In the previous posts in this series, we explored three important components to a micronutrient-rich diet:
1. Pack in the produce,
2. Include protein in every meal, and
3. Choose your carbs carefully.
In order to promote optimal health, we're exploring these groups of foods looking for rich sources of micronutrients. This post discusses fats, and the next (and final) post will address beverages before concluding this series. Alright, here's the skinny on fat.
4. All fats are not created equally.
Refined vegetable oils
According to an article abstract from the European Journal of Lipid Science and Technology, the process of refining canola, sunflower, and soybean oil destroys much of the oils' healthful and protective micronutrients. That's 93-98% of polyphenols, 10-36% of tocopherols (vitamin E), and 6-52% of total plant sterols. In addition to not providing the consumer with beneficial micronutrients, this loss means that the oils are more susceptible to oxidation - especially with high-heat cooking - which promotes free radical formation and can increase risk for cardiovascular disease. In Europe, industry has recognized this and appears to be looking for ways to retain the nutritional content of oils during the refining process. Until we achieve that in America, it is best to choose vegetable oils that are minimally processed. Conventionally processed vegetable oil, soybean oil, corn oil, and canola oil are highly refined and not the best oil choice. I definitely recommend avoiding margarine and vegetable shortening because these most often contain harmful trans fats. Better vegetable oil choices include flaxseed oil (use fresh only - do not heat), avocado oil, and walnut oil. Organic, cold-pressed or expeller-pressed canola oil, peanut oil, or sunflower oils are ok given the alternative processing they receive. Sesame oil is also a great choice for cooking or other uses. Toasted sesame oil is strongly flavored, so use the toasted version sparingly and only in foods appropriate for that strong flavor. Keep these oils in a cool, dark place and avoid those sold in clear glass/plastic bottles as this increases risk of oxidation (aka spoilage).
Olive oil is produced differently than the refined oils discussed above. It's made simply by grinding and squeezing olives, so it retains much more micronutrients than its refined counterparts discussed above. These retained micronutrients (as well as the traditional dark tinted bottle) help to protect against oxidation, which is important for your health. Olive oil's main polyphenol (powerful micronutrient), oleuropein, was found to prevent osteopenia caused by inflammation in rats. Polyphenols from virgin olive oil have been found in human HDL tissue where they continue to act as antioxidants inside the body. Not convinced yet? Another study showed that phenolic acid from olive oil helped improve blood vessel health in people with high blood cholesterol. There has been a lot of talk lately about olive oil fraud - taking cheaper vegetable oils and tinting them green to make them look like olive oil. This fraud has been reported in Europe, and seems to only affect imported oils. You can get around this potential issue by buying olive oil from California or elsewhere in the USA, or purchasing the imported stuff from a retailer you trust. UC Davis published an initial report on this topic - which has of course been contested. The New York Times reported on this as well.
I certainly don't recommend that everyone go out and eat a stick of butter, and I'm still on the fence about putting it in your coffee, but moderate use of butter (a few Tablespoons per day) does have benefits that are worth discussing. Butter does not go through the same refining process as vegetable oils. Butter made from cows's milk has a yellow color that is from a natural form of vitamin A. The color is often more pronounced in the Spring when cows eat more fresh grass instead of the grains they sometimes rely on for food in the winter. Two tablespoons of regular Land-O-Lakes butter contains 34% of a woman's daily requirement for vitamin A (26% of needs for a man). By contrast, most margarine has no vitamin A (some brands add it as an ingredient). Vitamin A plays all sorts of essential roles in the body, and because it is fat-soluble, it is absorbed better from foods like butter which contain fat. According to the Linus Pauling institute at OSU, Vitamin A is "involved in regulating the growth and specialization of virtually all cells in the human body," and it "has important roles in embryonic development, organ formation during fetal development, normal immune functions, and eye development and vision." So pregnant women and those who want normal immune function and vision: feel free to enjoy butter on your toast, fry your eggs in butter oil, and throw out that artificial buttery spread made of refined vegetable oils. Butter also contains short- and medium-chain fatty acids (such as butyric acid), which have immune system strengthening properties. It is one of only a few commonly consumed dietary sources of vitamin K2, which is another important, and often overlooked, nutrient. And it contains vitamin E as well as a trace amount of minerals such as magnesium and iodine. While all brands of real butter are nutritious, the best butter is from 100% grass-fed cows from brands such as Kerrygold.
