19 August 2012

Vegetable Oils - Health Hazards

In my post about Evolution, I mentioned that during more than 2 million years saturated fat was part of our diet. Evolution should be our best guide for what constitutes a healthy diet.  The longer we've been eating a certain food as a species, the less harm it is likely to do. We are supposed to consume food we are genetically adapted to. Most probably a few thousand years are enough to adapt to a new kind of food, but a few hundreds are not.
The diet of human beings consisted of a higher ratio of saturated fat vs. polyunsaturated fat until recently. Vegetable oils (polyunsaturated fat) became widely available on a daily basis only about 50 years ago. In the same time, the consumption of butter (saturated fat) declined. This means that over the past decades the composition of the fat in our diet changed from high saturated fat to high polyunsaturated fat.

Our brain is composed of 70% fat, mostly in the form of myelin that insulates nerve cells. Fat is also the primary component of cell membranes in our body. Any change in the composition in our diet can have profound physiological effects on our health.
"Changing the proportion of saturated to unsaturated fats in the diet, [...] might well change the composition of the fats in the cell membranes. This could alter the permeability of cell membranes, which determines how easily they transport, among other things, blood sugar, proteins, hormones, bacteria, viruses, and tumor-causing agents into and out of the cell. The relative saturation of these membrane fats could affect the ageing and the likelihood that blood cells will clot in vessels and cause heart attacks."
                                                                          - Gary Taubes
In the 1950s, a trial (Anti-Coronary Club Trial) had been conducted to see the benefits of a "prudent diet" which consisted of a high ratio of polyunsaturated fats (corn oil and margarine). The polyunsaturated fat ratio was 4 times greater than that of typical American diets. The control group consumed a typical American diet. Results: 8 members of the group died of heart attacks, nobody in the control group.

In 1969, Seymour Dayton reported the following of his trial where again in one group the saturated fat from butter, milk, cheese, ice cream, had been replaced with corn, soybean, safflower and cottonseed oils. The members of the other group were eating a diet higher in saturated fat from animal products. The death rate was equal in the two groups. The cholesterol level dropped in the first group, however the cancer rate was higher than in the saturated fat group. This vegetable oil diet failed to increase longevity. (Polyunsaturated fats also cause cancer in laboratory animals.)

The Helsinki Study: The same type of experiment as above: one group was given a high vegetable fat diet, the other a normal saturated fat diet. The men in the vegetable fat diet lived longer, but the women did not.

After the Minnesota trial (1968), where two groups of people were given a similar diet as described in the trials above, had similar results with the Helsinki Study: women had more heart attacks than the saturated fat group.

Overall, these vegetable fat diets were associated with an increased risk of heart disease.


1 comment:

  1. I eat even more butter now because of you. And it shows, everything is better. Thank you Ilona.
    ( It was anyway my favorite, comfort food and now I spoil myself almost everyday, especially when I am busy. ) :). One more thing, if the butter could come from GRASS FED cows it would make an even bigger difference. Don't look at the price. There is no price to high for the good fats, especially when is about children. And that will be the right signal for the food industry as well. That we know what is best, we want what is best and we are willing to pay a higher price for it. And hopefully things will slowly change, from the bottom to the top if not the other way around.
    Dear Mothers feed your children butter. I do it every day, like my mother used to do it. And they love it.
    One more think:
    The butter and the lack of sweet drinks and sweet snacks in my toddler's diet almost completely healed his teeth ( he was born with an enamel defect, six of his front teeth were just half covered with enamel; after eruption, they looked half white, half yellow. And when the dentist asked me this year ( two years after the last visit) if he lost his teeth due to cavities I proudly showed her his irresistible white smile. No sweets and lots of good butter on a balanced diet ( with reduced/without refined products from grains, consider white flour and white rice processed and refined) and one doesn't even need a dentist. And sometimes even better thinks will happen, like what it happened to my son - but when he has his buttered bread he eats almost equal amount of bread and butter and he eats it happily. And his teacher noticed it, he doesn't fall ill. His first year in kindergarden, with 50 kids around and he didn't get a day of holiday for being sick. I am a witness and he is a proof. Eat well - be healthy.
    Lili (romanian doctor)