Diet & Health
Human Evolution – Diet and Health
Fatty acids carry out many functions that are necessary for normal physiological health. The contribution of fats to our energy supply is important both qualitatively and quantitatively. In addition to being a mere storehouse of energy, they are critical for cell membrane structure and function, as well as for local “hormonal” signaling. Imbalances in fatty acid levels are known to affect the clinical course of several lifestyle-related disorders [6, 7, 8, 9, 10].
Omega-6 and Omega-3 Fatty Acids
The increased consumption of soy bean oil in the US has increased the intake of the essential Omega-6 Linoleic acid (LA) from an average of 0.01 kg/year in 1909 to the present level of 12 kg/year . The dietary Omega-6 Linoleic acid (LA) is converted to Omega-6 Arachidonic acid (AA) in the body, which is stored in our cell membranes. Bioactive components made from Omega-6 Arachidonic acid (AA) are responsible for both initiating acute inflammation and the continuation of chronic inflammation in the body, which may lead to several lifestyle-related health problems [6, 12].
Compared to the diet on which humans evolved, today’s Western diets are generally deficient in Omega-3’s. An alternative to the marine essential Omega-3 fatty acids EPA and DHA that the body needs as building blocks is the vegetarian Omega-3 fatty acid Alpha-linolenic acid (ALA). However, vegetable ALA is not sufficiently converted to EPA and DHA in the body to be able to act as a substitute for marine Omega-3 sources. Hence, they must be supplied by direct intake of EPA and DHA from marine sources. Using isotope-labeled ALA, the range of conversion of ALA to EPA has been estimated to be up to 8% in men and up to 21% in women of reproductive age [13, 14]. The overall efficiency of conversion from ALA is 0.2% to EPA, 0.13% to DPA and 0.05% to DHA . An ALA-rich vegetarian diet generally provides less than 4% Omega-3 (EPA+DHA) in the fatty acid profile in whole blood (BioActive Foods, in-house results).
The key message is that a balanced Omega-6/Omega-3 fatty acid ratio is an essential part of a balanced diet aimed to promote good health.
Polyunsaturated Essential Fatty Acids
Omega-3’s and Omega-6’s are polyunsaturated fatty acids (PUFAs), which means that these fatty acids have more than one double bond. In the Omega-3 fatty acids, the first bond is located between the third and fourth carbon atom from the methyl end (CH3) on the carbon chain. Omega-6 fatty acids have their first double bond between the sixth and the seventh carbon atom from the methyl end. In the human body, saturated and unsaturated fats can be synthesized from carbon groups in carbohydrates and proteins, but we lack the necessary enzymes to produce the essential polyunsaturated fatty acids, such as Omega-3’s and Omega-6’s. Essential fatty acids (EFAs) are fatty acids that the body cannot produce itself. Therefore, they must be provided through diet. The most important of these fatty acids are Linoleic acid (LA, C 18:2, Omega-6) and Alpha-linolenic acid (ALA, C 18:3, Omega-3). From LA and ALA the body can synthesize, under optimal conditions, Arachidonic acid (AA, C20:4, n-6), Gamma-linolenic acid (GLA, C18:3, Omega-6), Dihomo-gamma-linolenic acid (DGLA, C20:3, Omega-6), Eicosapentaenoic acid (EPA, C20:5, Omega-3) and Docosahexaenoic acid (DHA, C22:6, Omega-3).
The synthesis is performed through a number of desaturation (i.e. addition of double bonds) and elongation (i.e. addition of two carbon atoms) steps. LA and ALA compete for the same desaturation and elongation enzymes in the synthesis of the long-chained fatty acids AA, EPA and DHA, meaning that even though ALA is a preferred substrate in the process, a higher production of AA will occur due to our high dietary intake of Omega-6 fatty acids, compared to Omega-3 fatty acids.
Further on in the process, locally functioning hormones and signaling molecules (eicosanoids) will be produced from AA and EPA in what is called prostaglandin synthesis. The eicosanoids are formed after an enzyme, cyclooxygenase is released, and the prostaglandin synthesis is initiated by oxidation of the fatty acids AA and EPA. When these fatty acids are oxidized, the initial structure changes into the type of prostaglandin needed in the body at that particular time. COX1 is the enzyme responsible for maintaining normal prostaglandin levels in the body, while COX2 is initiated when tissue damage or infection occurs. Prostaglandin synthesis takes place in almost all of the cells in the body. They belong to the group “eicosanoids” because they consist of 20 carbon atoms. Prostaglandins have 1 to 5 double bonds, shown by the number after “PG E” so PG E1 has one double bond, PG E2 has two, etc.
