By Dr. Mercola
In February the Dietary Guidelines Advisory Committee (DGAC) submitted its 2015 Scientific Report1,2,3 to the US Departments of Agriculture (USDA) and Health and Human Services (HHS).
This report serves as the foundation for the development of US dietary guidelines.
In a surprise twist, the DGAC not only suggested eliminating warnings about dietary cholesterol, it also reversed nearly four decades of nutrition policy by concluding that dietary fats have no impact on cardiovascular disease risk.
Unfortunately, the DGAC didn’t set the record straight with regards to saturated fats, as it makes no firm distinction between healthy saturated fats and decidedly unhealthy trans fats.
For decades, healthy fat and cholesterol have been wrongfully blamed for causing heart disease, but over 70 published studies overwhelmingly dispute this.4
Trans Fat, Not Saturated Fat, Raises Your Heart Disease Risk
Now we can add yet another large study to this ever-growing list. The meta-analysis5,6,7,8 published in the British Medical Journal (BMJ), found no association between high levels of saturated fat in the diet and heart disease.
Nor could they find an association between saturated fat consumption and other life-threatening diseases like stroke or type 2 diabetes.
However, the study DID find a disease link to trans fat consumption. As reported by Newsweek:9
“[C]onsumption of trans unsaturated fats found in everyday supermarket goods such as margarine, processed cakes, and microwave popcorn can increase the risk of death from coronary heart disease (CHD) by 28 percent.”
Trans fats also increased all-cause mortality by 34 percent. This is important because many “experts” frequently confuse trans fat with saturated fat intake.
Moreover, a pooled analysis of 11 studies10,11 showed that replacing saturated fat (found in foods like meat, egg yolks, dairy products, salmon, nuts, avocados, coconut oil, and olive oil) with monounsaturated fat (vegetable cooking oils12), or carbohydrates (sugars and grains) raised the risk of non-fatal heart attacks.
This prompted the authors to comment that dietary guidelines for saturated fats and trans fats “must carefully consider the effect of replacement nutrients.” This too is in line with previous findings.
What Happens When You Replace Saturated Fat with Carbs?
In a 2014 editorial13 published in the Open Heart journal, research scientist and doctor of Pharmacy James J. DiNicolantonio reviewed the cardiometabolic consequences of replacing saturated fats with carbohydrates.
The health consequences are significant, including the following:
Shift to overall atherogenic lipid profile (lower HDL, increased triglycerides, and increased ApoB/ApoA-1 ratio) Increased risk of coronary heart disease, cardiovascular events, and death from heart disease and increased overall mortality (all causes) Increased thrombogenic markers Increased oxidized LDL Increased inflammation Reduced HDL Impaired glucose tolerance, higher body fat, weight gain, obesity, and diabetes Increased small, high-density LDL particles Increased risk for cancer
The Hazards of Replacing Partially Hydrogenated Oils with Vegetable Oils
The issue of what to replace trans fats (partially hydrogenated oils) with is equally important. Ideally, you’ll want to replace them with healthy saturated fats — NOT vegetable oils.
This is discussed in Nina Teicholz’ book, The Big Fat Surprise: Why Butter, Meat, and Cheese Belong in a Healthy Diet, and in the interview I did with her last year. Nina is an investigative journalist, and she was actually one of the reporters who broke the story on the dangers of trans fats, a little over 10 years ago.
Now she’s warning us that the vegetable oils many restaurants and food manufacturers are trading the trans fats in for may actually be more harmful than the trans fats! The reason for this is because when heated, they create highly toxic oxidation products, including aldehydes, which are extremely inflammatory.
So what’s the ideal fat to cook with?
Tallow and lard are two great options. Tallow is a hard fat that comes from cows. Lard is a hard fat that comes from pigs. They're both animal fats, and used to be the main fats used in cooking.
One of their benefits is that, since they're saturated fats, they do not oxidize when heated. And saturated fats do not have double bonds that can react with oxygen; therefore they cannot form dangerous aldehydes or other toxic oxidation products. Coconut oil is another healthy option, as it too resists oxidation when heated.
Food Industry Petitions FDA to Make Allowances for Trans Fats in Packaged Foods
The evidence showing trans fats are a major health hazard has prompted the US Food and Drug Administration (FDA) to remove partially hydrogenated oils — the primary source of trans fats — from the list of "generally recognized as safe" (GRAS) ingredients.
The initial proposal was issued in 2013, and on June 16, 2015, the decision was finalized.14 Food manufacturers have until 2018 to get partially hydrogenated oils (PHOs) out of their products.
