Fighting about Fat: Facts and Fallacies
Nutrition professionals and government officials have been fighting about fat since the 1960’s. Ansel Keys was a researcher who was interested in understanding the contributing factors to heart disease, and he wrote a famous report called the Seven Countries Study. In this study he showed that there was a positive relationship between the amount of animal fat consumed and the amount of heart disease in each of the seven countries studied. The conclusions of this study were almost immediately questioned by a number of other researchers, including – most importantly – John Yudkin. Yudkin’s book Pure, White and Deadly, suggested that high consumption of refined carbohydrates, in particular sugar, was most closely related to heart disease.
Keys prevailed as the “official” view and became part of American, and then worldwide, nutritional policy in the early 1970s. Americans were told to limit fat in their diet and to freely eat carbohydrates. This recommendation has been modified somewhat over the years as further research has been done. A recent study was published in August 2017 in The Lancet journal. Researchers followed over 135,000 people in 18 countries, including low-, middle- and high-income nations around the world over a period of 7.4 years. This study found that the lowest total mortality rate from all causes was associated with the highest amount of fat consumed. There was no relationship between the amount of fat consumed and cardiovascular diseases. The researchers found an inverse relationship between the amount of carbohydrates consumed and death. The people who ate the highest amount of carbohydrates had the highest level of total mortality from all causes.
If you have read many of my previous articles here or in Bella, you may recall that I believe strongly in bioindividual nutrition. There is no one way of eating that is appropriate for every single person. A lower fat diet will be appropriate for some people given their genetic makeup, current health status, and activity level, and a higher fat diet will work best for others.
Fats are named by the structure of their molecules: saturated, monounsaturated or polyunsaturated. Almost all foods with fat in them have a mixture of these types, but usually one type will predominate in a given food. Olives have predominantly monounsaturated fats. Meats and dairy have predominantly saturated fats, and certain fish and many nuts and seeds have predominantly polyunsaturated fats.
Omega-3 and Omega-6 Fats are Essential
While the ideal amount of total dietary fat will vary by person, everyone needs a minimum amount of the fats ALA and LA. The omega-3 fat ALA and omega-6 fat LA are essential in the human diet. Essential means that the body cannot make them from other elements, so we must eat them. The omega-3 fats EPA and DHA can be made in the body from ALA, but the conversion rate is low. Human conversion of ALA into EPA and DHA ranges from 1 to 20 percent, and women are usually better converters than men.
It is rare to be deficient in LA because most people eat too much omega-6 fat. The ideal dietary ratio of omega-6 to omega-3 is between 2 and 4 to 1, but the actual average is 20 to 1 for a majority of the population. A diet with adequate total fat for your individual needs and an omega-6 to 3 ratio of 4:1 or less should reduce inflammation.
Research has shown that higher intakes of omega-3 fats, especially fatty fish and fish oil, are associated with reduced heart disease risk. Low levels of omega-3 and high intakes of omega-6 fats have been associated with many diseases, including Alzheimer’s, type-2 diabetes, arthritis, macular degeneration, cancer, autoimmunity and a number of psychiatric disorders. Two to three 4-ounce servings of fatty fish per week will supply the needed amounts of DHA and EPA. ALA is found in large amounts in flax, chia and hemp seeds and oils, but because of the conversion problem, it is best to eat fish also.
You can lower omega-6 intake by eliminating refined vegetable and seed oils. All vegetable and seed oils, including canola, cottonseed, corn, soy, peanut, sesame, safflower and sunflower, contain very high amounts of omega-6 fats and very little, if any, omega-3 content. Flax oil is one exception as it is high in the omega-3 ALA and relatively low in omega-6. Olive oil is also low in omega-6 and is high in monounsaturated fats. Coconut oil, palm oil and butter are also low in omega-6 fats and are high in saturated fats.
Practical ways to balance omega-3 and omega-6 intake
- Eat fatty fish (salmon, sardines, herring, mackerel, lake trout, and albacore tuna) twice a week. I have come to like sardines and buy the boneless, skinless kind to add to my salads 2-3 times per week.
- Use ground flax, hemp or chia seeds in smoothies or salads.
- Make your own salad dressing using olive oil or flax oil. Virtually all bottled dressing is made with soybean oil or canola oil which are high in omega 6. I eat a large salad for lunch almost every day with homemade dressing.
- Cook with olive oil, butter or coconut oil, not canola or other seed oils.
- Avoid purchasing packaged foods as much as possible. Most of these include either corn or soy which are extremely high in the inflammatory omega-6 fats.
- Avoid eating fried foods in restaurants. These are always cooked in inflammatory omega-6 oils.
- Take your own homemade salad dressing to restaurants or use olive oil and vinegar.
If you follow the suggestions in this article you won’t be fighting about fat anymore. Instead you will be well on your way to an anti-inflammatory lifestyle. Find out more about Ginger’s Food Rules for healthy eating in this article.