Wednesday, April 9, 2014

Fats are not the enemy

Allison Aubrey presented a case for adding some fat to our diets on  NPR's Morning Edition as few weeks back.

Fats have been the target of most of the popular dietary plans. They are looked upon as the enemy to any healthy lifestyle. But is that justifiable and right?

It is well documented that saturated fats can raise the LDL ( Low-density lipoprotein)in the blood, which is the so-called bad cholesterol. Whereas on the other end, plant-based fats such as those found in nuts and olive oil are actually beneficial to our heart health and can help reduce the risk of heart disease. Yet it seems the risks might be more then the benefits, leading most of us to minimize fats intake whenever trying to eat healthy.

Thus the task of  convincing most of us to bring some ats back into our diets is a tough one.
Here is an excerpts of what experts had to say to Allison Aubrey on the subject;

"Fat was really the villain," says , who is chairman of the department of nutrition at the Harvard School of Public Health. And, by default, people "had to load up on carbohydrates."
But, by the mid-1990s, Willett says, there were already signs that the high-carb, low-fat approach might not lead to fewer heart attacks and strokes. He had a long-term study underway that was aimed at evaluating the effects of diet and lifestyle on health.
"We were finding that if people seemed to replace saturated fat — the kind of fat found in cheese, eggs, meat, butter — with carbohydrate, there was no reduction in heart disease," Willett says.
Willett submitted his data to a top medical journal, but he says the editors would not publish his findings. His paper was turned down.
"There was a lot of resistance to anything that would question the low-fat guidelines," Willett says, especially the guidelines on saturated fat.
Willett's was eventually published by a British medical journal, the BMJ, in 1996.

But here's where it gets interesting: "We've learned that carbohydrates aren't neutral," explains , an epidemiologist at Harvard Medical School.
"[Carbs] were the base of the pyramid," says Mozaffarian. The message was "eat all carbohydrates you want."
Americans took this as a green light to eat more refined grains such as breads, processed snack foods and white pasta.
"But carbohydrates worsen glucose and insulin — they have negative effects on blood cholesterol levels," he says. The thinking that it's OK to swap saturated fats for these refined carbs "has not been useful advice."
He says it's clear that saturated fats can raise LDL cholesterol, the bad cholesterol. But that's only one risk factor for heart disease.
There's now evidence that — compared with carbs — saturated fat can raise HDL cholesterol (the good cholesterol) and lower trigylcerides in the blood, which are both countering effects to heart disease, he says.
"When you put all of this together," says Mozaffarian, what you see is that saturated fat has a relatively neutral effect compared with carbs. He says it's "not a beneficial effect but not a harmful effect. And I think that's what the recent studies show." He points to a of studies published in 2010.

He also points to a highly publicized that concludes there's no convincing evidence to support the dietary recommendations to limit saturated fat.

The in that paper have created quite a bit of controversy. For instance, the American Heart Association it stands by its recommendations to limit saturated fat.


Although these new points of view don't say 'Go ahead and load up on fats' they do make it clear that fats should not be excluded from our diets completely. Maybe moderation is a good way to go with all diets. 

 
References:
Rethinking Fat: The Case For Adding Some Into Your Diet (NPR)

 

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