Lipids
Lipids are Organic Macromolecules that are insoluble in water but soluble in organic solvents. They are the Macronutrient with the Highest Energy Density — 9 kcal per gram — and perform fundamental biological functions that go far beyond their simple role as an Energy Reserve: they form the structure of cell membranes, transport Fat-Soluble Vitamins, regulate Hormone Production, and modulate Inflammatory Processes.
Classification
Lipids are divided into three major structural categories:
- Triglycerides — forms of Energy Storage in Adipose Tissue, consisting of a Glycerol molecule esterified with three Fatty Acids. They are the most abundant form of Lipids in food and in the body.
- Phospholipids — primary structural components of Cell Membranes. They have a hydrophilic head and two hydrophobic tails, a structure that forms the phospholipid bilayer. Phosphatidylcholine is the most abundant phospholipid in membranes.
- Sterols — molecules with a condensed ring structure. Cholesterol is the Animal Sterol par excellence: a precursor to Steroid Hormones, Bile acids, and Vitamin D. Phytosterols, which are of plant origin, reduce the Intestinal Absorption of Cholesterol.
Fatty acids: saturated, monounsaturated, polyunsaturated
The Fatty Acids that make up Triglycerides are classified based on the degree of saturation of their Carbon Chain:
- Saturated Fats (SF) — no double bonds. Solid at room temperature (butter, lard, coconut oil). A chronic excess of long-chain SF is associated with an increase in LDL cholesterol.
- Monounsaturated (MUFA) — one double bond. Oleic acid (Omega-9), abundant in olive oil, is the benchmark MUFA of the Mediterranean diet. It has a neutral or beneficial effect on lipid profiles.
- Polyunsaturated (PUFA) — two or more double bonds. These include essential fatty acids, which the body cannot synthesize on its own.
Essential Fatty Acids: Omega-3 and Omega-6
Essential fatty acids must be obtained through diet or supplementation. The two main families are:
- Omega-6 — parent compound: Linoleic Acid (LA), found in sunflower, corn, and soybean vegetable oils. The body synthesizes Arachidonic Acid (AA) from LA, which is a precursor to pro-inflammatory mediators. The Western diet often contains an excess of omega-6 relative to omega-3.
- Omega-3 — primary source: Alpha-linolenic acid (ALA), found in flaxseed, chia seeds, and walnuts. From ALA, the body synthesizes EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), which have cardiovascular, neurological, and anti-inflammatory effects. EPA and DHA are found in their preformed forms in fatty fish and marine microalgae.
The omega-6-to-omega-3 ratio in the contemporary Italian diet is estimated to be around 10:1–15:1, significantly higher than the optimal ratio of 4:1 recommended by the scientific literature. This imbalance is the reason behind the widespread use of omega-3 supplements, particularly EPA and DHA derived from fish oil or microalgae for plant-based formulations.
Main Biological Functions
- Structural — Phospholipids form the membranes of every cell in the body. DHA is particularly concentrated in the membranes of neurons and in the retina.
- Carrier of Fat-Soluble Vitamins — Vitamins A, D, E, and K require the presence of lipids to be absorbed in the small intestine.
- Inflammatory Modulation — EPA and DHA are precursors of resolvins and protectins, lipid mediators with documented anti-inflammatory effects.
- Hormone Production — Cholesterol is the precursor molecule for estrogens, testosterone, cortisol, and aldosterone.
- Thermal and Mechanical Protection — Adipose tissue provides thermal insulation and protects internal organs from impact.
Approved EFSA Claims
- EPA and DHA contribute to normal heart function (250 mg/day)
- DHA contributes to the maintenance of normal brain function and normal vision (250 mg/day)
- EPA and DHA contribute to the maintenance of normal blood triglyceride levels (2 g/day)
- Phytosterols contribute to the maintenance of normal blood cholesterol levels
High-dose Omega-3 Fatty Acid supplementation (more than 3 g/day of EPA+DHA) may interfere with blood clotting. If you are taking anticoagulant or antiplatelet therapy, you should consult your doctor before taking high-dose omega-3 supplements. During pregnancy, DHA supplementation is generally recommended, but always under the guidance of your healthcare provider.
Always remember that it is important to consult a healthcare professional before starting any new supplement or treatment.
Sofia
My name is Sofia, I am a Blogger, and I publish posts about dietary supplements, including their health benefits, recommended uses, potential interactions, and side effects. To report any inaccuracies, errors, or simple typos, you can write to me at redazione@encanto.it.
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