My dad loves to look at the weekly grocery ads. Like most families, we tend to focus on eating more poultry and fish, both for economic and health reasons. But since it’s the holidays, Dad is considering purchasing a standing rib roast so we can celebrate Christmas with a great feast. And surprisingly, recent studies are indicating that eating that hunk of beef may not be as bad for you as you think.
A study published in the American Journal of Clinical Nutrition reports that an analysis of 21 studies turned up no significant association between saturated-fat intake and an increased risk of heart disease or stroke. As reported by Reuters.com, the 21 studies included a total of 348,000 adults. Participants, who were in good health at the start of the various studies, described their diet habits and then were followed by researchers for up to 23 years. Approximately 11,000 of the participants developed heart disease or suffered a stroke during the time of the study. This study did have some limitations. “The analysis included what are known as epidemiological studies – where the researchers looked for associations between people’s reported diet habits and their risk of heart disease and stroke. These types of studies have inherent limitations, like depending on people’s recollection of their eating habits,” reporter Amy Norton wrote. “In addition, the study could not address whether saturated fat intake has different effects on heart disease and stroke risk for different age groups. Nor could it look at the effects of replacing saturated fat in the diet with polyunsaturated fats – like those found in vegetable oils and fish – or with carbohydrates.”
The December 2010/January 2011 issue of More magazine also cited another study from Australia which links eating more full-fat dairy products with fewer deaths from cardiac problems. And More also described a study that found that by decreasing your consumption of carbohydrates while eating a high saturated-fat diet can reduce the saturated-fat levels in the bloodstream, which potentially can ward off heart disease.
However, other studies point to other issues related to saturated fat. For instance, another Australian study provided information about the fat’s effect on Alzheimer’s disease. The researchers fed mice a diet of either saturated, monounsaturated or polyunsaturated fats. These mice were compared to mice that were genetically designed to develop Alzheimer’s. Within two months, the mice that were on the saturated fat diet had significant deterioration in their blood vessels. Furthermore, these mice had more amyloid deposits in their brain than the other groups of mice and their brains were very similar to the Alzheimer’s mice. No deterioration was observed in the mice that were fed the monounsaturated or polyunsaturated diets.
So why is this important? “Before now, there has been no dietary-driven approach to the prevention and treatment of Alzheimer’s disease,” Dr. John Mamo, national director of the Australian Technology Network’s Centre for Metabolic Fitness, told the Science Network of Western Australia. “Our study found that some dietary fats damaged the ‘blood-brain-barrier.’ The blood-brain-barrier is an important membrane that regulates what is normally allowed in and out of the brain, like nutrients.” Mamo and his research team found that saturated fats cause an increase in delivery of amyloid protein, which are originally produced by the small intestine and secreted in the blood, from the blood to the brain. Once these amyloids are in the brain, they cause inflammation in brain tissue and cell death.