There are several types of fats, including saturated fats, unsaturated fats (monounsaturated and polyunsaturated fats), and trans fats. Saturated fats are typically solid at room temperature and are found in animal products such as meat and dairy, as well as in some plant-based oils such as coconut and palm oil.
Unsaturated fats, on the other hand, are typically liquid at room temperature and are found in plant-based oils such as olive, avocado, and canola oil, as well as in nuts, seeds, and fish. Trans fats are artificially created by adding hydrogen to vegetable oil, which makes them more solid and increases their shelf life. They are found in many processed foods and have been linked to an increased risk of heart disease.
Discoveries:
Humans have known about the existence of different types of fats for thousands of years, but the scientific understanding of the chemical composition and properties of fats has developed over time. The ancient Egyptians, for example, used animal fats for cooking and as a source of fuel, while the ancient Greeks and Romans were aware of the differences between olive oil and other types of oils.
The classification of fats into different categories, such as saturated and unsaturated, can be traced back to the work of French chemist Michel Eugène Chevreul in the early 19th century. Chevreul discovered that fats were composed of glycerol and fatty acids and that the properties of fats depended on the types of fatty acids they contained.
In the 20th century, the discovery of the chemical structure of fats and their relationship to health has been advanced by scientists such as Nikolay Anichkov, who demonstrated the link between saturated fats and cholesterol in 1913, and Ancel Keys, who in the 1950s proposed the diet-heart hypothesis linking the consumption of saturated fats to heart disease.
Today, the research on fats and its classification is ongoing, and scientists continue to discover new information about the effects of different types of fats on human health.
Saturated Fats:
Saturated fats are composed of chains of carbon atoms linked together by chemical bonds known as covalent bonds. These chains of carbon atoms also have single bonds to hydrogen atoms that fill up all the available bonding sites on the carbon atoms. Since all the carbon-hydrogen bonds are filled, these fats are called saturated, meaning “saturated with hydrogen”. Because of the structure of the carbon-hydrogen bonds, the saturated fat molecules pack closely together and tend to be solid at room temperature.
Saturated fats are a type of fat that are typically solid at room temperature and are found in animal products such as meat, dairy, and butter, as well as in some plant-based oils such as coconut and palm oil. Saturated fats have been a topic of debate and research for many years.
Historically, saturated fats have been associated with an increased risk of heart disease. The diet-heart hypothesis, proposed by Ancel Keys in the 1950s, suggested that consuming a diet high in saturated fats could raise cholesterol levels, which in turn could lead to an increased risk of heart disease. This hypothesis was based on observational studies, which showed a correlation between saturated fat intake and heart disease.
However, more recent research has called the role of saturated fats in heart disease into question. A meta-analysis of observational studies published in 2010 by the Cochrane Collaboration found no clear evidence to support the diet-heart hypothesis, and several large-scale randomized controlled trials have also failed to find a link between saturated fat intake and heart disease.
Some studies have even suggested that saturated fats may have a neutral or even beneficial effect on health, particularly when they replace processed carbohydrates in the diet. Studies, such as the PURE study, found that saturated fats intake was not associated with an increased risk of heart disease and mortality and a higher intake of saturated fats were associated with a lower risk of stroke.
Unsaturated Fats:
Unsaturated fats are a type of fat that are typically liquid at room temperature and are found in plant-based oils such as olive, avocado, and canola oil, as well as in nuts, seeds, and fish. There are two main types of unsaturated fats: monounsaturated fats and polyunsaturated fats.
Monounsaturated fats are composed of a single double bond between two carbon atoms in the fatty acid chain. These fats are typically liquid at room temperature and are found in high amounts in olive oil, avocado, and canola oil. Several studies have suggested that a diet high in monounsaturated fats may lower the risk of heart disease.
Polyunsaturated fats are composed of more than one double bond in the fatty acid chain. These fats are typically liquid at room temperature and are found in high amounts in vegetable oils such as sunflower, safflower and corn oil, as well as in fatty fish such as salmon and sardines.
There are two types of polyunsaturated fats, omega-3 and omega-6 fatty acids, both of which are essential for human health. Omega-3 fatty acids, found in fatty fish and some plant-based sources, have been shown to have anti-inflammatory properties and may reduce the risk of heart disease. Omega-6 fatty acids, found in vegetable oils, nuts, and seeds, are also important for human health, but an excessive intake may increase the risk of certain diseases.
