These days, it seems like rarely a day goes by when you don’t see articles about saturated fat appearing in the mainstream press. Many of the articles that are published are written by journalists who don’t know much about nutritional science and have jumped on the recent bandwagon of saying that the war against saturated fat is unjustified and needs to end. Some journalists, bloggers, and even a few scientists here and there go as far as to say that saturated fat is completely harmless and something we can all can benefit from eating more of.
Public opinion on saturated fat is changing. Is that a good or a bad thing?
Not so long ago, the general consensus among the public was that saturated fat is bad; it’s not something we should eat a lot of. This perception is now changing. More and more people, including some health practitioners and scientists, are taking a stand against the nutritional establishment, saying that the notion that saturated fat is bad for us is not supported by good evidence. They claim that it’s time we stop being afraid of saturated fat and start eating more butter and bacon.
If you asked me 10 years ago, before I had delved into the science on saturated fat, whether I agreed with the proposition these “rebels” make, I may have said yes. However, if you asked me today, the answer would have been no. I don’t think it’s wise or healthy to eat a lot of saturated fat. The reason I once believed that saturated fat is fairly harmless wasn’t that I had seen convincing evidence to that fact, but rather that I had been persuaded by low-carb bloggers and researchers who used the conclusions of a few recent meta-analyses as the primary, or sole basis, of their arguments.
Today, I know more about this issue. Over time, as I’ve dissected the information on saturated fat that’s out there, I’ve become a lot more skeptical towards this nutrient. It has become abundantly clear to me that saturated fat is not harmless – it’s not a nutrient that should make up a substantial part of our diet. Every time I come across a blog post, video, or newspaper article that claims it’s healthy to eat a lot of butter, ghee, bacon, coconut oil, and other similar foods that are very high in saturated fat, I cringe. I can almost see people’s cardiovascular systems fill up with fatty substances and their immune systems reacting to the rise in the levels of circulating endotoxins.
Last year, I published an article entitled Saturated Fat: 7 Reasons Why It’s Not as Harmless as the Low-Carb Movement Claims. In that article I took an in-depth look at the scientific evidence pertaining to the link between saturated fat and human health, and I made the case that it’s unhealthy to eat a diet that’s high in butter, bacon, cream, and other similar high-fat foods. My stance on this matter has not changed since then. If anything, I’m now even more convinced that the statements I made in that article were correct.
In today’s post, I’m not going to take another in-depth look at the scientific data on this topic. Rather, thought I’d summarize the key point I made in last year’s article, as well as share some of my recent thought on this matter.
A brief summary of the evidence: 10 key points
(Visit my lengthy article on saturated fat for a more thorough examination of this topic, as well as links to relevant scientific articles)
- It’s a myth that preagricultural human diets were high in saturated fat
Contrary to what some people believe, saturated fat did not make up a large part of the ancestral diets that conditioned the human genetic make-up.
- None of the foods that were consumed by preagricultural humans contained high concentrations of saturated fat
Wild meats and nuts, the two densest sources of fat in ancient human diets, have a balanced fatty acid profile. They are relatively low in saturated fat and high in monounsaturated and polyunsaturated fats when compared to butter, ghee, cream, bacon, coconut oil, and other similar evolutionary novel, high-fat foods.
- Correlation doesn’t equal causation
The fact that some traditional people (e.g., the Maasai) seemingly maintain good health “despite” the fact that they eat a diet that’s fairly high in saturated fat doesn’t prove that it’s healthy to eat a diet that’s high in saturated fat. Correlation doesn’t equal causation. Many other factors (e.g., exercise, genetics) are involved, and it might be (I find it likely) that these people would have been even healthier if they took in less saturated fat and instead more of other nutrients (e.g., fiber, protein, mono- and polyunsaturated fats).
- Lauric acid, the primary fatty acid found in coconut, has some unique characteristics that separates it from saturated fatty acids with longer chain lengths
Lauric acid (C 12:0) doesn’t seem to affect the blood lipid profile in a similar manner as the longer chain saturated fatty acids. This can help explain why traditional people (e.g., the Kitavans) who are known to eat diets high in coconuts seemingly maintain good health and rarely get chronic diseases such as atherosclerosis and heart disease.
- Foods with a very high concentration of saturated fat, such as butter, bacon, cream, and ghee, have a low satiety index score, very high energy density, “imbalanced” fatty acid composition, and low nutrient density
These types of foods contribute a lot of calories that could otherwise have come from more satiating, nutrient-dense foods such as eggs, organ meats, fruit, seafood, and vegetables.
- Fat can make you fat – if you eat too much of it
Unlike what some people seem to believe, you can’t stuff yourself with as much fat as you want as long as you restrict your intake of carbohydrates. It’s certainly more difficult to get fat on a very low-carbohydrate diet, but it’s not impossible. Also, its important to remember that health is about so much more than just body weight. A low-carbohydrate diet that’s high in saturated fat may make you lose weight, but that doesn’t mean that its necessarily a healthy diet.
