Study under review: Skin photoprotective and antiageing effects of a combination of rosemary (rosemarinus officinalis) and grapefruit (citrus paradisi) polyphenols
Common knowledge tells us that using sunscreen helps prevent sun damage, yet regular application can sometimes be cumbersome. Wouldn’t it be great if we could get similar skin protection against UV light through our diet?
UVB rays primarily produce acute effects on the skin in the form of sunburns (erythema, see Figure 1), while UVA rays are primarily responsible for long term effects on skin quality and appearance, producing wrinkles, dryness, and loss of skin elasticity, collectively known as ‘photoaging.’
Photoaging and sunburns are both caused, in part, by inflammation and the formation of reactive oxygen species or ‘free radicals’ generated in the skin after UV light exposure. Thus, it seems reasonable to hypothesize that antioxidants could help protect against damage caused by UV radiation. This study used malondialdehyde (MDA) as a marker of oxidative stress in the skin, as it has been shown that MDA can be produced when free radicals react with lipids in the skin.
A previous study by the same group reported synergistic effects of rosemary and citrus extracts in a skin cell model, showing a decrease in reactive oxygen species and reduced DNA damage after exposure to UVB radiation. The same study included a small pilot trial in humans, showing that the combination of extracts was able to increase the dose of UV radiation necessary to cause a sunburn. The study discussed here aimed to build on those results by using living humans and different doses of the extracts. The supplement tested here was a proprietary blend of plant extracts, including rosemary and grapefruit, henceforth referred to as the R-G extract.
Reactive oxygen species have been linked to UV-induced photoaging, and it is hypothesized that antioxidants can protect against this damage. Few studies have investigated the protective properties of rosemary and citrus extracts, and most of them with limited relevance to humans. This study aimed to test the effectiveness of varying doses of extracts in a larger group of women.
Other Articles in Issue #24 (October 2016)
Can vitamin D-crease pain?
Pain involves the nervous and immune systems, among others, so it can be tough to address through supplementation. Vitamin D's multitude of roles hint at its possible use as a pain treatment.
Interview: Josh Mitteldorf, PhD
Josh is well-known in the life-extension community, for looking deep into the literature and connecting the dots. We'll get his take on some interesting longevity-related topics. After 30 years wandering in the plasma physics of extragalactic radio sources, Mitteldorf came to the study of aging in 1996 to correct a fundamental error in the foundations of evolutionary theory. After 20 years, the revolution in biological concept of aging that he initiated is only now coming to fruition
When nitrate supplementation doesn’t involve supplements
We've covered several nitrate supplementation studies in previous ERDs. This trial is unique in that it studied the impact of a nitrate-rich diet on exercise performance.
Eat a day, skip a day?
Typical dieting can be a chore. An alternative is to eat less (or not at all) during certain time periods, otherwise known as fasting. This is the first trial to compare regular calorie restriction to alternate-day fasting.
The high cost of high heat cooking
The delicious browning and crusting of steak or chicken could also be harmful. This one-year long randomized trial looked at high-heat cooking versus gentler cooking, and its impact on insulin resistance.
Interview: Courtney Silverthorn, PhD
Are you in the life sciences, but not sure if you want to work in a lab? Courtney is uniquely qualified to give advice about this.
Does being insulin resistant affect weight loss on a low-fat or low-carb diet?
Weight loss is not a simple issue. The impact of a diet could be influenced by whether or not you’re insulin resistant, as examined by this one-year trial of a low-fat versus low-carb diet.