Saturated fatty acid intake induces inflammation in the hypothalamus that can eventually lead to apoptosis of hypothalamic neurons and subsequent loss of the control of caloric intake and energy expenditure. The overall health of hypothalamic neurons requires their regular renewal, a process known as neurogenesis, which is impaired in obesity. Findings from a 2016 study showed that docosahexaenoic acid (DHA), a type of polyunsaturated fatty acid (PUFA), increased hypothalamic neurogenesis in mice.

DHA is an omega-3 fatty acid found in the human brain and the meat of fatty fish. DHA plays a key role in the development of eye and nerve tissues and is essential for normal brain function in humans.

The authors of the study conducted a six-protocol study in mice. They fed the mice a high-fat diet for eight weeks and then fed them diets containing varying concentrations and types of fats, including flaxseed oil and DHA. They also injected DHA or BDNF, a growth factor involved in neurogenesis, into the brains of the mice.

Mice that ate the DHA-containing diet showed improvements in body mass, glucose metabolism, activity levels, and response to leptin, a hormone involved in appetite control. Both the DHA-containing diet and the injected DHA increased levels of hypothalamic neurogenesis at rates similar to or superior to those observed with BDNF.

These findings suggest that dietary intake of PUFAs such as DHA show promise as a strategy to ameliorate hypothalamic neuronal losses associated with obesity.

• Link to full study.