BACKGROUND: DONAL O'MATHUNAponders the question
A recent traveller to Morocco encountered argan oil products with claims of great medicinal value. The oil is primarily used in cooking and cosmetics, but is starting to be advertised as a new miracle treatment. The oil is a staple food for the native Amazigh people who live where the argan tree grows. The “Amazigh diet” is an adaptation of the plant-based Mediterranean diet where olive oil is replaced by argan oil.
The argan tree is native to Morocco and grows in semi-desert soils, helping to prevent soil erosion. The tree has proven difficult to grow in other regions, making supplies of the oil limited and expensive. The Amazigh people also use the tree for firewood, which, along with damage from goats, has led to it becoming endangered. Unesco is working to conserve the trees by encouraging their planting along the edge of the Sahara Desert and developing fair-trade argan oil production.
The oil is usually cold-pressed from the nuts which minimises chemical changes (and classifies it as a virgin oil). The composition of the oil changes when it is processed in other ways, or when the trees are grown in other regions. This makes high-quality argan oil one of the most expensive oils available.
For the Amazigh, argan oil is the main source of lipids. They use it medicinally to prevent heart disease and treat rheumatic pain. As an ointment, it was used to prevent scar formation and treat skin infections. Cosmetically, it is now said to prevent wrinkles and evidence of ageing.
EVIDENCE FROM STUDIES
Argan oil is composed primarily of unsaturated fatty acids along with several antioxidants and small amounts of other compounds rarely found in plant oils. The antioxidants are mostly of the vitamin E type. The combined presence of these components could help reduce cholesterol levels and the risk of heart disease. However, very little research has been conducted on these claims. In the last few years, preliminary animal research has provided some support for these benefits. In humans, an observational study was conducted where people replaced their dietary butter with either virgin argan oil or virgin olive oil. People’s lipid and cholesterol levels improved in both groups, but to a greater extent with argan. In the only other human study located, replacing butter with argan oil improved people’s antioxidant and vitamin E levels to a greater extent than replacing butter with olive oil.
Adverse reactions to argan oil have not been reported widely. However, a few months ago a case was reported in the medical literature of a Moroccan man with a serious allergic reaction to argan oil. The cause appears to have been a protein similar to one involved in peanut and sesame seed allergies. Anyone with these allergies should be cautious if trying argan oil.
Efforts have been made to determine whether argan oil has more health benefits than olive oil, especially given the large difference in their prices. The oils contain many of the same compounds, but in different proportions. Compared to olive oil, argan oil has two to three times as much vitamin E which is mostly the form called gamma-tocopherol. This is believed to reduce the risk of some diseases better than the form in olive oil.
This component may also be important in cosmetic uses as gamma-tocopherol can reduce skin inflammation. However, many other compounds are present in small amounts in argan oil and their activities remain to be understood.
Moroccan researchers who conducted studies on argan oil recently commented that the “Amazigh diet” should not be seen as a solution to heart disease or obesity. They did recommend adding argan oil to a balanced diet. Whether or not this is viable will probably depend on how much people are willing to pay for their vegetable oils.
Dónal OMathúna has a PhD in pharmacy, researching herbal remedies, and an MA in bioethics, and is a senior lecturer in the School of Nursing, Dublin City University