PG E2 is produced from the Omega-6 fatty acid AA, via LA, or directly from AA which we find, for instance, in the meat of grain-fed animals. PG E2 is prothrombotic, meaning that it is responsible for stopping bleeding, as well as wound healing, but PG E2 can also cause thrombosis, affects blood pressure and the contraction of involuntary muscles. PG E2 is involved in all inflammatory and pain processes in the body, hence it is important that PG E2 is balanced by PG E3, among others, to avoid chronic inflammatory situations in the body as a result of high LA and AA intake.
PG E3 is produced from the Omega-3 fatty acid EPA, via ALA, or directly from EPA consumed as part of a diet rich in fatty fish. PG E3 has anti-coagulation effects in the blood and anti-inflammatory functions in the body .
Omega-6/Omega-3 Fatty Acid Balance and Prostaglandin Balance In The Body
The production of some prostaglandins is strongly affected by our diet, but also by the hormonal balance of the body, our health status, medication, etc. Many people have, due to a high intake of vegetable oils and meats, too much Omega-6 fatty acid AA in their body, resulting in high PG E2 production. If the diet is not balanced with an adequate intake of the Omega-3 fatty acids EPA and DHA, an imbalance between PG E2 and PG E3 can occur, resulting in an increased risk of developing chronic inflammation in the body. Prostaglandin synthesis may be balanced through a diet rich in Omega-3 fatty acids, which promotes the production of more of the beneficial prostaglandin PG E3.
Oxidative Stress and Health
All cells produce free radicals and reactive oxygen that can turn polyunsaturated fatty acids, such as Omega-3’s and Omega-6’s, in cell membranes rancid. The body has therefore developed its own defense mechanism against rancidity. Oxidative stress is a condition that arises when there is an imbalance between the production of rancidity products (free radicals) in the body and the body’s defense against rancidity (antioxidants). This often occurs after prolonged physical activity and is exacerbated by a diet that is unbalanced and pro-inflammatory. The imbalances that create oxidative stress in the body can be corrected by changing the diet. Good protection requires an intake of antioxidants found in about 5 to 9 portions of fruits, green vegetables or extra virgin olive oil every day [17, 18]. However, most people consume less than half of the recommended amount. People who exercise regularly but do not eat a balanced diet may have a level of oxidative stress that is too high. This suggests that active individuals with genetic susceptibility to disease are especially vulnerable if their daily diet is unbalanced and pro-inflammatory
Commercially Available Oils
Before modern technology was introduced to food processing, organically sourced and unprocessed oils for dietary consumption were the only options available. Nowadays, most of the commercially available oils are processed or refined. The refining process eliminates all flavors, odors and contaminating agents that might be harmful or spoil the smell, taste or look of the product. However, the process also removes natural antioxidants, vitamins and other minor components like polyphenols that have beneficial anti-inflammatory properties. The removal of nutrients and important anti-inflammatory components is only partly compensated by the addition of antioxidants for stabilization purposes. The removal of these important nutritional components from the oils we consume enhances the pro-inflammatory profile of our present diet. A very recent example is olive oil. During the refining process of olive oil, the polyphenols are removed. In October 2011, the European Food Safety Authority (EFSA) approved a heart health claim related to olive oil polyphenols: “Olive oil polyphenols contribute to the protection of blood lipids from oxidative stress”. Thus, removal of minor components during refining can affect the bioactivity of oils. A similar example is the removal of vitamin A and vitamin D during the refining of fish oil.
Zinzino Balance Products
To compensate for the loss of important nutritional components during the fish oil refining process, unique Zinzino Balance products contain a combination of biologically active antioxidants from cold-pressed olives (polyphenols), vitamin D and an adequate dose of marine Omega-3’s EPA and DHA from fish.
These components work together in a synergy, which is beneficial. Omega-3 EPA and DHA from fish that circulate in the blood are activated rapidly when inflammation occurs locally. They are converted into biologically active substances (resolvins and protectins) that ensure a balanced immune response. Polyphenols are also powerful anti-inflammatory agents blocking inflammatory and tissue-damaging enzymes [19, 20]. Polyphenols such as those from olives (tyrosol, hydroxytyrosol and more) also possess antioxidant properties protecting the cells and blood lipids from oxidative stress proportionally to intake [21, 22]. Vitamin D contributes to the normal function of the immune system.