Our story begins on a seemingly peaceful morning in September 1955. Dwight D. Eisenhower, the 34th president of the United States, was enjoying a round of golf under the blue Colorado sky.
It seemed like an ordinary leisure day, but something was about to happen. Eisenhower complained of severe indigestion; however, as the day progressed, the discomfort worsened. The president was rushed to the hospital, and the indigestion turned out to be a cruel warning: a massive heart attack.
The news soon spread; the Stock Market plummeted, losing 14 billion dollars. It was the worst day for markets since the start of World War II. The president was out of office for 10 days, but in addition to the immediate economic and political turmoil, that massive heart attack on the golf course was about to trigger one of the biggest public health upheavals in modern history: The rise of the saturated fat scare and of cholesterol starts here.
The 1950s were marked by a large increase in heart attacks in middle-aged American men. Nobody could understand why. During the 1950s to 1960s, cigarette consumption was at its highest in history.
It was a very common practice among middle-aged men; the act of smoking was highly encouraged in society. Eisenhower smoked more than four packs of cigarettes a day, however, this fact was ignored, and the answer was sought elsewhere. Enter Ansel Keys, an ambitious pathologist at the University of Minnesota, with a theory that seemed to explain everything.
His hypothesis, which ended up becoming famous, the "heart diet", suggested a direct link between the consumption of saturated fat, an increase in LDL cholesterol, and, consequently, heart disease. Keys relied on data that, although convincing at the time, cast doubt on a basic component of the human diet: fat. What many didn't know is that Ansel Keys was inspired by a previous study by Russian scientist Nicolai Anichkov, who in 1913 fed rabbits a diet rich in cholesterol purified from eggs.
The result was surprising: the rabbits developed fatty plaques in their arteries. This pioneering study laid the groundwork for understanding that diets high in certain types of fats could contribute to heart disease, a connection that Keys was more than eager to explore and expand on. However, a fundamental detail was ignored: rabbits are herbivores and humans are omnivores; that is, compared to humans, the fat metabolism of rabbits is very different.
Rabbits are not adapted to process fats. We, on the other hand, have a complex system that not only tolerates but benefits from certain fats. And here we can cite a very important example that challenges the idea that saturated fats are the real villains: breast milk.
Breast milk, a miracle of nature and the perfect food in the first months of life, can contain up to 50% saturated fats in its fat content, complemented by monounsaturated and polyunsaturated essential fatty acids , crucial for the baby's neurological development and health. . The importance of fat in breast milk goes beyond simply providing energy; it delivers fat-soluble vitamins and a range of bioactive components that are crucial for regulating metabolism and cellular function.
Given all this, the question remains: if saturated fat is as bad as we were led to believe, why would nature choose precisely this composition for breast milk? This nutritional treasure in breast milk plays important roles, such as providing energy for the baby's development, participating in the formation of cell membranes, especially nerve cells that have a high concentration of saturated fat. Fats are precursors of hormones and signaling molecules that regulate metabolic and physiological processes, modifying the composition and function of the intestinal microbiota.
The saturated fat in breast milk can increase the diversity and activity of beneficial bacteria that help with digestion, nutrient absorption, defense against pathogens, and modulation of the immune system. There is nothing in the world that has survived the tests of adaptation and evolution more than mother nature. To think that saturated fats, which were one of the bases of our diet for thousands of years and which are one of the components of the richest and most nutritious food that exists, breast milk, were the villains in the explosion of the epidemic of cardiovascular diseases, as a parallel To this, we experienced for the first time in our lives a very high consumption of sugar, refined wheat flour and processed vegetable oils, it is at least a bit of innocence and even arrogance on our part.
Saturated fat has been part of the human diet for millennia. Our ancestors depended on it, not only as a dense energy source, but also as a means to obtain fat-soluble nutrients essential for survival in often inhospitable environments. However, Ansel Keys, with his dietary theory, ignored all of this.