- A high intake of saturated fat is linked with chronic low-grade inflammation
A compelling body of evidence shows that a high intake of saturated fat can cause chronic low-grade inflammation, by increasing the absorption of endotoxins from the gut and activating toll-like receptor 4. The severity and exact nature of these effects depend on the quantity and type of fat consumed.
- A high intake of saturated fat may adversely affect the blood lipid profile
Some people seem to be under the belief that the idea that saturated fat causes unfavorable shifts in the composition of fatty substances (e.g., LDL, HDL) in the blood is nothing more than a myth. Well, I’m here to tell you that it’s not. Several RCTs and meta-analyses have shown that a high intake of saturated fat does indeed alter the blood lipid composition in such a way that the risk of heart disease and other cardiovascular disorders likely increase. In my mind, there is no doubt that a high intake of saturated fat adversely affects the blood lipid profile. This notion is based on everything I’ve read on the topic, as well as my personal experience. That said, the evidence in this area is not crystal clear. Some studies fail to show a link between saturated fat and lipid markers commonly associated with disease. It’s not surprising that studies in this area show conflicting results, given that it’s very difficult to adequately assess how the intake of a single nutrient affects long-term disease risk.
- Many of the recent clinical trials and systematic reviews that seem to refute the idea that saturated fat is bad for us have several flaws and limitations
Over the past decade, a large number of studies on saturated fat has been published. Many of these studies support the longstanding notion that a high intake of saturated is unhealthful. However, not all of them do. Some seem to show that there is absolutely no link between the intake of saturated fat and the risk of chronic diseases such as heart disease. “Saturated fat advocates” are quick to incorporate these studies into their arsenal and use them actively in their fight against the nutritional establishment, which according to them clings to outdated dogma regarding the link between saturated fat and human disease. Personally, I don’t agree with the nutritional establishment in everything – far from it. However, on the saturated fat issue, I think the mainstream nutritional community is more on the right tracks than the low-carb movement. It’s important to remember that all studies have limitations and flaws – none are perfect. It’s particularly difficult to investigate the relationship between the intake of a single nutrient (e.g., saturated fat) and chronic disease risk, due to the fact that chronic diseases develop over many years; a long list of factors are involved in the pathogenesis of all chronic diseases, many of which are difficult to adequately control for in a clinical trial; and the human diet is complex, consisting of a long list of nutrients. Simply looking at the conclusions or abstract of a study on saturated fat doesn’t get us very far. To really know if the study is credible and the conclusions are correct, we have to dig into the methods section and look at how the study has been carried out. I’ve not yet come across a study that has convinced me that saturated fat is innocent, and I probably never will, given that there are well-established biological mechanisms linking saturated fat with inflammation and disease.
- Saturated fat is not a villain, given that it’s consumed in the form of nutrient-dense, whole foods and doesn’t make up a large part of our diet
After having seen the 9 first points on this list, you may have gotten the impression that I think saturated fat is an evil nutrient that we should seek to avoid at all cost. Well, I don’t. Saturated is a natural part of healthy foods such as eggs and grass-fed meats. You shouldn’t avoid these types of foods just because they contain some saturated fat. The point I’m trying to make is not that we should seek to completely eliminate saturated fat from our diets, which would entail not eating animal foods at all. Rather, the message I’m trying to get across is that it’s not healthy to eat a lot of saturated fat, particularly if it’s derived from evolutionary novel, high-fat foods such as ghee, cream, butter, and processed meats.
The world is not separated into good and bad, black and white. Nutrition is no different. It’s time we stop thinking that it is. No single nutrient is wholly bad or wholly good. That’s true regardless of whether we’re taking about saturated fat, starch, fructose, or any of the other substances we derive energy from. The quantity and type of these nutrients we should take in depends on several factors, including our physical activity levels, health status, and perhaps most importantly, our ancestry.
A foundational model for healthy nutrition can be created by looking to our evolutionary past. Modern scientific research has shown again and again that we humans are best off adhering to a diet that is similar to the ancestral diets that conditioned the human genetic-make up over millions of years, which is exactly what evolutionary theory would predict. The practice of consuming large quantities of saturated fat in the form of fatty, domesticated meats, butter, ghee, cream, and other similar foods has been shown to have a range of negative health consequences, which is not surprising, given that this behavior is evolutionary novel and one that the human body is inadequately adapted for.
The bottom line: When consumed in small quantities, as part of a balanced, healthy diet, saturated fat doesn’t cause trouble. However, when consumed in large quantities, as part of a diet that’s high in foods that have only entered into the human diet quite recently, it does.