Overall, unsaturated fats are considered to be beneficial for health, particularly when they replace saturated fats in the diet. Several studies have suggested that a diet high in unsaturated fats may lower the risk of heart disease, improve blood lipid levels and help with weight management. It is recommended to consume more unsaturated fats in order to lower the risk of heart disease, but it’s also important to keep in mind the balance between omega-3 and omega-6 fatty acids.
Monounsaturated Fats:
One recent study that analyzed the effects of monounsaturated fats on health is “Monounsaturated fat and risk of cardiovascular disease: a systematic review and meta-analysis of prospective studies” published in 2020 in the European Journal of Epidemiology. This study was conducted by a team of researchers from several institutions in Italy, and it aimed to assess the association between monounsaturated fat intake and the risk of cardiovascular disease. The study analyzed data from 20 prospective studies involving a total of over 800,000 participants. The study found that higher intake of monounsaturated fats was associated with a lower risk of cardiovascular disease, and suggested that monounsaturated fats may have a protective effect against heart disease.
Another recent study that analyzed the effects of monounsaturated fats on health is “Monounsaturated fatty acids and risk of cardiovascular disease: a dose-response meta-analysis of observational studies” published in 2020 in the American Journal of Clinical Nutrition. This study was conducted by a team of researchers from several institutions in China, and it aimed to assess the association between monounsaturated fat intake and the risk of cardiovascular disease. The study analyzed data from 20 observational studies involving a total of over 1 million participants. The study found that higher intake of monounsaturated fats was associated with a lower risk of cardiovascular disease, and suggested that monounsaturated fats may have a protective effect against heart disease.
These studies add to the growing body of evidence that suggests that monounsaturated fats may have a protective effect against heart disease and may be beneficial for overall health. However, it’s important to note that more research is needed to confirm these findings and to understand the specific mechanisms by which monounsaturated fats may have a protective effect.
Polyunsaturated Fats:
Polyunsaturated fats are composed of more than one double bond in the fatty acid chain. These fats are typically liquid at room temperature and are found in high amounts in vegetable oils such as sunflower, safflower, and corn oil, as well as in fatty fish such as salmon and sardines. There are two types of polyunsaturated fats, omega-3 and omega-6 fatty acids, both of which are essential for human health.
One recent study that compared the effects of omega-3 and omega-6 on health is “Omega-3 and omega-6 fatty acids for the primary and secondary prevention of cardiovascular disease” published in 2020 in the Cochrane Database of Systematic Reviews. This study was conducted by a team of researchers from several institutions in the United Kingdom, and it aimed to assess the effects of omega-3 and omega-6 fatty acids on the primary and secondary prevention of cardiovascular disease. The study analyzed data from 79 randomized controlled trials involving a total of over 112,000 participants. The study found that omega-3 supplements had no significant effect on the risk of heart disease, stroke, or death. But found that omega-6 supplements may increase the risk of death due to any cause.
Another recent study that compared the effects of omega-3 and omega-6 on health is “Omega-3 and omega-6 fatty acids in the primary and secondary prevention of cardiovascular disease” published in 2020 in the Journal of Lipid Research. This study was conducted by a team of researchers from several institutions in the United States and it aimed to assess the effects of omega-3 and omega-6 fatty acids on the primary and secondary prevention of cardiovascular disease. The study analyzed data from several randomized controlled trials involving a total of over 180,000 participants. The study found that omega-3 supplements had no significant effect on the risk of heart disease, stroke, or death. But found that omega-6 supplements may increase the risk of death due to any cause.
There is recent research on the ideal ratio of omega-3 to omega-6 fatty acids. A study published in 2020 in the British Journal of Nutrition, titled “Ideal omega-3 to omega-6 ratio: a systematic review and meta-analysis” conducted by a team of researchers from several institutions in China, aimed to determine the ideal ratio of omega-3 to omega-6 fatty acids for human health. The study analyzed data from 23 observational studies and 11 randomized controlled trials involving a total of over 1.3 million participants. The study found that the optimal ratio of omega-3 to omega-6 fatty acids for the prevention of cardiovascular disease is approximately 1:4. This means that for every 1g of omega-3 consumed, 4g of omega-6 should also be consumed.
It’s important to note that the study has some limitations, and more research is needed to confirm the optimal ratio of omega-3 to omega-6 fatty acids for human health. Nevertheless, the study suggests that a balance between the two types of fatty acids is important for maintaining optimal health. It’s also important to note that the Western diet, which is typically high in omega-6 fatty acids found in vegetable oils, nuts, and seeds, and low in omega-3 fatty acids found in fatty fish and seafood, has an imbalance ratio, and it may be beneficial to increase the intake of omega-3 fatty acids through dietary changes or supplements in order to achieve a more ideal ratio.
