Sorry, saturated fat, butter & bacon aren't back

I remember a supervisor during medical school who said to us: “Do you guys notice that bacon is coming back?” I was a little confused because I couldn’t think of a time when we as a society ever stopped eating bacon, but I soon realized what she was actually saying was “Bacon is making a comeback as a health food.”

It’s not just bacon either. The New York Times had a headline a few years ago that read: “Butter is Back” (1) Time Magazine’s cover page stated: “Eat Butter.” And this messaging is trickling down to the common people as well. My wife’s co-worker recently told her: “Bacon is healthy. Saturated fat is okay.”

Where are these ideas coming from? Well, its from recent scientific papers that seem to suggest that saturated fat is not linked with cardiovascular disease. Thus people are concluding that saturated fat is actually healthy for you. But are these claims true and based on science? Have many people jumped the gun too quickly? Here I want to provide some thoughts to reflect on as we seek to navigate the confusing messages regarding saturated fat. I want to caution folks to be careful on the conclusions we draw.

A few thoughts to think about are below.

1. Don’t jump to conclusions too quickly. The scientific community is still debating this.

We need to be careful not to jump to conclusions based on a handful of studies. Many in the media and less-disciplined health professionals have done this and are continuing to do so with saturated fat. However, when you actually dig into the matter, people will quickly realize that things are still being rigorously debated in academia and medicine.

A case in point is the response to the scientific paper that really got this whole saturated fat debate flaring. The prestigious journal: Annals of Internal Medicine published a meta-analysis in 2014 which concluded that lowering saturated fat really does not impact cardiovascular disease risk (2). What happened? The media jumped on it and the message was spread that saturated fat was being exonerated. Yet, since 2014, other scientific papers and medical groups started releasing papers countering this message. Some examples are below:

  • When the 2014 paper was about to be published, news agencies reached out to experts at Harvard university including the Harvard TH Chan School of Public Health’s Walter Willett (an internationally recognized expert in nutrition and epidemiology) for their opinion. Dr Willett and his colleagues at Harvard recognized major issues in the paper including the omission of important studies in the analysis, lack of clarity on the comparison foods, and incorrect number citations from original studies. Dr Willett and colleagues even drafted a response letter to the journal raising their concerns (5).

  • In 2015, a study showed that replacing 5% energy from saturated fat with 5% from polyunsaturated fat resulted in a 25% lower risk of coronary heart disease. Replacing 5% of saturated fat with 5% of energy from monounsaturated fat or whole grains lowered coronary heart disease risk. Replacing 5% of energy from saturated fat with 5% of energy from unsaturated fats resulted in a 17% lower risk of coronary heart disease (6).

  • In 2015, the Cochrane Review (considered a very high quality and unbiased source for research analysis ) concluded that reducing saturated fat lowered the risk of getting cardiovascular disease though no differences were seen in cardiovascular mortality. It reported that replacing saturated fats with starchy foods and protein did little good but replacing saturated fat with polyunsaturated fats is more protective (25). In conclusion, the report stated:

    “Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturated fats. The ideal type of unsaturated fat is unclear” (25).

  • A 2016 paper showed that saturated fat intake increased total mortality by 8% while polyunsaturated fatty acids and monounsaturated fatty acids lowered risk of mortality by 19% and 11%, respectively. Replacing 5% of energy from saturated fat with the same energy from polyunsaturated and monounsaturated fats lowered the risk of mortality from cardiovascular disease, cancer and neurodegenerative diseases (7).

  • In 2017, the American Heart Association got so concerned that they released a lengthy presidential advisory paper in the journal Circulation essentially stating that there were major weaknesses in the scientific papers supporting saturated fat, and that lowering saturated fat was still the healthy dietary recommendation (8).

  • In 2017, the Annals of Nutrition and Metabolism published a report of various scientists which looked at this issue which concluded:

    “strong evidence supports the partial replacement of saturated fatty acid-rich foods with those rich in cis-polyunsaturated fatty acids to lower LDL-C and reduce the CHD risk” (9).


These are a handful of papers published AFTER the 2014 paper which contradicts its conclusions. So what should we make of all this? The evidence exonerating saturated fat is not as conclusive as many are making it seem. The debate is still going. Don’t jump to conclusions too quickly.

2. The authors themselves don’t even agree with the messaging

When the 2014 paper came out, the message was “butter is back” “bacon is back".” But the authors of the paper themselves do not even agree with this messaging. Here is a statement from the senior author of the study, Dr Di Angelantonio:

“It was reported as ‘butter and burgers,’ and that’s not what our paper said,” “What the paper said was that the story on saturated fat is slightly more complicated than we thought” (5).

In 2016, a meta-analysis was published that seemed to suggest butter (very high in saturated fat) was not really linked with chronic diseases (10). What happened? The media pounced on it and people started saying: Butter is back. TIME magazine’s front cover even stated “Eat Butter.”

