30-Plants-a-Week Challenge Boosts Gut Health

The more plants you include in your diet, the more health benefits you'll notice . This is why public health guidelines have long encouraged people to eat at least five servings of fruits and vegetables per day.

But the 30-plants-a-week challenge circulating online suggests that, instead of only aiming to eat five servings a day, we should instead aim to eat 30 different plant foods per week to improve our health. Fruits, vegetables, legumes, nuts, seeds, wholegrains, herbs and spices would all count as a plant serving.

Some advocates of the approach have even created some ground rules and have generated a points system that gives a point to each different type of plant you consume. However, not every plant counts as a full point. For instance, herbs and spices only count as one-quarter of a plant point. Refined plant products, such as fruit juices or processed wholegrains (such as white bread), don't count at all.

Current NHS dietary recommendations around fruits and vegetables (such as the five-a-day message) place the emphasis on quantity - ensuring people eat enough fruit, vegetables and wholegrains to get all the essential nutrients and fibre their body needs. But, the 30 plants approach shifts the focus to diversity - arguing that eating a wide variety of plant foods provides greater health benefits than eating the recommended amount of only a few select fruits and vegetables.

So does eating 30 plants a week offer any additional health benefits over eating five servings a day?

Exploring the science

The 30 plants a week challenge is based on the American Gut Project - a citizen science study of 10,000 participants from across the US, UK and Australia. The findings suggest that people who eat a greater variety of plant-based foods each week have a more diverse gut microbiome compared to those who eat fewer plants. The gut microbiome refers to the trillions of bacteria, viruses, fungi and microorganisms that live in our digestive tract.

Research shows a more diverse microbiome is associated with a lower risk of chronic disease , better immune function and even improved mental health .

So in simple terms, it looks like the more plant diversity we eat, the more diverse the population of microbes living in our gut are. This leads to better overall health.

But does eating 30 plants really provide a greater number of benefits compared to current public health messages ? These recommend we eat at least five portions of fruit and veg daily, choose wholegrain carbohydrates and limit refined sugar, processed meats and foods as much as possible.

Incidentally, research shows that following these recommendations also leads to a more diverse gut microbiome and better health outcomes compared to those who do not meet recommendations.

So, it looks like following either current public health recommendations or the 30 plants diet will improve microbial diversity and have benefits for health. While 30 is a meaningful and realistic target, it's important to recognise that small, sustainable changes can also have a lasting health impact.

Diet changes

Like any trend, the 30 plants message isn't without its drawbacks. One major concern is accessibility. Buying 30 different plant foods each week can be expensive - which could exacerbate existing health inequalities.

There are ways around these limitations, such as buying in bulk and freezing portions, using canned and frozen fruits, veggies, pulses and lentils and meal planning to reduce food waste.

However, these solutions often require extra resources such as storage, cooking space and time - which may not be possible for everyone.

There's also a risk that the message could oversimplify the complexity of public health guidance - potentially overlooking the importance of individual nutrients and overall dietary balance.

On the other hand, there's a strong argument that the 30 plants per week challenge is simply the same, old public health advice packaged in a slightly different, more engaging way. As a dietitian, I quite like that.

Current public health messages around food, nutrition and lifestyle are not landing. Despite the evidence for these guidelines , rates of lifestyle-related health problems are increasing. It's not that these recommendations don't work - it's that as a population we struggle to follow them.

The 30-plants-a-week challenge is a positive message that encourages adding more variety - rather than restricting foods. If people are encouraged to eat more plant-based foods, they may naturally displace less nutritious choices - which is a win for health.

If you're thinking of trying the 30-plants-a-week challenge, here are some easy ways to increase variety in your diet:

1. Swap your carbs: Swap white bread, rice or pasta for wholegrain bread, rice or pasta. You can also consider alternative wholegrain carbohydrates such as quinoa or wholegrain couscous.
2. Include nuts and seeds: Easily overlooked, but an effortless way to add diversity. A small handful is a portion.
3. Add pulses and lentils: Add lentils to a meat dish (such as spaghetti bolognese) for extra protein and more plant points.
4. Buy tinned and frozen foods: Stock up on frozen berries, mixed vegetables, canned beans and chickpeas to make plant variety easier to achieve and more affordable.

The challenge to eat 30 different plants is an exciting and positive way to potentially encourage nutritious choices. However, we don't yet fully understand its acceptability or impact on food choices in real-world settings. While the scientific evidence strongly supports the benefits of plant diversity for health, it would be valuable to gather more research on its practical effectiveness before incorporating it into public health messaging.

Aisling Pigott receives a research award from RCBC Wales/Health Care Research Wales Aisling Pigott is a non-executive director for the British Dietetic Association