He also ignored the alarming rise of trans fats that began to dominate the market with the popularization of processed vegetable oils in the early 20th century, the rise of smoking, and blamed traditional foods for the decline in modern health. Determined to prove his hypothesis to the world, he set out on a mission with an ambitious study that would cover several countries. Although data was available from 22 countries, Keys chose to include only seven in his analysis, a selection that generated intense debate about the representativeness and integrity of his results.
The selective choice of data gave rise to significant criticism, by omitting data from the other 15 countries that did not show such a clear correlation, it opened the door for accusations of confirmation bias. When analyzed in total, the data from the 22 countries showed a correlation close to zero. Other experts at the time, such as John Yudkin and George Mann, openly challenged Keys' conclusions, arguing that factors such as refined sugar, trans fats, and smoking played significant roles in the increase in heart disease.
However, despite criticism, Keys' theory gained prominence. This raises a reflection on how public health debates can be influenced by a complex web of factors. Some argue that openly questioning widely consumed and profitable products could face considerable resistance from powerful sectors of the industry.
A striking episode revealed the influence of the food industry on nutritional research. In the 1960s, the Sugar Research Foundation funded studies aimed at minimizing the relationship between sugar and heart disease by redirecting attention to saturated fats. Revelations published in JAMA Internal Medicine in 2016 highlight that about 56,000 current dollars were allocated to these studies.
Such investment aimed to protect the interests of the industry, contributing significantly to the promotion of Keys' theories. But the adoption of the recommendations suggested by Keys reached the highest level when President Dwight D. Eisenhower himself implemented the guidelines not only personally but also promoting it to the American nation.
It was support that reverberated globally, marking saturated fats and cholesterol as enemies of public health. However, more recent studies show us a more complex picture about the LDL particle, often labeled as "bad cholesterol. " This study, for example, is a key study in this field.
The study highlights that chronic inflammation plays a huge role in causing heart disease, indicating that LDL levels alone, without analyzing its subtypes or other health indicators, do not provide a complete picture of heart risk. The study also questions the effectiveness of the approach focused on reducing LDL, known as "bad" cholesterol, as the main prevention strategy. He suggests that interventions focused on reducing inflammation and promoting a healthy lifestyle could have a more significant impact on preventing heart disease.
Recent discoveries indicate that LDL is not a single substance, but rather a set of particles that vary in size and density. We can highlight two main types: small and dense LDL, which is more prone to oxidation and deposits in the arteries, and large and fluffy LDL, considered more benign and even protective. Interestingly, saturated fat tends to increase this type of LDL, which is big, fluffy, benign and protective.
On the other hand, the profile of small and dense LDL can be influenced by a combination of factors, including the consumption of refined carbohydrates and trans fats, as well as lifestyle habits such as a sedentary lifestyle, excessive alcohol consumption and smoking, among others. There is a wide range of peer-reviewed scientific studies that deepen our understanding of LDL and its relationship to heart disease. An example is this study available on PubMed, which specifically discusses the role of small, dense LDL in increasing cardiovascular risk.
The study highlights that the complexity of LDL particles is greater than previously thought, highlighting the diversity of LDL subtypes traditionally classified as good or bad. Both HDL and LDL have essential functions that are vital to the body. When we talk about saturated fat, cholesterol comes to mind, and I need to start this conversation by telling you that cholesterol is essential for our body.
That's right, this cholesterol will constitute cell membranes, the covering of the most important cells in our body, including the cells of the central nervous system. This cholesterol participates in the production of hormones, the absorption and also the production of vitamins that are very important for our existence, in addition to being a great source of energy. But I'm almost sure that everyone is scared of cholesterol, and therefore, scared of saturated fat, exactly that of animal origin.
And this history is very long and has been perpetuating misconceptions from decades ago, unfortunately still very present today, including and especially in academia , among professionals who deal with the population's health. From President Eisenhower's heart attack to misguided rabbit experiments, we've seen how context and circumstances can shape the scientific narrative. The truth is that saturated fat is not a monster lurking on our plates, but rather an element with important roles in the human body.
