Diabetes Diet

This Is the Only Bad Fat Now

We were wrong about saturated fat, which was probably the most terrible mistake in the history of nutrition. Not long ago we called trans fat the worst fat, as I wrote in 2002 at “New Label for Worst Fat” for Diabetes Wellness News. But now we know that it is the only bad fat, because saturated fat is off the hook.

food label

Nutrition Facts for Pop Secret “Jumbo Pop Movie Theater Butter”

Until the past few years most of us — myself included — believed the myth. It started with a deeply flawed study initiated by Ancel Keys and was written into official U.S. policy by the infamous 1977 McGovern committee report, as this article, “Time Magazine: We Were Wrong About Saturated Fats,” lays out so clearly.

During the last few years so many studies have debunked the myth about saturated fat that I have a hard time to keep up with them. But they include:

Association of Dietary, Circulating, and Supplement Fatty Acids With Coronary Risk: A Systematic Review and Meta-analysis” in Annals of Internal Medicine

Evidence from randomised controlled trials did not support the introduction of dietary fat guidelines in 1977 and 1983: a systematic review and meta-analysis” in Open Heart

Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease” in The American Journal of Clinical Nutrition

The Final Nail

The British medical journal, BMJ, has now driven the latest and hopefully final nail in the coffin of the myth that saturated fat is bad. Researchers at Canada’s McMaster University found that saturated fat isn’t associated with (1) an increased risk of death, (2) heart disease, (3) stroke, or (4) type 2 diabetes. They did find, however, that “industrial trans fat” was associated with (1) a 34 per cent increase in death for any reason,(2) a 28 per cent increased risk of coronary heart disease mortality, (3) and a 21 per cent increase in the risk of coronary heart disease.

The full text of the new review is free online at “Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes.” BMJ just published it a week ago. This massive review analyzed the results of 73 studies on saturated fat and 50 studies on trans fat published in the past 30 years and health outcomes in hundreds of thousands adults.

This new study is more interesting for what we learn about trans fat than about saturated fat. First, we need to notice that it is “industrial” trans fat that is the problem. Industrial trans fats are those that some companies have chemically altered by partially hydrogenated plant oils to increase the shelf life of some foods.

But when we eat meat we get some natural trans fat, because ruminants, including cattle, goats, and sheep, make it. This natural trans fat is not associated with cardiovascular heart disease or death from it, and in fact one ruminant trans fat, trans-palmitoleic acid, is inversely associated with type 2 diabetes.

Trans Fat Is Still in Our Food

Of course, the government can’t ban trans fat. It could in theory ban industrial trans fat as the media has reported. But it hasn’t done that, so we still need to use our own judgment.

What happened was that in June the U.S. Food and Drug Administration determined that trans fat is not “generally recognized as safe.” It gave food companies three years to get it out of our food or to petition it for an exemption. In fact, that’s exactly what the Grocery Manufacturers Association did a few days ago.

The associate’s statement says that food companies “have already voluntarily lowered the amount of trans fat added to food products by more than 86 percent.” Indeed, when I searched the cookie, candy, and cake aisle of a local supermarket a few days ago, I found far fewer foods with trans fats than when I did that in 2002 for my first article about trans fat.

But I was surprised at how much trans fat I found in some products, particularly in microwave popcorn, which is probably one of the worst foods for several reasons. I found two brands loaded with trans fat, Pop Secret and Kroger’s house brand. This proves to me that we can’t afford to relax our vigilance yet.

This article is based on an earlier version of my article published by HealthCentral.

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  • Frank Rocap at

    Just received this from MayoClinic. Why do places
    like Mayo Clinic and Harvard School of Public Health and Dr Gregor’s site still say the opposite?
    Received this 10-28-15.
    Eat well to control cholesterol
    High blood cholesterol can lead to cholesterol buildup and blockage in your arteries, which can cause complications such as stroke and heart disease. What you eat may significantly affect the amount of cholesterol in your blood. Here are some tips for adopting a heart-healthy diet that’s designed to keep your cholesterol at optimal levels.

    Avoid saturated and trans fats

    Saturated fats often make up the largest source of cholesterol in a person’s diet. Saturated fats increase low-density lipoprotein (LDL), or “bad,” cholesterol that clogs the arteries. Common sources of saturated fats are fatty meats; full-fat dairy products such as milk, ice cream and cheese; and certain tropical oils such as palm and coconut.

    Trans fats can have an even worse effect on your cholesterol levels. These fats form when hydrogen is added to vegetable oils in a process called hydrogenation that makes the oils less likely to spoil. Trans fats are commonly found in margarine, shortening, and commercially fried and baked foods.

    Choose unsaturated fats

    Replacing saturated fats with unsaturated fats can lower your total cholesterol. Find unsaturated fats in vegetable oils such as olive, safflower and soybean; nuts; olives; avocados; and fatty fish such as salmon and sardines.

    Minimize dietary cholesterol

    Cholesterol in foods can raise both total and bad cholesterol. Sources of dietary cholesterol include eggs, meats and full-fat dairy products; eggs contribute the most cholesterol. Doctors recommend decreasing dietary cholesterol to reduce LDL levels. The American Heart Association recommends consuming less than 300 milligrams of cholesterol a day

    • David Mendosa at

      Any establishment is always slow to change, Frank.

  • Thomas Baird at

    Saturated fat DOESN’T cause heart disease. The idea that it did was caused by a myth in the 1950s following a raft of faulty studies, one of which being the Seven Countries Study. when scientist Ancel Keys deliberately left out countries such as France which ate a diet high in saturated fat and had low heart disease rates.

