The human body is the most complex machine on earth. Like any other machine, it requires fuel input to function and various chemicals for proper maintenance. In this case, those requirements are met by food. However, food is incredibly complex, with even a simple meal made up of hundreds of compounds. It is foolish to think that we can make simple predictions about what will happen when something as complex as a food is introduced into a complex organism such as a living organism. especially given that the organisms involved may differ in genetics, gender, age, and health status. Still, simple nutritional advice is provided regularly.
For example, to reduce your risk of heart disease, you’re told to replace saturated fats found in red meat, dairy products, and tropical oils like coconut with unsaturated fats found in seed oils. Unfortunately, the story is more complicated. (Here’s a quick chemistry lesson: Saturated fats do not contain carbon-carbon double bonds in their molecular structure, whereas unsaturated fats contain one or more double bonds.)
This discussion was sparked by a study in which researchers in Nigeria came across a study in which they measured the fat composition of insects, specifically honey bees, winged termites, soldier termites, and mopane worms. These insects are eaten in some parts of Africa, and their nutritional content is attracting attention. What caught my attention in this report was the following statement: “The higher the ratio of polyunsaturated fatty acids (PUFA) to saturated fatty acids (SFA) in this study, the higher the nutritional utility of the dietary oil and the PUFA/SFA ratio.” Enough to stop it. ” Atherosclerosis is a buildup of plaque within the arteries that can lead to cardiovascular disease. The implicit message of this study is that eating insects is “good for your heart health.”
Insects are not an option in the Western diet, so this study actually has no practical relevance for us. But it’s too simplistic to paint polyunsaturated fats as angels and saturated fats as demons. For example, a large study in nine European countries found no strong link between dietary saturated fat and heart disease. Replacing saturated fat with unsaturated fat did not reduce the incidence of heart disease. However, the situation turned out to be different when considering the sources of saturated fat. Saturated fats found in red meat and butter increase your risk of heart disease, while saturated fats found in yogurt and cheese actually reduce your risk of heart disease.
The standard advice for many years is to replace saturated fats with unsaturated vegetable fats. That seems justified considering the “heart-healthy” Mediterranean diet, where unsaturated fats come primarily from olives, nuts, and fish. But the story is different when saturated fats are replaced with seed oils such as soybean, sunflower, cottonseed, and corn, as is common in the Western diet. The typical fatty acid found in these oils is linoleic acid (so-called an omega-6 fatty acid because of the presence of a double bond on the sixth carbon from the end of the molecule).
Disturbingly, research shows that replacing saturated fats with vegetable oils containing linoleic acid actually increases the risk of heart disease. This is despite the fact that total cholesterol and LDL cholesterol are decreasing! This is surprising since it is generally considered desirable to reduce blood cholesterol. In fact, many studies have shown that lowering elevated cholesterol using drugs such as statins reduces the risk of heart disease, but studies focusing on lowering cholesterol through diet are inconclusive. there is no. This may be because statins have antioxidant properties that reduce the risk of heart disease.
The problem with linoleic acid is that it is susceptible to attack by oxygen, meaning it is susceptible to oxidation. As with fatty acids, when linoleic acid is incorporated into LDL particles, it reacts with oxygen and breaks down to form “oxidation products” such as malondialdehyde and 4-hydroxynonenal. When LDL containing these oxidation products is deposited on artery walls and forms plaques, it causes inflammation and makes the plaques more susceptible to rupture. This can cause blood clots to form, which can lead to heart attack or stroke. In contrast, omega-3 fats found in fish are also polyunsaturated fats, but they are less susceptible to oxidation, and replacing saturated fats with omega-3 fats may have a protective effect.
Now, let’s go back to insects. Their fat content is mostly linoleic acid. Therefore, the suggestion that eating insects may reduce the risk of heart disease due to a “favorable PUFA/SFA profile” is incorrect. If the polyunsaturated fatty acids are mostly linoleic acid, the profile is unfavorable.
While the relationship between diet and heart disease is clearly complex, calling polyunsaturated seed oils, which are increasingly found in processed foods, “healthy” is misguided. The same goes for labeling all saturated fats as “unhealthy.” Generally, they raise cholesterol, but the degree varies depending on their molecular structure. Myristic and palmitic acids, which have 14 or 16 carbon atoms, raise cholesterol, while lauric and stearic acids, which have 12 and 18 carbon chains, are relatively harmless.
To further complicate the situation, saturated fats also raise HDL cholesterol, the so-called “good cholesterol.” In fact, the best measure of risk is not LDL, but the ratio of total cholesterol to HDL. Insert practical numbers here: Total cholesterol should be less than 5.2 mmol/L and HDL should be greater than or equal to 1.5 mmol/L. This means that this ratio should ideally be less than 3.5. However, replacing saturated fat with seed oils that are high in linoleic acid may lower this ratio, but still increase the risk of heart disease.
If it’s not too complicated, measuring the number of LDL particles in the blood is a better measure of risk than simply measuring LDL cholesterol levels. Apolipoprotein B (ApoB) is a protein found in LDL particles, and its presence indicates the number of LDL particles. Levels above 1.2 grams/L are considered elevated.
So let’s simplify things. It makes no sense to talk about the total intake of saturated and unsaturated fats. This is because the effects of fatty acids are different and also depend on the matrix of the food in which they are contained. Therefore, it makes much more sense to talk in terms of foods rather than specific nutrients. Let’s go. Limit red meat, white flour, sugar, salt, soft drinks, and be careful what comes in the box. Use oils like canola, olive, safflower, or avocado oil that are low in linoleic acid and saturated fat. Eat 5 to 7 servings of fruits and vegetables per day, along with at least one berry. Cheese and yogurt are fine. Emphasize fish and whole grains. Exercise for 30 minutes at least five times a week. It’s not that complicated. So, choose your parents carefully.
@JoeSchwarcz
