Good and Bad Fats
After a long obsession with low-fat dieting and avoiding ‘bad’ fats, North Americans are hearing more and more these days about the benefits of ‘good’ fats. These include monounsaturated and polyunsaturated and fats, and exclude most saturated fats and all human-made trans fats (created through heavy processing and hydrogenation of otherwise unsaturated fats). The terms ‘omega-3’ and ‘omega-6’ fatty acids are now commonly seen in newspapers and on all sorts of products, ranging from health supplements to eggs and even milk.
The types of fats eaten influence the character of cell membranes, thus allowing or disallowing for the smooth passage of signals through these membranes. This includes insulin receptors and the passage of insulin, as well as other hormones, such as thyroid hormone and adrenal hormones. The right kinds of fats slow digestion and absorption of carbohydrates, thereby lessening the insulin reaction. Thus the importance of eating correct fats cannot be overemphasized for any healthy diet, but especially for the diabetic diet. It is vital to your health to be aware of the qualities of the fats and oils you consume. Using the right kinds of fats slows carbohydrate digestion and absorption. This lessens the insulin reaction.
Bad Fats
Trans Fatty Acids
These fats increase diabetes risk, as well as the risk of many other serious chronic diseases, including heart disease and cancer. Trans fats become a part of the cell and block the cell’s utilization of essential fatty acids, while interfering with insulin receptors.
Trans fats are often found in all fried or deep fried foods, margarines (even soft margarines), commercially prepared snacks, and commercial baked goods, pastries, crackers, cookies, pies, and cakes. These fats should be totally avoided by everyone. They are very dangerous. More than 1 g per day puts anyone at risk for cardiovascular disease; the typical teenager in our society eats 35 g per day.
Genetically Modified Oils
Genetically modified oils, such as canola oil, which is most often produced from genetically modified oil seed, are not recommended.
Essential Fatty Acids
Essential fatty acids (EFAs) are fat soluble acids that must be obtained from the diet because they are, in fact, essential for healthy human metabolism. There are two main categories, known as omega-3 and omega-6, with a third type known as omega-9. Omega-3 fatty acids are especially important in the diet because they support the heart, eyes, skin, digestive system, immune system, joints, and brain. They also help fight insulin resistance, lower triglycerides, normalize blood pressure, reduce inflammation, prevent blood clots, and decrease the risk of stroke, dementia, and Alzheimer’s disease.
Most EFAs must undergo a conversion process in the body to make them available metabolically; however, this conversion process is compromised or nonexistent in diabetics. In their original state, omega-3 and omega-6 fatty acids exist as linolenic and linoleic acid, but require an enzyme called delta 6 desaturase to convert into their useful forms as eicosapentaenoic acid (EPA) and gamma linoleic acid (GLA), respectively. Direct sources of EPA (fish oils and wild game) and GLA (evening primrose, black currant, and borage oils) are thus an essential part of a diabetic’s diet.
Omega-6 to Omega-3 Ratio
Diabetics need to be particularly careful about selecting good sources of essential fatty acids and balancing them properly. A healthy ratio of omega-6 to omega-3 EFAs is in the range of 4:1 to 1:1; however, the North American diet typically contains an unhealthy EFA ratio of 20-25:1 omega-6 to omega-3 fatty acids. Diabetics need to eat fats and oils that address this imbalance.
While flaxseed oil is often recommended as a good fat because it contains high amounts of omega-3 EFAs, it is only utilized properly if insulin and blood sugar levels are well managed and nutrient cofactors are present in adequate amounts. Therefore, flax oil is generally not the best choice for diabetics as a source of omega-3 fatty acids.
Good quality cod liver oil in the winter and fish oil supplements in the summer are much better choices. Taking cod liver oil in the winter also helps to provide us with vitamin D that we derive from being in the sun. It can be taken in summer as well if you live in an overcast climate or avoid sun exposure and use sunscreen extensively. Be sure to check that fish oil supplements are free of contaminants, such as mercury.
Best Sources of EFAs
| EFA | Best Sources |
| Omega-3 essential fatty acids | Cod liver oil or fish oil supplementsFresh walnuts (soaked and dried first for best benefit) |
| Omega-6 essential fatty acids | Nuts, meats, and vegetables as part of the diet, not from added oils |
| Omega-9 essential fatty acids | Extra virgin olive oil. Best used raw, as in salad dressings, so as not to destroy enzymes.AvocadosMacadamia nut oil. Macadamia nut oil is higher in monounsaturated fat than olive oil and has a much higher smoke point, so it is a better choice for cooking and sautéing The natural vitamin E levels are also very high in this oil. |
Clinical Studies: Diabetes and EFAs
In addition to the broad spectrum of health benefits associated with EFAs, the importance of direct sources of these fats was demonstrated in a study conducted in London that examined the effects of GLA on diabetic neuropathy. Over a period of 1 year, 111 subjects with mild diabetic neuropathy were given either GLA or a placebo. By measuring 16 different parameters, the researchers concluded that significant beneficial effects were detectable in offering GLA to diabetics with neuropathy.
