In Part 2 of our four-part series, we focus on lifestyle factors that can help your customers optimize their immune health. For a cheat sheet on immune system definitions, check out Part 1.


1) Healthy Diet

Diet is an incredibly important component of immune health. One study on the topic explains: “At every stage of the immune response, specific micronutrients, including vitamins and minerals, play a key role, often synergistic, and the deficiency of only one essential nutrient may impair immunity. An individual’s overall nutrition status and pattern of dietary intake… and any supplementation with nutraceuticals… can influence positively or negatively the function of the immune system” (1).

Many diets don’t have much research performed on theirimmune supportive benefits. For instance, in spite of the fact that keto nixes sugars and has been shown to deliver a variety of benefits, research hasn’t yet shown major benefits for immune health. One study, published in March 2020, found that mice fed a ketogenic diet had a better T cell response—not due to glucose deprivation, but because the T-cell population is helped by fatty acid oxidation (2). Not to say that keto can’t help—Jonny Bowden, Ph.D., CNS, makes the case for a high-fat, moderate protein, low-carb diet in COVID-19, Immunity and Fat Burning: What’s the Connection? He explains, “the very same diet that helps you lose weight, reverse or stall the progression of diabetes, and lower your risk for heart disease is the very same diet that will help you survive a challenge like COVID-19, because it will reduce the likelihood of having the very underlying conditions that spell disaster if you get the virus.” Read his insights in The Nutrition Myth Buster column, and keep an eye out—it’s possible that this area may see more research in the future.

A diet that does have a glut of evidence pointing to its immune-protective effects: the Mediterranean diet. A randomized, controlled, U.K.-based study called NU-AGE found that in individuals who consumed a Mediterranean diet, there were small changes in T cell degranulation, cytokine production, and co-receptor expression (3). In older subjects, the diet helped improve aspects of innate immunity. This is particularly important, because that study notes that a hallmark of aging is immunosenescence—a decline of the immune system that affects both the innate and adaptive arms of the immune system. Inflammation (either as a result of or as a cause of immunosenescence) can increase with age, resulting in low-grade chronic inflammation, as well as inflammatory diseases. Thus, suggesting that your older customers look into a Mediterranean diet—or at least elements of one—may help them stave off inflammation, while helping their immune system age more slowly.

When it comes to customers who don’t adhere to a particular diet and are looking for immune health benefits, you can distill the above science into this advice: It is more important to ingest a wide range of nutrient-rich whole foods. Why? Consider vitamin C. The most common foods that come to mind are citrus fruits—but according to Healthline, on a list of high-vitamin C foods, oranges come in at #20. One medium-sized orange provides 70mg of vitamin C, not even the full daily requirement (4). Lemons, often considered an ideal source of vitamin C, contain 83mg of vitamin C—but that number is from one whole, raw lemon, and includes the peel, which is unlikely to be how your customers consume it. Sweet yellow peppers, grapefruit, and kale all contain approximately the daily value or more of vitamin C, with broccoli providing a hefty helping as well.

The takeaway: There are few foods that provide a full daily serving of any given nutrient, so while an orange a day is better than nothing, it is more helpful to eat a variety of foods over the course of a day. Furthermore, the body can only absorb so much of a given nutrient at once, so spreading out fruit-and-vegetable intake over the course of a day gives the body the best shot at absorbing it all.

Customers should, of course, discuss dietary changes with a health care provider first, particularly if they have a disorder that may be affected by their diet. And remind customers that even if they can’t adhere perfectly to the ideal diet, any step they take is a useful step forward. Offering recipe cards or selling cookbooks can help them find the inspiration necessary to eat a healthier meal.

When Food Treats Disease

We all know the power food has to heal or to harm. We also know that no diet is one-size-fits-all. However, for some, food has an immediate and obvious effect on their immune systems—not in terms of developing a cold, but in terms of an autoimmune disease. Autoimmune diseases occur when the body’s immune system mistakenly perceives the body’s own cells as pathogens and attacks them, causing systemic inflammation. Food is a common trigger, although it can be difficult to discern which food is the trigger.

Fortunately, there’s a diet for that. The Autoimmune Paleo (AIP) diet exists to calm the immune system, and then help dieters figure out what foods hurt them and what foods do not. The AIP diet calls for the elimination of dairy, gluten, grains, pseudo-grains, legumes, nuts, seeds, nightshades, eggs, modern vegetable oils, alcohol, added sugar or sweeteners, food additives, and NSAIDs, in an effort to remove everything that could be irritating the immune system (9).

Participants are encouraged to focus on vegetables, organic meat, wild-caught fish, fermented foods, healthy fats, and small amounts of fruits. AIP takes 30 days at least—Kelly Johnston, R.D., a Health Coach at Parsley Health, explains that it can take anywhere from 30 days to several months to see a significant improvement in an autoimmune condition, and suggests that dieters see a doctor to be checked for a reduction in inflammatory markers and an improvement in the gut microbiome to be objectively certain that the diet has decreased bodily inflammation. Once that reduction has been achieved, food groups can be introduced one at a time to figure out what the body can handle.

One thing on which Johnston is very clear: “If you don’t have an autoimmune disease, it’s unnecessary to follow the autoimmune Paleo diet. There is no need to fear any food groups if you are otherwise healthy and symptom-free” (9). Even those with autoimmune diseases aren’t meant to stay on the AIP diet long-term; the end goal is to develop a personalized diet with the broadest possible range of foods, without aggravating the disease.

