Natural Tree Extract Has Significant Effect in Protecting Immune Health
Daily consumption of larch arabinogalactan, a natural extract from larch trees, delivered a statistically significant effect in protecting immune health, according to a 12-week randomized controlled study published in Current Medical and Research Opinion. The study provides some of the strongest evidence to date supporting natural products for immune health, a $2.1 billion market some say is characterized by lofty claims not often supported by science.
According to the Nutrition Business Journal, Americans spent $2.1 billion in 2011 on natural immune products, with products containing vitamin C or Echinacea making up the majority of sales. However, some rigorous studies on the most popular products suggest little benefit in protecting immune health. While a 2012 survey conducted by the Opinion Research Corporation found that 70 percent of respondents believed that taking vitamin C helped their immune systems, authors of the Cochrane Systematic Review, which evaluated 29 studies using vitamin C in immune health, concluded that "routine prophylaxis is not justified."
In the larch arabinogalactan study, 199 healthy participants aged 18-70 took either 4.5 grams of larch arabinogalactan daily or placebo for 12 weeks. In the per protocol collective, people taking larch arabinogalactan group were 57 percent more likely to stay healthy on measured outcomes than those taking placebo.
The number-needed-to-treat (NNT) for the larch arabinogalactan group was seven, suggesting that seven participants needed to take larch arabinogalactan to keep one additional participant healthy. NNT is often favored as a measurement of effectiveness and accounts for placebo effect and the absolute risk of the condition being studied. Lower NNT values indicate better results. The NNT for the best general-population vitamin C studies evaluated in the Cochrane Review ranged from 14 to 1,747, suggesting that the benefit shown in the larch arabinogalactan study was between two and 250 times the benefit shown for vitamin C.
Arabinogalactan occurs naturally in various fruits and vegetables, and as such, has been safely consumed in the human diet for thousands of years. It would take two pounds or more per day of the right fruits and vegetables to deliver the amount of arabinogalactan tested in the study. The larch tree contains relatively high amounts of arabinogalactan, making it an ideal source. Larch arabinogalactan also counts as dietary fiber. Native Americans used preparations made from larch to treat wounds and ward off illness.
The new study adds to the evidence supporting larch arabinogalactan consumption in strengthening the immune system. "We knew that taking larch arabinogalactan daily improved immune biomarkers, but now we know what that really means from a practical perspective, that taking larch arabinogalactan daily can help keep you healthy," said Dr. Dan Johnston, board-certified physician and public health expert based in Washington, DC. "This is exciting because there is now something supported by good clinical evidence that people can take when they feel well and want to stay that way as opposed to taking medicines or other so-called immune products when they are not feeling well," Johnston added.
Alomune immune supplements, launched by Lonza in November 2012, contain larch arabinogalactan. Lonza manufactures larch arabinogalactan and funded the study. Although about 500,000 kilograms of larch arabinogalactan are sold annually to companies that put it into various foods, beverages, and supplements, little is sold in the US. The launch of Alomune and the publication of the study are efforts done with the goal of getting larch arabinogalactan on American radar screens as something beyond vitamin C.
"In the US natural immune health industry, companies are reluctant to invest into raising awareness of new ingredients because they feel that it can be an uphill battle against vitamin C and Echinacea, even though the benefit of taking those ingredients has been shown to be relatively minor in clinical research," said Marshall Fong, director of marketing for Alomune. "But we feel that products having the best clinical evidence will ultimately prevail with consumers and healthcare experts, and we have already seen strong consumer interest in Alomune."