Breastfeeding for 6 months or longer protects against liver disease

Australian researchers have found yet another benefit to breastfeeding for six months or more.

New findings, published in the Journal of Hepatology., have shown that babies who are breastfed for less than six months before starting infant formula are much more likely to develop non-alcoholic fatty liver disease (NAFLD) as teenagers. Non-alcoholic fatty liver disease is the most common liver disorder in developed countries, affecting up to one in four adults. It occurs when fat collects in the liver cells in people who do not drink excessive amounts of alcohol and is commonly associated with obesity and insulin resistance. According to the US National Health and Nutrition Examination Survey, NAFLD in teens has doubled over the last twenty years. Lead investigator Dr Oyekoya Ayonrinde, of the University of Western Australia's school of medicine, says that this is an area of disease prevention that has not been looked at in relation to breastfeeding:

"There have been studies into the benefits of breastfeeding on other diseases, but there is little information about benefits of breastfeeding linked to liver disease. We examined records of Australian adolescents to establish if infant nutrition and maternal factors could be associated with the subsequent diagnosis of NAFLD."

The research team performed liver ultrasounds on more than 1,100 teenagers aged 17 years, who have been followed since before birth as part of the Western Australian Pregnancy Cohort study. Records detailing maternal pregnancy and infant feeding corresponded with the presence of NAFLD during late adolescence. NAFLD was diagnosed in about 15 percent of the adolescents examined. Ninety-four percent had been breastfed as infants. The duration of breastfeeding before starting supplementary milk was four months in 55 percent and six months in 40 percent. Adolescent children of women who were obese at the start of pregnancy were twice as likely to have NAFLD, while those fed infant formula milk before completing six months of breastfeeding had a 40 percent increased likelihood of NAFLD. Interestingly, offspring of mothers who smoked at the start of pregnancy also had a significantly increased risk of NAFLD. Dr Ayonrinde says that the benefits of breastfeeding for longer are clear:

"A healthy weight of the mother and support with initiation and persistence with breastfeeding may have later benefits for the liver in their children. This provides additional reasons to support opportunities for women to breastfeed their infants for at least six months while delaying the start of infant formula milk. The important nurturing role of mothers in child health should not be underestimated."

In an accompanying editorial, Dr Anna Alisi of the Liver Research Unit at Rome's Bambino Gesù Children's Hospital, commented:

"This elegant observational study by Ayonrinde and colleagues is the first epidemiological evidence for the connection between maternal obesity, breastfeeding, and NAFLD. Human breast milk is indeed complex and it may contain various biologically-active constituents with a protective effect upon obesity and obesity-related conditions that remain largely unexplored."

Dr Alisi also emphasised the study's findings that there is a significantly increased risk of NAFLD in babies of mums who smoke at the start of pregnancy:

"This study further supports the need to encourage comprehensive healthy lifestyles before and during pregnancy and prolonged exclusive breastfeeding for the long-term health benefits of future generations."