This is Sangeeta Pradhan and I hope you have had a chance to at least skim my first 2 posts on the structure and functions of dietary fats as this podcast builds on that. As we have noted, fats do serve important functions in the body and we must have a certain minimum amount for good health. The Academy of Nutrition and Dietetics recommends approx. 20-35 % of calories from fats on a daily basis with a higher intake of polyunsaturated fats and reduced intake of saturated and trans fats.
I would also like to mention that dietary cholesterol ironically, has a relatively smaller effect on blood cholesterol compared to saturated fats and trans fats. Recently in the news there was a study that was calling into question the impact of saturated fats on heart disease. But the study was deeply flawed according to experts and a new version had to be released to correct several errors.
The research at this time points to replacing saturated fats and trans fats with mono and polyunsaturated fats. Hence it is important to replace those undesirable fats with desirable ones. When fats are replaced with refined carbohydrates however, this can decrease your healthy, HDL cholesterol that unclogs your arteries which is clearly counterproductive and increases another form of fat called triglycerides
The biggest drivers of blood cholesterol and LDL are saturated and Trans fats. It is advised that one keep one’s saturated fat intake down to 10 % of total calories, and less than 7% of total calories if you have heart disease and minimal amounts of trans fats. ( < 1%). Trans fats are also associated with decreased HDL and increased inflammation, the basis of all chronic disease and increase risk of Type 2 diabetes
So what exactly are trans fats? Trans- fats are produced when liquid vegetable oils are “hydrogenated” artificially by food manufacturers to produce a semi-solid spreadable product such as margarine. This process alters food texture, making baked products flakier (well, as it turns out, in more ways than one!), since these resulting trans fats as we now know are detrimental to health, perhaps even more so than saturated fats.
By law, since 2006, food manufacturers are required to display the amount of trans fats in grams on food labels. I would be on the lookout for ”partially hydrogenated” soybean or vegetable oils in a variety of commercial products, esp. baked goods as this is your cue that there is some trans fats lurking in there.
Last but not the least, I would also like to address the coconut controversy. Recently I was alarmed when some of my patients, (one of them being a nurse to my dismay), threw out her bottle of olive oil and replaced it with coconut oil. Her theory was that “she had been reading how healthy they were”
Turns out that medium chain fatty acids are not stored by the body and since coconut has Medium chain fats, these folks put 2 + 2 together and came up with 5! The fact of the matter is that the studies that were done were on medium chain fatty acids with 8 and 10 carbon chains. The medium chain fatty acids in coconut oil are primarily 12 and 14 carbon chains, so the studies did not even apply to them.
Coconut oil is very high in saturated fats, so I would caution you readers to limit your intake of coconut products at this time.
I hope this review was helpful, please stay tuned for more information on fats as we keep busting common myths associated with them next week. Have a great week! Thank you.
Sangeeta Pradhan, RD, LDN, CDE