Good Fats vs Bad Fats
Oh, gosh, yes, it's all changing -- the information we had twenty years ago was so wrong, and probably killed millions of people! Margerine with trans fats is a zillion times worse than butter -- in fact, manufactured trans fats have been banned in Denmark, and any food found to contain more than 2% trans fats gets you a couple of years in prison.
And with unsaturated fats, it depends if they're n-3 or n-6. You want n-3 or a mix. The ones that are bad -- again, worse than butter -- are corn oil, safflower oil, sunflower oil. They increase the risk of CVD.
Saturated fats -- meat ones are worse, whereas dairy ones are much better. Something about the dairy calcium is very heart healthy, whereas calcium salts -- which up until very recently doctors were prescribing to osteopenic postmenopausal women -- dangerously increase your risk of CVD.
For so long, studies focused on "if you have more of X vs less of X, and see a change, then it must be because of X" but they never looked at "if you have less of X, and therefore are substituting X with Y to keep calories constant, and see a change, is it due to less of X or more of Y?" Now they're going back and doing more meta analyses of old data and finding out that sure, substituting oatmeal for lard is a good thing. But substituting corn oil for butter is a bad thing!
And they're also seeing that substituting carbs for fat, as we were told to do for so long, is not necessarily the way to go. Carbs, particularly simple sugars, are being recognised as being bad. If you eat your normal diet and incorporate two glasses of water per day, your blood pressure remains unchanged (as you'd expect). If you eat your normal diet and incorporate two glasses of milk per day, your blood pressure goes down a bit.. If you eat your normal diet and incorporate two glasses of Coke per day, your blood pressure skyrockets.
The problem, of course, is that it takes so long for governments to act on information. Their policies are usually decades behind the research. And governments (well, the US government, anyhow) are made up of people who want to keep their jobs, and their jobs depend on votes, and votes depend on campaigns, and campaigns depend on money, and money depends on lobbyists, and lobbyists represent companies who have a vested interest in government policies. Lobbyists write the bills that senators present to Congress. And in the US, the corn and fast food industries are a lot bigger and have a lot more money than the dairy industry.....
(Yes, I went to a seminar recently by an international expert in this field of research and policy-making. It was awesome! I'm so lucky to work at a university where we have brilliant people, including Nobel prize winners, passing through regularly and giving talks.)
