Eyes
Episodes
Dr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
Dr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
In this clip, Dr. Rhonda Patrick describes a study in which stem cell-derived retinal cells were used to treat macular degeneration in a human.
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Rhonda Ketosis Heart Disease Omega-3 Fasting Pregnancy Eyes Muscle Sauna Protein Dairy Intestinal Permeability Brown Fat Moringa SupplementsDr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
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Rhonda Exercise Aging Sleep Telomeres Vitamin C Cholesterol Omega-3 DNA Damage Fasting Coffee Magnesium Eyes Calcium Time-Restricted Eating Breast Milk Moringa LactateDr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
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In this clip, Dr. Rhonda Patrick describes a study in which stem cell-derived retinal cells were used to treat macular degeneration in a human.
Topic Pages
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Carotenoids
Carotenoids, such as lutein and zeaxanthin, are bioactive plant compounds with eye and brain benefits.
News & Publications
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Some people appear to age slower (or faster) than others, exhibiting vastly different age-related physical changes and disease risks. Recognition of this biological phenomenon has given rise to the concept of biological age – a measure of a person’s physiological and functional state. Scientists use a variety of means to gauge biological age, including methylation markers, gray matter volume, and facial aging. Findings from a recent study suggest that retinas provide useful biomarkers in determining a person’s biological age.
The retina is a thin, multicellular layer lining the rear, interior portion of the eye. It plays critical roles in the cascade of events involved in visual processing, converting the energy of photons of the visible light spectrum into biochemical signals and transmitting those signals to the brain. Poor retinal health is often an indicator of systemic illness, such as cardiovascular disease or nutritional deficiency.
The authors of the study viewed more than 80,000 retinal images collected from adults (average age, 55 years) participating in the UK Biobank Study. They also collected information about the participants' demographics, lifestyles, and overall health. The researchers used deep learning, a type of machine learning that mimics the way humans learn, to analyze images of the retinas and assign a biological age, which they referred to as “retinal age.” Then they calculated the retinal age gap – the difference between retinal age and chronological age. Having a positive retinal age gap was reflective of an older-appearing retina; having a negative retinal age gap was reflective of a younger-appearing retina. Finally, the researchers looked at links between retinal age gap and all causes of premature death.
They found that their machine learning model accurately predicted retinal age and chronological age to within 3.5 years. For every year of positive retinal age gap difference, the risk of premature death from any cause increased 2 percent. Having positive retinal age gaps greater than three years increased the risk of premature death from specific diseases (other than cardiovascular disease or cancer) by as much as 67 percent. These findings held true even after taking other factors into account, such as body weight, high blood pressure, or smoking.
These findings suggest that retinal age, as predicted via deep learning, is a powerful predictor of biological age and premature death risk. Collecting retinal images is a low-cost, non-invasive procedure that may be beneficial in identifying people at risk for premature disease and death. Learn about other strategies for predicting biological age in our overview article on epigenetic aging clocks.
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Morning exposure to red light improves eyesight in older adults. www.sciencedaily.com
Aging, the collective physiological, functional, and mental changes that accrue in a biological organism over time, affects different organs and organ systems at different rates. The effects of aging on the eyes begins around the age of 40 years, when retinal cells called rods and cones undergo rapid decline due to mitochondrial dysfunction and loss, markedly impairing eyesight. Findings from a recent study suggest that a single exposure to red light in the morning improves eyesight.
Mitochondria have specific light absorbance characteristics that modulate their performance. For example, the mitochondrial electron transport chain is photosensitive to certain wavelengths of light. As a result, exposure to longer wavelengths, such as those in the 650 to 1000 nanometer range, improve mitochondrial function and enhance ATP production. Red light has the longest wavelengths on the visible spectrum, and previous research indicates that exposure to red light restores mitochondrial function in the eyes of older adults.
The current study involved 20 adults between the ages of 34 and 70 years who had no eye disease. The participants looked at a red light (670 nanometers) with their dominant eye in the morning (between 8 a.m. and 9 a.m.) or afternoon (between noon and 1 p.m.) for three minutes. The authors of the study assessed the participants' rod and cone sensitivity before the single-session intervention and again at three hours and one week post-intervention.
