Rose hips – the top of antioxidants

Antioxidants protect us against free radicals. A Norwegian investigation shows that rose hips contain the highest amounts of total antioxidants among fruits and vegetables (Halvorsen BL. J Nutr. 2002, 132(3): 461-71). Antioxidants include a range of organic substances such as vitamin C, E, and A, and carotenoids, for example lycopene (gives rose hips their red color). Lycopene is the strongest antioxidant of the carotenes and is 8-10 times more potent than beta-carotene. Rose hips from the south of Chile is known to contain high amounts of lycopenes due to the high sun intensity.

Analysis of rose hips from Chile shows that the content of vitamin C is a high as 6.5% (6.5 g per 100 mg) fresh weight (Joublan, J.P et al., 1996: 584-588, In: J. Janick (ed.), Progress in new crops. ASHS Press, Arlington, VA.).

Another important antioxidant factor of rose hips is the content of polyphenolics. This has been clearly demonstrated with rosehip extracts deprived of vitamin C. The main polyphenolics proanthocyanidins and flavonoids show a remarkable capability to eliminate reactive oxygen species (ROS) (Daels-Rakotoarison DA, et al, 2001, Phytother.Res 16: 156-161).

There is a good reason to believe that it is the high content of antioxidants that has led to the extensively use of rose hips and rose hip extracts in folk medicine.

Antioxidants and free radicals

Oxidation in cells leads to destruction of cells and tissue. The role of antioxidants is to inhibit these oxidation processes.
Free radicals are reactive molecules that arise naturally in the metabolism processes taking place in the body cells. They also arise from pollution, smoke, alcohol intake, sun radiation and stress. In normal cells there is a balance between the damaging free radicals and the protecting antioxidants.

If our natural protection is weakened or if we are exposed to too many free radicals, there will be an insufficient level of protecting antioxidants. The free radicals will attack our cells, and damage may arise. The first sign of damage is damaged skin. Free radicals brake down collagen and elastin that keeps the skin smooth and elastic and the skin turns gray, rough, and wrinkled. The consequence is a too early aging of the skin. Free radicals also lead to oxidation of cholesterol in the blood that may lead to artery-clogging plaque formation; weakening of the immune system, and DNA damage with the risk of cancer development. Free radicals may also contribute to development of diabetes and has been proposed as mediators of inflammatory damage in asthma and joints in rheumatoid arthritis.

It is known that consumption of adequate amounts of fruits and vegetables will improve the general health. (shown in a range of clinical trials, see for example Int. J. Vitam Nutr. Res. 2003, 73: 63-69; Am J Clin Nutr. 2003, 78(suppl),544-551). Fruits and vegetables are rich in antioxidants, but it is not known whether there should be one or more specific factors in fruits and vegetables that are responsible for the beneficial effects. Clinical studies with single vitamins as pills, (vitamin C, vitamin E, and beta-carotenes) have been disappointing with mostly negative results. The beneficial effects of fruits and vegetables are probably a combination of many different compounds (phytochemicals) present in plants.

Lycopene is probably the only antioxidant that alone can be correlated with increased health. A small trial with patients diagnosed with prostate adenocarcinoma showed an increase of blood lycopene after tomato consumption that was correlated with an increased death of prostate cancer cells (Biochim Biophys Acta. 2005, 1740: 202-205). It was suggested that other phytochemicals may have synergistic effects.

Other relevant publications:

The carotenoid composition of rose hips shows 6 different carotenoids (J. Agric. Food Chem 2000, 48, 825-828; J. Pharm. Biochem. Anal. 1997, 16: 521-528)

Rosehip – a new source of lycopene? (Boehm V.et al., 2003, Mol. Aspects Med. 24: 385-389).

The Effects of a Standardized Herbal Remedy Made from a Subtype of Rosa canina in Patients with Osteoarthritis: A Double-Blind, Randomized, Placebo-Controlled Clinical Trial (Current Therapeutic Research, 2003, 64: 21-31).

Rose hips have been shown to be a rich foliate source (J. Agric. Food Chem 2003, 51, 4291-95