Human studies show that elderberry, zinc, and vitamin C, taken in the early stages of a cold or flu, can activate the body’s immune functions and shorten the duration.
Colds and flu can make anyone miserable.
They pose a particular risk to older adults, who have reduced immune responses.1,2
Human studies show that three nutrients, taken in the early stages of a cold or flu, can activate immune functions to change the course of the illness.3-6
These nutrients can reduce duration and severity, making people feel better faster and decreasing the danger to older adults.
Over one billion colds occur in the U.S. each year,7 typically lasting about seven days.8
Up to 20% of Americans contract the flu each year, which can lead to sometimes-fatal complications including pneumonia—particularly in older adults.7
Flu vaccines don’t protect against colds7 and don’t even protect against all the strains of flu virus.9
In human studies, scientists have demonstrated that elderberry, zinc, and vitamin C can help target respiratory infections:3-6
Supplementation should be started as soon as possible after symptoms begin.3,4,6,10 This strategy applies to all approaches including anti-viral flu drugs such as Xofluza® to get people back on their feet quickly.11
Elderberries contain anthocyanins, which are plant pigments that have demonstrated immunomodulating, antioxidant, antiviral, and anti-inflammatory effects.5,12,13
Elderberries’ antiviral effects have been shown in two major reports:
Cell culture studies found that elderberry and its extract had direct antiviral effects against viral respiratory tract infections such as colds and flu.
In high (in vitro) doses, nearly 100% of cells were protected against infection.14,15 The positive outcomes were observed even in the virulent form of flu virus that caused the 1918 Spanish flu pandemic (H1N1). 15
Later studies demonstrated similar effects in humans. In one, people suffering from upper respiratory symptoms who used elderberry extract had their symptoms resolve four days earlier than those taking a placebo.4
Zinc is critical to maintaining immune system strength. It helps with normal development and function of key immune components, including:16
Zinc deficiency is common among the elderly.17,18 Data show that oral intake of zinc by the elderly boosts the stress response of white blood cells, enhancing immune response.19
Zinc also seems to coat the receptors that viruses use to bind to cells. This means that viruses may be kept out of body cells, effectively blocking them from replicating out of control.20
A meta-analysis of clinical trials evaluated the effects of taking more than 75 mg of zinc per day, in the form of zinc acetate lozenges every few hours throughout the day, starting after the first sign of symptoms. Results of this analysis showed:
Vitamin C enhances growth and survival of infection-fighting immune cells by:21-23
Scientists have also demonstrated broader immune benefits of vitamin C, including:23,24
A large review paper on vitamin C and infections found that vitamin C reduced duration of colds by 9.4% on average (8% in adults, 18% in children).6
Respiratory infections, such as colds and flu, have the potential to be life-threatening for aging people.
Research has found that zinc, elderberry, and vitamin C help support the immune system and can reduce the severity and duration of colds and flu when taken at the first sign of symptoms.
Zinc lozenges have been shown to reduce duration of colds by an average of 42%.
Elderberry extract helps resolve upper respiratory symptoms up to four days earlier than a placebo.
Vitamin C has been shown to reduce duration of colds by an average of 9.4% overall and by 18% in children.
Other studies have found that vitamin C reduces duration6,25,26 and incidence27-29 of colds. Some evidence has suggested greater benefit with higher doses and if intake begins right after symptom onset.8
The human body cannot produce or effectively store vitamin C. So, levels should be replenished daily.30
In an analysis of two clinical trials scientists found that a combination of 1,000 mg vitamin C plus 10 mg zinc over five days of treatment, was more efficient in reducing symptoms of cold than a placebo.31 This may indicate the importance of a multi-nutrient strategy.
Along with elderberry and zinc, vitamin C can provide important immune support.
Colds and flu can pose a substantial risk to older adults due to age-related immune decline.
Clinical studies demonstrate that, when taken for a short course at the first sign of symptoms, elderberry, zinc, and vitamin C can support the immune functions and reduce the severity and duration of certain viral infections.
(Scientifically reviewed by: Dr. Gary Gonzalez, MD, in December 2022. Written by: Michael Downey.)