Is Local Food Healthier?

New York Times health blogger, Tara Parker-Pope, posted about a new two-year study to be undertaken at the University of North Carolina to determine the public health impact of consumers moving toward a diet composed of more locally grown and produced foods.

This study will be the first to look at the health implications of eating locally grown fruits and vegetables, and I look forward to the results, since I am pretty certain already that the locally grown food we eat at our house has made us all healthier. I do remember in my nutrition classes learning that after a fruit or vegetable is picked, pulled, cut or otherwise removed from the parent plant, it begins to lose vitamins and other phytochemicals which are necessary for proper health. And, unfortunately, the “fresh” vegetables and fruits you see in supermarkets, no matter how beautiful, are not particularly fresh. Many of them were picked two weeks or more ago.

Some vegetables, such as winter squash, potatoes, onions and apples can all be stored for a long period of time without a noticeable loss of nutrient value, but other vegetables like leafy greens, or broccoli, or sugar snap peas, all lose their nutrients pretty quickly. And vegetables like tomatoes, which are picked green and then are forced to ripen in transit by the application of ethylene gas, never even get the full compliment of nutrients they would have had if they had ripened on the vine. (Not to mention that they taste like water and plastic.)

Marion Nestle, author of the weighty but useful tome, What To Eat, discusses these issues in her book and on her blog; I trust her works because she writes not from the perspective of a hippy-dippy idealist, (not that there is nothing wrong with being a hippy-dippy idealist–I have been one myself, and still am some days) but from the scientific point of view of a distinguished and well-respected professor of nutrition. She backs up her statements with the latest scientific studies, so when she tells you that the “fresh” foods in the grocery store produce department are lacking in vitamins and minerals because they really aren’t that fresh, you can trust her words are based on fact, not belief.

When you eat locally, buying from a local farmer, most often the food you purchase was picked that very morning. The foods at farmer’s markets generally are so much more fresh–in the truest sense of the word–than what you can find in grocery stores, that it stands to reason that when you eat them, you are getting more vitamins, minerals and phytochemicals which can help fight cancer, than you would be getting otherwise. At a farmer’s market, the only time a tomato is picked green is so you can take it home and make fried green tomatoes or green tomato pickle from it. Vine-ripened tomatoes are not only superior to grocery store tomatoes in vitamin content, they are worlds beyond them in taste and texture, so much so that you cannot really compare the two.

Large amounts of vitamins and minerals help boost human immune systems, and I have to say this–Kat has only had one major illness, no recurrent colds, no ear infections or other maladies common among infants and toddlers. Morganna still has allergies, but she doesn’t get colds or the flu very often, and neither Zak nor I have been sick in quite some time–I had one sinus infection a couple of months ago, but that was the first one in FIVE YEARS. This is astounding, since I used to have one ever six months when I was younger.

There is also the issue that it seems that once people start shopping at farmer’s markets, they seem to start eating a diet with more varied fruits and vegetables than before, in large part because they are exposed to interesting, different varieties of these foods than they see in grocery stores. And, I have anecdotal evidence from watching the eating and shopping patterns of some friends of mine who have been influenced by the foods they eat at my house to change their shopping patterns, that once you get a taste of really fresh produce, you will want more, and will eat more of it. (This also goes for high quality dairy products, eggs and meat as well.) Nothing compares to the sweet fragrance of just picked ripe local strawberries, and once you taste that, the cottony giants at the supermarket will never satisfy you again.

Frankly, anything that gets people to eat more fruits and vegetables and a little less meat is fine by me.

There is also the issue of food safety.

When you have food being shipped across our country and into our country from across the world, there is a significant risk of food contamination. Why?

Because other countries do not have to abide by the same safety standards in agriculture that farmers in the US do. When I was in culinary school, there was a local outbreak of e coli that was traced to raw scallions from Mexico, where they were irrigated with raw sewage. The usual washing procedures are not sufficient to safely remove all traces of any bacteria present in a scallion, because of the way they grow–in layers and concentric rings which can trap soil and more disturbingly, bacteria.

And, of course, there is the current outbreak of a rare form of salmonella that has been traced back to tomatoes grown either in the US southwest or Mexico.

This outbreak has caused local Texas health officials to state that it is perfectly safe to eat raw home grown tomatoes of any kind, but that full-sized and Roma tomatoes bought from grocery stores should not be eaten raw.

When you grow your own food, or when you buy it locally from a farmer you know and trust, you know exactly what went into growing it. When you grow it yourself, you know what was used to fertilize it, where the water came from that irrigated it, and who picked it. You know if it came into contact with possibly contaminated animal manures, you know how much or little it needs washed before eating and you know exactly how ripe or unripe it is.

I have been saying for a while now that for food security issues, that smaller, localized food production is safer. When you have huge farms growing one food and shipping it off to all corners of the country and globe, if there is ever anything wrong with that food, a hell of a lot more people are in danger of food-borne disease than would be otherwise. There is also the issue that tracing the source of illness is harder in a huge food system like this.

