Thanks to the internet, we’re living in a golden age of natural remedies. We no longer live in cooperative villages, in which community members can pass around traditional healing methods by word of mouth. For decades this knowledge was in danger of being lost, and now the internet has allowed us to share natural remedies in a truly unprecedented way. All around the world, people are learning that they have other options.

It wouldn’t be reasonable, however, to use the information-sharing technology of today while leaving aside the vast scientific advancements that are also available to anyone with wi-fi and the will to seek them out. The best natural remedies can only be respected if we have the foresight to acknowledge and push back against the remedies that we know are unsuccessful, particularly those which have no scientific backing in controlled studies.

That’s where sites such as Healthline come in handy, taking on common natural remedies and dividing the successful from the unreliable. Here’s a look at what they found on zinc supplements as a natural remedy for the common cold:

The Truth Behind Natural Cold Remedies

Zinc: Just the Evidence

The evidence for zinc as a cold remedy is mixed. Decades of research have been inconclusive about the ability of zinc lozenges and supplements to prevent or treat the common cold. Some trials showed a significant decrease in the number and duration of colds per year in individuals taking zinc lozenges and supplements, but others show no difference between zinc and control or placebo groups (Roxas, et al., 2007). According to the National Institutes of Health’s (NIH) evidence rankings, zinc lozenges are considered “possibly effective” for reducing the length of the common cold (NIH, 2011). The NIH also reports that zinc pill supplements and nasal sprays are probably not useful for preventing colds.

Evidence in favor of zinc lozenges has shown preventive power and a great reduction in the duration of symptoms and absenteeism (Mossad, et al., 2006Prasad, et al., 2000Singh, et al., 2011). However, many studies have also shown no real effect of zinc on cold prevention, symptoms, or duration (Macknin, et al., 1998Marshall, 2000). Zinc nasal sprays and gels have research supporting their effectiveness (Gorman, 1999;Hirt, 2000Mossad, 2003). Despite their promise, nasal sprays have been criticized for ineffectiveness and occasional permanent or significant negative side effects (Belongia, et al., 2001Eby, et al., 2006). Overall, zinc lozenges appear to be effective at treating symptoms, but are unproven for preventing colds; zinc nasal sprays have been shown to effectively treat symptoms but have not been thoroughly studied regarding prevention (due to potentially extreme side effects).

The Downside of Zinc

Although studies have shown mixed results on the effectiveness of zinc, there is little controversy over its side effects. Zinc can cause metallic taste, local irritation, nausea, vomiting, diarrhea, and other problems. These side effects are more likely to occur with heavy or frequent zinc supplementation than from single lozenges. Overuse can cause coughing, fever, stomach pains, fatigue, and problems with blood iron levels. In large doses (10–30 gm.), zinc can be fatal (NIH, 2011).

Zinc also interacts with many medications and natural supplements. Penicillamine, which is commonly used to treat rheumatoid arthritis, can be rendered much less effective when combined with zinc. Zinc can also decrease the body’s ability to use antibiotics, such as quinolone or tetracycline medications. It may also interfere with the cancer drug cisplatin (Platinol-AQ) and cause a zinc overdose when used with the “water pill” amiloride (Midamor). Zinc may interact with supplements of calcium, chromium, copper, iron, magnesium, and manganese.

Warning: Zicam Zinc Nasal Sprays and Loss of Smell

After more than 130 reports of permanent or long-lasting loss of the ability to smell caused by zinc nasal sprays, the FDA issued a recall of Zicam intranasal products (FDA, 2009). These zinc-based nasal spray products were available without a prescription and were used to relieve cold symptoms and the duration of colds. Further research into this serious side effect has confirmed the ability of zinc nasal sprays to cause loss of smell (Duncan-Lewis, et al., 2011Jafek, et al., 2004).

What do you think? Have you ever taken zinc supplements? If so, do you find this to be a fair review? Whatever your opinions, we’d be very interested to read them in the comments’ section.