But what about saturated fat? This is a complicated topic. We're finding more and more these days that the saturated fat story is a complicated one, and many factors come into play when looking at the health effects of a saturated fat-rich diet, including genetics. Saturated is a term that applies to many different fatty acids, some with more benefits than others. I think where we went wrong is we lumped all saturated fat into one category and called it "bad." As saturated fat is technically a macronutrient, we'll have to save this topic for another blog post.
The coconut is an important fruit. It provides food for millions of people and is often called the "tree of life." Coconut plays a role in Ayurvedic medicine and its medicinal use was documented 4,000 years ago. Coconut meat, oil, and water have many applications in health and in food and nutrition. Unfortunately, the beneficial aspects of coconut are sometimes exploited by people who are not likely to understand its traditional uses such as in Ayurvedic medicine. This is how a traditionally useful plant becomes a "superfood" and a "cure-all" on a TV segment. The truth about coconut is that we have more to learn. Coconut oil is high in saturated fat, but it is specifically rich in medium chain triglycerides (MCT), which have many benefits. MCT is a big topic that deserves its own blog post in the future. [Source for this paragraph can be found here].
While virgin coconut oil does appear to have some antioxidant activity, and there are some trace minerals, there don't seem to be a whole lot of micronutrients in coconut oil. While coconut oil makes for delicious pan-fried fish, is great in baking, and has other health benefits, it is not necessarily a winner in the micronutrient category.
Yes, we know that lard contains saturated fat, which as discussed above is a topic for another day. It's not all saturated though - 50% of the fat in lard is monounsaturated. We know that animals tend to store toxins in fat tissue, so lard from non-organic animals can carry agricultural toxins. But organic lard is actually a great source of vitamin D! If you have a friend or other source that properly renders lard from organic livestock, consider adding it into your cooking oil rotation, especially if your doctor told you that you need more vitamin D.
Oils consumed naturally in foods like nuts, seeds, and avocados
The most micronutrient-rich way to get your fats is to eat them as part of real foods! Enjoy avocados, olives, nuts, seeds, well-raised meat and eggs knowing that the fat helps your body to even better utilize the micronutrients packed into these nutritious foods.
Whew! That was a long post. And it took me all month to write. I hope to make the posts a little lighter and shorter in the future. I'm just so passionate about looking at the diet from a micronutrient-rich viewpoint! I hope you enjoyed this, and learned a thing or two as well. I'll leave you with a recipe.
Recipe: Roasted Salmon and Olive Mustard Butter with Orzo by Epicurious
The inclusion of butter, olives, and salmon means this recipe contains several micronutrient-rich sources of fat. Substituting a whole grain like brown rice or farro for the orzo would make for an even more nourishing meal. Please comment if you try this dish - I'd love to know what you think! The recipe is here. I think the olive-mustard butter would be good on other meats too, such as chicken.
Source for nutrition information: usda nutrient database, available at https://ndb.nal.usda.gov
Additional references: http://www.westonaprice.org/know-your-fats/why-butter-is-better/, http://well.blogs.nytimes.com/2016/10/14/since-milk-is-white-why-is-butter-yellow/?_r=0, http://lpi.oregonstate.edu/mic/vitamins/vitamin-K#food-sources
Lindsey Hays, RDN, LN
Lindsey Hays is licensed as a Nutritionist/Dietitian in the state of South Dakota. While she holds a Registered Dietitian Nutritionist (RDN or RD) credential which is nationally recognized by the Commission on Dietitian Registration, she is not licensed to practice as a nutritionist or dietitian in states other than South Dakota. She is a Certified Dietitian in the State of Washington. The information on blackhillsnutrition.com is not intended as medical advice. The content of this site is not intended to provide or replace medical advice, nor should it be used to diagnose, treat, cure or prevent disease. Always consult a qualified healthcare professional before changing your diet or medications. For full disclaimer statement click here.