Tis the season for watching the snow fall…drinking hot cocoa and reading by the fireplace…and getting hit with viruses, which thrive in colder weather. 

You already know about the immune-enhancing powers of zinc, vitamins C and D, and medicinal plants such as echinacea and ­elderberry. But several other powerful supplements exist that may decrease your chances of getting sick and help you recover faster if you do get sick. Note: These supplements are generally safe in the amounts mentioned here, but discuss taking them with your doctor, especially if you are immune-­compromised or taking medication. 

Immune-Boosters for Everyone 

N-acetylcysteine (NAC) is an amino acid that supports immunity directly. Also, the body easily converts NAC into the antioxidant glutathione—more on glutathione later. NAC is well-tolerated, inexpensive and so effective against influenza that in one Italian study, only 25% of elderly people taking 600 mg twice daily throughout flu season exhibited flu symptoms, versus nearly 80% of those in the placebo group. Of those who did show symptoms, NAC significantly decreased the severity and intensity. 

Daily dose: 1,200 mg daily, divided into two 600-mg doses. At the first sign of influenza or cold symptoms, increase to 3,600 mg to 4,000 mg ­daily for adults, divided into two doses a day, and continue until symptoms subside. 

Probiotics. For decades, naturopathic doctors have been saying a healthy gut, populated by beneficial bacteria, is necessary for a healthy immune system. This immune booster might not be as surprising as the others, but probiotics are so powerful and vital for a healthy immune system (the word probiotic itself means “beneficial for life”) that they cannot go unmentioned.

Good bugs: While the cold virus and influenza are most certainly bad bugs, probiotics are the kind that are good for you. These bacteria, which come in several strains, including Lactobacillus, Bifidobacteria and Saccharomyces, live in your gut and have many jobs, including regulating the immune system. In fact, about 70% to 80% of your
immune system resides in your gut! 

Supplemental probiotics taken regularly for preventive defense have been shown to decrease ­duration of the common cold in the elderly, adults and children. 

New: “A clear decrease” has been seen in numbers of Lactobacillus and Bifidobacterium strains in the guts of patients with COVID-19, according to an August 2020 Frontiers in Microbiology study.

Daily dose: Probiotics are measured in CFUs—colony-forming units, which represent the bacteria’s potential to divide and reproduce. Aim for 20 billion CFUs a day. You can get there via a combination of food and supplementation…

Food. When you consume ­probiotic-rich foods and ­beverages, such as kefir, yogurt, kimchee, ­sauerkraut, miso soup and other fermented foods, you bathe your gut in helpful bacteria. Kefir is especially good, as it has multiple strains of bacteria, whereas yogurt typically offers only one or two. Try: Lifeway Kefir, with 12 strains and 25 billion to 30 billion beneficial probiotic CFUs per cup ($2.99 to $4.99 for 32 ounces). There also are dairy-free yogurts such as those with an almond, soy or coconut base that contain healthful bacteria.

Supplements. When choosing a daily probiotic, look for one containing strains used in published human studies, such as Lactobacillus paracasei and Lactobacillus plantarum. Try: Metagenics ­UltraFlora ­Immune Booster ($44.14 for 30 capsules).

Note: Some probiotics are stable at room temperature, but if a product’s label says that it needs to be refrigerated, buy it only if it has been refrigerated at the store. This could help prevent some of the bacteria from dying on the shelf before you get the product home. 

For an Even Bigger Boost 

If you are immune-compromised with a chronic health condition or want to be more proactive, you also can add these supplements…

Glutathione. Known as “the mother of all antioxidants,” ­glutathione is one of the body’s most powerful weapons against immune-damaging compounds. When viruses, bacteria or even toxins such as pesticides and heavy metals enter the body, the liver begins secreting glutathione to help neutralize them. Besides being worthwhile for those who are ­immune-compromised, taking glutathione preventively is beneficial to those who are exposed to a lot of toxins in the workplace, such as someone working in a hair salon or as a welder or painter, etc. 

Powerful research: In a study published in European Journal of Nutrition, 54 healthy nonsmoking adults were given either 250 mg or 1,000 mg of glutathione every day for six months or a placebo. By three months, those receiving the larger supplement dose showed ­double the natural killer-cell activity, meaning that they were producing twice as many of these cells known for scavenging the bloodstream for bacteria, viruses and even cancer cells. 

Created by a combination of three amino acids (cysteine, glutamic acid and glycine), glutathione also binds to free radicals—naturally occurring yet damaging by-products of daily living that contribute to cellular damage and premature aging. 

Production of this important immune-system protector decreases with age and is compromised in individuals with chronic conditions such as obesity and type 2 ­diabetes, as well as in those who smoke. When levels drop, white blood cells are diminished, allowing viral and bacterial infections to thrive. 

Link with COVID-19? A number of new studies have identified glutathione deficiency as a possible contributing factor to COVID-19 deaths in the elderly and people with chronic diseases. Higher levels of glutathione may protect against acute respiratory distress syndrome and cytokine storm—the massive flood of inflammatory cells into the body that can lead to death in COVID-19 patients—by inhibiting replication of the virus. 

Daily dose: Glutathione is made by the body and also is found in small amounts in certain foods, including cruciferous veggies such as cauliflower and broccoli, asparagus, avocado, cucumber, green beans, apples and spinach. Most Americans consume only about 150 mg of glutathione per day through the foods they eat, just half of the minimum daily amount recommended by most experts, making supplementation an excellent strategy. Try 200 mg/day to 250 mg/day for general immune support, or 250 mg twice daily if you’re sick. 

I like Setria, the brand used in the European Journal of ­Nutrition study ($11.94 for 60 250-mg capsules). Note: Although the label says to take this supplement with a meal, I think it is best to take it on an empty stomach so that it does not compete with other amino acids.

Beta glucan. Derived from yeast or mushroom extracts, beta glucans are naturally occurring polysaccharides—chains of sugar molecules linked together—that activate the soldiers of your immune system known as macrophages. Once activated, macrophages gobble ­up viruses and signal the rest of the immune system to stand at attention. Various studies have shown that beta glucan supplementation reduces the number of symptomatic cold episodes…reduces ­upper-respiratory symptoms in colds and other infections…and reduces sleep difficulties caused by colds. In one study, 75 marathon runners between the ages of 18 and 53 took either 250 mg or 500 mg of a commercial form of beta glucan called Wellmune WGP, which is yeast-­derived, or a placebo every day for four weeks post-marathon, a time when the immune system can become run down from overexertion. Those in the beta glucan groups reported significantly fewer upper-­respiratory symptoms, increased energy and better overall health compared with the placebo recipients. Beta glucan supplements
also can help combat the immunosuppressive effects of daily stress. 

Daily dose: Aim for 250 mg to 500 mg for prevention and treatment. Try: Wellmune Beta Glucan Supplement, 250 mg ($39.99 for 30 capsules). 

If You Catch a Cold…Pelargonium

Should you catch a cold, you can give Pelargonium sidoides a try. This South African plant, known as umckaloabo, effectively relieves cold symptoms, sinusitis, sore throat and bronchitis. It is available in syrup, drops, powder and chewable tablets. 

Try: Nature’s Way Umcka ColdCare Soothing Hot Drink Packets in Lemon flavor ($10.99 for 10 packets)…Nature’s Way Umcka ColdCare Cherry syrup ($10.99 for four ounces)…or Integrative Therapeutics V Clear EPs 7630 Original Flavor syrup ($16 for four ounces). Follow package directions for dosing.