly. Buy these fats cold pressed and store them in a cool, dry, dark place. Using these oils for cooking is only recommended at low temperatures and in moderation.
Polyunsaturated fats are missing several hydrogen atoms and are especially prone to oxidation. These fats are found in high concentrations in corn oil, soy oil, cottonseed oil, and sunflower oil. These oils have been oxidized during factory processing and it’s best to avoid them entirely. Although canola oil has lower concentrations of polyunsaturated fats, it’s in the same category as the above oils because of the methods used in processing.
3. Raw and Low Heat Food Preparation: Keep in mind that all fats are made up of a percentage of saturated fat, monounsaturated fat and polyunsaturated fat. For instance olive oil is about 74% monounsaturated fat, 13% saturated fat, and 8% polyunsaturated fat. To avoid oxidation include mostly raw and low heat methods of preparing food and limit recipes that involve cooking at high temperatures.
4. Trans Fats: Evidence suggests trans fats will in fact increase your risk of heart disease and other life threatening diseases. Trans fats are found in margarine, most deep fried food, processed foods like chips, microwave popcorn, granola bars and even cereal.
5. Sugar and Processed Foods: One of the problems with presenting evidence that points to the health benefits of a higher fat diet is that people tend to blindly add more fat to their diet without considering all of the data. Adding fat to an already high carbohydrate diet can actually be worse than a low-fat diet. This is the conundrum and it’s why some anecdotal studies actually do show an increased risk of heart disease in people who eat more fat. Most of the time these people are also eating a diet high in sugar, grains, and processed carbohydrates. Many experts who have studied fat and cholesterol in detail believe that coronary artery disease has more to do with damaged cholesterol than cholesterol itself. One of the ways cholesterol can become damaged is when sugar molecules attach themselves to LDL and change their shape.
6. Fruits and Vegetables: Another problem with reporting the health benefits of fat is that people will again blindly add more fat to their diet while ignoring the need for nutrient rich fruits and vegetables. Vegetables, especially leafy green ones, are by far the most nutrient dense foods on the planet. That means they pack the most nutrition per calorie. Some of the key nutrients found in greens are iron, calcium, potassium, magnesium, vitamins K,C, and E, folate, fiber and even small amounts of Omega-3. That’s why pastured animals that graze on grass all day are so much higher in Omega 3 fats than their grain fed counterparts. Some scientists believe our ancient ancestors ate up to 6 pounds of leaves per day.
Fruits are also high in vitamins, minerals, and fiber, but too much modern-day fruit can have an unfavorable impact on your health. Over thousands of years through hybridization growers have made fruits larger and sweeter than what you’d find in the wild. In excess, these high sugar fruits can contribute to the oxidation of cholesterol.
7. Bio-individuality: Bio-individuality is a term coined by Joshua Rosenthal, founder and director of The Institute for Integrative Nutrition. It’s the idea that no one diet works for everyone and what is good for one person, may harm another. Diets that include upwards of 70% fat have been successfully used in some people to control weight, depression, anxiety, epilepsy, and blood sugar with no evidence of adverse affects. An extremely high fat diet may not be right for everyone.
Bjork, Cassie (2015) 7 Things Your Doctor Didn’t Tell You About Your Heart Health. www.dieticiancassie.com
Chowdhury, Warnakula, Kunutsor, Crowe, Ward, Johnson, Franco, Butterworth, Forouhi, Thompson, Khaw, Mozaffarian, Danesh, Angelantonio (2014) Association of Dietary, Circulating, and Supplement Fatt Acids With Coronary Risk: A systematic Review and Meta-Analysis. Annals of Internal Medicine. Vol. 160 No. 6
Gillespie, David (2013) Toxic Oil
Hilleboe, Herman E. and Yerushalmy, J. (1957) Fat in the Diet and Mortality from Heart Disease
Keys, Ancel (1953) Atherosclerosis: A problem in Newer Public Health
Klement and Kämmerer (2011) Is there a role for carbohydrate restriction in the treatment and prevention of cancer? Nutrition & Metabolism, 8:75
Klein, Tyrlikova, Mathews (2013) Dietary Treatment in Adults with Refractory Epilepsy, Neurology, 4/83
Kresser, Chris (2010) How too much Omega-6 and not enough Omega-3 is making us sick, www.chrisskresser.com
Minger, Denise (2014) Death By Food Prramid
Perlmutter, David (2013) Grain Brain
Siri-Tarino, Sun, Hu, and Krauss (2010) Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease, The American Journal of Clinical Nutrition, 10.3945/ajcn.2009.27725
Swedish Council on Health Technology Assessment (2013) Dietary Treatment of Obesity: A systematic Review