Dietary Fats

With all the information out there, I doubt there is anyone that doesn’t know what dietary fats are. Underneath that umbrella, however, there are a few nuances. There are lots of different types of fats and honestly, I struggle to keep them straight. I don’t talk to my patients about polyunsaturated and monounsaturated fats – because if I can’t organize them in my head (after the gazillion science classes I have taken in my life), how am I supposed to ask my patients to memorize these classifications?

In my office, I teach my patients about nature-made fats and man-made fats. Much easier to understand and classify. It’s not a perfect system, but neither is the college admissions process and we put it with it, right? We talk about the fact that Mother Nature provided us with some fats – and that these fats are typically great for our health. She gave us avocado trees and olive trees and coconut trees and the fruit of those trees can be eaten right there – without having to cook or process it. I don’t know of anyone that has developed excess weight or chronic disease from simply eating too many olives.

Mother nature also gave us cows and pigs. Whether or not you agree with eating these things (or eating the milk that the cows produce) is a story for another day, but most of the time, eating fat that comes from cows’ milk or from eating dear old Wilbur isn’t going to cause obesity or chronic disease. We didn’t evolve to eat as much of the milk products and the meat as we do the avocados – the sheer amount of labor involved in turning milk into cheese and butter would prohibit mass consumption of these things. Plus, in a hunter/gatherer world, the animals would have been a part of our day-to-day lives, and sacrificing them to make bacon and sausage wouldn’t have been done on a daily basis.

Sadly, during the last hundred years or so, human beings have figured out how to trick the system – to get cows to make more milk and how to fatten up the animals faster to maximize the meat from them. We’ve learned that if we feed them something like corn pellets and inject them with antibiotics, they will gain weight faster, we can make more money off each animal, and people will like the taste of the meat better. Although this dramatically decreases the health value of the meat and milk products, for most of us, we either ignore it or justify it because we like the cost savings. And since we don’t have to tend to the needs of our pigs and cows, we can eat them (and the foods that come from them) without much tugging at our emotional heartstrings.

Along the way, we have also figured out how to synthesize fats from things that otherwise wouldn’t have been doable. Things like sunflowers and corn and soybeans and this crazy, weird, genetically engineered plant called a rapeseed plant (which, once processed, gives us canola oil). Kudos to the people that figured out how to turn these things into fats. I wouldn’t say they are healthy fats (and they are certainly lower quality fats than those obtained directly from olives or avocados) but in general, they aren’t toxic.

Being an ambitious species, however, we couldn’t stop there. In the early 1900’s we figured out something else. We figured out how to take these fats and make them solid at room temperature. We figured out how to modify them so that they don’t get rancid – so they can be stored safely for a long time without turning fuzzy and funky. We learned how to add hydrogen atoms to these oils – in other words, how to partially hydrogenate them. And when we first figured it out, it was earth-shattering. Using partially hydrogenated fats (or trans fats) in place of butter or olive oil meant that we could keep that food in the pantry for months instead of days. Restaurants didn’t have to change out the oil in the fryer machines nearly as often – they could turn the fryers off and head home at the end of the night, then fire it back up the next day.

And, even better, most people liked the taste and the texture of foods better when we used trans fats in place of “healthy fats”. Triple bonus. Foods made with these fats were cheaper, lasted longer on grocery store shelves, and people wanted them more than they wanted the stuff made with butter. So we kept cranking these things out.

Until.

Until we discovered that manufactured trans fats are killing us. Trans fats create inflammation, which is linked to heart disease, stroke, diabetes, and other chronic conditions. They contribute to insulin resistance, which increases the risk of developing type 2 diabetes. Even small amounts of trans fats can harm health: even a small amount (less than 2% of daily calories) increases the risk of death from any cause by 34% and from coronary heart disease (CHD) by 28%. Trans fats have no known health benefits at all. In fact, trans fats are so unhealthy that in 2015, the FDA banned the use of trans fats in all foods sold in American restaurants and grocery stores, declaring that by 2018, they needed to be completely eliminated.

Sadly, when the FDA made this declaration, the food industry fought back. The FDA has repeatedly extended this deadline for products produced prior to 2018. In addition, some foods were considered to be exempt from the ban. Consequently, they are still found in some products, such as fried or baked foods and non-dairy coffee creamers.

It can be tricky to completely avoid trans fats. In the United States, food companies can label their products as “trans-fat-free” as long as there are fewer than 0.5 grams of these fats per serving. As long as they adjust the serving size, the label can round down to zero. However, a few “trans-fat-free” cookies could quickly add up to harmful amounts. To avoid trans fats, it’s a good rule of thumb to avoid foods that have any partially hydrogenated items on the ingredients list.

At the same time, reading labels doesn’t always go far enough. Some processed foods, such as regular vegetable oils, harbor trans fats but fail to name them on the label or ingredients list. One U.S. study of store-bought soybean and canola oils found that 0.56–4.2% of the fats were trans fats — without any indication on the packaging.

Since you can’t make trans fats without a factory, the most obvious way to avoid trans fats is to avoid highly processed foods. However, if you are going to eat highly processed foods, these are the ones mostly likely to harbor the deadly fats:

• Baked goods, such as cakes, cookies and pies
• Shortening
• Microwave popcorn
• Frozen pizza
• Refrigerated dough, such as biscuits and rolls
• Fried foods, including french fries, doughnuts and fried chicken
• Nondairy coffee creamer
• Stick margarine

Moral of the story – always know what you are eating. Even better, make what you are eating. And keep learning.

You know where to find me if you want to learn more

Courtney Younglove, M.D.