Palm olein may be less heart-friendly than thought

NEW YORK Tue Nov 15, 2011 4:20pm EST

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NEW YORK (Reuters Health) - Palm olein, a liquid form of palm oil used in cooking and baking, has been considered neutral in its effects on cholesterol but a new Danish study suggests the vegetable fat could behave more like lard in the body.

Men who ate a series of three diets, substituting a portion of their fats with olive oil, palm olein and lard, had lower levels of LDL ("bad") cholesterol and total cholesterol after the olive oil diet than after the other two.

Researchers did not show that the increased cholesterol levels had an effect on the men's health, but high cholesterol is thought to lead to an increased risk of having a heart attack.

The rise in cholesterol seen in this study "would increase the risk of heart disease by at least five percent," said Dr. Peter Clifton at the University of Adelaide in Australia, who was not involved in the work.

The research team, led by Tine Tholstrup at Copenhagen University, asked 32 normal-weight young men to replace a portion of the fats in their usual diets with palm olein, olive oil or lard during each of three weeks.

The order of the diets was randomly assigned and the study fats were contained in buns and cakes.

At the start and end of each week, the researchers collected blood samples and measured the men's weights.

After their week eating olive oil, the men had 4.5 percent lower total cholesterol levels, on average, than after the other two diets. The difference was largely due to lower LDL levels.

Lard, made from pig fat, had similar effects on blood cholesterol levels as palm olein.

Though previous studies have not always agreed on whether palm oil is bad for cholesterol levels, Clifton told Reuters Health in an email that he was not surprised by the results and that they provide a "very clear" answer.

"The majority of studies support the concept that palmitic acid in palm oil raises LDL cholesterol," Clifton wrote in an editorial that accompanied Tholstrup's study in the American Journal of Clinical Nutrition.

Palmitic acid is a saturated fatty acid found in a variety of oils, and is the primary fatty acid in palm oil.

High levels of LDL cholesterol, as opposed to high-density lipoprotein, or HDL, cholesterol, are considered bad for people's cardiovascular health.

But the authors write in their report that the increase in cholesterol after the palm olein diet was small, "and may not be of any clinical significance."

Tholstrup's team also tested the men for levels of C-reactive protein -- used to predict cardiovascular disease risk -- and did not find any differences among the three diets.

Tholstrup recently published a study that found cheese and butter, despite both being made from milk fat, produced differing effects on cholesterol levels (see Reuters Health story of November 14, 2011).

"The role of saturated fat is controversial, as newer studies have not been able to find an association between intake of saturated fat and coronary heart disease," Tholstrup told Reuters Health in an email.

Still, Tholstrup said she recommends people choose cooking oils with unsaturated fat such as olive, rape seed, sunflower, soy bean and grape seed oils.

The current study was funded by the Malaysian Palm Oil Board, a government trade agency.

SOURCE: American Journal of Clinical Nutrition, online November 9, 2011.

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Comments (3)
Loutronics wrote:
It’s now clear that dietary fats don’t effect cholesterol or inflammation. Simple carbohydrates and sugars do. Eating “buns and cakes” causes inflammation (c-reactive protein) and heart disease. The study was based on 40+ year old disproved science. Most people still don’t seem to know it, but a “cave man” diet of vegetables, eggs, and meat but virtually no sugars or simple carbohydrates makes your cholesterol and weight go way down. Oils shouldn’t be used for cooking, though if they must, coconut oil has by far the best balance of Omega-3/6 and lots of medium chain fatty acids. Eat as much as you can raw, or lightly cooked, since cooking destroys much of the nutrition and creates carcinogenic compounts. Eat all you want, lose weight, and dramatically improve your health. Really.

Nov 15, 2011 5:21pm EST  --  Report as abuse
David_Brown wrote:
Scientists need to realize that when saturated fats raise LDL, the effect is purely physiological (not pathological) and likely beneficial.

On the other hand, consuming omega-6 industrial seed oils is problematic.

Nov 16, 2011 12:48am EST  --  Report as abuse
E.T. wrote:
There’s never been a proporly designed study showing any link between saturated fat consumption and heart disease. There’s never been a valid study showing that lowering LDL in normla people has any effect on heart disease.

Twenty years ago, normal cholesterol was calculated using a simple formula, “200+age” and that didn’t change until statins were widely prescribed.

Interestingly enough, a study performed by the World Health Organization, which collected mortality (i.e. death from oany cause) data from 164 countries, showed that lowest overall mortality was correlated with a total cholesterol between 200 and 240. When total cholesterol dropped to 150, mortality increased four fold and cardiovascular mortality doubled.

Nov 16, 2011 6:16am EST  --  Report as abuse
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