Why Should I Eat Seasonal? Does Eating Organic Matter?

The wise Michael Pollan once said, “Don’t eat anything your great-grandmother wouldn’t recognize as food.” While this all sounds well and good, truth is this practice can be quite hard to accomplish. Farming and agriculture practices have changed drastically in the past 100 years, bringing about both positive and negative consequences. Yes, we have greater access to food year-round, but at what cost to our health and environment? On the contrary, if we only eat seasonally might we be at risk of inadequate micronutrient intakes in the “off seasons,” when fresh produce is not available? Grab a cup of something tasty and let’s review what the research tells us.

Fact: Until about a hundred years ago, human diets were tied closely with what was in season. Depending on where you lived, acquiring a fresh tomato in the dead of winter was difficult, if not impossible. That’s not to say our ancestors didn’t adapt; for centuries, fresh produce has been stored to extend the period that food is available (canning, fermenting, etc.). Our bodies are designed to thrive on a wide variety of foods, however, when it comes to eating real food there are several nutritive benefits to trusting nature’s perfect timing.

Here are some examples:

  • A tomato develops over half of its lycopene concentration in the final stages of ripening.
  • Greater sun exposure yields higher level of antioxidants in fresh produce; when you select in-season berries, grapes, avocados, apples, greens, eggplants, etc., you’ll be majorly upping that antioxidant dose.
  • A study comparing in-season and out-of-season broccoli found that the out-of-season broccoli only had half the concentration of vitamin C when compared to the in-season option.
  • Cucumbers and summer squash (which ripen in the hot summer months) help cool the body and provide extra water and antioxidants needed to beat the heat, while winter produce like onions and kale are more calorically dense and provide a different set of phytonutrients (1).

Nutrient retention is optimized if fruits and vegetables are gently handled, exposed to proper sunlight and stored at high relative humidity. Storing in boxes and spraying with hormones just can’t mimic nature’s perfect recipe; when produce is picked prior to ripening, it is often sprayed with hormones to speed up that ripening process and produce a ripe-ish looking berry. Problem is, prior to hitting shelves, that berry is crammed into a tiny box with no exposure to sunlight, therein given no chance to ripen properly and accumulate all those tasty nutrients.

Speaking of produce hitting store shelves, how long does that process really take? According to a publication from UC Davis, in the U.S. fruits and vegetables may spend weeks (if not months) in transit before making it to the consumer. The journey starts from harvest where food spends about five days “on the road” before arriving at a distribution center. From there, transportation time from these distribution centers range from as little as a few days if going by air freight to several weeks if sent by refrigerated ship. Produce then spends 1-3 days on a shelf (if not longer) and an estimated seven days on home shelves before consumption. That’s a whole lot of time for nutrient degradation to occur in a tiny little box (cringe!). Furthermore, transporting produce sometimes requires irradiation (zapping the produce with a burst of radiation to kill germs) and preservatives (such as wax) to protect the produce (2). But what’s a gal or fella to do? I don’t know about you, but I don’t have a live-in chef. It’s just me and my brood, living paycheck to paycheck, doing our best to get a home-cooked meal on the table each night.

If the USDA recommends making half your plate fruits and vegetables, how realistic is it to fill that plate with only local, in-season selections? Enter The 100 Mile Diet. This was a project started by a couple who wanted to see if it was possible to consume only locally-produced food (defined as staying within 100 miles from Vancouver city) over the course of one year. I’d highly recommend checking out the book for yourself, but in a nutshell, the couple did achieve their goal. However, they described the time needed to acquire and prepare a nutritionally balanced, seasonal diet throughout the year as being equivalent to a part-time job. (3) Yowzas.

