[Xdafjgneoiwe]

There is: Butter contains 3 % trans fats. And even keto fanatics admit that trans fats are extremely unhealthy. You could say it doesn't have a huge impact and that might be true because it's only a small part of the diet.

However, any amount of trans fat is dangerous. The body's enzymes can hardly remove any trans fat build up in the arteries.

[soundwave106]

From the studies I can Google, the jury still seems to be out on the dominated trans fat in animal sources, vaccenic acid, and related compounds known as conjugated linoleic acids. The later group of trans fats actually might be beneficial to human health: some studies have linked it to anti-cancer properties (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4964663/) and fat loss (http://ajcn.nutrition.org/content/85/5/1203.long), although as indicated studies are very preliminary at the moment, so you really can't conclude anything definitely about this.

I can even Google papers such as this -- https://www.ncbi.nlm.nih.gov/pubmed/19935865 -- that seem to say vaccenic acid might not be that bad, which is contrary to the link you provided. Again -- this is more not to say vaccenic acid is good, and more that I believe the science is inconclusive right now.

Elaidic acid (the "bad" partially hydrogenated vegetable oil trans fat) is present in natural sources as well, but in much smaller quantities.

Small amounts of trans fats are pretty much found in any animal product, so it is difficult to avoid trans fats entirely unless you become completely vegan. Personally... my guess is that a small amount of animal based trans fat is not going to be a big deal overall, so a little butter is fine. The studies are most damning at the moment over partially hydrogenated vegetable oil.

[zenon]

Trans fat from partially hydrogenated vegetable oil is (mostly) Elaidic acid, which is probably harmful. Butter contains other trans fats, like Vaccenic acid. We don't know much about the long-term health effects of Vaccenic acid.

[Xdafjgneoiwe]

"Published data suggest that all fatty acids with a double bond in the trans configuration raise the ratio of plasma LDL to HDL cholesterol."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2830458/

[mlindner]

> Butter contains 3 % trans fats.

_No_ it does not. Trans fats are a completely artificial creation originally thought to avoid weight gain because it's specifically _not_ butter. They don't exist naturally in any butter.

[DanBC]

The Google Instant answer for the question [does butter contain trans fat?] says 100 g butter contains 3.3 g of trans fat.

http://imgur.com/a/i7qw0

Trans fats sometimes occur naturally in food. They're created by bacteria in an animal's stomach.

Trans fats were nothing to do with weight loss. Trans fats were used because they're cheap and have long shelf life.

[Xdafjgneoiwe]

Yes they do contain trans fats - just not the same kind - and recent research shows that they are probably just as damaging as the artificial creations. See my comment to the other poster.

[tomp]

> Butter contains 3 % trans fats

Source?

[Xdafjgneoiwe]

Normally I am all for asking for sources, but this isn't really in dispute nor hard to find. Just one of a thousand sources:

"50% of the fat content in butter is saturated fat and 4% is trans fat."

https://www.heartfoundation.org.au/healthy-eating/food-and-n...