Almonds could boost smokers' antioxidant defences

By Stephen Daniells

- Last updated on GMT

Related tags Antioxidant

A big handful of almonds every day could boost the antioxidant
defences of smokers, a group at risk of low antioxidant levels due
to higher oxidative stress, by up to 35 per cent, says a joint
Chinese-US study.

The randomised, crossover clinical trial with 60 healthy male smokers found that the body's antioxidant defences increased as a result of a daily 84 gram helping of almonds.

The study is published in December issue of the Journal of Nutrition .

The results suggest smokers could benefit from upping their intake of almonds although expert advice is clearly to avoid tobacco smoke altogether.

One in three Europeans are smokers, while the US figure is one in five.

Tobacco smoke contains over 4,000 compounds, of which 60 are known carcinogens.

The oxidative stress levels of smokers are significantly greater than non-smokers, and as such there is a bigger drain on the levels of antioxidants in the body.

The men smoked between five and 20 cigarettes per day, and were assigned to receive a daily supplement of either almonds (84 g) or pork (120 g) for four weeks.

A four-week washout period separated the interventions.

The researchers report that baseline levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker for oxidative stress, and malondialdehyde (MDA), a reactive carbonyl compound and a major end product of lipid oxidation, were 185 and 64 per cent higher in smokers than non-smokers.

Moreover, activities of the antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (Gpx), and catalase (CAT) were 15, 10, and nine per cent lower in smokers than non-smokers, respectively, said the researchers from the Chinese Center for Disease Control and Prevention and the Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University.

After the four-week almond intervention, SOD and Gpx levels increased by 35 and 16 per cent in the smokers, compared to baseline.

In addition, 8-OHdG and MDA levels decreased by 28 and 34 per cent, respectively, said the researchers.

Almonds, a rich source of vitamin E, also resulted in a ten per cent increase in blood levels of alpha-tocopherol.

The authors stress, however, that the OHdG levels among smokers were still 98 per cent in smokers than non-smokers after almond supplementation.

"These results suggest almond intake can enhance antioxidant defenses and diminish biomarkers of oxidative stress in smokers," concluded lead author Ning Li.

Demand for almonds, a rich source of flavonoid antioxidants, vitamin E and magnesium has increased in recent years as the tastes of various almond-eating ethnic communities have expanded into more mainstream foods.

And the almond boards have provoked greater consumption of the nut through better and more frequent marketing.

There is also growing demand from countries to which the US exports 75 per cent on its almonds, namely Europe - in particular Germany and Spain - and India, which buys nuts in their shells for direct consumption and shelling.

The US Department of Agriculture's agricultural exports forecast published last year revealed a total increase of $1.5bn from the revised 2005 estimate.

Rising $600m, almonds account for nearly half the increase.

Source: Journal of Nutrition 2007, Volume 137, Pages 2717-2722 "Almond Consumption Reduces Oxidative DNA Damage and Lipid Peroxidation in Male Smokers" Authors: N. Li, X. Jia, C.-Y.O. Chen, J. B. Blumberg, Y. Song, W. Zhang, X. Zhang, G. Ma, and J. Chen

Related topics Ingredients

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