In Your 40s

Fish Oil
Fish oil has stellar anti-inflammatory properties — plus, aids in brain, skin, and mood health — as well as decades of research showing its healthy-heart side effects by helping to lower triglycerides (the bad cholesterol). What you probably need daily: around 1,000 mg a day — but the key is that it needs to be molecularly distilled, a.k.a. highly purified. As for all the buzz on recent research that has trumped its heart-healthy powers? Some experts say that a single paper cannot counteract decades of research. Because most people don’t get two-to-three servings a day of fatty fish, which is where it’s naturally found (as in salmon and tuna), a supplement is the way to go. And remember we’re talking omega 3, not 6 — so, no, guac or olive oil doesn’t count for this one. Gans says that it’s best to start taking ample omega 3 way before now as a preventive measure. “Why wait until something happens — your heart isn't working great or your cholesterol is high?” she says. “It’s better to be proactive.”

Magnesium
This mineral helps with lessening muscle cramps, so it’s especially good for those working out and feeling sore all the time, and therefore could be taken, of course, at any age. However, in your 40s, you might feel a few more aches and pains than you have in previous years. Also, you might not sleep as well, and lack of magnesium could be to blame. “Just like it calms muscles, it calms the body all over and relaxes you, and therefore, promotes better sleep,” says Morrison, who says to take it at night so you can get the double benefit. Try to get approximately 200 mg of magnesium a day (and load up on magnesium foods in your diet, too, such as peanuts, raw broccoli, cooked spinach, and black beans).