In The News: Vision Loss in Mice Reversed with Epigenetic Reprogramming

Vision Loss in Mice Reversed with Epigenetic Reprogramming

Vision loss due to glaucoma and aging in mice was reversed with the use of epigenetic reprogramming, according to the results of a study published in Nature.*

This approach proposes that changes to the body’s system that activates and deactivates genes (the epigenome) cause cells to read the wrong genes, leading to degenerative diseases.

Co-author, geneticist Dr. David Sinclair and colleagues at Harvard Medical School, utilized a virus to deliver three of four youth-restoring genes known as Yamanaka Factors into the retinas of mice. The genes were previously found to eliminate epigenetic markers on cells and return cells to the embryonic state from which they can develop into other types of cells.

After receiving the genes, mice with damaged optic nerves experienced nerve regeneration, and vision loss was restored in a mouse model of glaucoma. Vision was also restored in 12-month-old mice that had aging-related visual impairment.

Editor’s Note: “These data indicate that mammalian tissues retain a record of youthful epigenetic information—encoded in part by DNA methylation—that can be accessed to improve tissue function and promote regeneration in vivo,” the authors stated.

* Nature. 2020 Dec;588(7836):124-129.

Metabolic Syndrome Factors Improve with L-Carnitine Supplementation

A review and meta-analysis of randomized, placebo-controlled trials found improvement in factors that characterize metabolic syndrome among people given L-carnitine, according to an article in Nutrients.*

Metabolic syndrome is determined by the presence of three or more factors that include high blood pressure, elevated fasting triglycerides, low levels of HDL cholesterol, increased abdominal circumference and high fasting blood glucose. The presence of metabolic syndrome is associated with an increased risk of developing type II diabetes and cardiovascular disease.

The researchers selected nine articles that reported the findings of trials that evaluated the effects of L-carnitine supplementation among 508 participants and reported data concerning fasting blood glucose, triglycerides, waist circumference, blood pressure, or HDL cholesterol. L-carnitine doses ranged from 750 mg to 3,000 mg per day.

Supplementing with L-carnitine was associated with significant reductions in waist circumference and systolic blood pressure in comparison with the placebo groups.

Editor’s Note: When studies that tested doses of one to three grams were analyzed, L-carnitine was additionally associated with a significant decrease in fasting blood glucose and triglycerides, and an increase in beneficial HDL cholesterol. “Ultimately, two to three grams a day of supplemented L-carnitine is recommended,” the authors stated.

* Nutrients. 2020 Sep 12;12(9):2795.

Severity of Male-Pattern Hair Loss Linked to Decreased Levels of Vitamin D

An association was found between deficient vitamin D levels and greater severity and premature onset of androgenetic alopecia (otherwise known as male-pattern hair loss) in young men, an article in the International Journal of Dermatology reported.*

Researchers conducted a case-control study that age-matched 50 men with premature androgenetic alopecia with 50 healthy, control subjects who did not have the condition. Participants were limited to those who were 30 years of age or younger.

Eighty-six percent of the men with hair loss were deficient (<12 ng/mL) in the vitamin and 14% of them had insufficient (12-20 ng/mL) levels.

The mean levels of serum vitamin D were significantly lower in men with the condition, compared to the controls (20.10 ng/mL vs. 29.34 ng/mL).

Vitamin D levels were not found to be related to how much sun exposure the men received.

Editor’s Note: “Our study showed a significant correlation between vitamin D deficiency and the severity of androgenetic alopecia,” the authors concluded. “This suggests that vitamin D may play a role in the premature onset of androgenetic alopecia.”

* Int J Dermatol. 2020 Sep;59(9):1113-1116.

Lower Alzheimer’s Risk Linked to Greater Flavonol Intake

An article in the journal Neurology reported an association between consuming more compounds known as flavonols, and a lower risk of developing Alzheimer’s disease.*

Flavonols are found in many fruits and vegetables, as well as in tea.

The study included 921 participants with an average age of 81. The subjects did not have Alzheimer’s disease at the beginning of the study.

Questionnaires completed at enrollment and then annually during a six-year average follow-up period, provided data on dietary intake that was analyzed for flavonol content. Participants were also evaluated yearly for the presence of Alzheimer’s disease.

Over the course of follow-up, 220 individuals developed the disease.

Participants were divided into five groups, according to their level of flavonol intake. Among those whose intake was highest, at an average of 15.3 mg per day, 15% developed Alzheimer’s disease, compared to 30% whose intake was lowest, at approximately 5.3 mg per day—a 48% lower, adjusted risk.

Editor’s Note: The authors stated that, “Eating more fruits and vegetables and drinking more tea could be a fairly inexpensive and easy way for people to help stave off Alzheimer’s dementia.”

* Neurology. 2020 Apr 21;94(16):e1749-e1756.