Jeffrey M. Smith, author of Genetic Roulette: The Documented Health Risks of Genetically Engineered Foods and founding executive director of The Institute for Responsible Technology, a leading source of GMO-health-risk information, says several animal studies indicate serious health risks associated with genetically modified food, including infertility, immune problems, accelerated aging, faulty insulin regulation and changes in major organs and the gastrointestinal system. In fact, the American Academy of Environmental Medicine has asked physicians to advise all patients to avoid genetically modified foods altogether. Ready to go GMO free? Here are 10 ways to shop smarter: 1. Go organic. The USDA National Organic Standards prohibit GMOs, so shopping organic is a great way to avoid them. 2. Load up on fruits and veggies. Most fresh produce is non-GMO, says Smith, but zucchini, yellow summer squash, edamame, sweet corn and papaya from Hawaii or China are considered high risk and are best avoided. Only buy those high-risk fruits and vegetables if they are labeled "organic" or "non-GMO," he advises. 3. Look for the non-GMO-verified seal. Since GMOs require no labeling, this seal is one of the best ways to tell when foods are free of genetic modification. 4. Join the Tipping Point Campaign. This network of local activists is working to educate communities on the dangers of GMOs. 5. Beware of additives. The five most common GMOs -- corn, canola, soy, cotton and sugar beets -- often end up as additives (in the form of corn syrup, oil, sugar, flavoring agents or thickeners) in packaged foods.