哈哈，这个周末打开电梯，打开收音机听日常新闻节目啥的
大家都在quote斯坦佛的一个study，结论是，有机蔬菜和普通蔬菜对人体好坏无影响
连农药残余的区别都可以忽略不计
小资们，这可咋办啊，还去不去whole foods啦？
google organic food就可以出来很多网站转载这个new study
Yes, organics is a $29 billion industry and still growing. Something is
pulling us toward those organic veggies that are grown without synthetic
pesticides or fertilizers.
But if you're thinking that organic produce will help you stay healthier, a
new finding may come as a surprise. A new study published in the Annals of
Internal Medicine finds scant evidence of health benefits from organic foods.
"There's a definite lack of evidence," says researcher Crystal Smith-
Spangler at Stanford University School of Medicine, especially when it comes
to studies of people.
She and her colleagues collected 200 peer-reviewed studies that examined
differences between organic and conventional food, or the people who eat it.
A few of these studies followed people who were eating either organic or
conventional food and looked for evidence that the choice made a difference
in their health.
One study, for instance, looked at whether eating organic food while
pregnant would influence the likelihood of eczema and other allergic
conditions among children, and another looked at whether eating organic meat
would influence the risk of a Campylobacter infection, a bacterial food-
borne illness. When the researchers looked at the body of evidence, they
found no clear benefits. But they say more research is needed.
It's important to note, though, that such studies have a really hard time
uncovering subtle effects of our environment, or what we eat, on our health.
Too many other powerful influences get in the way. Also, these studies only
followed people for a very short time — about two years or less. That's
hardly enough time to document any particular health benefit.
Most of the studies included in this collection looked at the food itself —
the nutrients that it contained as well as levels of pesticide residues or
harmful bacteria.
As you might expect, there was less pesticide contamination on organic
produce. But does that matter? The authors of the new study say probably not
. They found that the vast majority of conventionally grown food did not
exceed allowable limits of pesticide residue set by federal regulations.
Some previous studies have looked at specific organic foods and found that
they contain higher levels of important nutrients, such as vitamins and
minerals. We've reported on one particularly ambitious experiment, which is
supposed to go on for a hundred years, comparing plots of organic and
conventional tomatoes. After 10 years, the researchers found that tomatoes
raised in the organic plots contained significantly higher levels of certain
antioxidant compounds.
But this is one study of one vegetable in one field. And when the Stanford
researchers looked at their broad array of studies, which included lots of
different crops in different situations, they found no such broad pattern.
Here's the basic reason: When it comes to their nutritional quality,
vegetables vary enormously, and that's true whether they are organic or
conventional. One carrot in the grocery store, for instance, may have two or
three times more beta carotene (which gives us vitamin A) than its neighbor
. That's due to all kinds of things: differences in the genetic makeup of
different varieties, the ripeness of the produce when it was picked, even
the weather.
So there really are vegetables that are more nutritious than others, but the
dividing line between them isn't whether or not they are organic. "You can'
t use organic as your sole criteria for judging nutritional quality," says
Smith-Spangler.
Of course, people may have other reasons for buying organic food. It's a
different style of agriculture. Organic farmers often control pests by
growing a greater variety of crops. They increase the fertility of their
fields through nitrogen-fixing plants, or by adding compost instead of
applying synthetic fertilizer.
That can bring environmental benefits, such as more diverse insect life in
the field or less fertilizer runoff into neighboring streams. But such
methods also cost money. That's part of what you are buying when you buy
organic.
So if you really want to find the most nutritious vegetables, and the
organic label won't take you there, what will?
At the moment, unfortunately, there isn't a good guide. But a lot of
scientists are working on it.
They're measuring nutrient levels in all kinds of crops, and discovering
some surprising things, as The Salt reported last week — such as
supernutritious microgreens. They're trying to breed new varieties of crops
that yield not a bigger harvest but a more nutrient-rich harvest.
The problem is, farmers still get paid by the pound, not by the vitamin. And
consumers buy their food the same way. What this really requires is a whole
new food system that can track those extra-nutritious crops from farmer's
field to consumer's shopping basket.
Maybe, down the road, you will actually see signs in the supermarket that
advertise, for instance, iron-rich beans. Maybe they'd be organic, or maybe
not.
