During an 8 year period, almost 50,000 women, ages 50 to 79, participated in a study sponsored by the Women’s Health Initiative (WHI) Dietary Modification.
Results suggested that we abandon low-fat diets as apparently they do not protect against breast cancer, colorectal cancer or cardiovascular disease and do not result in lower body weight.
The WHI trial was the most expensive study of diet ever conducted so we should listen to what the results suggest, shouldn’t we?
Let’s look at this more closely.
This study was begun at a time when the low-fat diet was being promoted as the solution to epidemics of heart disease, cancer and obesity in North America. At least their heart was in the right place.
These women received dietary counseling to increase their intakes of fruits, vegetables and whole grains and lower the fat content of their diet. Yes, we need to be educated to make the right choices.
All kinds of things were tracked and compared to those with higher fat intakes.
In the low-fat group, only LDL cholesterol levels were significantly lowered. There were trends toward a lower risk of breast cancer and lower body weight, but these were not statistically significant. In other words, the numbers didn’t make enough of a difference to recommend reducing fat in your diet.
Looking at this study at face value is not in our best interest. There are some issues that stand out.
It seemed that a big challenge for the women was their difficulty in following a low-fat diet despite all the counseling and education they received. Although the target was 20% dietary fat, most were only able to achieve 38% to 29%.
A big flaw in this study also had to do with the fact that it relied on self-reporting of dietary change. It is likely that the women were underestimating their dietary fat because testing for triglycerides and HDL cholesterol levels showed no differences. It’s like letting the wolf watch over the sheep.
The women were also told to limit their overall use of fat including good fats as well as the bad saturated and trans fats.
If current thinking suggests that polyunsaturated and monounsaturated fats, such as olive oil, are health promoting, then it makes little sense to exclude these fats too.
In spite of all this money spent , we have learned very little. It may be that smaller, better designed studies that can be repeated with varying criteria may be a better way to go.
In any case, introducing a raw, cold-pressed olive oil to your diet will benefit you greatly and should be one of only three oils that should make it into your cupboard.
My next post will address this topic in detail.
Tags: cholesterol, HDL, low fat
