‘Tis the season of sniffles and coughs. Whether the snot-nosed monster is only lurking in the shadows or has already got hold of you and reduced you to a miserable coughing, nose-dripping wretch, the following tips can help protect you against catching a cold or flu, or speed up your recovery time.
1. Cut back your sugar intake
In 1973, scientists at Loma Linda University gave study volunteers 100 grams of sugar to consume – that’s about 20 teaspoons of sugar or roughly the amount in one liter of soda1. They then drew some blood from the participants and infected the samples with some bacteria. And this is what they found:
The white blood cells (aka fighters of bacteria, viruses and all that’s bad) of the volunteers who were given sugar gobbled up significantly fewer bacteria, with the effects lasting a few hours following high sugar consumption. In other words, large amounts of sugar may curb your resistance to infection. So if you’re try to avoid getting ill, or have already been struck down with the a cold or flu, now’s really not the time to be suppressing your immune system by eating high sugar foods.
A more recent study also suggests that sugar can inhibit the proper functioning of white blood cells in other ways too; sugar may thwart the transformation of lymphocytes, a type of white blood cell that can change into B-cells (develop into plasma cells that secrete antibodies), T-cells (attack foreign cells and destroy antigens) Natural Killer cells (fight microbes) .2
There isn’t a heck of lot of research on the sugar-immune system connection. But it is unlikely that anyone’s ever proved that refined sugar or high fructose corn syrup is good for you, so cutting back on it can never be a bad thing. You’ll also be reducing your risk of obesity, diabetes, tooth decay and a host of other health problems. 13
2. Get enough sleep
Skipping on the ZZZs can make you more vulnerable to colds and other infections. Scientists found that the risk of catching a cold increased 3 fold in individuals who slept less than 7 hours compared to those who slept at least 8 hours. 3
Quality of sleep also matters: people who spent less than 92% of their time in bed asleep were 5.5 times more likely to be sick compared to those who were asleep for at least 98% of their time in bed. It seems that a lack of sleep or sleep disturbances may suppress the immune system making it less resistant to infections.
3. Add zinc to your diet
A zinc deficiency can suppress the immune system and cause excessive inflammation.
Research shows that supplementing with may decrease the duration and severity of a cold if taken early (within 24 hours of symptoms onset). 4 Before you start popping zinc pills several side effects that can afflict some people. The most common downsides of zinc supplementation are altered taste and nausea. Zinc for colds is popular and you’ll easily find combos of zinc and vitamin C in almost any store.
If you’re not into pills and supplements, you’ll be glad to learn that dietary zinc can also modulate the immune system. 5
Great sources of dietary zinc: oysters and other seafood, turkey and chicken (the darker meat) as well as wild beef. You can also get a nice dose of zinc in nuts, seeds and legumes.
4. Don’t forget selenium
This trace mineral has been found to play a key role in the proper functioning of the immune system. Research shows that selenium plays a role in helping build up white blood cells, boosting the body’s ability to fight illness and infection.
Indeed, a selenium deficiency may even be associated with the flu virus to becoming more virulent.6 What’s even more alarming is that a selenium-deficiency may result in the cold virus mutating into a new strain that affects even those with normal selenium stores.
A French study found that elderly people who took zinc (20mg) and selenium (100mg) supplements, had immune systems that responded better to the flu vaccine compared to those who took placebo, and were less likely to develop a respiratory infection over a two-year period. The elderly at most at risk of suffering serious complications and even death from the flu, so the benefits of supplementation are likely to extend to younger adults too! 11
Foods rich in selenium: Fish, shellfish, Brazil nuts, wheat germ, garlic and seeds.
5. Top up on Vitamin D
Vitamin D stimulates your immune system to produce things called defensins and cathelicidins that kill viruses. 7 However, we get the majority of our Vitamin D from sunlight, so there is massive seasonal variation in our Vitamin D levels. Vitamin D levels are highest during summer and lowest in winter. So just when we need it most, our vitamin D stores are low.
In fact, many scientists believe the reason we’re susceptible to cold and flu in the first place, is due to the decreasing Vitamin D levels in winter.