If your store is frequented by those with autoimmune diseases, you can help by providing an easy place for them to pick up foods approved by their health care provider, who may be monitoring their condition throughout the diet period. Providing organic—and, if possible, regenerative—meats and produce makes it easy for these customers to stick to their doctor-approved diet. While food bars aren’t open these days, packaged heat-and-eat meals can be a lifesaver on busy days, and once food bars reopen, offering foods made without pepper—which Johnston suggests avoiding—can be a big help, too.
2) Stress Management

These days more than ever, stress and isolation are taking their toll. The American Psychological Association (APA) notes that since 1992, there have been studies performed linking stress with lowered immune function (5). One study found that immune function dropped every year for medical students under the stress of a three-day exam period—specifically, students had fewer natural killer cells, nearly stopped producing gamma interferon, and their T-cells responded only weakly to test-tube stimulation.

Since then, APA explains, further studies have found that short periods of stress—as in a few minutes—forced a burst of “first responder” activity, along with signs that the immune system was beginning to weaken. Stress of any duration at all, whether a few days or several months, caused all aspects of immunity to drop. Those who are older or already sick are more prone to stress-related immune changes.

Lack of social support, too, has been cited as a risk factor for depression, which can suppress an older person’s immune system—and has been shown to be a risk factor on its own (5). APA points to a 2005 study of college students that found that social isolation and feelings of loneliness each weakened first-year students’ immunity.

To help customers address stress and isolation, draw on your community. Perhaps you can’t host in-person events, but virtual, interactive, educational events regarding the benefits of different foods and supplements may help your customers connect to each other and to an educator, while helping them feel more in control of their health.

Partnering with a local yoga or Zumba instructor and hosting classes over Zoom can help your customers get exercise; if there’s a period before or after the class wherein participants can freely interact with each other and the instructor, it can help your customers feel more connected to each other, reducing feelings of isolation and stress. Offering discounts on active nutrition supplements to attendees can help them get the nutrients they need to be successful in these enterprises—and can serve as a reminder of certain New Year’s Resolutions.

Live cooking classes, particularly with kid-friendly recipes, can serve the fourfold purpose of teaching customers and their kids about healthy eating, getting kids engaged in an activity, introducing customers to new ingredients, and saving parents the struggle of figuring out what to cook for dinner that night. Releasing the recipe ahead of time and bundling major ingredients for sale in-store can help customers prepare for the night. These cooking classes could also easily survive the transition out of quarantine, and, when families become busy again, could provide time for parents and kids to bond.

Quick Tip!

Lifestyle is complex, and changing it is difficult—particularly when it’s not as easy as purchasing a supplement. What can you do to help? Start with diet—a proper diet can get customers the nutrients they need to help their body function optimally, which can increase stress resiliency and promote healthy sleep.
3) Quality Sleep

Hand-in-hand with stress comes lack of sleep, which can in turn increase stress—and decrease immunity. Eric J. Olson, M.D., with Mayo Clinic, writes that studies show that people who don’t get enough quality sleep or enough sleep in general are more likely to get sick after being exposed to a virus, and more likely to stay sick longer (6). During sleep, the immune system releases cytokines—some of which help promote sleep, some of which are required to fight infection. Sleep deprivation can decrease production of these cytokines. Additionally, antibodies are reduced during periods of sleep deprivation, directly affecting the body’s ability to fight off viruses. Dr. Olson recommended seven to eight hours of sleep each night for most adults and nine to 10 hours for teenagers, and noted that school-aged children may need 10 or more hours of sleep nightly.

Melatonin can be useful here, although Jason DuBois, PharmD, explained in a blog that it isn’t for long-term use (7). For those looking for long-term help, consider recommending ashwagandha—one recent study performed on KSM-66 suggested that it could help insomniacs (8). For more suggestions and an in-depth look at options like tulsi, lemon balm, and cannabidiol, go to and search “Sleep-Stress Connection.” And for more on immune health, check out parts 1, 3, and 4 of this series. WF
    1. Luigi Barrea, Giovanna Muscogiuri, Evelyn Frias-Toral, et al. “Nutrition and immune system: from the Mediterranean diet to dietary supplementary through the microbiota,” Critical Reviews in Food Science and Nutrition. 2020.
    2. Andrea C. Pardo, “Ketogenic Diet: A Role in Immunity?” Pediatric Neurology Briefs. 34. 5(2020). Maijo, Kamal Ivory, Sarah J. Clements, et al. “One-Year Consumption of a Mediterranean-Like Dietary Pattern With Vitamin D3 Supplements Induced Small Scale but Extensive Changes of Immune Cell Phenotype, Co-receptor Expression and Innate Immune Responses in Healthy Elderly Subjects: Results From the United Kingdom Arm of the NU-AGE Trial,” Frontiers in Physiology. 2018.
    3. Vitamin C Caroline Hill, “20 Foods That Are High in Vitamin C,” Healthline. Posted 6/5/2018. Accessed 1/1/2021.
    4. APA stress: “Stress Weakens the Immune System.” Posted 2/23/2006. Accessed 1/1/2021.
    5. Eric Olson, “Lack of sleep: Can it make you sick?” Mayo Clinic. Posted 11/28/18. Accessed 1/1/2021.
    6. Jason DuBois, “Can Melatonin Help You Sleep & Fight COVID-19?” WholeFoods Magazine. Posted 12/10/2020. Accessed 1/1/2021.
    7. WholeFoods Magazine Staff, “KSM-66 May Support Sleep Quality in Insomniacs, Study Suggests,” WholeFoods Magazine. Posted 10/13/2020. Accessed 1/1/2021.
    8. Kelly Johnston, “How the Autoimmune Paleo Diet Heals the Immune System,” Parsley Health. Posted 6/19/2020. Accessed 1/1/2021.