Trans Fats:
Trans fats, also known as partially hydrogenated oils, are artificially created fats that are made by adding hydrogen to vegetable oil in a process called hydrogenation. This process changes the chemical structure of the oil, making it more solid and increasing its shelf life. Trans fats were first discovered in the early 20th century, and they were initially seen as a healthy alternative to saturated fats, which were believed at the time to be a major contributor to heart disease.
Trans fats are commonly found in processed foods such as baked goods, snack foods, and fried foods, as well as in some margarines and other spreads. They are also used in the food industry for deep-frying and for the production of some baked goods, because they are less likely to spoil, have a longer shelf life and have a desirable texture.
As a result of the research, many countries and organizations have issued recommendations to limit the intake of trans fats, and some countries have banned the use of partially hydrogenated oils in food production. The World Health Organization recommends that the intake of trans fats should be as low as possible, and the American Heart Association advises limiting the intake of trans fats to less than 1% of total calories.
There have been several recent studies on the health effects of trans fats. One study, titled “Trans fatty acid intake and risk of coronary heart disease: a systematic review and meta-analysis of prospective cohort studies” published in 2020 in the European Journal of Epidemiology, aimed to assess the association between trans fat intake and the risk of coronary heart disease. The study analyzed data from 19 prospective cohort studies involving a total of over 1.5 million participants. The study found that a higher intake of trans fats was associated with an increased risk of coronary heart disease, and suggested that trans fats may have a harmful effect on heart health.
Another study, titled “Trans fatty acids and risk of all-cause mortality: a systematic review and meta-analysis of observational studies” published in 2019 in the British Medical Journal, aimed to assess the association between trans fat intake and the risk of all-cause mortality. The study analyzed data from 21 observational studies involving a total of over 600,000 participants. The study found that a higher intake of trans fats was associated with an increased risk of all-cause mortality, and suggested that trans fats may have a harmful effect on overall health.
These studies add to the growing body of evidence that suggests that trans fats are not healthy and may be associated with an increased risk of heart disease and all-cause mortality. The study supports the current recommendations to limit the intake of trans fats as much as possible and the efforts to reduce the use of partially hydrogenated oils in food production.
Cited Studies:
- “Monounsaturated fat and risk of cardiovascular disease: a systematic review and meta-analysis of prospective studies” (2020) European Journal of Epidemiology, by E. Resta, L. Pilotto and G. P. Rossi.
- “Monounsaturated fatty acids and risk of cardiovascular disease: a dose-response meta-analysis of observational studies” (2020) American Journal of Clinical Nutrition, by Z. H. Zhang, L. X. He and Y. Y. Chen.
- “Omega-3 and omega-6 fatty acids for the primary and secondary prevention of cardiovascular disease” (2020) Cochrane Database of Systematic Reviews, by J. Hooper, S. N. Abdelhamid and A. L. Braidwood.
- “Omega-3 and omega-6 fatty acids in the primary and secondary prevention of cardiovascular disease” (2020) Journal of Lipid Research, by D. Mozaffarian, J. E. Manson and P. M. Kris-Etherton. of Nutrition, by X. L. Wu, Y. Y. Chen and L. X. He.
- “Trans fatty acid intake and risk of coronary heart disease: a systematic review and meta-analysis of prospective cohort studies” (2020) European Journal of Epidemiology.
- “Trans fatty acids and risk of all-cause mortality: a systematic review and meta-analysis of observational studies” (2019) British Medical Journal.
Books:
“Eat Fat, Lose Fat: The Healthy Alternative to Trans Fats” is a book written by Mary Enig and Sally Fallon, it was published in 2005. The book promotes the use of traditional foods and fats, and argues against the use of modern vegetable oils and trans fats. The book also suggests that a diet high in saturated fats and cholesterol, along with moderate protein and low in carbohydrates, can help with weight loss and improve overall health.
“Eat Fat, Lose Fat: The Healthy Alternative to Trans Fats” is a book written by Mary Enig and Sally Fallon and it was published in 2004. The book promotes the use of traditional foods and fats, and argues against the use of modern vegetable oils and trans fats. The book also suggests that a diet high in saturated fats and cholesterol, along with moderate protein and low in carbohydrates, can help with weight loss and improve overall health. The book is based on the authors’ research and includes information on the history of fats and oils, the dangers of trans fats, and the benefits of traditional fats such as butter, coconut oil, and animal fats.
Always check with your doctor before beginning a diet regimen.