Studies supporting balance of healthy fats with whole foods
Fats aren't the nutritional monster we need to vanquish according to studies, but Refined carbohydrates are. A recent meta-analysis looked at 76 studies and trials and found no evidence to support national dietary guidelines aimed at reducing the risk of heart disease.
Since the 1980s, the message from National Institutes of Health and the American Heart Association has been: saturated fat -- meat and whole dairy -- is bad. Polyunsaturated fats -- nuts, seeds and the oils made from them -- are good.
But opposing evidence is growing. Last year, in an editorial in the Mayo Clinic Proceedings, another group of doctors questioned the benefit of exchanging saturated fats with polyunsaturated fats and carbohydrates, and concluded "that doing the opposite would be more relevant." They claim that the effects of saturated fat on blood cholesterol are weak and don't last long. They noted that long-term studies found that people who eat the most dairy have the lowest mortality risk, heart disease, and diabetes. In 2009, a Swedish study concluded that eating fruits and vegetables every day was associated with a lower risk of coronary heart disease when combined with "high dairy fat consumption." Eating fruits and vegetables every day didn't lower the risk when diets were low in dairy fat. The reason? Many vitamins "and other essential substances" are fat-soluble, the researchers said.
Another large, longitudal study, published in the New England Journal of Medicine in 2013, compared a low-fat diet with the Mediterranean diet in people at risk for heart disease. The low-fat diet was difficult to stick to, but the Mediterranean diet, rich in olive oil, nuts, legumes, fresh vegetables, and fish, reduced the risk of incidents of major cardiovascular events.
What all the studies point to is we can't isolate food types. It's all connected. And it's clear that eating a well-rounded diet of whole foods like fruit, vegetables, whole grains, farm-fresh eggs, and fish is healthier than eating processed and refined foods.
Low-fat products came on the scene in the mid-80s. The low-fat faze had "disastrous consequences," according to Walter Willett, chairman of the department of nutrition at Harvard's School of Public Health. Americans replaced fat with refined carbohydrates and started eating more. Quickly absorbed, refined carbohydrates, with their high glycemic index, bring on fluctuations in blood sugar. And that makes us hungry. Some doctors say eating refined carbohydrates stimulates the production of fat.
Americans have lowered their consumptions of fats. In 1965, fats made up 45% percent of the daily diet. In 1995, 35 percent. Today, it's about 33 percent (with saturated fats making up 11 percent of that). Carbohydrates make up about 50 percent of Americans' diets. And we're getting fatter. Today, more than two-thirds of Americans are obese or overweight. True, only 1/3 of adults get proper exercise.
Studies questioning the low-fat orthodoxy have been around for 20 years, but have had a difficult time gaining acceptance. In the mid-90s, Willett conducted a study to see if there was an association between saturated fat intake and coronary heart disease in middle-aged and older men. The study didn't support the association. Willet says he had a hard time getting the study published in the United States, though it was published in the British Medical Journal in 1997.
Willett's study did, however, support the "preventative effect of linolenic acid," from plants and seeds, on coronary heart disease. It also found the benefit of reducing the amount of saturated fat is modest unless the amount of fiber-rich foods is increased.
A 1997 study in the Journal of the American Medical Association found that women who ate carbohydrates with the highest glycemic index were 47 percent more likely to get type 2 diabetes, but the amount of fat the women ate didn't affect the risk of getting diabetes.
Despite the recent meta-analysis that challenged its dietary guidelines, the American Heart Association is sticking by them. The AHA recommends limiting the amount of saturated fat we eat each day to 7 percent. That's 140 of the daily recommended 2,000 calories. They recommend replacing saturated fats with polyunsaturated fats, rich in Omega-6 linolenic acid (sunflower, safflower, sesame and flax) and monounsaturated fats like olives and nuts. And they still promote eating low-fat products.
So what's wrong with low-fat products? They don't make us feel satisfied. Fatty foods make us feel satiated.The key is moderation. A little bit of butter or a little bit of cheese adds richness to a dish. It helps to be choosy about the quality of the food we eat and to know where our food comes from. Eggs laid by pasture-raised chickens have an increased amount of omega-3s and Vitamin E than factory-farmed birds. Fresh, real-extra virgin olive oil is higher in polyphenals than much of what passes for olive oil. Vegetables grown in your back yard or at a near-by farm taste better and have more nutritional value than those shipped from far away.
Your best bet? Eat more whole foods. Stay away from processed stuff. Eat a balanced diet. And savor the fats you eat, enjoy a creamy avocado, rich salmon, and, yes, a little cheese. And don't forget to exercise!
Last Modified Date: July 22, 2014
