Adding to our diets more of the omega-3 fatty acids in fish (or fish oil supplements) has been controversial in recent years, but a new study adds some interesting neurological evidence to their effectiveness. Cognitive decline is a too-common side effect of aging, and Alzheimer’s disease is unnervingly prevalent. So it’s nice to feel like we’re doing something to reduce the odds. Eating fatty fish regularly might be one way to this, and so might taking fish oil supplements – but it depends on the kind.
A team at the University of South Dakota looked at 1,100 postmenopausal women who’d taken part in the Women’s Health Initiative Memory Study. The levels of the fatty acids DHA and EPA, found in fatty fish, were measured in their red blood cells, and the volume in different areas of their brains, as well as total brain volume, were measured via MRI at the end of the eight-year study.
It turned out that women who had the highest levels of the fatty acids in their red blood cells had greater overall brain volume than women with the lowest. They also had greater volume in the hippocampus – about 2.7% greater – than women with the lowest levels. The hippocampus is the brain area that’s thought to be the seat of learning and memory, and the one most affected by Alzheimer’s disease.
What are these fats doing in the brain? “It’s likely that fish oil doesn’t increase brain volume, but prevents brain shrinkage with age,” study author James Pottala tells me. “This could be due to several mechanisms. The brain metabolizes DHA into several anti-inflammatory compounds that could help prevent cell death. Also, DHA is concentrated in nerve cell membranes, so if a sufficient amount is not available in the blood for replenishment then it makes sense that the amount of brain matter would decline over time.”
He adds that consuming higher levels of omega-3 fatty acids could be the equivalent to two extra years of brain health. For people who don’t consume much fish, supplements might be necessary. This is because the body is very poor at converting the omega-3s found in plant sources (namely ALA) to the heart- and brain-healthy DHA and EPA. Therefore, says Pottala says, “most organizations recommend that all adults should eat non-fried ‘oily’ fish (e.g. salmon, herring, tuna, sardines, etc.) at least twice a week,” or taking high-quality fish oil supplements.
Unfortunately, not all supplements are created equal, as another study has just reported (see below for a nice graphic of the top 10 brands in both quality and value). On average, supplements contained about 14% less DHA than indicated on the label, but there was huge variation across brands. The highest quality supplements were Dr. Tobias, Nordic Naturals, and Axis Labs. The best value supplements were Nature Made, Axis Labs, and NOW Foods.
While there’s no failsafe way to protect the brain against disease, eating a healthy diet full of antioxidants and essential nutrients, is one way to help reduce the risk. Always talk to your doctor about adding supplements to your diet.
As Originally Published on Forbes