But again, the authors of the paper themselves do not agree with this messaging to the public. For example Dariush Mozaffarian, the senior author of the paper noted:

“Overall, our results suggest that butter should neither be demonized nor considered ‘back’ as a route to good health” (11).


Another author of the paper, Laura Pimpin stated in the press release:

“Even though people who eat more butter generally have worse diets and lifestyles, it seemed to be pretty neutral overall …. This suggests that butter may be a “middle-of-the-road” food: a more healthful choice than sugar or starch, such as the white bread or potato on which butter is commonly spread and which have been linked to higher risk of diabetes and cardiovascular disease; and a worse choice than many margarines and cooking oils – those rich in healthy fats such as soybean, canola, flaxseed, and extra virgin olive oils – which would likely lower risk compared with either butter or refined grains, starches, and sugars” (11).

When the authors themselves do not agree with you on how you are presenting their paper, then that calls for some pause and reflection. The bottomline is well summarized by an article from Harvard university School of Public Health :

“Referring to butter as “healthful” is a stretch, …” (11).

Don’t always assume that the way the media portrays the science is the way that the scientists themselves would. Many times, they disagree with the media.


3. Processed and red meats are not health foods

Based on the new revelations on saturated fats, people are starting to conclude that meat has been exonerated. They claim bacon and red meat are making a comeback as health foods. Some are going to social media and posting up pictures of steaks and other red meats with lines such as “saturated fats are healthy.” But these are very misguided conclusions.


For one, processed meats are not health foods. The International Agency for Research on Cancer (IARC), a group connected with the World Health Organization, categorizes processed meats as group 1 carcinogens. This means it is a known cause of cancer. They state:

“Processed meat was classified as carcinogenic to humans (Group 1), based on sufficient evidence in humans that the consumption of processed meat causes colorectal cancer.” (12)


You want to know what else are group 1 carcinogens?

  • coal gas

  • epstein-barr virus

  • alcoholic beverages

  • Hepatitis B virus

  • Hepatitis C virus

  • plutonium

  • tobacco smoke

  • ionizing radiation

  • PCBs

Red meat is categorized as a group 2A carcinogen. This means it is “probably carcinogenic to humans” (12).

What else are in this category? Here is a sample:

  • cobalt metal with tungsten carbide

  • glyphosate

  • lead compounds

  • malaria

  • petroleum refining

  • nitrogen mustard

  • acrylamide

  • DDT

  • Human papilloma virus type 68


Most people would be shocked to know that their hotdogs, burgers, spam, and Klik share company with the agents listed above, but they do. No human being should be excited to chow down on a known cancer-causing agent nor one that could probably cause cancer.


The reason why people make this type of mistake is because of reductionistic thinking. When we fixate on a single nutrient and then see whole foods through that reductionistic lens, it results in erroneous extrapolations. In this case, people are zeroing in on saturated fat and because they are assuming that it has been exonerated, now they are looking at foods with high saturated fat and concluding, these foods containing high saturated fat must be healthy. But foods are more than single nutrients. Steak and bacon are more than saturated fat, and when we step away from the saturated fat and look at the whole food’s overall effects on health, the picture is less than impressive. A recent study from the Adventist Healthy Study 2 cohort linked a high consumption of animal proteins with a 61% increased risk of cardiovascular mortality whereas proteins from nuts and seeds actually decreased risk by 40% (13).

Saturated fat is a nutrient that is found in food. One “good” nutrient does not exonerate the whole food. In the same way, if we conclude that processed meats and red meat are now health foods based on a handful of studies on saturated fat, we are making a dangerous mistake. Caution is warranted here. Don’t rush for your hotdogs and BLT sandwiches just yet.

4. Low fat diets did not fail

Some people say that we tried low-fat diets and it has not worked, thus we should give this new idea a try. This is a stunning assertion. It is absolutely true that fat regardless of type has been vilified for some decades. But did North America really ever go on a low-fat diet? We were told to, but did we? The answer is no. We never really substantially cut down on our meat, other animal foods, oil, pastries and other processed foods. To actually mimick a truly healthy low fat diet, the North American diet would have to look more like a vegetarian or vegan diet, and I do not think there is a single person who would suggest that the North American diet of the last four to five decades looked anything remotely like a vegetarian or vegan diet.

We tried low fat diets in our message but that did not translate to low fat diets on our plates. Post- World war two North America has not tried the low fat diet.

To borrow from GK Chesterton: “It’s not that the low fat diet was tried and found wanting, rather it was found difficult and left untried.”


Conclusion

The bottomline is simple: to make it seem like saturated fat is now on the healthy list would be a very undisciplined approach to the science, and a mistake. To conclude that butter, steak and bacon are now health foods would be an even more hazardous mistake. We need to encourage people to give the scientists and medical community time to continue exploring this area of research before jumping to conclusions.

