Consuming extra virgin olive oil during pregnancy boosts the quality of breast milk, according to new research.
The salad dressing is rich in omega 3 and omega 6 fats which fuel a baby's growth.
They even cross the placental barrier - improving development of the child in the womb.
Lead author Dr Maria Rodrigues-Lagunas said: "This is the first study to report transmission of extra virgin olive oil plant compounds from mother to offspring during breastfeeding."
The findings are based on female rats fed olive oil for six weeks. Analysis of blood samples identified chemical derivatives in the mothers - and their pups.
The antioxidants called hydroxytyrosol and tyrosol destroy free radicals that damage DNA.
Dr Rodrigues-Lagunas said: "Our results support that diets enriched with extra virgin olive oil could modify or even increase the chemical content of breast milk - with potential health benefits for the infant.
"Moreover, promising levels of olive oil compounds and their metabolites were detected in offspring plasma."
Breast milk is the best source of nutrition for infants. It contains essential nutrients, hormones and antibodies that protect against infections and metabolic diseases.
Breastfeeding also provides many short and long term benefits to the mother - including reducing risk of breast cancer.
Extra virgin olive oil is the main source of fat in the Mediterranean diet - long hailed for its health benefits.
Dr Rodrigues-Lagunas, of the University of Barcelona, said: "Our findings shed fresh light on the importance of the maternal diet during pregnancy and lactation.
"They provide the basis for future studies on the impact of plant compounds on the health of mother and offspring."
Extra virgin olive oil is easy to digest and helps gastric functioning, preventing constipation and colic.
It helps in the absorption of vitamin D, important for growing babies and children because it regulates calcium.
It also encourages the intake of minerals that are essential for strengthening bone and muscle.
This gives children added protection against bone fractures in their tender years and the risk of osteoporosis in old age.
Olive oil lowers bad cholesterol, a great contributor to obesity that affects one out of three children between six and nine years of age. Doctors have recommended replacing animal fats with it.
There has also been reported a lower risk of asthma in mothers who have consumed a consistent amount of olive oil throughout pregnancy.
Their babies have been found to have a more developed immune system, lower risk of rhinitis and allergies.
In Italy doctors strongly recommend using olive oil in solids for babies that are being weaned off breast milk.
They even recommend adding it to formula milk to gain the benefits of the substance - especially for babies suffering from colic.
Added Dr Rodrigues-Lagunas: "To date, several studies had described the composition of breast milk can be affected by biological and environmental factors to which the mother is exposed, such as the mother's diet.
"Therefore, the nutritional interventions during pregnancy and the breastfeeding period can have an impact on the quality of breast milk, and consequently, on the infant's health."
Extra virgin olive oil is found in Italian breads like pizza and focaccia. It can also be used for baking or frying vegetables or drizzled on soups and pastas.
The study is published in the journal Food Chemistry.
