Dairy fat, sugar and heart disease
It used to be that the world was simple. Everyone knew that cholesterol caused heart disease and dairy fat contained cholesterol, so it had to be avoided. Then some people started to ask too many questions and it all became complicated.
One thing we came to learn is that most cholesterol is made in the liver, and the liver keeps on making it whether we eat cholesterol or not. So the question became, why on earth does the liver make all this cholesterol, endangering our health? A few interesting new studies could point us in a new direction.
In the first study (Br J Nutr 2004, Apr; 91 (4): 635-42) researchers started out with a statement of fact (from when the world was simple): “milk fat is high in saturated fatty acids (SFA) and high intakes of SFA are associated with cardiovascular diseases.”
Oddly enough, though, when they looked at the occurrence of first-ever heart attacks in a north Sweden population, they couldn’t find any link between these two. In fact, when they analyzed some recognized risk factors for heart disease, including insulin resistance (a pre-diabetic condition) they actually found an inverse correlation between them. This means that some important risk factors for cardiovascular disease decreased as people ate more milk fat.
In another study (BMJ 2003; 327: 777-782, 4 October) researchers analyzed intakes of saturated fat in more than 40,000 US healthcare workers. They then looked at rates of stroke within this group over a period of 14 years and concluded that “intakes of red meats, high-fat dairy products, nuts, and eggs were not appreciably related to risk of stroke.”
So if milk fat does not cause first heart attacks or strokes, what does? The answer to this question is probably complex and multi-factorial, but a third study (Obes Res 2003 Sep; 11 (9): 1069-103) does at least give us a hint. The study found that when carbohydrate consumption goes up, the body rapidly starts to produce fat. Not only that, but the excess carbohydrates apparently activate genetic factors that are programmed to keep on making more fats (including cholesterol). Could sugar be the real culprit? Remember, too, that when people cut fat from their diets they inevitably end up eating more carbohydrates because of the unavoidable law of nature that says you’ve got to eat something.
