New research suggests that an early intake of omega-3 polyunsaturated fatty acids through the mother's breast milk may lower the risk of type 1 diabetes in infants.
The condition is an autoimmune disorder, in which the body's own immune cells attack the so-called beta cells. Beta cells are responsible for producing insulin, which, in turn, is needed to decrease the levels of sugar in the blood. Therefore, in type 1 diabetes, the body cannot produce insulin, and patients with this condition must have it administered artificially in order to survive.
Type 1 diabetes used to be called "juvenile-onset" diabetes, as the disease tends to be diagnosed when the patient is in their mid-teens. In fact, studies have shown that between 2001 and 2009, the number of cases of type 1 diabetes increased the most between those aged 15 to 19.
A new study suggests that something could be done to prevent the onset of type 1 diabetes. Dr. Sari Niinistö, of the National Institute of Health and Welfare in Helsinki, Finland, and team set out to investigate whether or not maternal intake of omega-3 polyunsaturated fatty acids can help to prevent type 1 diabetes in infants.
Omega-3 fats are a subtype of polyunsaturated fats - that is, the "good" kind of fat - and are found most commonly in fish and fish oil, although they can also be found in nuts, leafy vegetables, and other vegetable oils.
The findings were published in the journal Diabetologia.
Studying the link between omega-3 serum levels and autoimmunity
Dr. Niinistö and team used data from the Finnish Type 1 Diabetes Prediction and Prevention Study. They examined whether particularly high serum levels of omega-3 during infancy are associated with autoimmunity development in children who already had a higher risk of developing type 1 diabetes.
The researchers examined 7,782 infants between 3 and 24 months old who were at genetic risk of developing type 1 diabetes. They monitored their islet cell autoantibodies, taking blood samples regularly. Blood samples were also taken up to the age of 15.
Pancreatic islets are clusters of cells that contain the insulin-producing beta cells.
The researchers also used food questionnaires and diaries to track the use of breastfed milk and formula - which are the two main sources of fatty acids for infants.
Of these newborns, 240 infants, together with 480 controls, developed islet autoimmunity. The researchers analyzed the samples of serum fatty acids that had been collected at 3 and 6 months old.
The researchers also looked for insulin and glutamic acid decarboxylase autoantibodies in these patients - both markers of type 1 diabetes.
Omega-3 from breast milk lowers risk of type 1 diabetes autoimmunity
The results revealed that high serum levels of omega-3 fatty acids correlated with a lower risk of insulin autoimmunity.
Specifically, high levels of docosahexaenoic acid and docosapentaenoic acid seemed to lower the risk. However, a high ratio of alpha-linolenic acid to docosahexaenoic acid, as well as a large ratio of omega-6 to omega-3, were associated with a higher risk of autoimmunity.
Additionally, the researchers found a correlation between fatty acids and the type of milk feeding.
Infants who had been breastfed had increased serum levels of fatty acids - such as pentadecanoic acid, palmitic acid, docosapentaenoic acid, and docosahexaenoic acid - and had a lower risk of autoimmunity, compared with infants who were fed cow's milk-based formula.
By contrast, a higher intake of formula correlated with an increased risk of autoimmunity. Dr. Sari Niinistö and colleagues summarize their findings:
"[Our] findings support the view that breastfeeding, or some components of breast milk, including fatty acids, are protective, particularly with early autoimmunity [and] that long-chain omega-3 status during the early months, at a time when the immune system is maturing and being programmed, is critical."
However, the authors caution that their study is purely observational and, as a result, does not explain causality.