  • lynn at

    more on pufas and the omega6/omega 3 ratio – http://www.medpagetoday.com/PrimaryCare/DietNutrition/50978

  • Michael K at

    There is so much mounting evidence that a low fat high carb diet was the wrong way to go and that it escalated the diabetes epidemic and heart disease. http://www.scientificamerican.com/article/carbs-against-cardio/ We need fat for our bodies to function properly:
    I suggest you read Wheat Belly and Grain Brain. It is very difficult to figure out the truth in anything and once we are indoctrinated in a specific point of view we become attached to it, we are on that team, and we fight for our team. I am as guilty of this as the next person, but it makes it even more difficult.

  • lynn at

    My sense is the verdict is also out on PUFAs – http://www.medpagetoday.com/PrimaryCare/DietNutrition/50978

    And that the ratio of Omega 3/6s is wayyyyy out of whack for many of us today.

  • Steve Cox at

    the 6.0 was about 2 months after starting. It may be lower the next time I check it. I do know my fasting BS went from 180-200 with Metformin to 90-110 without meds. Overall I like not being affected so much by BS levels and enjoy my new weight.

    Mostly I eat carbs now and no longer worry over “resistance” being an issue. I really feel the low carb life-style is what led to my heart attack.

  • Michael K at

    An A1c of 6 is an average blood sugar of 135
    Dr Bernstein would consider that still diabetic.
    You could lower that considerably if you ate fat(especially Virgin Coconut oil) and protein and cut your carbohydrate intake.From what I have read Esselstyn’s patients never seem to get truly normal blood sugars on his diet.

  • Frank Rocap at

    So confusing, Dr Gregor is always quoting studies
    condemning saturated fat, just read my Mayo clinic
    heart newsletter and again avoid saturated fat. Are
    none docs the only ones reading the saturated fat
    studies? There was an article from the Harvard School of Public Health that pointed out the discrepancies in the “Butter Is Back” article. Gee it’s nice everyone seems to agree on “trans fat”. Now I just wish we could have some agreement on
    the other fats. It’s my life I’m concerned about.
    Everyone has a creditable study, just pick one that you like.

  • Cjuan at

    Thanks for the timely update on saturated fats and trans fats, David.

    What is even more surprising is this: at least one saturated fat has already been found to be, yes, anti-diabetic (!). The same fat has been found to be beneficial to those with metabolic syndrome too. While the initial research is on dolphins, the director of the study has hypothesized it as a causative factor in the global diabetes pandemic:

    “…Researchers from the National Marine Mammal Foundation (NMMF) discovered that dolphins are able to switch in and out of a diabetes-like state… the researchers looked into their diet… It turned out that the saturated fat heptadecanoic acid was most beneficial… and dolphins with the highest levels in their blood had lower insulin and triglyceride levels. Several dolphins with low heptadecanoic acid levels were then fed fish high in the saturated fat. Within six months, their markers of metabolic syndrome, including elevated insulin, glucose, and triglycerides, were normal. Also striking, elevated levels of ferritin (iron), which is a precursor to metabolic syndrome, were also lowered within three weeks of the high saturated fat diet. The fish in the study with the highest level of heptadecanoic acid (aka margaric acid or C17:0) was mullet – but it’s also found in whole fat dairy products – whole milk, whole milk yogurt and butter… Study author Dr. Stephanie Venn-Watson, director of NMMF told Science Daily:

    “We hypothesize that widespread movement away from whole fat dairy products in human populations may have created unanticipated heptadecanoic acid deficiencies… and, in turn, this dietary deficiency may be playing a role in the global diabetes pandemic.”

    Source: Saturated Fat Helps Avoid Diabetes, posted August 11, 2015

  • Steve Cox at

    I was type two starting in the mid-80’s (about 30 years) and have been up to 11+ on A1c and maxed out on Metformin, two heart issues, etc…

    Through research (due to angina creeping up in January) I decided to try the VERY LOW FAT Dr. John McDougall’s “Starch Solution” and Dr. Caldwell Esselstyn’s “Prevent and Reverse Heart Disease” diet.

    My last A1c was 6.0, I now no longer take any medication except aspirin, my podiatrist just told me my feet were in very good condition and my cardiologist felt my condition was improving. (I’ve dropped 40 lbs too)

    My thoughts are that limiting fats may be a good idea because I no longer think I’m diabetic and my overall condition is improving.

  • Sally at

    So are you implying diabetics should stop taking statins or non diabetics? Is there any benefit or diabetics in taking statins?

  • Brian (BSC) at

    Thanks for writing about this David. Despite what seems like overwhelming evidence that dietary saturated fats are not harmful I think it will still be literally years before it makes it into dietary guidance. Hopefully, blogs like yours can enable patients to know the truth without waiting.

    I’d also like to add to what Sheri mentioned and that is that food manufacturers have been very evasive and current nutrition labels allow trans fats to be shown as zero when there is less than 1g of trans fats in a serving of a product. For products with small serving sizes this means that significant trans fats can still be present.

    In addition, while “Partially Hydrogenated Oils (PHOs)” are supposed to be reported as trans fats on FDA approved labeling, it seems that manufactures have not always complied so you need to look for PHOs in the ingredient list. And the ruling from this June from the FDA that you list is important not just because it addresses trans fats, but the FDA has recognized that PHOs are the primary source of trans fats and has moved to remove PHOs from the list of Generally Recognized As Safe (GRAS). This ban over the next three years will be on PHOs as well as added transfats. Yay!

  • Sheri Colberg-Ochs at

    In addition to trans fat, interesterified fats should also be added to the “bad” list and banned. They are an alternate to trans fat that manufacturers have been adding to foods in place of trans fat, and IEF do not have to be listed on the food labels. Some studies have shown them to be as bad for metabolic health as trans fats.

    • David Mendosa at

      Thank you, Sheri. I have read very little about interesterified fats and appreciarte your bringing them to our attention.