Saturated fat mainly comes from animal-based ingredients such as meat and dairy products. What we see in many of these studies, going all the way back to the Harvard Nurses's Study in the 70's and 80's, is that while saturated fat was reduced in the diet to measure the health impact, the proportion of animal-based and plant-based ingredients in the diet remained unchanged. Among many participants, instead of eating plant-based food to reduce saturated fat intake, they simply ate leaner meats. Since the rate of chronic illness did not decrease, it was concluded that saturated fat intake was not correlated with health.
It is the position of many plant-based nutritionists and scientists that consuming any type of animal-based food, whether low or high in saturated fat, promotes chronic illness, including heart disease and cancer. In fact, according to Dr. T. Colin Campbell of The China Study, in this paper, the disease promotion may be linked more to animal proteins than to other nutrients. However, Dr. Esselstyn from the Cleveland Clinic has shown that removing all saturated fat from the diet can reverse heart disease.
In order to see health improvements or a decrease in chronic illness risk, those in the studies should have increased the amount of plant-based ingredients in their diet and focused less on the single nutrient of saturated fat. Plant-based ingredients act to fight and reduce disease risk and are the best known source for moving the needle when it comes to positive health changes. Further, by focusing on increasing the proportion of plant-based to animal-based ingredients in the diet, if not eliminating animal-based ingredients altogether, study participants and the general population would lessen the importance of any single nutrient in the diet, called reductionism, and be more focused on providing their systems with a wide range of complex carbohydrates, anti-oxidants, phytonutrients, and fiber, which act in unison to keep us healthy.
As more studies are conducted and specific nutrients such as saturated fat make headlines, knowing how to analyze the results can go a long way to making 'wholistic' health decisions which have viable and positive long term benefits.