Don't eat margarine or any other fake butter substitutes. And, definitely don't avoid butter because you think it is bad for you. It's not.
Butter–from grass fed cows–is one of the most ultimate, nutrient dense foods one can consume.
Butter is basically animal fat with slight traces of dairy proteins and sugar. However, the key here is: eat only butter from pastured, grass-fed animals.
Butter from factory-farmed animals that are fed grain contain an unhealthy balance of fatty acids and vitamins. And, this in turn makes grain-fed butter not so healthy for you (in fact these differences make grain-fed butter the likely culprit in inflammation and disease).
Let's break it down:
CLA (conjugated linoleic acid): This naturally occurring “good” trans-fat has been shown to reduce obesity, belly fat, suppress the growth of tumors and improve overall heart health. Interesting tidbit, there is 3-5 times more CLA in grass-fed butter than grain-fed butter.
Vitamin A: This fat soluble vitamin is imperative for an optimal immune system, vision, bone development and reproduction. It is only present in animal products–however, some fruits and vegetables contain what are carotenoids which your body can convert to vitamin A. When it comes to grass-fed butter–vitamin A is the reason for its rich golden color (compare that to your vitamin A lacking factory farmed pale white butter).
Vitamin K2: Another fat-soluble vitamin that helps with calcium absorption. More importantly, vitamin K2 has been shown to prevent, reduce and counteract arterial plaquing (yes, counteract arterial plaques!). This amazing vitamin is found in healthy doses in the fat of pastured animals. You see, cows eat a lot of green grass that contains vitamin K1; in the cows stomach K1 is transformed into K2 and then K2 is found in the dairy and fat from these cows.
FYI: the grain fed to commercially raised cows does not contain much vitamin K at all. Hence you're not getting any vitamin K2 from the butter these animals produce (and, that means you're not getting any of the heart protecting effects of vitamin K2.)
Omega 3 to 6 ratio: The ratio of these two essential fatty acids is really important. Ideally, we are ingesting them in a 1:1 ratio. However, the typical American diet–high in plant oils (like soy and corn oil) and processed, packaged foods is very high in Omega 6's. It is estimated that most people following the SAD (standard American diet) consume a 10:1 or 20:1 ratio of omega 6's to 3's. Science shows that this excess of Omega 6 to Omega 3 is the main reason for inflammation and diseases like diabetes, obesity, rheumatoid arthritis, cancer and all autoimmune diseases.
So, why am I telling you all of this?
Butter from grass fed cows have an omega 6 to3 ratio of 1:1. And, the ratio in butter from grain fed cows is upwards of 10:1. Now, you see that eating butter from grain-fed cows is actually detrimental to your health BUT eating butter from grass-fed cows is actually beneficial to your health. AHA!
Takehome: eat grass-fed butter! I recommend consuming about 4 tablespoons per week. It tastes so damn good and is a major source of disease fighting nutrients. Don't be afraid to put a pat of butter on your sweet potato or to cook with it. And, definitely don't cook with Omega 6 heavy vegetable oils like corn, soy, safflower or canola oil (read this blog on the best oils to cook with).
The best store-bought brands of grass-fed or pastured butter are:
Kerrygold and Organic Valley
Also, most local farmer's markets will carry some awesome butter from grass-fed cows. Yum!