Many of us were raised on the idea that consumption of fat (aka lipids), especially from animal sources, results in obesity and heart attack. Yes, an overconsumption of lipids, calories, or sugar results in obesity and potentially metabolic syndrome. However, the reality is that healthy lipid consumption does not equate to obesity or heart attack. In fact, healthy lipid consumption promotes cellular health, provides cellular energy, improves absorption of Vitamins A, D, E and K, provides the precursor (cholesterol) to many hormones, as well as supporting other metabolic processes. 1
Lipids that are called oils are liquid at room temperature, while those that are solid at room temperature are called fats. Lipids come in the form of fatty acids, triglycerides, phospholipids and sterols. They are named based on the number of carbon atoms, the number and position of double bonds (saturated fatty acid (SFA) has all single carbon-carbon bonds and unsaturated fatty acids (UFA) contain one or more double bonds), and the position of the hydrogen bonds (cis fatty acid is bent versus trans fatty acid which is straight).
Saturated fatty acids (SFA) are primarily from animal sources and are considered stable and solid at room temperature. The stability indicates that their shape doesn’t change when they are heated.
Sources of high SFA:
Mother’s breast milk
Lard (beef fat, pork fat)
Unsaturated fatty acids (UFA) can be monounsaturated or polyunsaturated. The more double bonds present, the more bends that occur indicating the potential to change. Unsaturated fatty acids tend to be liquid at room temperature and are considered oils. They tend to be more fragile and heat sensitive.
Sources of High Unsaturated fatty acids (UFA):
*see below for associated positive health benefits
Unsaturated fatty acids can be further categorized into trans or cis depending on the location of the hydrogen atoms around the double bond. The cis form has the two Hydrogen atoms on the same side of the double bond, which results in a bend. Whereas the trans form has the Hydrogen atoms on opposite sides resulting in a straight fatty acid. Therefore, the trans fatty acids (TFA) are more likely to be solid at room temperature. This occurs naturally in some fats like dairy and beef. However, this most commonly occurs commercially via the process of partial hydrogenation. 1
You see this in margarine and shortening used for baking. It produces a desirable texture and reduces spoiling. The main sources of TFA in our diet are in baked items.
Sources of High Trans fatty acids (TFA):
Hydrogenated vegetable oil
Partially hydrogenated vegetable oil
Margarine (soft butter spreads)
Why does this matter?
Incorporating lipids (fat) is essential for cellular health, cellular energy, vitamin absorption and hormone production. However, industrialized high TFA is actually detrimental to health. There has been a causal link associated with TFA consumption from partially hydrogenated vegetable oil and cardiovascular disease. A systematic review and meta-analysis study distinguished between ruminant –TFA (that which occurs naturally in beef or dairy) and industrial-TFA (partially hydrogenated vegetable oils for example). The conclusions support that industrial-TFA is positively related to heart disease, while ruminant-TFA was not. 2
Another review article supported these findings, but noted that there was no lower limit that has been found to be safe as far as ingestion of industrialized TFA. In fact, consumption of the TFA that occurs naturally in beef and dairy seems to have minimal cardiovascular risk when consumed with a balanced diet. 3
I often emphasize the fact that our body systems never act in isolation and in fact work in a complementary way. So it is of no surprise that recovering from a sports injury still requires remodeling of neural pathways related to motor learning. In relation to TFA, there have been studies that indicate that consumption of industrialized TFA can affect other body systems beyond the cardiovascular system.
