Alpha-linolenic acid

Like linoleic acid,alpha-linolenic acid belongs to the group of polyunsaturated fatty acids. Both fatty acids are essential. According to their chemical structure, polyunsaturated fatty acids, such as those found in humans, are aliphatic monocarboxylic acids with a chain length of 18 to 22 carbon atoms and 2 to 6 double bonds. Polyunsaturated fatty acids are classified into 3 fatty acid families: omega-3, omega-6 and omega-9 fatty acids. These fatty acids are also commonly referred to as n-3, n-6 and n-9 fatty acids. The difference between the families lies in the position of the first double bond in the molecule. Alpha-linolenic acid is an n-3 fatty acid. The more highly unsaturated, longer-chain representatives of the n-3 series are formed endogenously from it by introducing a double bond (desaturation) and chain extension (elongation). The n-6 fatty acid series is derived from linoleic acid.

However, there is a bottleneck: the fatty acid families compete for the same enzyme system for the reaction steps. As a result, the amount of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and arachidonic acid (AA) formed depends strongly on the concentration of the starting fatty acids.

Alpha-linolenic acid, the new star among the fatty acids

Alpha-linolenic acid belongs to the n-3 fatty acids. Science has paid particular attention to these since n-3 fatty acids, especially EPA, were discovered in fish oil as a guarantee for the healthy hearts of the Eskimos. Because fish oil and fatty marine fish have not established themselves as sources of EPA in the diet, there is great interest in healthy alternatives in both science and practice.

ALA is interesting in two respects

1. The positive effects known from EPA can be transferred to ALA because ALA is a direct precursor for EPA. Prerequisite: the conversion rate in humans must be sufficiently high.
2. ALA itself appears to exert positive effects in the metabolism that are independent of the conversion to EPA.

Several intervention studies show that long-chain n-3 fatty acids, especially EPA, protect against heart attacks (Burr, 1989; De Lorgeril, 1999; GISSI-investigators, 1999). The positive effect is explained by the eicosanoids formed from EPA. The GISSI study with a total of over 11,000 patients who had suffered a heart attack showed that supplementation of EPA and DHA over 3 to 5 years significantly reduced mortality from heart attacks and also overall mortality compared to a normal diet. The human organism also appears to fulfill the requirement that ALA is converted to EPA. Up to 10 % of the essential fatty acids supplied are converted into the corresponding longer-chain derivatives in the human organism under normal nutritional conditions (Demmelmair, Koletzko 1999).

It can be assumed that in humans 6% of the amount of ALA ingested is converted to EPA and 3.8% to DHA. However, if the diet is rich in n-6 fatty acids, especially linoleic acid, the conversion of ALA to EPA can be reduced to 40 to 50 % (Gerster, 1998; Valsta, 1996). The background: for the endogenous synthesis of EPA and DHA from ALA, these n-3 fatty acids compete with the fatty acids of the n-6 family for a common enzyme system. Sufficient EPA and DHA can only be formed if there is not too much linoleic acid present. This suggests a ratio of n-6 to n-3 fatty acids of at least 5:1.

There is also evidence that ALA can protect against heart attacks

The Lyon study impressively demonstrated that a Mediterranean diet rich in oleic acid and ALA significantly reduces the rate of reinfarction and overall mortality in patients after a heart attack. A comparison was made with a diet rich in linoleic acid. The decisive factor for the positive effect was the high proportion of rapeseed oil. The ratio of LA to ALA was around 4:1 (de Lorgeril, 1999). Other important observations support the assumption of the independent effect of ALA. Various observational studies have shown that the higher the intake of ALA, the lower the incidence of sudden cardiac death (Ascherio, 1996; Dolecek, 1992; Hu, 1999; Pietinen, 1997). It has also been observed that the risk of stroke is reduced as the proportion of ALA in the diet increases. An increasing ALA content of cholesterol and phospholipids has been discussed as a possible mode of action (Dolecek, 1992). Research into the mechanisms of action of ALA against cardiovascular diseases is still in its infancy.

There are various indications that the effect of ALA on the coronary arteries differs from the effect of EPA or DHA. As a conclusion from these and other study data, the new D-A-CH reference values recommend increasing the intake of ALA from a preventive perspective and at the same time limiting the intake of linoleic acid. In line with the recommendations in Canada and Australia, LA and ALA should be in a ratio of up to 5:1. In fact, a ratio of 10:1 to 7:1 has been achieved to date under normal dietary habits. In practice, the question arises as to how the new findings can be implemented in daily nutritional practice.

One interesting use of ALS for weight training would be to improve the insulin sensitivity of the muscles. By stimulating the so-called Glut1 and Glut4 glucose transporters, both insulin-dependent and insulin-independent carbohydrate uptake in the muscles is increased. In studies with diabetics, a reduction in insulin requirements was observed with ALS supplementation. It is quite conceivable that even healthy people can improve their insulin sensitivity by taking ALS.

This can at least be concluded from the experience reports of athletes who have tried this substance. They report a significantly improved pump during training and fuller muscles. An improvement in insulin sensitivity also optimizes the transport of amino acids into the muscle cells, so that anabolic processes are promoted. Creatine uptake into the muscles, which is largely insulin-dependent, is also improved.

Demand in sport

An interesting use of ALS for weight training would be to improve the insulin sensitivity of the muscles. By stimulating the so-called Glut1 and Glut4 glucose transporters, both insulin-dependent and insulin-independent carbohydrate uptake into the muscles is increased. In studies with diabetics, a reduction in insulin requirements was observed with ALS supplementation. It is quite conceivable that even healthy people can improve their insulin sensitivity by taking ALS. This can at least be concluded from the experience reports of athletes who have tried this substance.

They report a significantly improved pump during training and fuller muscles. An improvement in insulin sensitivity also optimizes the transport of amino acids into the muscle cells, so that anabolic processes are promoted. Creatine uptake into the muscles, which is largely insulin-dependent, is also improved. As ALS is rapidly absorbed by the body, it is recommended that the dosages are divided into several individual doses per day. 50-400mg per day is sufficient to utilize the antioxidant effects of this substance. To improve insulin sensitivity, 600-1200mg per day is necessary.

Safety and side effects

Alpha-linolenic acid is probably safe and harmless for most adults when used in the amounts found in food. There is not enough information to make a statement about the safety and harmlessness of higher amounts. Alpha-linolenic acid from food sources is very well tolerated.

Precautions and warnings

Pregnancy and lactation: Alpha-linolenic acid is probably safe and harmless during pregnancy and lactation at normal dietary levels. However, not enough is known about the safety and harmlessness of higher amounts during pregnancy and breastfeeding, so pregnant and breastfeeding women should avoid using alpha-linolenic acid supplements to be on the safe side.

High triglyceride levels in the blood: Alpha-linolenic acid should not be used if you suffer from high triglyceride levels, as alpha-linolenic acid could further worsen these blood values.

Prostate cancer: You should not use alpha-linolenic acid supplements if you suffer from prostate cancer or have an increased family risk of prostate cancer. There is evidence that alpha-linolenic acid may increase the risk of prostate cancer.

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