Despite the evidence of harm, and less than a week after the BMJ study’s publication, the Grocery Manufacturers Association (GMA) petitioned the FDA to permit “small amounts” of trans fats in certain packaged foods.15 Proposed allowance for trans fats in the GMA’s petition include adding PHOs during processing, as an:
Anti-caking agent, free flow agent, and lubricant Emulsifier Solvent for fat-soluble ingredients Textural agent to improve textural characteristics of the food Dough strengthener Moisture retainer Stabilizer Thickener Surface-finishing agent Heating medium, such as frying oil
In its petition, the GMA argues that “low-level uses of PHOs are as safe as the naturally occurring trans fat present in the normal diet.” Incidentally, this is NOT what the BMJ study16 found. In it, they found no observed link between naturally occurring trans fats in foods like meat and dairy and heart disease.17 That link was only found for artificially created trans fats.
According to the authors, this discrepancy “might reflect a true difference between sources or might be a function of consumption levels...” noting that the average consumption of industrially produced trans fats was about 250 percent greater than that of naturally-derived ruminated trans fats. The assertion that low levels of trans fats is safe also flies in the face of a previous determination by the Institute of Medicine (IOM), which as far back as 2002 noted there is "no safe level of trans fatty acids and people should eat as little of them as possible."
Heart Healthy Benefits of Nuts and Olive Oil
In related news, both nuts and olive oil — which are sources of healthy fats — have been shown to promote heart health. As noted by Dr. Michael Greger, MD,18 a number of studies in which subjects added nuts to their diet (without replacing specific foods, which might skew results one way or another), found that nuts significantly improved arterial health. Moreover, while some studies show mixed results in terms of the level of benefit, there’s no evidence that nuts might actually worsen health (provided you’re not allergic).
According to Dr. Greger:
“Eating at least one serving of walnuts per week may drop our chances of a cardiovascular-related death by 50 percent.19 However, walnut consumption may only drop our cholesterol levels about 5 percent. How could we get a 50 percent drop in cardiac mortality from just a 5 percent drop in cholesterol? Walnuts must have some other heart-protecting benefits besides lowering cholesterol.
The ability of blood vessels to relax and open normally is considered an excellent barometer of underlying vascular health... So what effect do nuts have? A 2011 review20 in the journal Nutrition, Metabolism, and Cardiovascular Diseases found five clinical trials analyzing the effect of nut consumption on arterial function, and all three studies on walnuts showed an improvement in endothelial function measured in the arm.”
Other recent research21 again confirms the health benefits of extra virgin olive oil, showing it improves blood sugar and cholesterol after meals to a greater degree than corn oil. As reported by Reuters:22
“Lowering (post-meal) blood glucose and cholesterol may be useful to reduce the negative effects of glucose and cholesterol on the cardiovascular system,’ lead study author Francesco Violi, a researcher at Sapienza University in Rome, said...
On two separate occasions, researchers gave 25 healthy people a typical Mediterranean lunch. For one meal, they added 10 grams (about 2 teaspoons) of extra virgin olive oil, and for the other, they added 10 g of corn oil.
Blood tests done before and two hours after the meals found that blood sugar rose after eating in all the participants, which is normal. But blood sugar rose much less after a meal with olive oil compared to one with corn oil. That’s in line with previous research linking EVOO to elevated levels of insulin, a hormone that helps convert glucose into energy, Violi said.”
Take-Home Message: Unprocessed Saturated Fat Is Good for You
Focusing your diet on REAL FOOD (raw whole, ideally organic, and from pasture raised cows) rather than processed fare is one of the easiest ways to sidestep dietary pitfalls like harmful fats — not to mention other harmful ingredients like refined sugars, genetically modified organisms (GMOs) and additives that have never been properly tested for safety. Beyond that, it’s really just a matter of tweaking the ratios of fat, carbs and protein to suit your individual situation.
One key though is to trade refined sugar and processed fructose for healthy fat, as this will help optimize your insulin and leptin levels. We’ve spent decades trading healthy saturated fats for carbs and trans fats, and there can be no doubt that this has had an enormous influence on disease statistics, raising incidence of obesity, diabetes, heart disease, and Alzheimer’s — all the top killers.
Healthy fat is particularly important for optimal brain function and memory. This is true throughout life, but especially during childhood. So, if processed food still make up the bulk of your meals, you’d be wise to reconsider your eating habits. Not only are processed foods the primary culprit in obesity and insulin resistance, processed foods can also affect the IQ of young children. One British study23 revealed that kids who ate a predominantly processed food diet at age three had lower IQ scores at age 8.5. For each measured increase in processed foods, participants had a 1.67-point decrease in IQ.
Another study published in the journal Clinical Pediatrics24,25,26 also warns that frequent fast food consumption may stunt your child’s academic performance. For more detailed dietary guidance, please see my optimal nutrition plan. It’s a step-by-step guide to feeding your family right, and I encourage you to read through it. I’ve also created my own “food pyramid,” based on nutritional science, which you can print out and share.