Echinacea and elderberry have been dominant in the immune health category; however, a number of other herbs used as natural remedies since ancient times have shown promising results in clinical trials.
Most people have realized good immune health is the foundation of a high quality of life, especially when our lives have been completely disrupted by the COVID-19 pandemic. Ingredients that can support the immune system are being sought. As more consumers look to herbal and botanical ingredients, echinacea and elderberry have been dominant in the immune health category; however, a number of other herbs used as natural remedies since ancient times have shown promising results in clinical trials and should not be omitted.
Garlic, the “Common Kitchen Ingredient”
One of them is garlic. Garlic is a plant in the onion family. While garlic has played an important role in cooking, its health and medicinal properties were recognized as early as 3000 BC. The ancient Greek Olympic athletes were given garlic as the earliest “performance enhancing” agent.
Garlic preparations, including garlic supplements, are most commonly consumed for their hypolipidemic, antiplatelet, and procirculatory effects. In addition to benefiting the heart and blood system, garlic preparations also appear to enhance foreign compound detoxification, restore physical strength, and improve immune functions. Allicin is the main active ingredient in garlic. However, allicin is unstable and quickly converts to other organosulfur compounds. The health benefits of garlic preparations likely arise from the synergistic activity of multiple phytochemicals.
Clinical studies have shown that garlic preparations may decrease the incidence, duration, and severity of upper respiratory tract infections. The first randomized, double-blind, placebo-controlled trial in this area was published by Garlic Centre, UK, in 2001.1 In this study, 146 participants were randomly assigned to receive either 1) an allicin-containing garlic supplement (n=73), or 2) a placebo (n=73) once a day for 90 days. A self-reported daily diary was used to record the cold infections, symptom severity, and duration. The results showed for the first time:
Another randomized study2 conducted 10 years later by Susan S. Percival and colleagues from the University of Florida investigated the effect of aged garlic extract supplementation on cold symptoms and its potential mechanism of action. In this study, 120 healthy subjects between the ages of 21 and 50 were randomly given either 1) four aged garlic extract capsules (2.56 g), or 2) four placebo capsules per day for 90 days during cold/flu season. Aged garlic extract is a commercially available as an odorless product resulting from long-term extraction of garlic for up to 20 months. The illness diaries were recorded by participants through the 90 days of supplementation. On day zero and day 45, blood was obtained from fasting subjects to measure immune system function. The results showed:
Ginseng, the “Root of Longevity”
Ginseng, often dubbed the “root of longevity,” has been used in traditional medicine over centuries. Nowadays, ginseng preparation is one of the most popular herbal medicines available over the counter.
The two most commonly used and best-studied types of ginseng are Asian or Korean ginseng (Panax ginseng C.A. Meyer) and American ginseng (Panax quinquefolius). Asian ginseng treated with heat transforms into a form of ginseng called Korean red ginseng, which has biological activity similar to Asian ginseng.
Both Asian ginseng and American ginseng are believed to boost energy, improve physical performance, reduce stress, manage sexual dysfunction in men, and improve conditions associated with diabetes. There are over 100 bioactive compounds isolated from ginseng, including ginsenosides, polysaccharides, saponins, and peptides. Among them, the polysaccharides have been shown to exert immunomodulatory effect.
Andrographis paniculata, the “Indian Echinacea”
Andrographispaniculata, also known as “king of bitters,” is a bitter-tasting herb used in Ayurveda and traditional Chinese medicine for centuries. It is used by local people to treat hepatitis, stomach and intestine disorders, kidney problems, and infectious diseases. Andrographis paniculata is popular in Scandinavia as a cold and influenza remedy and is also called “Indian echinacea.” The medicinal value of this plant has been attributed in part to andrographolide, the main diterpene lactone of Andrographis paniculata which shows anti-inflammatory and immune-stimulating activity.
Several clinical trials have shown that Andrographis paniculata preparations are able to improve recovery from common colds.
Dr. Snow Jiang is a consultant in dietary supplement formulation. Snow obtained her PhD in Food Science from Cornell University. She also minored in Nutrition and Marketing. Snow’s research focuses on 1) the health benefits of phytochemicals in fruits, vegetables, and whole grains; and 2) natural products and herbal formulations for antioxidant, anti-aging, and anti-cancer activities. Snow’s career goal is to apply her knowledge in educating consumers so that they may make healthier selections in their diet.