Avocado diet increases chance of IVF success: Study

The study by researchers at the Harvard School of Public Health found that monounsaturated fat -- which is found in olive oil, sunflower oil, nuts and seeds -- was better than any other kind of dietary fat for would-be mothers.

Those who ate the highest amounts were 3.4 times more likely to have a child after IVF compared to those who ate the lowest amounts, the researchers found.

In contrast, women who ate mostly saturated fat, found in butter and red meat, produced fewer good eggs that could be used in fertility treatment, they found.

The researchers believe that monounsaturated fats, which are already known to protect the heart, could improve fertility by lowering inflammation in the body.

"The best kinds of food to eat are avocados, which have a lot of monounsaturated fat and low levels of other sorts of fat, and olive oil," the study leader Professor Jorge Chavarro was quoted as saying by the Daily Mail.

Prof Chavarro, however, said the study was small and the findings required further investigation.

In the study, the researchers looked at 147 women having IVF at the Massachusetts General Hospital Fertility Center.

Their intake of different dietary fats was recorded and the result of fertility treatment compared between the highest and lowest third of intake in each category.

Women eating the highest levels of all types of fat had fewer good eggs available for use in treatment.

Prof Chavarro said that the link was driven by saturated fat intake, as high levels of polyunsaturated fat consumption lead to production of poorer quality embryos.

Higher intakes of monounsaturated fat were linked to a 3.4 times higher live birth rate than those with the lowest intake. For those eating least, monounsaturated fat made up nine per cent of calories in their diet while it comprised a quarter for those eating the most.

"Different types of fat are known to have different effects on biological processes which may influence the outcome of assisted reproduction - such as underlying levels of inflammation or insulin sensitivity," Prof Chavarro said.

"However, it is not clear at this moment which biological mechanisms underlie the associations we found," he added.

He insisted that fish remained a source of "good" omega 3 fatty acids, although the research was unable to pin down its contribution.