When consuming our regular diets, we would hardly eat 50 grams of fat in a single meal. If you had normal or mildly elevated cholesterol, this would the last thing you would voluntarily consume. However, a group of volunteers in Malaysia did just that to help researchers determine how various cooking oil blends affected their cholesterol levels. You may be surprised to learn that their HDL (good) cholesterol levels rose when they consumed higher amounts of palm olein.
The amount of fat circulating in our blood stream rises after a meal. And with the frequency that most of us eat, experts estimate that our blood fat stays elevated for more than 16 hours on a typical day. This can be concerning, especially if your cholesterol levels are above normal and/or you are trying to reduce your risk of developing cardiovascular disease.
But are current dietary recommendations for fat intake correct? We’re told that saturated and trans fats are the bad guys; monounsaturated fats and polyunsaturated fats are the good guys. Is this a hard-and-fast rule? Researchers at the National University of Malaysia decided to put several different edible fat blends to the test by measuring their impact on volunteers’ cholesterol levels. Their results were published in the Nutrition Journal.
The volunteers were all university students and faculty, and they either had normal or mildly elevated cholesterol. None of them smoked or drank alcohol. Nor did they take prescription medications or nutritional supplements. They were randomly assigned to two groups, each group alternating between three different diet rotations. The participants were provided with all three meals for seven days. The only difference in their meals was the type of cooking oil blend that was used:
1. Low polyunsaturated fat to saturated fat ratio (0.27): The cooking oil used was entirely palm olein sourced from Malaysia.
2. Medium polyunsaturated fat blend (1.0): The cooking oil used was a blend of palm olein and soybean oil. The ratio is in keeping with the American Heart Association’s diet.
3. High monounsaturated blend (1.32): The cooking oil used was a blend of palm olein and canola oil.
On the eighth day, after fasting for 10 hours overnight, they had their blood drawn to determine their baseline cholesterol levels. Then they were given a test meal prepared with 50 grams of their group’s cooking oil blend. The fats in their blood were measured after 1.5 hours, 3.5 hours, 5.5 hours and 7 hours. This is called post-prandial testing.
The most exciting finding was that higher post-prandial HDL levels were associated with higher amounts of palm olein present in the cooking oil blend. And this happened without affecting total cholesterol levels. Perhaps not all saturated fats are detrimental to heart health after all! The researchers indicate that more studies on people with higher cholesterol levels are definitely warranted.