Skip's Shortcut: This is an important post on fat and your health. You need to know this stuff, but maybe I gave too much information. Sorry, I do that sometimes. So here's the shortcut—read the three lessons of Dr. Holman below, skip down to the table "Healthiest Cooking Oils," then jump to Healthy Change #16. Oh, and please don't forget to leave a comment.
You may take a pass on Dr. Ralph Holman’s favorite lunch—sardine and herring with canola oil on rye bread, followed by an apple—but what he learned during his career should influence what you do eat. Holman studied the blood fats in people around the world and made three key discoveries:
1. Omega-3 and omega-6 fats—both essential to life—compete for the same metabolic space in our body. One will crowd the other out, so to get enough of each, they must be balanced in our diet.
2. There is an annual cycle in nature: the green plants of spring are rich in omega-3, while the seeds harvested in fall are full of omega-6.
3. Year around, Americans eat too much omega-6 and too little omega-3 and this is a known cause of depression, dementia, memory dysfunction, attention-deficit disorders, mental diseases, and vision problems. Though not proven, some theorize that obesity and violent behavior can be added to the list.
The culprits behind our excessive omega-6 fat intake are the “seed oils.” Originally they were called vegetable oils, which gave them a healthy sound. The so-called edible oil industry grew around their use. Edible is not the best word as these oils were usually hydrogenated, but in the beginning we were ignorant of the danger of manufactured trans fats.
The consumption of seed oils exploded in the last century with the rise of processed foods. The first big product was Crisco, introduced in 1911 (originally made from cottonseeds, later mostly soybean oil) which handily displaced lard; next was margarine, which overtook butter in the 1950s; along the way salad oils (liquid shortening) found their way into our dietary.
Soybeans are the dominant edible oil source. If you check the ingredient list of chips, crackers, cookies, breads, and processed foods in your grocery store you will find soybean oil (with a little corn, cottonseed, or safflower oil). These oils are also found in margarine, sandwich spreads, salad oils, shortenings, and mayonnaise. They’re common to most processed foods, especially fast foods.
The War Against Saturated Fats
America got itself into a crazy mess regarding fats. In a misguided attempt to reduce heart disease, influential scientists vilified saturated fats—like butter and lard—despite millennia of safe use. The newly invented polyunsaturated fats—found in seed oils—were wrongfully hyped as the cure. It made a good business but the oils were bad medicine.
Europeans, by contrast, chose to stay with traditional fats. The French, despite their creamy sauces and butter, largely avoided heart disease. In recent decades, heart disease in southern Europe has declined to even lower levels as prosperity put more saturated fats on the dinner table.
There is painful irony in our anti-saturated fat experiment: In attempting to solve a problem, we made it worse. When we reduced saturated fats, we replaced them with hydrogenated seed oils and sugar, both now implicated as causes of heart disease. Worse, we sowed the seeds of two additional epidemics: overweight and type 2 diabetes. It’s a big fat mess.
High-Oleic Seed Oils
For years seed oils were falsely promoted as healthy because they were polyunsaturated and certain polyunsaturated fats (omega-3 and -6) are essential to life. Unfortunately, omega-3s are reactive to oxygen when refined so to extend shelf life they were removed by hydrogenation. The resulting trans fats were a health disaster.
To reduce the need for hydrogenation, seed plants are being modified through GMO (genetically modified organism) and other techniques to reduce polyunsaturated fats. Given names like “high oleic” oil, many food products now use these new oils and products made from them proudly carry the “zero trans fats” banner. But are these modified oils healthy enough for long-term use? Though the FDA allows their use, some observers are uncomfortable. After all, the FDA still allows the sale of food with trans fats. In time we may know, but for now here are some concerns with high-oleic oils:
1. About ninety percent of the soybean and corn crops are GMO per reports. The long-term healthiness of consuming GMOs is a hotly debated but unsettled issue. In Europe GMOs are generally not allowed.
2. The new “high oleic” varieties are low in omega-3, and have an unhealthy omega 6:3 ratio.
3. Seed oils are refined using chemical solvents like hexane (a hazardous pollutant per the EPA) plus heat exposure (during hexane recovery, bleaching, and deodorization) that can harm the nature of the fats.
Though approved by the FDA, we cannot be sure about the long-term healthiness of these oils. My plan is to follow the “century rule” and avoid them as best I can.
To date, two of fifteen Healthy Changes have addressed fats. Healthy Change #2 addressed the worst source of trans fats—deep fat fried foods. There are still plenty of sources in the grocery store unfortunately, mainly in processed foods, particularly fast foods. A rule of thumb is to eat nothing that has the term “hydrogenated” in the ingredient list.
Healthy Change #11 recommended that two traditional fats, butter and olive oil, be returned to our dietary, and suggested that people reacquaint themselves with a product their great-grandmothers used—lard.
Dietary fat is the subject of two more healthy changes: this post explains how to eat less omega-6 seed oils, and a future post will show how to eat more omega-3 fats from plants and animal sources.
Note: If your diet is based on herbs (vegetables, legumes), fruits, whole grains, nuts and a little meat, you will automatically consume a healthy fat profile. The problems start when we replace whole food with processed and fast foods. Briefly, the average American should eat 1/3 as much omega-6 and more omega-3.
Please comment on how you include healthy fats and oils in your diet.
Need a reminder? Download our Healthy Change reminder card. Print and fold, then place in your kitchen or on your bathroom mirror to help you remember the Healthy Change of the week.
An "amen" to this post can be found in the American Journal of Clinical Nutrition's May 2011 issue (out now in digital form). The article is titled "Changes in consumption of omega-3 and omega-6 fatty acids in the U.S. during the 20th century" and confirms the points in this post:
a.) We are eating too much omega-6, about ten-fold more than omega-3, and the main cause is the astounding increase in soybean oil since World War II. (Main sources are processed and fast foods, and fried restaurant foods.)
b.) There has been a decline in our intake of omega-3 DHA, critical to the brain, eyes and nerves.
So all the more important to adopt the Healthy Changes noted above.