Omega-3 fatty acids are essential for many biological functions and have been linked to preventing heart disease, stroke, and depression. And a recent study published in the journal Neurology reveals that a diet lacking in omega-3s may cause your brain to age faster and increase memory loss.

Since dementia is a disease that happens over decades, it pays to start lowering your risk as soon as possible. Healthy men should aim for 200 mg of DHA and 300 mg of EPA daily.

There are three types of omega-3 fatty acids—eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA)—your body most easily uses EPA and DHA. Those two types are found in fatty fish like mackerel, herring, tuna, and salmon. So the best way to include omega-3s in your diet would be to go for the fish.

If you simply can’t stand eating fish, then try to find alternatives like eggs labeled DHA. You can also eat foods rich with ALA, which is obtained from plant-derived food like spinach, canola oil, walnuts, Brussels sprouts, flax seed, squash, romaine lettuce, and green beans.