Eat your vegetables and live longer

Live Long

I realize that sometimes the e-Alert may sound like a protective mother. Eat your vegetables! Get more exercise! No smoking! Be home by 10:00!

Of course, I’m not nagging. Just the opposite. I’m simply reporting on current research. So if there’s any nagging going on, blame the research, not me.

That said, I would just add this: Eat your vegetables!

Why? Because according to recent research, your chances of living a longer life may significantly improve if you eat plenty of vegetables that are rich in beta-carotene.

So clean that plate or there’ll be no television!

Two for ten

In the October 2005 issue of the American Journal of Clinical Nutrition, researchers from the Netherlands’ Wageningen University report on an observational study that used blood tests to measure levels of two antioxidants – beta-carotene and alpha-tocopherol (vitamin E) – in more than 1,100 elderly subjects.

For ten years, researchers monitored their subjects’ rates of disease and mortality. Analysis of the data showed that plasma alpha-tocopherol was not associated with a reduced risk of specific diseases or early mortality. (Too bad they only measured for alpha-tocopherol and not the full spectrum of vitamin E forms. That’s like reporting on the outcome of a football game with a recap of just the first quarter.)

Results for beta-carotene were much different. High levels of plasma carotene were associated with an overall lower mortality risk. More specifically, lower cancer mortality rates were recorded among those with the highest beta-carotene levels. Cardiovascular disease rates were also lower, but only for subjects whose body-mass index was less than 25. (A BMI of more than 25 is considered overweight.)

The researchers compared their results to a meta-analysis of five antioxidant studies that also followed all-cause mortality among the elderly. The five studies confirmed the link between beta-carotene and lowered risk of all-cause mortality.

Beta-carotene (a precursor of vitamin A) is abundant in dark green leafy vegetables, colorful orange vegetables and fruits such as pumpkins, squash, sweet potatoes, peaches, apricots, cantaloupes, mangoes and (of course) carrots.

Smoke gets in your eyes

Studies have shown that smokers with a high intake of beta-carotene may be at greater risk of developing lung cancer. But new evidence contradicts that finding.

In the Wageningen study, beta-carotene intake was linked to a lower risk of cancer death even among smokers. And this finding is supported by a recent study conducted in France. Researchers believe high levels of beta-carotene alone may pose a danger for smokers, but when beta-carotene is consumed with other antioxidant-rich foods the danger appears to be significantly reduced.

This was also the conclusion of a Yale School of Medicine study I told you about last spring (“Waxy Buildup” 6/6/05). Researchers followed medical and dietary data on more than 27,000 male smokers for nearly 15 years. Those who had the highest intake of a variety of antioxidants (vitamins C and E, carotenoids and flavonoids) had a 16 percent lower risk of lung cancer, compared to men with the lowest overall antioxidant intake.

Scientists still don’t know exactly what it is about beta-carotene that may produce an adverse effect in smokers. What’s not a mystery, however, is what your mom’s advice would be on this topic: No smoking!

Sources:
Plasma Carotene and Alpha-Tocopherol in Relation to 10 Year All-Cause and Cause-Specific Mortality in European Elderly” American Journal of Clinical Nutrition, Vol. 82, No. 4, October 2005, ajcn.org
“Beta-Carotene Linked to Lower Deaths Among Elderly” NutraIngedients-USA, 10/14/05, nutraingredients-usa.com