Waiting to have kids? Make sure your diet’s up to par. A healthy intake of micronutrients—including vitamin C, E, folate, and zinc—can boost sperm DNA quality in older men, according to a study published in the journal Fertility and Sterility.Researchers had 80 men ages 20 to 80 estimate their average daily vitamin intake, then took semen samples to analyze the men’s DNA.The results: The more antioxidants and micronutrients a guy’s diet had, the smaller the risk for sperm with DNA damage, especially in older men. In fact, men ages 44 and older who ate the most vitamin C had 20 percent less damage compared to men of the same age who consumed very little vitamin C.That’s positive news for older men who still want to have kids, since you need healthy DNA for genetically normal children, says study author Andy Wyrobek, Ph.D., senior staff scientist with Berkeley Lab’s Life Sciences Division.Want to ensure stronger swimmers, no matter your age? Incorporate these three nutritional gold mines into your diet to keep your semen in tip-top shape. (And if you’re still hungry for more sex-savvy foods and secrets, pick up a copy of The Men’s Health Big Book of Sex for hundreds of ways to upgrade your sex life.)Fatty Fish Men who eat more omega-3 fatty acids have higher-quality semen than those who skimp on omega-3s, according to a study in Human Reproduction. And even though the researchers say this may be merely a correlation, omega-3s are still loaded with other sex-boosting benefits. The omega-3 fatty acids DHA and EPA found in fish help to raise dopamine levels in the brain that trigger arousal, according to sexologist Yvonne K. Fulbright, Ph.D. Your move? Add oily coldwater fish like salmon, mackerel, sardines, and tuna to your weekly meal lineup.Walnuts Eating just 75 grams of walnuts a day—roughly a handful—can improve the quality of your semen, says a study published in Biology of Reproduction. Researchers monitored the diets of 117 healthy men, asking half to incorporate 75 grams of walnuts into their diets. After 3 months, guys who ate walnuts saw an improvement in the shape of their sperm, as well as the movement and vitality of their swimmers. Why? Researchers believe the alpha-linolenic acid (ALA)—a natural plant source of omega-3—in walnuts may be behind the sperm’s extra boost. (Walnuts aren’t the only convenient snack that will strengthen your sperm. Check out these 12 other Super Sex Foods.)Oysters Besides being the ultimate aphrodisiac, the zinc in oysters can work wonders for your semen. In a study in Fertility and Sterility, sub-fertile men who took zinc sulfates daily saw a 74 percent increase in total normal sperm count after 26 weeks, compared to men who were treated with placebos. Your move: Pop six oysters a day to double the daily recommendation of 15 milligrams of zinc. Other good sources of zinc are shrimp, red meat, pumpkin seeds, poultry and pork, eggs, and dairy products.