Does saturated fat really ’cause’ heart disease?

Listening to the radio a few days ago, I caught a report which warned of a mince pie shortage this Christmas, as a result of the growing demand for British lard by Eastern European food manufacturers. Given animal fat’s deathly reputation, some may believe that the siphoning off of suet to other parts of the World can only bring glad tidings regarding the health of our nation. However, if the results of a recent study are to be believed, it seems that a cutting back of animal fat in the diet might actually have undesirable consequences for heart health of some individuals.

The study in question was published in last month’s edition of the American Journal of Clinical Nutrition. In it, researchers studied 235 post-menopausal women with known heart disease. At the start of the study the women had state of the arteries around their hearts assessed through a technique known as angiography (which involves injecting dye into the arteries while X-rays are taken). Three years later, each women was subjected to a repeat angiography. Dietary analysis revealed that women with the highest intakes of saturated fat saw no progression on the artery-blocking process known as atherosclerosis. In contrast, those with the lowest amounts of saturated fat in their diets saw a significant narrowing in their coronary arteries over the course of the study.

It is possible, of course, that this relationship between saturated fat and atherosclerosis might have been due to differences in other factors such as age, history of diabetes, smoking and exercise habits, and body weight. However, even when such factors were taken into account, the apparent protective effect of saturated fat remained.

While these results may come as a shock to some, they are in fact in keeping with a growing body of evidence suggesting that the link between animal fat consumption and heart disease is far from clear, particularly in women. For instance, research published in the New England Journal of Medicine found that, once the effects of other dietary components had been taken into account, there was no significant relationship between saturated fat consumption and heart disease risk in a group of more than 80,000 women. Another study published in the journal Diabetes Care found that higher saturated fat intakes were associated with reduced risk of heart disease in diabetic women.

One potential explanation for this phenomenon relates to differences in the consumption of not fat, but carbohydrate. Lower fat diets tend to be higher in carb – excesses of which can bring about changes expected to increase heart disease risk such as a lowering of ‘healthy’ high density lipoprotein (HDL) cholesterol and an increase levels of unhealthy blood fats known as triglycerides. Several studies show that low-fat diets can have unfavourable effects on these, and other, blood parameters. In keeping with this research, the recent American Journal of Clinical Nutrition study found that a higher carbohydrate intake in women was associated with increased risk of atherosclerosis, and that this was particularly true for foods that give substantial rises in blood sugar such as those rich in refined sugar and flour. For women at least, it seems that it’s the sweet, rather than the meat, in mince pies that is best avoided.

One Response to Does saturated fat really ’cause’ heart disease?

  1. Bo Piltson 12 January 2007 at 1:36 pm #

    A report that saturated fat is harmless is no big deal. I have spent the past year trying to find evidence that it is harmful, since this is what is always reported in the popular press.
    This involved writing to about 30 writers/columnists/nutritionists, etc. in 4 countries asking for the evidence they relied on. Among thos who replied at all, no one of came up with credible such evidence. Some brought up epidemiological statistics known to have been faked. I had asked for clinical evidence, none arrived.
    So I must include this among popular nutritional idiocies/superstitions.
    Do you have an idea why it is so insistently repeated when there is no evidence to back it up? Or do YOU have it?

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