The neurological system is negatively affected by industrialized TFA. In fact an animal study done by Trevizol et al in 2015, demonstrated a link between consumption of hydrogenated vegetable fat (high in industrialized TFA) was linked to neurological changes that corresponded to hyperactive behavior, oxidative damage and molecular changes, which may lead to development of neuropsychiatric conditions like bipolar disorder. 4
Even the integumentary system, which includes skin and hair, is negatively impacted by industrialized-TFA consumption. Barcelos et all in 2014 performed an animal study to measure the effects of soybean oil, fish oil or hydrogenated vegetable fat (high industrialized TFA). They fed pregnant rats the different oils and maintained them thru breastfeeding. They then observed the skin of the offspring as it responded to ultraviolet exposure. They found that fish oil was protective of the offspring’s skin to ultraviolet radiation exposure. However, the group receiving industrialized TFA offspring showed increased skin wrinkles, reactive oxygen species and decreased mitochondrial integrity and glutathione levels, the master antioxidant of the body. All together that puts the skin prone to develop photoaging and skin cancer. 5
*As Barcelos showed consumption of fish-oil (a naturally occurring fatty acid) demonstrated protective to the skin. A few adult human studies have also shown positive effects of fish oil and olive oil (naturally occurring unsaturated fatty acids). Marques demonstrated that supplementation of fish-oil reduces markers of muscle damage, inflammatory disturbances and neutrophil death that is induced by intensive exercise. 6 Venturini demonstrated that olive oil and fish oil are also protective of oxidative stress in people with metabolic syndrome. 7
So what’s the take home message?
Lipids (fat) are an important macronutrient that our bodies need in order to sustain proper cellular health, cellular energy, vitamin absorption and hormone production. However, those lipids that are best to consume are nearest to their whole and natural form. Organic, grass fed whole milk, butter or yogurt are good additions to the diet. Even eating oily fish like salmon contributes to healthy metabolism and reduces inflammation. Even beef can be eaten safely in moderation. So, don’t be scared to add a little butter or coconut oil to those sautéed mushrooms that are high in Vitamin D that with lipids present allows your body to absorb them!!!
Lipid in the form of industrialized-trans fatty acid or hydrogenated vegetable has no place in our diet. None.
Remove. Replace. Restore.
Remove ALL forms of hydrogenated vegetable oil and industrial-TFA. Read the labels on EVERYTHING, especially salad dressing, cookies, and crackers. Remove all “fake butter spreads” from your refrigerator. Kick canola oil, vegetable oil and shortening out of your baking.
Replace with healthy fats/lipids. For baking or heating use butter, ghee (clarified butter), lard and tallow from organic grass fed sources, or coconut oil. For low heat or salad dressing, use olive oil. Fish oil is fragile, so get from a reputable source or simply eat it in its whole form from fatty fish like salmon, sardines, or troll caught tuna. If snacks are your downfall, like crackers/cookies, then replace with a crisp green apple or fresh berries.
Restore cardiovascular, metabolic, integumentary, and neurological health. If you are working on restoring metabolic or cardiovascular health, then consult your physician to monitor your blood values while you make dietary changes. Moderation of lipid consumption within a well balanced diet and activity is the key. But, fat doesn’t seem to be ALL, bad like we once thought. Remember to listen to your body….always!
Eat well. Feel Well. Thrive On.
1. McGuire M, Beerman K, eds. Nutritional sciences; from fundamentals to food. Third Edition ed. Wadsworth; 2013.
2. Bendsen NT, Christensen R, Bartels EM, Astrup A. Consumption of industrial and ruminant trans fatty acids and risk of coronary heart disease: A systematic review and meta-analysis of cohort studies. Eur J Clin Nutr. 2011;65(7):773-783.
3. Nestel P. Trans fatty acids: Are its cardiovascular risks fully appreciated? Clin Ther. 2014;36(3):315-321.
4. Trevizol F, Roversi K, Dias VT, et al. Cross-generational trans fat intake facilitates mania-like behavior: Oxidative and molecular markers in brain cortex. Neuroscience. 2015;286:353-363.
5. Barcelos RC, Vey LT, Segat HJ, et al. Cross-generational trans fat intake exacerbates UV radiation-induced damage in rat skin. Food Chem Toxicol. 2014;69:38-45.
6. Marques CG, Santos VC, Levada-Pires AC, et al. Effects of DHA-rich fish oil supplementation on the lipid profile, markers of muscle damage, and neutrophil function in wheelchair basketball athletes before and after acute exercise. Appl Physiol Nutr Metab. 2015:1-9.
7. Venturini D, Simao AN, Urbano MR, Dichi I. Effects of extra virgin olive oil and fish oil on lipid profile and oxidative stress in patients with metabolic syndrome. Nutrition. 2015;31(6):834-840.