High levels of homocysteine, an amino acid, have been linked to an increased risk of Alzheimer’s disease, memory loss, heart attacks, and strokes. According to Dr. Andrew Weil, elevated homocysteine contributes to the plaque that eventually damages artery walls. Since some studies have suggested vitamin B12 and folic acid helps lower these levels, some studies have suggested taking supplements can stave off memory decline. But this wasn’t the case in a recent (as well as the largest to ever look at long-term use of these supplements) study.

Published in the journal Neurology, the study conducted randomized, controlled trials of 2,919 people with high levels of homocysteine. Participants either took a tablet of vitamin B12, folic acid, or a placebo every day for two years. And at the beginning and end of the study, researchers tested participants on their memory and overall thinking skills.

The results: "While the homocysteine levels decreased by more in the group taking the B vitamins than in the group taking the placebo, unfortunately there was no difference between the two groups in the scores on the thinking and memory tests," Dr. Rosalie Dhonukshe-Rutten, lead study author of Wageningen University in the Netherlands, said in a press release.

But, don’t ditch those supplements just yet. Per Dr. Weil, “an inadequate intake of B vitamins, as well as genetic factors that affect the body's absorption and use of folic acid, can lead to elevated homocysteine levels.” Not to mention a vitamin B12 deficiency can lead to anemia, which is why vegetarians and vegans are encouraged to take supplements; meat is a rich and convenient dietary source of the vitamin. Being anemic means your body doesn’t have enough healthy blood red cells, preventing your body tissue from getting enough oxygen.

Fish, chicken, eggs, fortified breakfast cereal, and enriched soy or rice milk are also dietary sources of vitamin B12 if supplements aren’t your thing. The best part is that fish is associated with memory loss. Or rather, the omega-3 fatty acids found in fatty fish, like salmon and sardines, are. One study published in the American Journal of Preventive Medicine found people who ate more fish had 14 percent more gray brain matter, which science finds is an essential part of maintaing healthy memory and cognition. Other studies have shown omega-3s preserve brain volume, reduce risk for dementia, and slow aging altogether.

So no, vitamin B12 supplements on their own most likely won't prevent memory loss. But high levels of the vitamin, plus omega-3s, packs undeniable benefits to your overall health.

Source: Neurology, 2014.