The body needs fatty acids for a variety of functions, and the health benefits of taking fatty acid supplements have long been debated. DHA (docosahexaenoic acid) is an omega-3 fatty acid, and it's thought to be involved in vision, brain function, and the regulation of inflammatory processes. DHA has also been linked to a reduction in the risk of cancer.
Some tumor cells are thought to replace sugar or glucose with fat or lipids in their acidic microenvironment, which can promote tumor growth. Tumor cells in these acidic microenvironments may be some of the most aggressive and prone to metastasis. Metastatic cancer is also the deadliest. Researchers at the University of Louvain (UCLouvain) are combining all of these research findings to learn more about how tumor cells behave when they've exposed to different fatty acids.
The UCLouvain scientists have now found that tumor cells in an acidic environment have different reactions to different fatty acids. Some fatty acids appear to stimulate tumor growth, but one can kill them; DHA seems to poison cancerous tumor cells. The findings have been reported in Cell Metabolism.
In this work, the researchers used 3D cell culture models called spheroids. When exposed to DHA, they grew until they exploded. In a mouse model of tumors, the tumors grew more slowly in those on a DHA-supplemented diet compared to those on a normal diet.
DHA appears to cause a phenomenon known as ferroptosis, which is a type of cell death that's been associated with the peroxidation of some types of fatty acids. Cells will normally store fatty acids inside of a lipid droplet, where they are prevented from oxidation. But as unsaturated fatty acid levels rise in cells, there is a greater likelihood that they'll be oxidized. When tumor cells carry a high amount of DHA, they become overwhelmed with it and aren't able to sequester it. The DHA is then oxidized in those cells, and the cells die.
Lipid metabolism inhibitors can prevent the formation of the lipid droplets, which amplifies the entire effect. The researchers suggested that this could open up new therapeutic options.
The UCLouvain researchers noted that the recommended intake of DHA for most adults is 250 milligrams. However, they added that most diets are thought to only provide about 50 to 100 milligrams per day, which is clearly well below what is recommended. This study seems to show that DHA has anti-cancer potential.
DHA is found mainly in fish, with the content varying by species, and influenced by whether they are wild or farm-raised. The highest levels are thought to be in farmed and wild Atlantic salmon. Seaweed, spirulina, chlorella, and nori are some of the only vegetarian sources of DHA.