So here’s where I land. Yes, the undesirable storing and acquisition of an out-of-season veggie may not be the most nutritious option. However, I daresay eating an out-of-season vegetable is worse than eating no vegetable at all. But, if we’re really trying to challenge ourselves, I’d recommend trying to eat in season as much as possible. I’ve created this fancy 5-star system to simplify things:

– eat a vegetable

★★ – eat an organic vegetable from the “Dirty Dozen” (see link below)

★★★ – eat an organic, in-season vegetable

★★★★ – eat a local, organic, in-season vegetable

★★★★★ – GROW a local, organic, in-season vegetable

I’m totally digging (pun definitely intended) this past post on Gardening 101. If you live in the city, try planting some fresh herbs or a small pot of lettuce in your window. Investigate the community garden situation in your area—these are often free and right in your backyard. If you are able to plant a garden in your yard, give it a try and do NOT feel discouraged if your harvest isn’t plentiful the first season or two. Gardening isn’t for the faint of heart and takes patience.

Finally, try to eat sustainably, even if it’s in modifying one grocery item per week. When you select cheap produce, we do so by passing on the environmental costs of pollution and degradation to our future children, great-grandchildren and so on. Check out EWG’s list of the Dirty Dozen to know specifically which organic produce is worth the extra pennies. Avoid pesticides and wash fresh produce. While studies have not shown a direct correlation with reduced disease risk and consuming an all organic diet, by selecting organic produce when possible you will be reducing your exposure to possible disease inducing pesticides.

It’s all at your fingertips, friends, city girl or farm boy—pay no mind. All you need is some dirt, a pot, sunshine and a positive attitude. Farmers markets and CSA’s are amazing options for obtaining fresh, delicious, in-season food for your enjoyment while also supporting your local economy. These websites are great for connecting you with a local CSA or farmers market (US residents & Canada). Get out there and get your fingernails dirty! – Sarah

A note from Lindsey:

Hey everyone! In my last post on gut health, I briefly discussed the benefits of fermenting. This fall, if you’re feeling blue about the long, cold, winter months ahead with minimal access to fresh produce, take heart; fermenting vegetables is a great way to get crafty in the kitchen and prolong those summer (or fall, or winter) crops. The fermentation of vegetables (like sauerkraut and kimchi) was born of practicality—a way to preserve the harvest well into winter. But this also serves as a dual purpose of increasing beneficial bacteria, enzymes, and vitamins (4). By preparing foods traditionally, we are maximizing their nutrient density. 

Credits // Author: Sarah O’Callaghan with contributions from Lindsey Kelsey. Photography: Elsie Larson.
References: 1. Bliss, Nishanga (2012). Real Food All Year. Oakland, CA: New Harbinger Publications 2. Halweil, Brian (2004). Eat Here: Homegrown Pleasures in a Global Supermarket. W.W. Norton & Company 3. Smith, Alisa & MacKinnon, J.B. The 100 Mile Diet: A Year of Local Eating. (2007) Random House Publishers 4. McGruther, Jennifer (2014) The Nourished Kitchen: Farm-To-Table recipes for the Traditional Foods Lifestyle.
  • im just double checking on this! so it’s worse to eat an out of season veggie and better to eat no veggies if all you have is out of season?

    thank you in advance and i hope you’re having a wonderful day!!

    • I think any vegetable is better than no vegetable at all 🙂 I’m afraid my star-chart may have made that a little confusing, apologize if so!

  • Thank you for this post !

    So happy to see the benefits of eating clue,

  • I love this post – super helpful and insightful. I would love to see a guide on seasonal veggies, I have an idea of what produce is in season but a full guide would be amazing!

    • I love this idea and wanted to incorporate it into the post, however found it difficult considering our readers are located all over the world! If you’re a US resident you may find this link helpful -https://www.seasonalfoodguide.org – otherwise, I’d suggest getting in touch with a local CSA for more information on what’s in season where you live.