They found that after the age of 40 years the participants' rod and cone performance underwent marked decline. These declines were rescued by exposure to red light, but only when the exposure occurred in the morning. Color sensitivity, a feature of the cone cells, improved by up to 20 percent in older participants.
These findings suggest that simple light therapies show promise as strategies to ameliorate vision loss in older adults. Interestingly, sulforaphane, a bioactive compound derived from some cruciferous vegetables, helps protect retinal cells against oxidative stress – a driver of mitochondrial dysfunction. Learn more about sulforaphane in this episode featuring Dr. Jed Fahey.
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Lutein and zeaxanthin supplementation improves visual processing in younger healthy adults. journals.plos.org
Cognitive function, including complex executive functions like working memory and basic functions like sensory processing, progressively declines with age. While executive function loss is highly variable and easily measurable in older adult populations, younger adults usually perform at a level consistent with their peers, which makes studying cognitive decline in younger adults difficult. In a 2014 report, researchers measured visual processing ability in young adults before and after supplementation with lutein and zeaxanthin.
Visual processing refers to the brain’s ability to utilize and interpret visual information. Because visual processing utilizes similar brain architecture as more complex tasks such as working memory, it is a useful measure in assessing brain health and cognitive decline.
Lutein and zeaxanthin are carotenoid pigments found in foods that accumulate in the retina and throughout the brain and perform light-absorbing, antioxidant, and anti-inflammatory functions. Animal research has demonstrated that the density of these pigments in the eye is a good indicator of their density in the brain, providing researchers a non-invasive means to measure the relationship between pigmentation and cognitive function. Higher pigment density in the eye[has been associated with better cognitive performance and visual processing speed in older adults with or without cognitive decline.
Researchers measured the baseline visual processing speed and retinal concentration of lutein and zeaxanthin in healthy young adults (average age, 22 years). They assigned participants to consume either placebo, zeaxanthin only (20 milligrams), or a combination of zeaxanthin (26 milligrams), lutein (8 milligrams), and mixed omega-3 fatty acids (190 milligrams) per day for four months. They measured retina pigmentation and visual processing speed again following the intervention.
The authors reported a moderate, yet statistically significant, relationship between baseline retinal pigment levels and visual processing speed. Following the intervention, both supplement groups demonstrated a significant increase in retinal pigmentation compared to placebo. Finally, participants in the supplement groups also performed 12 percent better on the critical flicker fusion test and decreased visual motor reaction time by 10 percent, two measures of visual processing.
The authors conclude that lutein and zeaxanthin supplementation may be an effective way to increase visual processing speed, even in young healthy adults.
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Exposure to red light improves vision in adults over the age of 40 years. www.sciencedaily.com
Mitochondria play critical roles in cellular energy and function. The decline in mitochondrial quality and activity that occurs with aging is linked to the development of a wide range of age-related diseases. The highest concentrations of mitochondria in the body are found in the rods and cones of the eyes, where they support multiple aspects of vision. Findings from a new study indicate that viewing a red light restores mitochondrial function in the eyes of older adults.
Mitochondria have specific light absorbance characteristics that modulate their performance. For example, the mitochondrial electron transport chain is photosensitive to certain wavelengths of light. As a result, exposure to longer wavelengths, such as those in the 650- to 1,000-nanometer range, improve mitochondrial function and enhance ATP production. Red light has the longest wavelengths on the visible spectrum.
The intervention study involved 24 adults between the ages of 28 and 72 years who had no eye disease. The participants were instructed to look at a red light with their dominant eye every morning for three minutes every day for two weeks. The authors of the study assessed the participants' rod and cone sensitivity before and after the intervention.
The authors of the study noted that the participants' rod and cone performance declined considerably after the age of 40. However, exposure to red light (670 nanometers) improved both rod and cone function in the participants over the age of 40. The participants' ability to detect colors – a function of cone sensitivity – improved by up to 20 percent in some participants. These findings suggest that simple light therapies show promise as a means to ameliorate visual loss in older adults. Larger studies are needed to confirm these findings.