A new study suggests that women may need more antioxidants than men because they experience more oxidation, a link to higher risk of heart disease and other diseases.
Researchers in California noted that there are few large-scale surveys describing oxidative damage that occurs in humans and the demographic, physical, or nutritional factors that may be associated with it. Such information is essential for the design and analysis of studies investigating the role of oxidative stress in health and disease, said the team.
Oxidative stress can be caused by smoking for example, but also by the build up of damaging free radicals in the body. It is thought to contribute to the ageing process and several diseases.
Dr Gladys Block and her team measured oxidative damage in 298 healthy adults, aged from 19 to 78. The study included 138 cigarette smokers, 92 nonsmokers and 68 people who reported exposure to secondhand smoke.
The researchers measured levels of malondialdehyde and F2-isoprostanes, both markers of oxidative damage, produced when lipids are oxidised.
They concluded that sex was in fact the strongest predictor of lipid peroxidation and was even stronger than smoking. However they were unable to explain the unexpected higher level of oxidative damage in women.
The researchers considered the higher percentage of body fat in women, but after studying body mass index (BMI), women still had higher levels of oxidation.
Oxidative stress was lower in people who ate the most fruit and in those who had higher blood levels of vitamin C and carotenoids.
Yet factors such as smoking, age, alcohol use and other dietary measures, such as intake of alpha-tocopherol (vitamin E) did not seem to affect levels of oxidative stress.
The authors noted that their research may have particular relevance when looking at the statistics which have found that women are at greater risk of lung cancer than men exposed to similar levels of cigarette smoke.