It’s true—what you eat can affect your immune system. Eating a healthy, well-balanced diet will not only help your body, it’ll help your immunity as well. Your food choices actually have a major impact on the strength of your immune system. If you eat a variety of healthy foods, rich in fruits and vegetables, lean sources of protein, whole grains, and healthy fats, you will be in great physical shape, and will have a robust immune system as well.

There are some nutrients that are particularly important for your immune system. These include antioxidants, like vitamins A, C, and E, as well as minerals like zinc and selenium. Vitamin A is found in sweet potatoes, carrots, pumpkin—several orange-colored foods. It’s also found in dark green, leafy vegetables like spinach and kale. Vitamin C is found in many fruits and vegetables, especially citrus fruits. Vitamin E is abundant in nuts, especially almonds. Selenium is abundant in brazil nuts, as well as a variety of fish and seafood, and various types of grains. Zinc is found in abundance in oysters, as well as various types of lean meats and seafood.

While food is always best, if you think your diet isn’t well balanced, you can choose a vitamin supplement or a daily multivitamin to help fill in the gaps in your diet. Just be careful not to depend on your multivitamin supplement too much—nothing can replace the consumption of foods containing these important vitamins and minerals. The reason for this is that the nutrients within natural food items are combined with several other nutrients and phytochemicals that work together in a way that cannot be replicated. If you’re eating fast food or junk food, but taking a multivitamin to get your recommended daily allowance of all the needed micro-nutrients, be aware that your body will not utilize the nutrients in the same fashion as it would with foods that contain them.

Probiotics are also important. These are actually healthy bacteria that are found in the digestive system and are critical for immune system function. These are found in abundance in yogurt with live active cultures. Other foods with probiotics are fermented foods like miso soup and sauerkraut.

As for foods to avoid if you want a strong immune system, you first need to avoid a diet with lots of sugar. Sugar can negatively impact the immune system function, so limit desserts and candy to a minimum. Also, alcohol should be limited as well. Too much alcohol can deplete your body of certain nutrients. Alcohol is a sugar, so too much alcohol will act like too much sugar and therefore will negatively affect your immune function. Being overweight is also bad for your immune system, as an excess of body fat releases inflammatory chemicals that affect your entire body, including your immune system.