However, as with any component of the diet, moderation and individual context are key. Each person is unique, with different nutritional needs, influenced by factors such as genetics, lifestyle, pre-existing health conditions, and personal goals. Therefore, there is no one-size-fits-all approach when it comes to saturated fat; what works for one person may not be ideal for another.
And blocked arteries are exactly what causes heart attacks and strokes, which are still the main causes of death in the world today. Of course, they will depend a lot on the quality of the cholesterol - I repeat, quality, not just quantity. So, learn to analyze this very well.
They will also depend on several other factors, such as age, diabetes, smoking, high blood pressure, chronic inflammation, people living there with high uric acid, high ferritin - very important markers that are easy to measure in blood tests. Visceral fat, exactly the type of fat that accumulates in the viscera, the most common place in the liver, non-alcoholic hepatic steatosis, is a disease derived from inadequate carbohydrate consumption. In fact, of all these factors I just mentioned, age and smoking have nothing to do with carbohydrate consumption.
All other factors - diabetes and the like, pre-diabetes, insulin resistance , age, high blood pressure, chronic inflammation, visceral fat - are directly dependent on the consumption of simple, refined and ultra-processed carbohydrates. Exactly everything you eat and drink all day, thinking everything is fine, increases your blood sugar. Note that this has nothing to do with saturated fats, those of animal origin.
You are looking and blaming the wrong side of this story. So, when you continue in this life, thinking everything is fine, over the years, you will damage your arteries, get old, ruin their walls, worsening the quality of your blood, your cholesterol, and leading to the formation of fatty plaques. The story is drawn, right?
Up front, we are going to have heart attacks and strokes, unfortunately, that is what has been happening, and no one has done anything to change the old and current recommendations of the nutrition guidelines of Cardiology societies around the world. The anti-inflammatory potential of saturated fats is particularly interesting. There is a range of research that points to this potential, especially when consumed within a healthy lifestyle context.
A great example is the systematic review and meta-analysis published in the Journal of the American College of Cardiology in 2020. This study is particularly relevant not only for reevaluating the role of saturated fats in cardiovascular health, questioning traditional dietary guidelines, but also for analyze a vast set of data from observational studies and randomized controlled trials. The review proposes a new perspective, showing that when included in a healthy diet, saturated fats do not increase inflammatory markers and may even contribute to reducing chronic inflammation.
Coconut oil, for example, often at the center of discussions about saturated fats, perfectly illustrates the complexity of these issues. Coconut oil is rich in lauric acid, a type of saturated fat that the body can convert into monolaurin, a substance with antimicrobial, antiviral and anti-inflammatory properties. But, as well explained in this article, "peer-reviewed medical literature shows that coconut oil can cure multiple diseases that Big Pharma wants to sell you drugs for.
" Stop to think: Who owns this cholesterol, how it lives, what it does and so on. Always be your best scientific study. Compare the interventions, the changes you proposed to make, with your results before and after.
Study, question: Why do we still have so many cases and continue to grow of blocked arteries, consequently of heart attacks and strokes, if there has been a demonization of cholesterol and a witch hunt in relation to saturated fats for decades? What's going wrong? And be careful that you don't die prematurely from blocked arteries with low cholesterol, with the "ideal" numbers as the recommendations still require your results to be presented.
While there was an epidemic of cardiovascular diseases, the industry and the lobby, mainly in sugar, tobacco, and agriculture related to the production of vegetable oils and wheat flour, worked hard to mask the harmful effects of these substances and their rampant consumption. of these substances. It's even ironic, but if you search on Google in the 50s, 60s and 70s, you will find cigarette advertisements with doctors and dentists on the cover, encouraging use, or reducing the harm, or recommending this brand in favor of that one because "this one is good for your teeth" and everything.
And if you're from the 90s, like me, probably at your neighborhood bakery, when you were younger, you already ate that chocolate "cigarette" they sold, which is absurd, right? A chocolate bomb, vegetable fat encouraging one of the worst habits that ever existed for our health. Fortunately, science has managed to prove and establish this strong causal relationship between lung cancer and smoking; It is estimated that 85% of lung cancer deaths are due to smoking.