Additionally, a diet high in monounsaturated fat, such as olive oil, has been shown to increase insulin sensitivity in Type II diabetics. In a 15-day study of 10 subjects, researchers concluded that a diet that emphasized monounsaturated fats and lowered carbohydrate consumption decreased postprandial glucose and plasma insulin, and reduced fasting plasma triglyceride levels.
Key Terms
Saturated Fats: Found in higher amounts in most meats and in regular-fat dairy products, these fats are usually solid at room temperature. Too much saturated fat in the diet is considered unhealthy.
Unsaturated Fats: Found mostly in plant products and fish, unsaturated fats are considered healthier than saturated fats. Unsaturated fat exists as either monounsaturated fat or polyunsaturated fat, depending on which fatty acids are used to build them.
Saturated Fats
These fats are found in meats and meat products from ruminant animals. Studies of these saturated fats at one time placed them in the same ‘bad’ category as hydrogenated trans fats. If these animals are grain-fed, saturated fat does have a negative impact in raising insulin levels. However, when these animals are pasture-fed, not-grain fed, their fat contains high levels of omega-3 fatty acids and CLA, as well as other beneficial substances. These saturated fats are used by the body to stimulate the immune system, protect arteries, metabolize calcium, and stabilize cell walls and intestinal walls. Aim to eat meat from pasture-fed ruminant animals, and be aware that even ‘organic’ meats may come from grain-fed animals.
Monounsaturated Fats
These omega-9 fats tend to lower LDL, the bad cholesterol, but do not change the levels of HDL, the good cholesterol. Monounsaturated oils contain oleic acid, which provides many health benefits, including protection from heart disease. Oleic acids may also increase the incorporation of omega-3 fatty acids into cell membranes. These oils are rich in enzymes, including the lipases, which are activated in the stomach and facilitate the breakdown of triglycerides into free fatty acids.
Extra virgin olive oil (unfiltered, cloudy, golden yellow) and a quality brand of cold-pressed macadamia nut oil are highly recommended as a monounsaturated fats. Roasted macadamia nuts are an excellent snack food. Avocados also provide many of these same benefits. In November 2004, the FDA began to allow health claims for olive oil, including its heart health benefits. Olive oil also contains many powerful antioxidants.
Polyunsaturated Fats
These largely omega-6 fats are needed only in small amounts. Nuts, seeds, meats (if grain-fed), and vegetables will adequately supply our needs. In fact, if these fats are excessive in our diet, they may increase the free radicals in our bodies. This contributes to increasing our risk of cardiovascular disease, cancer, and premature aging. Excessive omega-6 fatty acids may also have an adverse effect on blood clotting, immune function, and inflammation.
There is no need to add polyunsaturated oils to our diet beyond what is found in nuts, seeds, meats, and vegetables; rather, the key is to add foods or oils containing omega-3 fats to achieve an omega-6 to omega-3 ratio in a healthy range of 4:1 to 1:1.
Over consumption of omega-6 fatty acids, as well as the consumption of trans fatty acids, can interfere with the body’s ability to manufacture GLA, EPA, DHA, and AA (arachidonic acid). These fatty acids are critical to many bodily functions, including immunity, inflammation, and blood clotting through their influence on prostaglandin production. To obtain adequate EPA and DHA, include organ meats, egg yolks, fish, and fish oils in your diet. GLA can be found in evening primrose oil, borage oil, and black currant oil and should be taken in supplemental form by diabetics to prevent and treat neuropathies. Butter, tallow, and organ meats are sources of AA.
Medium Chain Fatty Acids
While 90% of the fats consumed in the world are long chain fatty acids, medium chain fatty acids (MCFAs) are more easily digested, so much so that they do not need pancreatic enzymes or bile to be digested. They are already broken down into individual fatty acids by the time they enter the intestines. MCFAs provide a good source of energy and are not stored in the body as body fat, nor do they create arterial plaque. Because MCFAs are so stable and so resistant to oxidation, they greatly help to prevent cholesterol and unsaturated fats from oxidizing.
Extra virgin coconut oil is an excellent source of MCFAs, enhancing the absorption of nutrients and some amino acids, generally making them more bioavailable.
Coconut oil has been found to stimulate metabolism and to help restore the thyroid gland to normal function. This oil can contribute to weight loss and lower the risk of heart disease. Coconut oil is also the best source of lauric acid. Lauric acid is an essential fatty acid that enhances the immune system and is a strong antimicrobial that fights bacteria, viruses, yeasts, parasites, and other pathogens.
In some older studies, coconut received an undeserved bad reputation for increasing the risk of heart disease; however, hydrogenated coconut oil (trans fatty acids) was used in these studies. More recent research using extra virgin organic coconut oil has found it to be a healthy food, superior for cooking, baking, and sautéing.
Good Fat Sources
Monounsaturated Fats
- Olive oil, peanut oil
- Avocado
- Peanuts, hazelnuts, cashews, almond
- Margarine with olive oil base
Polyunsaturated Fats
- Safflower, sunflower, corn, and soy oil
- Fish oils and seafood
- Walnuts, Brazil nuts, seeds
- Polyunsaturated margarine
