A high-fat diet may be better for you than cutting back on overall fat intake, if it's the right kind of fat.
That's the early read of ongoing research, as published in the Annals of Internal Medicine, according to The Early Show medical correspondent Dr. Emily Senay.
She explained to co-anchor Hannah Storm Friday that the study is comparing people who've made an effort to reduce their total fat intake with people eating so-called Mediterranean diets. They include large quantities of olive oil and nuts that grow on trees, such as walnuts, hazelnuts and almonds.
The full study will last for four more years. But, Senay says, the early indications are that adding certain fats through a Mediterranean-style diet is more beneficial that cutting fats across the board.
The researchers are seeing strong indications that Mediterranean diets can lower blood pressure in people with hypertension. A low-fat diet's beneficial effect on blood pressure appears to be far more limited. Study participants eating Mediterranean diets have seen their HDL, or "good cholesterol" rise, while their LDL, or "bad cholesterol" has fallen. At least in this study, limiting overall dietary fat hasn't significantly affected cholesterol numbers. Also, indicators of potentially harmful inflammation within the body have been lower in the Mediterranean diet group.
What makes the fats in the Mediterranean diet different from the ones we're always being warned to avoid?
The fats in olive oil, a staple of Mediterranean foods, are mono-unsaturated, Senay says. While they are fats, their chemical structure is very different from that of the saturated fats in foods such as meat and dairy, and certain vegetable products, like coconut oil or palm oil. While there's a clear link between saturated fats and increased heart risk, the evidence continues to indicate that the fat in olive oil decreases heart risk. Keep in mind that virgin olive oil was found to be more beneficial than so-called "refined" olive oil, whose acidity level is higher. Also, fat compounds appear in the tree nuts in the form of beneficial fatty acids.
Another encouraging sign?
More fat in the diet generally means higher calorie intake, which in turn can lead a person to put on weight. But, says Senay, at least in these preliminary results, it appears that adding the fats in olive oil and tree nuts doesn't induce weight gain.
There were some people in the study who had trouble chewing tree nuts, or didn't like the way nut fragments stuck in their teeth. But most solved that problem pretty easily by getting the nuts ground up and eating them in yogurt.
The researchers say they should have a better feel for whether improvement in cholesterol, blood pressure and the other indices they've been measuring actually translates into better heart health for the patients being studied. The numbers they now have suggest improved heart health is likely, but in a few years, the actual health results should be apparent, and measurable.
So far, at least, the evidence does suggest that people who eat the Mediterranean way are onto something, Senay concludes.