Eat your greens

New findings confirm what we were all told as children: eating your greens really is good for you.

Most of us know by now that red, orange and yellow fruits and vegetables are good for us but, until recently scientists, have been focusing on beta-carotene as being the ‘magic’ ingredient which helps fight cancer and other diseases. There are plenty of studies that indicate a diet rich in these foods extend a healthy life, but no randomised controlled studies have succeeded in showing significant benefits for people taking beta-carotene supplements. So researchers from the Centers for Disease Control and Prevention in the US have begun to assess the impact of alpha-carotene, found in dark green fruit and vegetables.

Fruit and vegetables

The researchers assessed data from more than 15,000 adults, all of whom had taken part in the Third National Health and Nutrition Examination Survey Follow-up Study (in the US). All participants had a medical check-up and provided blood samples regularly over a period of six years. Their progress was followed up for a further 12 years. Over this period 3,810 participants died.

When the researchers analysed the data, they found that high levels of alpha-carotene (assessed via the blood samples) were associated with increased longevity. Those who had concentrations of between 2 and 3mcg/dl (micrograms per decilitre) were 23% less likely to die than those who had levels of between 0 and 1mcg/dl. As the concentration of alpha-carotene increased, so the risk of death decreased – those who had 9mcg/dl were 39% less likely to die within the study period. High alpha-carotene levels were also associated specifically with a lower risk of dying from cancer, as well as from cardiovascular disease.

Foods with high alpha-carotene levels include dark green vegetables such as broccoli, green beans, peas, spinach and kale. But, says registered nutritionist Carina Norris, it would be a mistake to start swapping all your red foods for dark green ones: “It’s best not to concentrate on a single nutrient, such as alpha- or beta-carotene, but instead to hedge your bets with a wide range of brightly coloured fruit and veg,” she says. “That gives you the broadest possible spectrum of different nutrients. Also, since studies using supplements have failed to replicate the full health benefits shown from eating the nutrients in food form, concentrate on real food, rather than tablets.”