For these reasons and more, I am looking forward to the new study on the health impact of local food. While I believe that local food is healthier and I have a lot of circumstantial evidence to support my contention, there is a difference between believing something and knowing it for a fact.

Besides, there is nothing wrong with more knowledge in the world.

10 Comments

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1. Cool! I am interested in her findings too.

   I LOVE my CSA farmer! I feel so much better knowing who grows my tomatoes (and lots of other produce) personally. I’m sure I can trust him not to poison me!

   The only produce I get from the grocery store anymore is stuff that doesn’t grow well around here (tropical fruits, potatoes) or things I use so much of that my farmer can’t keep up with my demand (onions and garlic).

   Also, if you HAVE to buy your veggies from the grocery store, I’ve heard frozen produce is actually healthier than “fresh” because it’s flash-frozen as soon as it’s picked.

   I don’t know if locally grown food is healthier, but it’s worth it for just how much tastier it is. And my CSA is such a good deal that it turns out to be cheaper too! No middlemen to go through, I guess.

   Comment by Neohippie — June 9, 2008 #

2. I can attest that more different varieties of things help with a diverse diet. When I started shopping at the farmer’s market I learned that a lot of things that I thought were only grown in one variety — for example, peaches, plums, cherries, and even oranges — actually come in a lot of different varieties, some of which I like more than others. I never used to like peaches much and now I like certain kinds that I can get at the farmer’s market. It’s also encouraged me to keep trying interesting and different types of vegetables. I think I was pretty good about eating fruit and veggies before, but I’m definitely better now.

   Comment by Alexis — June 9, 2008 #

3. Barbara, this question doesn’t relate to the tomato ban or to local eating per se, but I was just speculating… do you think there may be a connection between how flavorful a fruit or vegetable is and how much nutrients it contains? For example, would it be at all likely that a home-grown, vine-ripened, picked-at-the-peak-of-deliciousness tomato would have more of the “tomato nutritional contents” than a cardboard, middle-of-winter, supermarket tomato? Is this crazy talk on my part? Just curious.

   Comment by Kate — June 10, 2008 #

4. p.s. – I should clarify, since I didn’t do a very good job in my original question; I’m trying to ask if you think our noses and our tastebuds (in matters of fresh fruits and vegetables) could be a reliable guide to how nutritious the food may be.

   Comment by Kate — June 10, 2008 #

5. I, so totally agree with your thoughts. Ever since I started eating the fruits from our local farmer’s market, the fruits from the grocery store just doesn’t cut it for me. The taste difference is so perceptible. This forces me to eat and include more fruits and vegetables in my diet – simply because I love it and am sure that provides a good nutritional benefit.

   Comment by A-kay — June 10, 2008 #

6. I think Barbara’s argument is muddled, and includes points that aren’t relevant. Before everyone starts yelling at me, I’m not arguing against locally produced food. Just that the points of argument/discussion are a bit mixed up and I am interested in unmixing them.

   These are the points as I perceive them. I rely on Barbara to tell me if I have her points wrong. Further, I infer that Barbara’s talking about produce and not about meat. So I’m addressing only fruits & veggies and not meats.

   1. Locally grown food has been harvested more recently, and food harvested more recently is healthier than food harvested longer ago.

   2. Locally grown food is grown under safer conditions and is less subject to contamination.

   3. People who eat locally grown food tend to eat more produce and more varied produce.

   4. You know more about the conditions under which locally grown food is grown.

   I don’t think that each of the points is 100% right or directly related to the point of the post. In order, then:

   1. Probably and generally yes – and certainly I can’t think of anything that gets *healthier* some time after its harvested. There’s some evidence that the same veggie grown under different conditions (angle of sunlight, length of day, soil conditions, etc.) has a subtly different nutritional profile. A’course, this would have to balanced against the fact the food isn’t as fresh.

   1A. This needs to be balanced against what’s available at what time of year. A New Englander in January will have a healthier diet (more varied, greater range of foods and nutrients) if he buys non-local fresh produce than if he eats only what was grown within 50 miles and then preserved.

   2. This depends entirely on specifics. Last year’s tainted California spinach, for example. It was grown in the US so adhered to US standards. It was triple-washed before being bagged. The farms it grew on were clean. The problem was that the farms were contaminated by other farms nearby (IIRC the soil was contaminated by run-off from meat farms). This could happen to my local CSA guy as well.

   3. Irrelevant to the question of whether *this* tomato or *that* tomato is healthier. (It does seem to be true, though.)

   4. Only if you go visit the farm and even then you get only a snapshot and a process review.

   Comment by Harry — June 11, 2008 #

7. Neohippie–you are right about frozen veggies and fruit from the grocery store having more vitamins than the “fresh” foods at the grocery store. Marion Nestle discusses that in her book, What To Eat and gives statistics from various studies that prove that. So, yeah–eat frozen instead of fresh from the grocery store when you can.

   Kate–evolutionarily speaking, I suspect you are correct that our tastebuds and noses steer us toward fruit and vegetables that are ripest–and thus also more filled with vitamins and minerals. And the fact is–truly ripe and truly fresh plant based foods taste better than those which are old and tired and which may not even be properly ripe anyway.

