“No study published over the last 20 years has reported a relationship between dietary cholesterol intake and heart disease risk in the general population.”
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Straightforward facts on dietary fat and health
It’s actually an essential nutrient, and our obsession with dietary cholesterol is misguided, experts say
By David Feder Special to the Tribune
August 26, 2009
We’ve become a culture where a serving of fettuccine Alfredo is nicknamed " heart attack on a plate" and french fries are frequently mentioned with the prefix "artery-clogging."
Rarely does an article about dietary fat inform us that fat is an essential nutrient without which we would surely die. However, for most of us, fretting over dietary fat and cholesterol is unnecessary.
For generations, experts have prescribed a set of rules for everyone based on risk factors of illness in only one segment of the population.
"The results of cholesterol and heart disease research was not meant to be applied to healthy people or the world at large," said Dr. Donald McNamara, a cholesterol research scientist and director of Eggs for Health Consulting in Laurel, Md. He compares such an approach to "prescribing the same pair of glasses to everyone."
Few experts argue that for those with cholesterol levels outside the norm, or with high risk factors for cardiovascular disease, dietary change often can be a valid intervention. But when it comes to high-fat foods such as burgers, cheese, butter and cream being liberally shunned by those bent on lowering their cholesterol intake, it’s time to lard the conversation with a little straightforward science on dietary fat and health.
Your body knows how to handle dietary fat, and if you’re not overweight and have no other high-risk conditions, your risk of heart disease is probably low. That means even if you occasionally eat several slices of pizza with a Haagen-Dazs chaser, you needn’t punish yourself with guilt and worry. The stress will probably do more damage than the Super Bowl special you just ate. According to Mark Anthony, nutrition science instructor at St. Edward’s University, Austin, Texas, and author of "Gut Instinct: Diet’s Missing Link," analysis of the research into cholesterol and disease is bearing this out.
In 2006, scientists at the University of Surrey in Guildford, England, published a comprehensive analysis of multiple studies on dietary cholesterol and serum cholesterol in the British Nutrition Foundation Nutrition Bulletin. Their conclusion was emphatic: "The idea that dietary cholesterol increases risk of coronary heart disease (CHD) by turning into blood cholesterol is compelling in much the same way that fish oil improves arthritis by lubricating our joints."
Specifically, the team noted, "the scientific evidence to support a role for dietary cholesterol, [or the cholesterol we eat, as opposed to serum cholesterol, which is the cholesterol in our bloodstream], in CHD is relatively insubstantial in comparison with the incontrovertible link between its circulating blood relative in LDL cholesterol and CHD."
McNamara concurs: "No study published over the last 20 years has reported a relationship between dietary cholesterol intake and heart disease risk in the general population." He also points to data from the famous "Seven Countries Study" that analyzed subjects with the same levels of cholesterol, across different cultures. Absolute rates of heart disease varied widely. Another eye-opening statistic cited by McNamara is that roughly half the incidents of heart disease occur in people with normal cholesterol.
The type of fat in your diet does matter to some degree. Trans fat, derived predominantly from highly processed oils, was shown to be more strongly associated with cardiovascular disease. It was ultimately subjected to strict labeling and voluntarily removed from thousands of foods and beverages.
However, many research studies have shown that natural fat in foods such as eggs and dairy products has no effect on the risk for cardiovascular disease. Some studies have shown a positive effect of dairy consumption on reduction of disease risk. Saturated fats from sources other than eggs and dairy, such as from meat, once were associated with increased disease risk. Later studies are proving the issue to be more complex than that. And studies of saturated fats from plants such as coconut and palm oil are revealing positive health benefits.
Most important, mono- and polyunsaturated fats from olive oil, nut oils and vegetable oils, and the omega oils found in fish, flax and nuts boast thousands of studies backing their benefit to health for everything from protection against cancer, heart disease, certain birth defects, depression, cognitive decline and more.
Authors of the Harvard School of Public Health OmniHeart Study comparing popular diets and food intake concluded that, "in the setting of a healthful diet, partial substitution of carbohydrate [with] monounsaturated fat can further lower blood pressure, improve lipid levels and reduce estimated cardiovascular risk."
Simply put, the connection between the amount of fat we eat and the fat clogging our arteries and stopping our hearts turns out to be far more complicated than a blanket prescription of " low-fat diets for everyone" can address.
It doesn’t negate the value of eating a balanced diet, with the majority of calories coming from fruits, vegetables and whole-grain foods. But it does mean that, if we have been taking care of ourselves by maintaining a healthy weight and staying active, we don’t have to seek penance every time we butter our toast.
David Feder is a registered dietitian and director of S/F/B Communications Group, a national co-operative of food, health and nutrition experts.
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