Eating 30 different plants a week can boost the diversity and health of your gut microbiome. And in turn, it may affect many other aspects of your health.
If 30 sounds like a lot, you’ll be pleased to hear: It’s not just fruits and veggies that count.
You can include grains, nuts, seeds, herbs, and spices, too.
Studies still suggest that eating 5 portions of fruit and vegetables a day can have a significant positive impact on your long-term health.
But many experts now believe that eating a variety of plants could be just as important.
Below, we explore the scientific evidence behind the target of 30 plants per week. We also go into detail about what counts and how to get more plants into your diet.
Why should you try to eat 30 plants a week?
It’s sometimes called the 30-plant challenge, but the idea of eating 30 types of plants each week is more than just a fad. There’s real science to back it up.
Eating patterns, like the Mediterranean diet, which contain a wide range of plant foods have strong links to a reduced risk of long-term health conditions, such as heart disease and type 2 diabetes.
These ways of eating may even lower your risk of cancer and help you stay healthy as you age.
But eating a variety of plant foods is also important for the health of your gut microbiome — the community of bacteria and other bugs that live in your gut.
The prebiotics in plants include different types of fiber and other carbohydrates, as well as chemicals called polyphenols.
Polyphenols are responsible for the colors of many plants, and they also have antioxidant and anti-inflammatory properties.
Different plants contain different prebiotics, which in turn feed different gut bugs. This means that eating a wide range of plants is likely to support the diversity of the bugs in your gut microbiome.
A more diverse microbiome, rich in beneficial bugs, has links to a better functioning and more resilient gut.
Some scientists think it may even help you live a longer and healthier life.
Where does the ‘30’ come from?
You may have heard experts like ZOE Co-Founder Prof. Tim Spector recommending that you eat 30 different plants a week. Or, you’ve seen it mentioned as a “challenge” on social media. But where did this number come from?
In 2018, scientists published results from the American Gut Project, a collaboration of researchers and more than 10,000 “citizen scientists” from the United States, the United Kingdom, and Australia.
Tim led the U.K. arm of the research, called the British Gut Project.
The volunteers shared detailed information about their eating habits. They also provided samples of their poop. The researchers analyzed these to find out which gut bugs they contained.
The study showed that participants who ate a wider variety of plants had more diverse gut microbiomes.
Participants who ate 30 or more different plants per week were more likely to have certain “good” gut bugs than those who ate just 10. Their poop samples also contained higher levels of healthy chemicals produced by the bacteria.
What counts as a plant?
If the idea of eating 30 plants in a week sounds daunting, we have good news.
“Increasing the variety and amount of plants in your diet doesn’t have to be difficult,” says Tim, “especially once you expand your idea of what counts as a plant-based food to include spices, herbs, nuts, and seeds.”
Also, you don’t need to eat any specific amount of a plant for it to count. Even small pinches of herbs and spices matter.
But when it comes to herbs and spices, you might want to try and eat them a few times throughout the week to get the full benefits.
Meanwhile, keep an eye out for different colors of veggies. For example, red, green, and yellow bell peppers count as three different plants.
That’s because different colors mean different polyphenols, which fuel different strains of gut microbes — and have different health benefits.
Vegetables come in all shapes, sizes, and colors.
Your 30 plants can include different types of root vegetables, salad leaves, cruciferous veggies (also called brassicas) and alliums, like onions, garlic, and chives.
Here are some examples to consider:
There’s a huge range of fruits to choose from, including types you might associate with savory dishes.
Here are just a few examples:
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Some specific examples include:
soybeans or edamame
Some grains and cereals that count toward your 30 include barley, different colors of rice, and the types that often become flour, like wheat and rye.
It’s best to choose whole grains, which offer you all the plant’s fiber.
Overall, whole grains contain more nutrients than refined grains like white flour and white rice. They’re also better for your blood sugar and blood fat levels.
So, some options that count toward the total include:
whole wheat flour
Nuts and seeds
Nuts and seeds contain protein, fiber, healthy fats, vitamins, and minerals. They’re great as a snack, and they can add a satisfying crunch to many meals.
Some nuts to consider include:
Seeds to try include:
Herbs and spices
Herbs and spices are a healthy way to add an extra hit of flavor to your meals. Both fresh and dried ones count.
Herbs you could opt for include:
Popular spices include:
Because we tend to eat herbs and spices in small amounts, it may be a good idea to use them several times during the week to make sure your gut gets the full benefit.
Foods you might not expect to count
They may not seem like plant foods (or drinks). But healthy versions of these all count toward your target of 30 plants per week:
Dark chocolate: Chocolate comes from the seeds of a tropical fruit, contains polyphenols, and can have health benefits. The healthiest versions have a high proportion of cocoa solids — 70% or above — and no artificial additives.
Popcorn: These corn, or maize, kernels count as whole grains. If popcorn is air-popped and doesn’t have too much salt or butter, the American Heart Association considers it a healthy snack.
How to increase the variety of plants you eat
Here are some tips for getting more plant types into your diet each week:
Stock up: Even if you have loads of fresh fruit and veggies to hand, keep your cupboards stocked with canned fruit and beans, and packets of pulses.
Supercharge salads: Nuts or seeds can give your salads a nice crunch, and apples or fennel can make them more interesting. Herbs can add flavor, and pulses or diced tofu can add substance.
Liven up yogurt: Plain live yogurt and kefir are great for your gut. And adding nuts, seeds, or fruit, like berries, takes yogurt to the next level.
Embrace beans: Beyond adding them to salads and stews, you can make beans into delicious dips, or replace meat in recipes with lentils or tofu. Instead of using just one type of bean, try a mix of two or three varieties.
Add hidden greens: Leafy green vegetables, like spinach, or finely sliced cabbage wilt quickly when stirred into dhals, stews, and stir-fries, subtly boosting your meal’s plant count.
Be snack savvy: Swapping out snacks like chips or candy for mixed nuts, berries, or sliced peppers will bring you closer to your target.
Meatless Mondays: This is a great way to make sure you’re prioritizing plant-based foods in your diet at least once a week.
With ZOE’s personalized nutrition program, you can find out about the best plant foods for your body and get recipe and meal suggestions tailored to you. Learn more about how it works and take our free quiz.
If you’re planning plant-packed meals, here’s some inspiration. Switch things up by adding or swapping plant foods to create your own versions.
oatmeal with sliced apple, walnuts, and pumpkin seeds
yogurt or kefir with mixed nuts and berries
avocado on sourdough bread topped with pumpkin seeds and radish
smoked tofu salad with avocado, cherry tomatoes, lettuce, sauerkraut, mixed seeds, chopped nuts, herbs, and olive oil
vegetable omelet with onions, mushrooms, and spinach served with a side salad dressed with olive oil and vinegar
lentil bolognese with wilted spinach on whole wheat pasta
butter bean, pinto bean, and mushroom stew with carrots, onions, garlic, and paprika
Snacks or treats
dark chocolate (containing at least 70% cocoa) and hazelnuts
a raw fruit and nut bar
fruit, like berries or an apple
roasted chickpeas or wasabi peas
hummus with veggie sticks
Adding more plants to your diet can improve many aspects of your health, including your risk of developing chronic illnesses.
Research suggests that eating 30 plant types every week could have a particularly positive effect on the diversity and health of your gut microbiome.
Reaching that target may not be as hard as it sounds. You can count nuts, seeds, herbs, and spices — even coffee and dark chocolate — along with fruits, vegetables, and grains.