We speak often about the importance of dietary diversity, and of that, especially diversity of plants in one’s diet, but we’ve never really focused on it as a main feature, so that’s what we’re going to do today.

Specifically, you may have heard the advice to “eat 30 different kinds of plants per week”. But where does that come from, and is it just a number out of a hat?

The magic number?

It is not, in fact, a number out of a hat. It’s from a big (n=11,336) study into what things affect the gut microbiome for better or for worse. It was an observational population study, championing “citizen science” in which volunteers tracked various things and collected and sent in various samples for analysis.

The most significant finding of this study was that those who consumed more than 30 different kinds of plants per week, had a much better gut microbiome than those who consumed fewer than 10 different kinds of plants per week (there is a bell curve at play, and it gets steep around 10 and 30):

American Gut: an Open Platform for Citizen Science Microbiome Research

Why do I care about having a good gut microbiome?

Gut health affects almost every other kind of health; it’s been called “the second brain” for the various neurotransmitters and other hormones it directly makes or indirectly regulates (which in turn affect every part of your body), and of course there is the vagus nerve connecting it directly to the brain, impacting everything from food cravings to mood swings to sleep habits.

See also:

• Making Friends With Your Gut (You Can Thank Us Later)
• The Brain-Gut Highway: A Two-Way Street

Any other benefits?

Yes there are! Let’s not forget: as we see often in our “This or That” section, different foods can be strong or weak in different areas of nutrition, so unless we want to whip out a calculator and database every time we make food choices, a good way to cover everything is to simply eat a diverse diet.

And that goes not just for vitamins and minerals (which would be true of animal products also), but in the case of plants, a wide range of health-giving phytochemicals too:

Measuring Dietary Botanical Diversity as a Proxy for Phytochemical Exposure

Ok, I’m sold, but 30 is a lot!

It is, but you don’t have to do all 30 in your first week of focusing on this, if you’re not already accustomed to such diversity. You can add in one or two new ones each time you go shopping, and build it up.

As for “what counts”: we’re counting unprocessed or minimally-processed plants. So for example, an apple is an apple, as are dried apple slices, as is apple sauce. Any or all of those would count as 1 plant type.

Note also that we’re counting types, not totals. If you’re having apple slices with apple sauce, for some reason? That still only counts as 1.

However, while apple sauce still counts as apples (minimally processed), you cannot eat a cake and say “that’s 2 because there was wheat and sugar cane somewhere in its dim and distant history”.

Nor is your morning espresso a fruit (by virtue of coffee beans being the fruit of the plant, botanically speaking). However, it would count as 1 plant type if you eat actual coffee beans—this writer has been known to snack on such; they’re only healthy in very small portions though, because their saturated fat content is a little high.

You, however, count grains in general, as well as nuts and seeds, not just fruits and vegetables. As for herbs and spices, they count for ¼ each, except for salt, which might get lumped in with spices but is of course not a plant.

How to do it

There’s a reason we’re doing this in our Saturday Life Hacks edition. Here are some tips for getting in far more plants than you might think, a lot more easily than you might think:

• Buy things ready-mixed. This means buying the frozen mixed veg, the frozen mixed chopped fruit, the mixed nuts, the mixed salad greens etc. This way, when you’re reaching for one pack of something, you’re getting 3–5 different plants instead of one.
• Buy things individually, and mix them for storage. This is a more customized version of the above, but in the case of things that keep for at least a while, it can make lazy options a lot more plentiful. Suddenly, instead of rice with your salad you’re having sorghum, millet, buckwheat, and quinoa. This trick also works great for dried berries that can just be tipped into one’s morning oatmeal. Or, you know, millet, oats, rye, and barley. Suddenly, instead of 1 or 2 plants for breakfast you have maybe 7 or 8.
• Keep a well-stocked pantry of shelf-stable items. This is good practice anyway, in case of another supply-lines shutdown like at the start of the COVID-19 pandemic. But for plant diversity, it means that if you’re making enchiladas, then instead using kidney beans because that’s what’s in the cupboard, you can raid your pantry for kidney beans, black beans, pinto beans, fava beans, etc etc. Yes, all of them; that’s a list, not a menu.
• Shop in the discount section of the supermarket. You don’t have shop exclusively there, but swing by that area, see what plants are available for next to nothing, and buy at least one of each. Figure out what to do with it later, but the point here is that it’s a good way to get suggestions of plants that you weren’t actively looking for—and novelty is invariably a step into diversity.
• Shop in a different store. You won’t be able to beeline the products you want on autopilot, so you’ll see other things on the way. Also, they may have things your usual store doesn’t.
• Shop in person, not online—at least as often as is practical. This is because when shopping for groceries online, the store will tend to prioritize showing you items you’ve bought before, or similar items to those (i.e. actually the same item, just a different brand). Not good for trying new things!
• Consider a meal kit delivery service. Because unlike online grocery shopping, this kind of delivery service will (usually) provide you with things you wouldn’t normally buy. Our sometimes-sponsor Purple Carrot is a fine option for this, but there are plenty of others too.
• Try new recipes, especially if they have plants you don’t normally use. Make a note of the recipe, and go out of your way to get the ingredients; if it seems like a chore, reframe it as a little adventure instead. Honestly, it’s things like this that keep us young in more ways than just what polyphenols can do!
• Hide the plants. Whether or not you like them; hide them just because it works in culinary terms. By this we mean; blend beans into that meaty sauce; thicken the soup with red lentils, blend cauliflower into the gravy. And so on.

One more “magic 30”, while we’re at it…

30g fiber per day makes a big (positive) difference to many aspects of health. Obviously, plants are where that comes from, so there’s a big degree of overlap here, but most of the tips we gave are different, so for double the effectiveness, check out:

Level-Up Your Fiber Intake! (Without Difficulty Or Discomfort)

Enjoy!