Longevity Link Corporation
Detection of skin carotenoids via reflection spectroscopy – LifeMeter
While only two of all carotenoid species, i.e. lutein and zeaxanthin, are concentrated in the macular region of the retina, they are present along with beta carotene, lycopene, and beta cryptoxanthin also in the human skin. Depending on the individual subject, the combined lutein and zeaxanthin level in the skin can reach up to 30% of all skin (or blood) carotenoids. Based on this relatively high contribution, it is possible to track increases caused by dietary supplementation with lutein and zeaxanthin via skin carotenoid scanning. Importantly, skin carotenoids have been found to correlate with macular pigment levels, so the total skin carotenoid score can serve as convenient surrogate biomarker. In 2023, MacuHeatlh, Inc., a leading eye supplement company in the U.S, licensed our skin carotenoid detection scanning technology for exclusive use in Optometry and Ophthalmology. Employing a modified user interface, MacuHealth markets the Veggie Meter® as “LifeMeter” in the eye care field (for details see lifemeter.com).
Longevity Link Corporation was founded in 2004 to develop widely applicable reflection- and fluorescence-based detection methods for micro-nutrients in living human tissue. Our company facilities are in University of Utah Research Park, Salt Lake City, Utah.
Our current efforts expand on the optical detection possibilities for tissue micronutrients, targeting more widespread applications in the fields of general nutrition, public health, nutrition science, and medicine. We are a privately held company; our product development is funded from private contracts and product sales.
Detection of carotenoids in the human retina—macular pigment imaging
Based on highly specific protein binding processes, lutein, zeaxanthin, and meso-zeaxanthin – the latter converted from lutein in the retina via enzymatic processes - are typically located in high concentrations in the center of the human retina, the macula. The macula concentrates also the color sensitive photoreceptor cells and is responsible for high acuity color vision. The three carotenoids, known as macular pigment, protect this area and help prevent the onset of macular degeneration, the leading cause of blindness in the elderly. The macular pigment concentration can be increased with lutein and zeaxanthin-containing vegetables or with lutein and zeaxanthin containing supplement formulations. We are currently developing our patented fluorescence imaging method (US patent # 8,326,405) as an early-age screening test for concentration levels and spatial distributions of the macular pigment.
Previous Technology Commercialization Experience
In the late 1990s, Werner Gellermann, Ph.D., Dept. of Physics at the Univ. of Utah, started a long-term interdisciplinary research collaboration with Dr. Paul Bernstein, a medical doctor and Professor at the University’s Moran Eye Center. Their goal was to explore laser-optical methodologies for the detection of carotenoid pigments in the macular region of the human retina. Funded via technology commercialization grants from the National Institutes of Health (STTR grants), the State of Utah (COE grants), and private investments, initial work centered on Resonance Raman spectroscopy for the detection of macular pigment, development of Raman instrumentation useable with patients in a clinical setting, and clinical trials.
In 1999, Werner Gellermann and colleagues founded Nutriscan, Inc. and Caroderm, Inc., with the specific aim of developing portable Resonance Raman spectroscopy methods for skin carotenoid measurements in clinical and filed settings. In 2002 and 2004, respectively, both companies were acquired by NuSkin/Pharmanex, a global nutritional supplement company. In a collaborative effort, this acquisition resulted in the development of the first portable skin carotenoid measurement device (“Biophotonic Scanner”). The Raman spectroscopy-based scanner made it possible to prove the efficacy of antioxidant-containing multivitamin supplements with an objective test. To date, NuSkin has placed more than 10,000 scanners with their distributors.
Detection of skin carotenoids via reflection spectroscopy – the VEGGIE METER®
Human skin contains all carotenoid species circulating in the human blood stream, i.e. beta carotene, lycopene, beta cryptoxanthin, lutein, and zeaxanthin. Levels can be readily increased with a carotenoid-rich diet, as existing in a healthy diet centered on fruit and vegetable consumption. Based on this tissue response, skin carotenoid levels can serve as an index of fruit and vegetable (F/V) intake and integrative biomarker associated with better health. Using our patented reflection spectroscopy method (US patent # 8,260,402 and multiple international patents) in the design of the VEGGIE METER®, we can quickly measure the level of carotenoids present in a subject’s skin in a non-invasive objective fashion. As a convenient tissue site we use the tip of a finger. Large subject populations can be screened rapidly, and individual carotenoid level increases can be tracked over time in response to dietary and/or supplement interventions. Carotenoids have a characteristic absorption band in the blue wavelength region of the visible light spectrum. The absorption strength in the skin scales directly with their concentration in this tissue. The VEGGIE METER® is invaluable for population studies investigating F/V consumption as well as for studies investigating potential correlations of F/V intake with health and disease outcomes. To date, the Veggie Meter® technology is used in hundreds of research institutions worldwide, including in the U.S., Canada, Europe, Japan, Australia, New Zealand, China, Africa, Singapore, Hongkong, and Nepal. Sales in Japan are handled by Longevity Link Japan Corporation (llcjapan.jp). A list of peer-reviewed “Veggie Meter® articles” published over the past several years in the scientific literature can be found here. Most articles can be accessed through the PubMed website.
Detection of flavonoids via fluorescence spectroscopy
Flavonoids are another important family of plant-derived micro-nutrients taken up with the diet. Like carotenoids, they are thought to have antioxidant functionality in human tissues. While carotenoids are fat soluble, flavonoids are water soluble. Epidemiological studies show consistently that the consumption of flavonoid-rich food lowers the risk of cancers anywhere from 30 to 75 percent. We are developing a non-invasive optical detection approach for the presence of flavonoids in skin based on our patented fluorescence method (European patent EP 2387712) and are currently investigating the tissue uptake kinetics of these compounds as well as a potential integration of the flavonoid detection capability into the VEGGIE METER®. In the meantime, it can be assumed that a high Veggie Meter® score is very likely to indicate also a high flavonoid consumption since on average both antioxidant groups are present in a varied fruit and vegetable diet.
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