You’ll probably recognize the following tips as sensible suggestions. What you may not recognize is that, while they seem simple enough, these strategies are strongly supported by current medical thinking—and each one can make a big difference in your health.

Spend time with friends For men, marriage helps protect against depression. But for women, female friendships keep the blues at bay. Social ties appear to bolster the immune system as well. According to a study conducted at Carnegie Mellon University in Pittsburgh, people with a wide variety of social relationships are less vulnerable to colds and have milder symptoms when they do get sick.

Eat your vegetables Fresh vegetables and fruits provide the fiber you need to prevent colon cancer. Among women, it’s the third leading cause of death from cancer. (Lung cancer is the leader and breast cancer is number two.) Fruits and vegetables are also loaded with antioxidants, vitamins, and minerals. Aim for three to five cups a day.

Drink water Water keeps all your body’s systems running smoothly. Eight glasses each day is recommended, but you’ll need more if you exercise or spend time in very hot, cold, or dry climates. You’ll know you’re getting enough when your urine runs almost clear at least once each day. Symptoms of dehydration include fatigue, headaches, constipation, and even dizziness.

Know your fats Saturated fats (found in meat, dairy products, and coconut and palm oils) are known to increase cholesterol levels. It’s healthier to replace these with monounsaturates (like canola oils) or even polyunsaturates (like corn or fish oils). Limit your daily fat intake to an average of 30 percent of your total calories.