   Harry–I wasn’t making arguments per se–just stating my opinions, which I admit are mostly unsupported. You are correct, however, that my first point is that locally grown fresh food is actually fresh–as opposed to food which has spent two weeks going from the farm to the table. And it is a fact that the longer a plant food sits unpreserved after it is harvested, the more vitamins and minerals it loses. So that, you agree is a relevant point, and to my mind the most relevant point in the entire post. Which is why I stated it first.

   I disagree with your point 1A, however. For one thing, you would be amazed as to what can be grown in cold frames even in New England during the winter–a cold frame being essentially a small unheated greenhouse. Carrots and dark leafy green vegetables can all be grown that way–and while there are only a few farmers doing it now, if demand rises, more will start growing in that way. In this way, they could provide better fresh food for New Englanders in the winter.

   Also, I disagree–I think that preserved food–frozen, for example–that was grown locally is still going to be higher in nutrients than “fresh” food that has been sitting in transport trucks, warehouses and produce departments for two weeks is. Again, I got statistics on this from Marion Nestle, who doesn’t just state beliefs in her writings, she deals in facts.

   In fact, I think that anyone, if their only source of vegetables is the grocery store, is better off buying frozen vegetables than fresh and canned tomatoes than fresh, because these are preserved at the peak of ripeness, right after being harvested.

   Your point number two is that it depends. Yes it does. Yes, the spinach case in California had to do with our own food regulations and testing systems not being adequate to the task of providing safe food, but the instance I note about the green onions from Mexico has to do with the fact that other countries do not have to comply with our food safety regulations. Which I think rather sucks.

   And yes, contamination could happen with your local CSA guy, too–but tracing the source of the illness outbreak would be much easier than tracing the current tomato crisis has been because the chain from farm to plate is much much shorter. And the number of people affected would be smaller.

   I’ll give you that you may think that my points 3 and 4 are irrelevant, but again, I was mostly giving my thoughts on the issue, and if some of them are somewhat peripheral, well, that is what happens on a blog! Not everything a blogger writes has a laser-beam focus.

   That said, I don’t mind your critique at all, I just wanted to point out that I disagreed on a few of your points.

   Comment by Barbara — June 11, 2008 #

8. I still trust my CSA farmer a lot more than a huge faceless corporation. After I joined I realized how neat it is to know who grows your food personally. Maybe this doesn’t work with all CSA’s, but I’ve visited my farmer’s farm/home, met his wife and kids, petted his dogs and cats, and he’s given me a tour of the place. He does that for any of his customers who want to come.

   He maintains a thick band of trees and shrubs all around the farm to block the drift of any pesticides from neighboring non-organic agriculture, and there aren’t any factory farms or feedlots around.

   So I still side with Barbara that local food is for the most part safer, because not only is it easier to trace any contaminants, but I think contaminants are less likely with local farmers as well. One of my college professors called that the “I know your mama” factor as an advatage of local businesses in general.

   Comment by Neohippie — June 12, 2008 #

9. Barbara –

   I was using “argument” in the sense of “a statement to support a thesis and persuade others” and not in the sense of fighting. You and your readers do such a good job of not fighting that the second meaning didn’t occur to me till too late.

   Can you believe I forgot about cold frames? [hangs head]

   I would definitely agree that, sy, in the winter local food that was flash frozen is better than nonlocal “fresh.” Now we get into details again: how does your local grower freeze her food? Flash freezing food does an excellent job of preserving nutrients but I don’t know about other freezing methods, and I understand flash freezing equipment requires an industrial-sized investment. Can anyone enlighten?

   When I visit a CSA or see pix/webpage of a Pennsylvania farm that supplies my local farmer’s market, I get the warm fuzzies and some sense of comfort. (More so with the visit than the pix & website, of course.) But I don’t kid myself that this represents a real health inspection.

   There’s a point you didn’t make, which I think you should. Locally produced MEAT is almost certainly much, much better than industrially grown meat. Double for non-industrially-slaughtered meat. Ye gods, it could hardly be any worse. The prices make me wince so I can’t always buy it. I’m working my way from rare treats – such as bacon and fancy sausages – and maybe someday I’ll be able to afford lots of chicken (the mainstay of my diet).

   Another point to make, again not directly related to yours: what’s in season tends to be both cheapest and freshest. It’s all about supply and demand. What’s in season is what’s plentiful. What’s plentiful is what’s cheap. What’s in season is also what’s tastiest. This is what I tell my spouse when ze wants to buy raspberries in December “They’re too expensive so we know they’ll taste like cardboard.”

   Comment by Harry — June 12, 2008 #

10. Update about the 2006 A spinach e. coli outbreak:

    It was even weirder than I remembered. A pack of wild boars wandered from a cattle field to the spinach field, breaking fences along the way and carrying e. coli on their hooves.

    http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2006/10/13/MNG71LOT711.DTL

    Comment by Harry — June 13, 2008 #

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