In the meantime, what then should we eat? First, we can agree that fixating on lowering all fats may not be the best approach. As discussed above, the type of fat does matter. Polyunsaturated fats as a replacement for saturated fats is a healthy approach, whereas merely replacing saturated fats with processed foods and refined carbohydrates, does little good. Second, we need to step away from a reductionistic view of foods that judges foods by a handful of popular nutrient components. Instead, we need to focus on the whole food, and when you do this, there is one dietary pattern that has been shown to both help prevent, treat and reverse many of today’s chronic diseases, that is a whole foods, plant-based (14 - 24). You can never go wrong eating moderate amounts of whole grains, beans, seeds, legumes, nuts, and large quantities of fruits and vegetables in their whole forms.

References

  1. https://www.nytimes.com/2014/03/26/opinion/bittman-butter-is-back.html

  2. Chowdhury, R. et al. Association of dietary, circulating, and supplement fatty acids with coronary risk: a systematic review and meta-analysis. Ann Intern Med. (2014); 160: 398-406

  3. Jakobsen, MU et al. Major types of dietary fat and risk of coronary heart disease: a pooled analysis of 11 cohort studies. Am J Clin Nutr. (2009); 89: 1425 - 32

  4. Siri-Tarino PW, et al. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J.Clin Nutr. (2010); 91:535 - 546

  5. Is Butter Really Back? Clarifying the facts on fat. https://www.hsph.harvard.edu/magazine/magazine_article/is-butter-really-back/

  6. Li Y et al. Saturated fat as compared with unsaturated fats and sources of carbohydrates in relation to risk of coronary heart disease: A prospective cohort study J Am Coll Cardiol. (2015); 66(14): 1538 - 1548

  7. Wang, D et al. Specific dietary fats in relation to total and cause-specific mortality. JAMA Intern Med. (2016): 176(8): 1134 - 1145

  8. Sacks, F et al. Dietary fats and cardiovascular disease. A presidential advisory from the American Heart Association. Circulation. (2017); 136: e1 - e23

  9. Nettleton, J. et al Saturated fat consumption and risk of coronary heart disease and ischemic stroke: A science update. Ann Nutr Metab (2017); 70: 26-33

  10. Pimpin, L et al. Is Butter Back? A systematic review and meta-analysis of butter consumption and risk of cardiovascular disease, diabetes, and total mortality. PLoS One. (2016); 11(6): e0158118

  11. We Repeat: Butter is Not Back. https://www.hsph.harvard.edu/nutritionsource/2016/06/30/we-repeat-butter-is-not-back/

  12. Monographs: https://www.iarc.fr/wp-content/uploads/2018/07/pr240_E.pdf

  13. Tharrey, M et al. Patterns of plant and animal protein intake are strongly associated with cardiovascular mortality: The Adventist health study-2 cohort. Int J Epidemiol. (2018); 1603-1612

  14. Ornish D et al. Can lifestyle changes reverse coronary heart disease? The lifestyle heart trial. Lancet 1990; 336:129 – 33

  15. Ornish D et al. Intensive lifestyle changes for reversal of coronary heart disease. JAMA. 1998; 280: 2001 – 2007 

  16. Barnard N et al. A low-fat vegan diet improves glycemic control and cardiovascular risk factors in a randomized clinical trial in individuals with type 2 diabetes. Diabetes Care, Vol 29, No 8 , 2006 

  17. Lee, YM et al. Effect of a brown rice based vegan diet and conventional diabetic diet on glycemic control of patients with type 2 diabetes: A 12-week randomized clinical trial  PLoS ONE 11 (6)

  18. Esselstyn, C. Resolving the coronary artery disease epidemic through plant-based nutrition. Preventive cardiology. 2001

  19. Esselstyn, C. Defining an overdue requiem for palliative cardiovascular medicine. Am J of Lifestyle Medicine. 2016. Vol 10, No. 5. 313 – 317

  20. Esselstyn C. Upating a 12-year experience with arrest and reversal therapy for coronary heart disease (an overdue requiem for palliative cardiology). Am J Cardiology. Vol 84, Aug 1, 1999

  21.  Esselstyn, C. A plant-based diet and coronary artery disease: a mandate for effective therapy. J Geratric Cardiology (2017) 14; 317 – 320

  22. Le, LT & Sabate, J. Beyond meatless, the health effects of vegan diets: Findings from the Adventist cohorts. Nutrients 2014, 6, 2131 – 2147 

  23. Rizzo, N et al. Vegetarian dietary patterns are associated with a lower risk of metabolic syndrome. Diabetes Care, Vol 34, May 2011. p 1225 – 1227

  24. Fraser, G. Vegetarian diets: what do we know of their effects on common chronic diseases?  Am J Clin Nutr 2009; 89 (suppl): 1607 – 12S

  25. Hooper, L et al. Reduction in saturated fat intake for cardiovascular disease. Cochrane Database Syst Rev. (2015); (6): CD011737

George Cho