If you can’t get enough sunshine, you may want to talk to your physician regarding the need for a vitamin D supplement. Research suggests that Vitamin D supplementation may help prevent the usual winter onslaught of cold and flu symptoms. 12
Researchers at the University of Connecticut reviewed 27 studies and found that taking Echinacea decreased the risks of catching a cold by 58% and also sped up recovery. 9
This spice has been shown to fight rhinoviruses, the most common cold virus. 8 For better results, grate some fresh ginger root and allow it to infuse in a covered cup of green tea for a minute or two. This soothing drink should help provide some relief against coughs, pain and fever.
8. Kiwi fruit
According to a study from New Zealand, this small brown fuzzy fruit may reduce the duration and severity of a sore throats and head congestion from 5.4 to 2 days and 4.7 to 0.9 days, respectively. 10
While the research was funded by the largest marketer of kiwifruits, it remains that this fruit is loaded with vitamins C and E, folate, carotenoids, polyphenols and other nutrients that can strengthen your immune system. Plus, kiwi does taste great, so you can’t really lose!
9. Chicken soup!
Last, but certainly not least. The old wives’ tale may have some scientific merit: researchers found that chicken soup reduced the inflammation that causes several flu symptoms. 8 It appears that veggies, chicken and broth act synergistically to decrease fevers and sore throat.
For an even more potent concoction, Dr James Duke, a renowned American botanist, recommends adding lots of garlic, ginger, shallots, basil and sweet bell peppers.
Don’t forget to wrap up warm! And remember to up your H2O intake to keep yourself well hydrated.
- Sanchez, A., et al. (1973) Role of Sugars in Human Neutrophilic Phagocytosis. American Journal of Clinical Nutrition; 261:1180-1184.
- Bernstein, J., al. (1997) Depression of Lymphocyte Transformation Following Oral Glucose Ingestion. American Journal of Clinical Nutrition; 30:613.
- Cohen, S., Doyle, W. J., Alper, C. M., Janicki-Deverts, D., & Turner, R. B. (2009). Sleep habits and susceptibility to the common cold. Archives of internal medicine, 169(1), 62.
- Singh M, Das RR. (2011) Zinc for the common cold. Cochrane Database Syst Rev.2:CD001364
- Ferenčík, M., & Ebringer, L. (2003). Modulatory effects of selenium and zinc on the immune system. Folia microbiologica, 48(3), 417-426.
- Beck, M. A. et al. (2001). Selenium deficiency increases the pathology of an influenza virus infection. The FASEB Journal, 15(8), 1481-1483.
- Cannell, J. et al (2006). Epidemic influenza and vitamin D. Epidemiology and Infection, 134(06), 1129-1140.
- James A. Duke The Green Pharmacy Guide to Healing Foods: Proven Natural Remedies to Treat and Prevent More Than 80 Common Health Concerns (Rodale, 2008).
- Roxas, M. & Jurenka J. (2007) Colds and Influenza: A Review of Diagnosis and Conventional, Botanical, and Nutritional Consideration. Alternative Medicine Review 12(1).
- Hunter DC, Skinner MA, Wobler FM, et al. (2012) Consumption of gold kiwifruit reduces severity and duration of selected upper respiratory tract infection symptoms and increases plasma vitamin C concentration in healthy older adults. British Journal of Nutrition, 108, pp 1235-1245
- Girodon F, Galan P, Monget AL, Boutron-Ruault MC, Brunet-Lecomte P, Preziosi P, Arnaud J, Manuguerra JC, Herchberg S. Impact of trace elements and vitamin supplementation on immunity and infections in institutionalized elderly patients: a randomized controlled trial. Arch Intern Med. 1999;159(7):748-54.
- Cannell JJ, Vieth R, Umhau JC, Holick MF, Grant WB, Madronich S, Garland CF, Giovannucci E. Epidemic influenza and vitamin D. Epidemiol Infect. 2006;134(6):1129-40.
- Lustig RH1, Schmidt LA, Brindis CD. Public health: The toxic truth about sugar. Nature. 2012;482(7383):27-9.