And then, even with strong pressure from the industry, we managed to implement tobacco control programs very well, which obviously did not happen with sugar, flour or vegetable oils. Quite the contrary, one of the things that has been forgotten and left a little aside is that it is estimated that cigarettes are also the cause of around 30 to 35% of all strokes and 40 to 50% of all acute heart attacks. of the myocardium.
Not only is smoking harmful for lung cancer; it is a pro-inflammatory substance that also triggers the formation of atheroma plaques and vascular fragility. How many Have you ever questioned the veracity of the information you receive, especially the information you reproduce? You may have heard about "wireless phones", right?
It seems like child's play. You receive information there, capturing it, and what you hear you are completely sure is right and you pass it forward, you pass on this information, but what arrives in the end is a big snowball of misinformation. That's exactly what happened with the saturated fat story.
We had a major event, the heart attack of the President of the United States, which had a major impact, mainly financial, on the Stock Exchange. When we looked around, we saw that other people were also suffering from the same problem: cardiovascular diseases were increasing , and this needed an answer, a solution. But the big issue is that science and health are not done quickly and simply.
To paraphrase a best-selling author that I greatly admire, Dr Solto, he always says in all his media: "Mechanism of action is the paving of the road to hell. " That's a big truth. Often, we think that things happen in a way that makes sense, but when we check the studies, we see in practice how it works and realize that it doesn't happen that way.
If you stop to think about the history of fats, it really makes sense, right? After all, why am I having a heart attack? Why am I having a stroke?
Everything is related to cholesterol, fat, right? It's the fact that I get fat and gain weight, it's the fact that I have fat in my liver, that I have fat in my arteries and they are being clogged. So, if I eat fat, that fat deposits on my body in some way, right?
Maybe not. Think about it with me: if we already know that fat is the great villain, especially saturated fat, and since that time we have been reducing our consumption of these fats at any cost - skimmed milk, butter cannot, red meat cannot - and We are increasingly consuming more carbohydrates and more grains. .
. Why is it that nowadays we continue to keep cardiovascular diseases at the top of our list, mainly as a cause of death, and obesity is on the same line of growth? There's something wrong, right?
If I'm reducing fat and the problem of cardiovascular disease is increasing, obesity is increasing, it seems like this doesn't add up. And when I bring this a little more into my niche, it is very clear in hepatology. Patients usually arrive at the office saying: "Doctor, I have fat in my liver, it showed up here on the ultrasound, but I don't eat any fat at all, I don't know what's going on.
" And that's when we start to make a transformation in our diet, because we normally consume the three main macronutrients, right? Protein, fat, and carbohydrate. If I completely remove one of them, as in the case of fat, it will weigh down the other two, and normally we put this more on the carbohydrate side, because it's easier, it's cheaper, and it's more palatable, right?
So, it is much easier to eat carbohydrates than to eat protein. And then we see everything falling apart. We see metabolic syndrome happening, insulin resistance also happening, fat in the liver which is a consequence of all this happening, and especially cardiovascular diseases, the risk of heart attack and stroke always increasing.
When we adjust this diet, it comes back with fat, including saturated fats from a good source, right? Animal and plant. When we eat meat, vegetables, avocado, for example, ah, a source of good saturated fat, we see all the magic happening: with the reduction of carbohydrates, especially refined ones, ultra-processed sugars, that's when we see liver fat disappears, insulin resistance improves, diabetes often goes into remission, and we progress with much better health for this patient.
Therefore, it is necessary to raise awareness about the responsibility we have to communicate this, both to health professionals and to other communicators: journalists, people who have access to the internet who propose to pass on some content, to guide someone. Do you actually check the information you are passing on? The veracity of it, the origin of it, that makes all the difference.
Given these findings, a crucial question arises: Are we overlooking the real factors behind the rise in chronic inflammation and chronic disease? The normalization of self-consumption of sugar, refined carbohydrates, inflammatory and nutrient-poor diets, the normalization of self-consumption of alcoholic beverages, a sedentary lifestyle, and of course, processed seed oils that flood our bodies with toxic compounds, are all often factors underestimated.
