- Industrially-produced trans fats in processed and packaged foods pack some heavy health risks.
- Natural trans fats such as CLA, found in grass-fed meat and dairy, can benefit your health.
- The slight differences in molecular structure between natural and artificial trans fats spell major differences for your body.
- Aim for a diet with zero industrially-produced trans fat, but don’t worry about those from grass-fed meats and dairy.
- Use this list of trans fat foods to avoid while grocery shopping
Trans fats are well known to cause bad cholesterol, heart disease, and obesity. The very thought triggers images of deep fryers, tubs of margarine, and other trans fat foods, like those mysteriously shelf-stable packaged cakes. It’s so universally accepted that trans fats will damage your health, that the FDA declared a trans fat ban, with June 2018 as its deadline for food manufacturers to remove artificial trans fats from their products.
But if trans fats are so bad, why do you feel, perform, and look better when you’re loading up your coffee with butter? In case you didn’t know, small amounts of trans fat naturally occur in red meat and dairy products. But should you worry about this type of trans fat in your grass-fed steak? Turns out, all trans fats are not created equal, and while artificial trans fats certainly deserve their bad reputation, those produced naturally fit into a healthy diet, and may even reduce the risk of some diseases.
What is trans fat?
Trans fats (or trans-fatty acids) are made through the partial hydrogenation of unsaturated fats, which can occur naturally and industrially. Adding hydrogen atoms straightens out the molecular bonds in a fat, making it more solid at room temperature. The food industry uses hydrogenation as a cheap way to make foods last longer on the shelf, enhance their textures, and withstand repeated dunks in the deep fryer.
For baking, partially hydrogenated fats are an artificial intermediate between unsaturated and saturated fats. This seemed like a great idea back in the ‘50s, when we wrongly thought saturated fats were bad for you, but we still wanted those flaky pie crusts. Nowadays, science shows that these industrial trans fats are kryptonite, and have no role in nourishing your body.
Fortunately, you can avoid foods with artificial trans fats by eliminating ultra-processed foods from your diet (more on that in a bit).
This doesn’t mean that your diet will be entirely trans-fat-free: dairy and meat from ruminant (grass-eating) animals contain naturally-produced trans fats, but not the kind you need to worry about. Bacteria in the guts of ruminant animals, such as cows, sheep and goats naturally hydrogenate small amounts of unsaturated fats found in their diets, such as linoleic acid and vaccenic acid, into beneficial trans fats like conjugated linoleic acid (CLA). The slight differences in molecular structure between natural and artificial trans fats spell major differences for your body.
Why industrial trans fat is bad for you
Artificial trans fats are just that: artificial. These are fats that nature never intended to hydrogenate, and your body doesn’t really know what to do with the end product. This leads to chronic inflammation, increasing your risk of stroke, heart disease, type 2 diabetes, and obesity. Trans fats raise the ratio of bad LDL to good HDL cholesterol. Studies also link artificial trans fats to various cancers, pregnancy complications, and weaker brain function.
The World Health Organization recently released a plan to help countries eliminate industrially-produced trans-fatty acids from their food supplies, claiming that this action could save 500,000 lives annually from death by cardiovascular disease. All things considered, industrial trans fats are the absolute worst fats for your health.
What about trans fat in butter and beef?
So, trans fat foods = bad, right? Most people are surprised to learn that conjugated linoleic acid (CLA), a popular health supplement, weight-loss aid, and star component of grass-fed butter, is actually a trans fat. CLA, and its precursor, vaccenic acid, are naturally produced by microbes in the first stomach (rumens) of grass-eating animals such as cows, so you ingest it in your grass-fed meat and dairy products.
In many ways, CLA actually works in the opposite way as industrial trans fats in your body. Unlike other trans fats, CLA actually raises your good cholesterol (HDL). Multiple studies have shown that vaccenic acid and CLA had no adverse impacts on cardiovascular risk, and some show that they improve cardiometabolic risk factors. Studies link CLA to weight loss, building muscle, and lowering your risk of diabetes. This anti-inflammatory superstar is also important in boosting your immune function, fighting cancers and heart disease, and protecting your bones.
The best natural food sources of trans fat CLA are grass-fed beef, butter and full-fat dairy.
How to avoid trans fat foods
The Dietary Guideline for Americans and the European Guidelines on cardiovascular disease prevention both recommend limiting trans fats to as little as possible, while the European Guidelines specify “preferably no intake from processed food, and <1% of total energy intake from natural origin.” While these recommendations are spot on for industrial trans fats, Dr. Clemens von Schacky, head of preventive cardiology at the University of Munich, warns the generalization of natural trans fats may be harmful: “It is important to note that no evidence is cited supporting the reduction in natural trans fats, so there seems to be simple extrapolation from health effects of industrially produced trans fats to health effects of naturally occurring trans fats.”
His study followed a group of at-risk patients in the Ludwigshafen Risk and Cardiovascular Health study. Among his participants, those with higher intakes of naturally occurring dairy trans fat were less likely to die of cardiovascular events such as sudden cardiac death. While this study does not show a cause-and-effect link, it definitely supports that more research is needed to fully understand the differences between naturally and industrially-produced trans fats. Without any direct evidence, von Schacky believes, “the advice to cut down on intake of trans fats from natural origin is counterproductive.”
Ideally, aim for a diet with zero industrially-produced trans fat, but don’t worry about those you get from grass fed meats and dairy.
Walking through your grocery store, this might seem like a piece of (packaged) cake: Everything on the shelf says 0 g trans fat! Thanks to lobbying by packaged food companies, a sneaky loophole was written in to the FDA’s ban on trans fats: any food item containing under 0.5g of trans fat per serving can be labeled as 0 g. A CDC-published study found that 84% of packaged foods with trans fats still listed “0 grams.” Even small amounts add up, meaning that consumers are tricked into eating unhealthy amounts of industrial trans fats without a clue.
Your best bet for avoiding hidden trans fats in food is to avoid packaged and processed foods entirely. When that’s not possible, go straight to the ingredients list to check for canola oil, or any hydrogenated or partially hydrogenated oils.
Here’s a list of common trans fat foods to avoid:
- Unnatural peanut butter
- Granola bars
- Crackers and snack mixes
- Prepared cakes and pies — especially those with frosting
- Cake and brownie mixes
- Pancake and waffle mixes
- Microwave popcorn
- Candy with cream filling
- Frozen dinners
- Ice cream
- Doughnuts and muffins
- Fast food
- French fries
- Fried or battered food, including fish sticks and chicken nuggets
- Frozen pizza
- Biscuits, crusts, and anything with a flaky texture
- Non-dairy creamers
- Breakfast sandwiches