  • Thank you so much for this post! As a newbie farmer, passionate localvore, and Program Director at our local Farmers’ Market, I’m always happy to see the benefits of eating seasonally shared with those who may not have clue, be new to it all, or aren’t quite sure where to start! <3

    • I’m so glad you enjoyed it! Thank you for all YOU do for your community 🙂

  • I always wonder if it’s better (environmentally speaking) to buy local or to buy in season – or is it actually kind of the same thing, because you can only buy local things if they are in season, because otherwise they would have to be imported anyway? I’m also unsure if it’s theoretically better to buy organic bananas from let’s say South America, rather than non-organic strawberries which are currently in season and are grown somewhere close to where I live – I would choose the strawberries, but would you agree?

    • I wanted to chime in on this question with a similar one.

      I’m in the Netherlands, a country filled with green houses that are used year round, which of course costs a lot of energy in winter. How does that amount of energy used (often from unsustainable sources) relate to the carbon footprint of a truck filled with produce grown in the open air in let’s say, Spain?

      Also I heard that the efficiency of transportation of local produce is often very low, which does away with some of the good reasons to buy local. I’m not sure if that’s a European thing though, it’s probably very European that trucks are held to more stringent regulations than the small vans local farmers would use.

      Lastly I heard on Wendy Zukerman’s excellent podcast Science Versus that a lot of farms in the US use some (but not all) of the practices they would have to use to qualify as organic, even if they don’t feel the need to go organic all the way. As such, it’s not entirely black or white between organic and non-organic.

      Okay very last. THanks Sarah for the excellent tip on the 100 mile diet. Sounds very very interesting!

      • Hey Erika! Such good questions and perhaps a little more than I’m equipped to tackle in this post. I do know there is a some debate when it comes to the environmental implications of growing and procuring your own food. I’d love to have an environmental scientist weigh in 🙂 I argue that if we can all work together, make small changes and adapt to the Earth’s needs surely there is a way we can all coexist (dietitians, farmers, environmentalists etc). I’ll have to check out that podcast rec (sounds fascinating!) but I do know in the US, according to the USDA, we have some pretty strict guidelines which must be met in order to give food an organic certification – only caveat being small farmers (who sell less than $5,000 a year I believe) whom do not have to obtain an organic certification. I hope that helps!

    • Technically, when you buy local produce you SHOULD be buying in season (trusting the food was grown outdoors in a natural setting). However buying local doesn’t give any direct info about the nutritional or production practices used. For example say you’re buying local beef, that doesn’t necessarily mean the meat wasn’t produced in a factory farm setting so that’s why it’s important to talk with the farmer to determine if you’re okay buying their products. I’m with you on the strawberries but I would suggest speaking with the farmer to be sure the strawberries were grown free of any pesticides, as they are listed on the Dirty Dozen.

  • very good information and from a great source, will bookmark this very helpful post, thank you!

  • Yikes! I knew a little about some of these things…. but not most of it. I’m glad your next post is on starting a garden. lol

  • Hi Sarah and Lindsey,

    I’m interested in learning about your experience of becoming a registered dietician. Would you be open to writing a post about becoming a registered dietician? Also, is this a field with growing employment opportunities?
    Thanks for all that you do on this blog. 🙂


    • Thanks for the idea! That would be an awesome topic to address in the future.

  • So does eating organic matter? You didn’t really answer…

    • Yes it sure does, especially when it comes to the “Dirty Dozen” (link in post). By selecting organic produce – when possible – you will be reducing your exposure to possible disease inducing pesticides. Hope that clears things up a little!

  • I always try to eat seasonally, especially if you think about the environment, and it’s much cheaper. I would love to eat organically, but it’s rather expensive…

    • You’re doing a fantastic job! Awareness and mindfulness is the first step. The affordability of in-season produce is also huge perk!

  • I always buy seasonally – it’s just cheaper that way and I’m lucky because I’m not picky about my veggies and fruits. When it comes to organic though, I can’t always afford it – if I could I would! 🙂

    Charmaine Ng | Architecture & Lifestyle Blog

    • Organic can be more expensive, no doubt about that. If anything, try to spend the extra pennies on produce from the Dirty Dozen. Thanks for the feedback!

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