Navigation

Alpha-Linolenic Acid

Other Name(s):

Acide Alpha-Linolénique, Ácido Alfa Linolénico, Acide Gras Essentiel, ALA, Acide Linolénique, Acide Gras N3, Acide Gras Oméga 3, Acide Gras Polyinsaturé Oméga 3, Acide Gras Polyinsaturé N3, Essential Fatty Acid, Linolenic Acid, LNA, N-3 Fatty Acid, N-3 Polyunsaturated Fatty Acid, Omega 3, Omega 3 Fatty Acids, Omega-3, Omega-3 Fatty Acids, Omega-3 Polyunsaturated Fatty Acid.

Overview

Alpha-linolenic acid is an essential omega-3 fatty acid. It is called "essential" because it is needed for normal human growth and development. Nuts, such as walnuts, are good sources of alpha-linolenic acid. It is also found in vegetable oils such as flaxseed (linseed) oil, canola (rapeseed) oil, and soybean oil, as well as in red meat and dairy products.

Alpha-linolenic acid is popular for preventing and treating diseases of the heart and blood vessels. It is used to prevent heart attacks, lower high blood pressure, lower cholesterol, and reverse "hardening of the blood vessels" (atherosclerosis). There is some evidence that alpha-linolenic acid from dietary sources might be effective for all these uses except lowering cholesterol. Not enough is known yet to be able to rate alpha-linolenic acid's effect on high cholesterol.

Alpha-linolenic acid is used to treat rheumatoid arthritis (RA), multiple sclerosis (MS), lupus, diabetes, renal disease, ulcerative colitis, and Crohn's disease. It is also used to prevent pneumonia.

Other uses include treatment of chronic obstructive pulmonary disease (COPD), migraine headache, skin cancer, depression, and allergic and inflammatory conditions such as psoriasis and eczema.

Some people use alpha-linolenic acid to prevent cancer. Ironically, alpha-linolenic acid may actually raise some men's risk of getting prostate cancer.

You have probably heard a lot about other omega-3 fatty acids such as EPA and DHA, which are found in fish oil. Be careful. Not all omega-3 fatty acids act the same way in the body. Alpha-linolenic acid may not have the same benefits as EPA and DHA.

How does it work?

Alpha-linolenic acid is thought to decrease the risk of heart disease by helping to maintain normal heart rhythm and heart pumping. It might also reduce blood clots. Although alpha-linolenic acid seems to benefit the cardiovascular system and might reduce the risk of heart disease, research to date does not show it has a significant effect on cholesterol levels.

Uses & Effectiveness

Possibly Effective for...

  • Reducing the risk of hardening of the arteries (atherosclerosis). High dietary intake of alpha-linolenic acid seems to reduce the "plaque" in arteries serving the heart. Plaque is the fatty build-up that characterizes atherosclerosis.
  • Reducing the risk of heart disease and heart attacks. High DIETARY intake of alpha-linolenic acid over a period of 6 years seems to reduce the risk of a first heart attack by as much as 59% in both men and women. Increasing DIETARY intake of alpha-linolenic acid by 1.0-1.2 grams per day appears to decrease the risk of death due to heart disease by 20% or more in people with or without existing heart disease. It is not known if alpha-linolenic acid supplements have these same benefits. Some research suggests alpha-linolenic acid has a greater effect on coronary heart disease when intake of fish oils is low.
  • High blood pressure. Eating a diet high in alpha-linolenic acid seems to reduce risk of hypertension by about a third.
  • Pneumonia. Eating a diet high in alpha-linolenic acid seems to reduce the risk of getting pneumonia.

Insufficient Evidence to Rate Effectiveness for...

  • Prostate cancer. There is contradictory evidence about the role of alpha-linolenic acid in prostate cancer. Some research suggests that high dietary intake of alpha-linolenic acid might increase the risk of getting prostate cancer. But other research finds no increased risk or even a slight decreased risk. Reasons for the conflicting results are not clear, but the source of alpha-linolenic acid seems to be important. Alpha-linolenic acid from dairy and meat sources has been positively associated with prostate cancer. Alpha-linolenic acid from plant sources, such as flaxseed, does not appear to affect prostate cancer risk.
  • Lung infections in children. Preliminary clinical research suggests that alpha-linolenic acid, in combination with linoleic acid, might reduce the number of respiratory infections in children.
  • Crohn's disease..
  • Depression.
  • Diabetes.
  • High cholesterol.
  • Kidney disease.
  • Migraines.
  • Multiple sclerosis.
  • Rheumatoid arthritis (RA).
  • Skin diseases.
  • Systemic lupus erythematosus (SLE).
  • Other conditions.
More evidence is needed to rate alpha-linolenic acid for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

Side Effects

Alpha-linolenic acid is LIKELY SAFE for most adults when used in amounts found in foods. There isn't enough information to know if it is safe in higher amounts. Alpha-linolenic acid from food sources is very well tolerated. However, it is high in calories and may cause weight gain if consumed in excess.

Special Precautions & Warnings

Pregnancy and breast-feeding: Alpha-linolenic acid is LIKELY SAFE in amounts found in food. But not enough is known about the safety of alpha-linolenic acid during pregnancy and breast-feeding when used in higher amounts than those typically found in foods. Stay on the safe side and avoid using alpha-linolenic acid supplements.

High levels of blood fats called triglycerides: Don't take alpha-linolenic acid supplements if you have high levels of triglycerides. Alpha-linolenic acid might make the condition worse.

Prostate cancer. Do not take alpha-linolenic acid supplements if you have prostate cancer or are at high risk for getting prostate cancer (e.g., you have a father or brother with prostate cancer). There is some evidence that alpha-linolenic acid might increase the chance of getting prostate cancer.

Dosing

The following doses have been studied in scientific research:

BY MOUTH:

  • For prevention of coronary heart disease and related events like chest pain or a heart attack: Approximately 1.2-2 grams per day from dietary sources seems to be associated with the greatest benefit.
  • For prevention of a second heart attack or other second event in people with coronary heart disease: Approximately 1.6 grams per day as part of a Mediterranean diet appears to be beneficial.
The National Institute of Medicine has set Adequate Intake level for alpha-linolenic acid. Adequate Intake is a recommended average daily intake level. The amount varies with age: 0 to 12 months, 1 gram/day; 1 to 3 years, 0.7 grams/day; 4 to 8 years, 0.9 grams/day; girls 9 to 13 years, 1.0 grams/day; boys 9 to 13 years, 1.2 grams/day; girls 14 and older, 1.1 grams/day; boys 14 and older, 1.6 grams/day; for women, 1.1 grams/day; for men, 1.6 grams/day; during pregnancy, 1.4 grams/day, and during breast feeding, 1.3 grams/day.

IMAGES

See Images