Lemon and orange peels, their essential oils, and the oil from the flowers have all been used for medicinal purposes over the centuries and admitted as official drugs in various pharmacopoeias. Some studies have shown that drinking lemon and orange juice can increase glucose, inhibit the release of insulin, and lower uric acid in the blood, as well as increase the amount of uric acid eliminated in the urine.
In a recent study, Italian scientists tested lemon and orange juices for their effects on blood fats in rats with high serum cholesterol levels. In the rats that were given orange juice, cholesterol decreased 31 percent, low-density lipoproteins decreased 44 percent, and triglycerides dropped 33 percent after fifteen days. High-density lipoproteins increased nearly four times. In the rats given lemon juice, cholesterol, LDL, and triglycerides decreased by 49 percent, 50 percent, and 51 percent, respectively. HDL increased nearly three times.
The researchers recommended that people drink orange and lemon juices regularly as a way of protecting against disease induced by high levels of blood fats.(1)
Extracts of witch hazel (Hamamelis spp.) have been used in cosmetics and astringents for a long time, but rarely have they been the subject of scientific research. A preliminary study by researchers in Youkaichi, Japan, however, has taken more than a skin-deep look at the yellow-flowered shrub.
The genus Hamamelis is among 100 or so plant groups found only in both eastern Asia and eastern North America. There are two North American species of witch hazel and two to four Asian species. The researchers studied American witch hazel (H. virginiana), the principal species whose extract is used commercially worldwide.
The group initially screened extracts of sixty-five plants for their potential for protecting skin cells against destructive oxygen molecules called radicals. Seven were found to be promising and were selected for further study: witch hazel, sage, rosemary, salad burnet, smartweed, an oak, and horse chestnut. Both witch hazel and horse-chestnut extracts showed strong antioxidant activity in skin tissue, and the scientists proposed that their potential role in preventing aging or wrinkling of the skin should be examined further.(2)
Tea, whether black or green, iced or steaming, has become a hot health topic in recent years. Much of the interest has revolved around the antioxidant effects of green tea, whose polyphenols have been shown to reduce the activity of certain cancer-producing chemical by-products in the body. In addition, in animal studies, polyphenols suppressed the development of chromosome damage in bone marrow cells and, in laboratory experiments, compounds in green tea reduced the size, growth, and number of skin tumors.
Now, a research group at the Toxicology Research Center of the Korea Research Institute of Chemical Technology has examined the effect of green tea on male cigarette smokers. Researchers used a blood-compound measure that indicates a greater predisposition to cancer development. Fifty-two clinically healthy men were assigned to four groups: nonsmokers, smokers, smokers who drank green tea, and smokers who drank coffee. Members of the latter two groups smoked an average of ten cigarettes and drank two to three cups of the designated beverage daily.
After six months, smokers who drank green tea had levels of the target blood compound comparable to that of nonsmokers, whereas coffee-drinking smokers showed levels not significantly different from those of smokers. This preliminary study implies that consuming green tea could help protect smokers from various cancers. Of course, so could quitting smoking.(3)
(1) Trovato, A., et al. Phytomedicine 1996, 2(3):221–227.
(2) Masaki, H., et al. Biological and Pharmaceutical Bulletin 1995, 18(1): 162–166.
(3) Shim, J. S., et al. Cancer Epidemiology, Biomarkers and Prevention 1995, 4(4): 387–391.