Fats and Fatty Acids
Both excessive and insufficient intake of fats and fatty acids can disrupt important metabolic processes. Total fat intake should therefore not exceed 30% of daily energy intake (%E). A balanced fat and fatty acid intake can primarily be achieved by following a Mediterranean-style diet. With the right dietary measures, a significant positive impact on a patient’s lipid profile and fatty acid status can be achieved.
Functions of Fatty Acids
Fatty acids serve a wide range of functions:
- Fatty acids are essential building blocks of lipids (e.g. triglycerides, phospholipids, glycolipids, cholesterol esters, and waxes).
- They act as energy stores in the form of fats.
- They can modify proteins (e.g. acetylation).
- As membrane lipids, they are the main component of all biological membranes.
- Fatty acid derivatives serve as precursors for tissue hormones (eicosanoids such as prostaglandins), which play a key role in pain signalling, fever, and inflammatory processes.
Polyunsaturated fatty acids (PUFAs) are vital components of phospholipids and are crucial for the formation of cell membranes – those of nerve cells included. They also serve as precursors of eicosanoids (e.g. prostaglandins). The most important types of PUFAs include omega-3 and omega-6 fatty acids. Both omega-3 and omega-6 fatty acids are essential and must be obtained from the diet. The higher the proportion of unsaturated – especially polyunsaturated – fatty acids, the more dynamic the membrane and thus also the cell becomes. Sufficient intake of polyunsaturated fatty acids is essential at every stage of life, but especially during the prenatal and postnatal phases, for the structure and function of the nervous system. Thus, adequate intake is particularly important during pregnancy and breastfeeding.
Monounsaturated Fatty Acids
Monounsaturated fatty acids can generally be synthesised by the human body. Their impact on lipid metabolism is considered neutral to beneficial. They help lower LDL cholesterol while maintaining HDL cholesterol levels. From a nutritional therapy perspective, increasing monounsaturated fatty acid intake can be recommended, especially when replacing saturated or even polyunsaturated fats.
Olive oil and rapeseed oil have a favourable fatty acid profile and are high in monounsaturated fatty acids. Rapeseed oil is rich in the essential omega-3 fatty acid alpha-linolenic acid, while extra virgin olive oil contains high levels of vitamin E and phytochemicals. Therefore, it is often recommended to use rapeseed and olive oils as the primary oils in the kitchen – olive oil especially for cold dishes, and rapeseed oil for cooking and frying.
Saturated Fatty Acids
A high intake of saturated fatty acids, which is typically part of an unhealthy diet, has a detrimental effect on blood lipids (e.g. LDL cholesterol). Saturated fats are primarily consumed through animal-based products such as fatty meats, sausages, cream, butter, and cheese. Additionally, a carbohydrate-rich diet with simple carbohydrates can lead to increased production of saturated fats. Saturated fat intake should therefore be limited to no more than 10% of total calorie intake.
Diagnostics
At MVZ GANZIMMUN GmbH, the following parameters are assessed in the fatty acid profile:
Polyunsaturated Fatty Acids (PUFA) | Monosaturated Fatty Acids | Saturated Fatty Acids | |
Omega-3 fatty acids | Omega-6 fatty acids | MUFA | SFA |
Alpha-linolenic acid Total omega-3 fatty acids | Linoleic acid Total omega-6 fatty acids | Myristoleic acid Total MUFA | Myristic acid Total SFA |
Total PUFA Relative PUFA (calculated value) |
| ||
Total fatty acids | |||
Analytical methods are available from both serum and erythrocyte membranes, providing different insights depending on the sample type:
1. Measurement from EDTA blood → Erythrocyte membrane analysis
Fatty acids are key components of biomembranes and thus essential for erythrocyte membranes. Due to their lifespan (~120 days), erythrocytes serve as a long-term indicator for fatty acid diagnostics. Their fatty acid composition is representative of cell membranes in other organs and offers insights into the patient's health and disease risks.
2. Measurement from serum
Serum fatty acid concentrations vary significantly with recent dietary intake. They reflect the fat consumption of the past 3-4 days and allow for short-term conclusions regarding current dietary habits. Hence, this method is suitable for assessing short-term dietary changes, e.g. verifying successful fatty acid supplementation and intestinal absorption.
