Rosemary Protects Against Macular Degeneration

For modern cooks, rosemary is best known as the perfect herb to pair with a good roast chicken or lamb. But as with other herbs, it also has powerful and ancient medicinal properties. Modern science is catching up to what the ancients knew.  One scientific study finds that a compound in rosemary promotes eye health and may even protect against age-related macular degeneration.

Reporting in the journal Investigative Ophthalmology & Visual Science, a team of scientists from Sanford-Burnham Medical Research Institute led by Stuart A. Lipton, M.D., Ph.D. discovered that carnosic acid, a component of the herb rosemary, protects your retina from degeneration and toxicity.

What is age-related macular degeneration?


Rosemary's health benefits

Age-related macular degeneration is the most common eye disease in the U.S.  It affects close to 11 million Americans, most over the age of 50. According to the American Health Assistance Foundation, macular degeneration causes deterioration of the central area of the retina, resulting in blind spots and blurred or distorted vision. One-third of people over the age of 76 suffer from the condition.

The underlying cause of macular degeneration is not known but some of the risk factors include smoking, sun exposure, high blood pressure and obesity. Genetics are believed to play a role in most cases.

Some earlier studies had suggested that the disease might be slowed by antioxidants that fight free radicals. That's where rosemary comes in.

In this study, Lipton and his colleagues found that retinal cells treated with carnosic acid found in rosemary triggered the production of antioxidant enzymes in the cells.  That in turn lowered cell-damaging free radicals.

They also tested carnosic acid in animals, finding that mice treated with it suffered less vision damage whden exposed to light.

Protection from macular degeneration is just the latest in rosemary's many health benefits which have been known for thousands of years. The ancient Greeks prized rosemary for its ability to boost memory.  And Greek students are reported to have worn rosemary sprigs in their hair when studying for exams.  Lipton and his team are also exploring whether rosemary may be useful in preventing certain forms of dementia.

In addition, rosemary has traditionally been used to stimulate the immune system, improve digestion, increase circulation and act as an anti-inflammatory.

In animal studies rosemary has been shown to act as an antidepressant, improve type 1 diabetes and even prevent weight gain from a high fat diet.

A Kansas State University study found rosemary to be the most effective of six spices tested in reducing the formation of heterocyclic amines (HCAs).  HCAs are carcinogenic compounds produced when animal foods such as beef, chicken, pork or fish, are barbecued, grilled, boiled or fried. Consuming HCAs through meat increases risk factors for colorectal, stomach, lung, pancreatic, mammary and prostate cancers.

Native to the Mediterranean region, rosemary can be found just about everywhere today. A relative of mint, it grows in small shrubs and its leaves resemble pine needles.  It's widely available as a dried herb, supplement or essential oil.

Try placing whole fresh sprigs inside a roasting chicken or turkey, or in a pot of chicken soup. 

Rosemary is easily grown in pots at home.  At the holidays you can find decorative plants trimmed in the shape of small trees.  Keep one handy in your kitchen to remind you of its many health benefits.  

This Is Your Brain on Coffee

This column appears in the June 9 issue of The New York Times Magazine.

For hundreds of years, coffee has been one of the two or three most popular beverages on earth. But it’s only recently that scientists are figuring out that the drink has notable health benefits. In one large-scale epidemiological study from last year, researchers primarily at the National Cancer Institute parsed health information from more than 400,000 volunteers, ages 50 to 71, who were free of major diseases at the study’s start in 1995. By 2008, more than 50,000 of the participants had died. But men who reported drinking two or three cups of coffee a day were 10 percent less likely to have died than those who didn’t drink coffee, while women drinking the same amount had 13 percent less risk of dying during the study. It’s not clear exactly what coffee had to do with their longevity, but the correlation is striking.

Other recent studies have linked moderate coffee drinking — the equivalent of three or four 5-ounce cups of coffee a day or a single venti-size Starbucks — with more specific advantages: a reduction in the risk of developing Type 2 diabetes, basal cell carcinoma (the most common skin cancer), prostate cancer, oral cancer and breast cancer recurrence.

Perhaps most consequential, animal experiments show that caffeine may reshape the biochemical environment inside our brains in ways that could stave off dementia. In a 2012 experiment at the University of Illinois at Urbana-Champaign, mice were briefly starved of oxygen, causing them to lose the ability to form memories. Half of the mice received a dose of caffeine that was the equivalent of several cups of coffee. After they were reoxygenated, the caffeinated mice regained their ability to form new memories 33 percent faster than the uncaffeinated. Close examination of the animals’ brain tissue showed that the caffeine disrupted the action of adenosine, a substance inside cells that usually provides energy, but can become destructive if it leaks out when the cells are injured or under stress. The escaped adenosine can jump-start a biochemical cascade leading to inflammation, which can disrupt the function of neurons, and potentially contribute to neurodegeneration or, in other words, dementia.

In a 2012 study of humans, researchers from the University of South Florida and the University of Miami tested the blood levels of caffeine in older adults with mild cognitive impairment, or the first glimmer of serious forgetfulness, a common precursor of Alzheimer’s disease, and then re-evaluated them two to four years later. Participants with little or no caffeine circulating in their bloodstreams were far more likely to have progressed to full-blown Alzheimer’s than those whose blood indicated they’d had about three cups’ worth of caffeine.

There’s still much to be learned about the effects of coffee. “We don’t know whether blocking the action of adenosine is sufficient” to prevent or lessen the effects of dementia, says Dr. Gregory G. Freund, a professor of pathology at the University of Illinois who led the 2012 study of mice. It is also unclear whether caffeine by itself provides the benefits associated with coffee drinking or if coffee contains other valuable ingredients. In a 2011 study by the same researchers at the University of South Florida, for instance, mice genetically bred to develop Alzheimer’s and then given caffeine alone did not fare as well on memory tests as those provided with actual coffee. Nor is there any evidence that mixing caffeine with large amounts of sugar, as in energy drinks, is healthful. But a cup or three of coffee “has been popular for a long, long time,” Dr. Freund says, “and there’s probably good reasons for that.”