Feeding Your Immune System

7 Diet Tips to Get You Through the Cold & Flu Season

By Nicole Gould, RDN, CLT Kemper Cognitive Wellness

With back-to-school season in full swing and cooler weather on the horizon, your body needs as much support as possible. You may be wondering what you can do to make sure your immune system is up for the challenge.

For starters, getting at least 7 hours of good quality sleep, engaging in stress management (like meditation, deep breathing, or yoga), testing for vitamin D deficiency, and practicing good hygiene (wash those hands for at least 20 seconds!) are all great ways to fight off germs. You can also support the immune system through the diet.

The following is a list of foods that you should make a regular part of your diet to stay healthy now and all year long.

Fermented Foods  

With over 70% of our immune cells in the gut, nourishing and supporting our microbiome (trillions of beneficial microbes that live on and in us) is one of the best ways to keep your immune system at its best. Fermented, or cultured foods are foods that have been preserved using beneficial bacteria and yeast to extend shelf life, increase nutrition, and change the taste of food. Think of the difference between milk and yogurt (fermented milk). The immune boost from fermented foods is due to the fact that they are a great source of probiotics (good bacteria and yeast) that feed your microbiome to keep it thriving.

Common fermented foods include kimchi, kefir, tempeh, kombucha and sauerkraut. Just make sure to get the truly fermented versions of these foods. The label should say something like “cultured”, “naturally fermented” or  “live cultures” and is often in the refrigerator section rather than on the shelf.

Garlic & Onions 

The immune-boosting properties of garlic and onions seem to be due to their sulfur compounds, such as allicin and sulfides.  These compounds possess potent anti-inflammatory, antiviral, antibacterial, and anti-fungal properties. Though both are beneficial, garlic seems to have more therapeutic benefits as it contains much higher levels of allicin when compared to onions. Whether eaten raw or added to your favorite recipe, these aromatic foods pack a ton of flavor and can be used to ward off more than just vampires!

Herbs & Spices  

Herbs and spices have been used medicinally for thousands of years, adding much more than just flavor to your meals.

A few of my favorites this time of year:

  • Ginger has been shown to increase the body’s ability to fight off infections and help helps kill viruses. It’s also very soothing for the stomach, helping with nausea and indigestion.
  • Turmeric acts as a powerful antioxidant and anti-inflammatory. It also contains antibacterial properties and aids in detoxing the liver.
  • Rosemary is another high antioxidant herb that stimulates the immune system, increases circulation, and supports digestion.

Omega-3 Fatty Acids

The omega-3 fatty acids found in fatty fish (such as salmon, sardines, and mackerel) have well-known anti-inflammatory action. They have also been shown to support the immune system by enhancing the activity of immune cells and protecting the body against damage from over-reactions to infection. Eat plant sources like hemp seeds, chia, walnuts, and almonds daily and aim for fatty fish 3 times a week. Make sure to get wild-caught fish instead of farm-raised. If you are vegan, consider supplementing with an algae-based Omega-3.


There might be a reason we crave soup when we are sick. Beyond containing many of the immune-boosting ingredients (garlic, onions, herbs) mentioned above, homemade chicken soup has healing properties, thanks to the bone broth created during the cooking process. Chicken soup has actually been shown to break up congestion and ease the flow of nasal secretions. Next time you make soup, make sure to double the recipe and freeze, so you have some on hand when you are feeling under the weather.


A hot cup of tea is more than just a comforting hot beverage.  Drinking tea is soothing to the throat and can even strengthen the immune system. Researchers believe many of the benefits come from the amino acid, L-theanine, shown to resist infection and build up T-cells, the body’s first line of defense. In addition, one study showed that tea drinkers had up to five times the amount of anti-bacterial proteins in their blood than those who did not drink tea. Whether you like white, green or black tea, they come from the same plant, all delivering potent antioxidants. To boost up your cup, try a teaspoon of manuka honey in your tea for an added infection-fighting boost.


A specific type of elderberry, Sambucus nigra or black elderberry, is another traditional food used to strengthen the immune system. Black elderberries can be consumed daily to fight off illness and have been shown to shorten the duration and severity of cold and flu-like symptoms. Rather than eat it raw, the berry needs to be cooked or dried and consumed as a tea or syrup. Avoid a “gummy” form, which has a lot of sugar and little active elderberry.

If you are prone to frequent illness, or you just want to do everything you can to stay healthy, try incorporating these foods into your diet. Consuming these foods regularly should give your immune system the boost it needs to keep you healthy, and if you’re already sick, they help you recover faster. Don’t forget to fill up on vegetables, fruits, nuts, and seeds to ensure you are getting enough vitamins and minerals which are critical to keeping your immune system functioning at its best.

Eat up and stay well!