From the Dirty Dozen to the Clean Fifteen, consider this a must-read cheat sheet for every grocery run.

Written by: Samantha Nice
Written on: June 22, 2025
We all know organic is the healthier, more environmentally-friendly choice, but let’s be honest, it’s not always easy to justify the higher price tag on every item. With grocery bills climbing and organic options often costing double, the real question is: when does it actually matter?
The truth is, not all produce is created equal when it comes to pesticide exposure. Some fruits and veggies are worth the organic upgrade whilst others, not so much. In this guide, we’ll break down which foods are worth the splurge and which ones are safe to buy non-organic. Think of it as your cheat sheet for shopping a little smart… and savvier.
Organic food isn’t just a trendy label - it’s a farming and food system that’s designed to be better for your health, the planet and often, animal welfare too. But what does that actually mean and what are the benefits?
“Organic refers to the way food is grown and processed,” explains nutritionist, Clarissa Lenherr. “Organic farming avoids pesticides, livestock feed additives, man-made fertilisers, GMOs and irradiation,” she adds. “In the UK, products labelled organic must meet strict certification standards, such as those set by the Soil Association.”
Here’s a closer look at the benefits:
One of the biggest reasons people choose organic produce is to reduce their exposure to synthetic pesticides. While all food sold in the UK must meet safety standards, conventional farming still uses a wide range of chemical pesticides. Organic farming severely restricts or eliminates their use altogether.
Organic farmers use natural fertilisers like compost or manure instead of synthetic ones, which are linked to soil degradation and pollution. Organic food in the UK is also GMO-free, which ticks a big box for those who prefer food in its most natural form.
Organic farming tends to support healthier soil, greater biodiversity and more sustainable land use too which is another big win. It avoids harmful practices like the overuse of nitrogen fertilisers, which contribute to greenhouse gas emissions and water pollution.
When it comes to meat, dairy and eggs, organic standards generally mean higher welfare for animals too. This often includes access to outdoor space, more natural diets and no routine use of antibiotics or growth hormones.
“From a nutritional point of view, some research suggests that organic produce may contain higher levels of certain antioxidants, and organic animal products may have a better fat profile, including more omega-3s,” adds Clarissa.
Sold on the benefits and wondering which are worth investing in? Clarissa suggests focusing on foods most likely to contain pesticide residue. “Dubbed the ‘Dirty Dozen’, PAN (Pesticide Action Network) UK releases an annual report which lists the fruits and vegetables found to carry the highest levels of pesticide residues when tested - even after washing. You can access the latest version on their website here - www.pan-uk.org,” she adds. Many of these are thin-skinned or typically eaten raw, which makes them harder to clean and more likely to absorb chemicals.
PAN UK’s Dirty Dozen includes soft citrus (like tangerines and satsumas), oranges, lemons, grapes, pears, dried fruit like sultanas, bread, carrots, spring onions, dried beans (like black-eyed beans), peas and green beans.
Published annually by the Environmental Working Group (EWG), the US version of the Dirty Dozen names the following as the most common offenders; strawberries, spinach, kale (and other leafy greens), peaches, pears, nectarines, apples, grapes, peppers, cherries, blueberries and green beans.
“Whilst it’s worth considering both lists, I also recommend going organic if the food has a thin skin or if you eat the food with the skin on like blueberries for example,” adds Clarissa.
On the flip side, some fruits and vegetables consistently test low for pesticide residues, even when grown conventionally. In the US, these are known as the ‘Clean Fifteen’ and include items like avocados, sweetcorn and onions that typically have thick skins, protective husks or natural pest resistance, making them less likely to retain harmful chemicals. The full list from EWG includes pineapple, sweetcorn, avocados, papaya, onions, frozen sweet peas, asparagus, cabbage, watermelon, cauliflower, bananas, mangoes, carrots, mushrooms and kiwi.
Buying these non-organic can be a smart way to save money without compromising on safety. However, Clarissa notes a key caveat for UK shoppers: “The Clean Fifteen list is not published in the UK, and is a reflection of US data.”
It’s easy to focus on fruit and veg when thinking about organic, but what about the rest of your trolley - things like meat, dairy and packaged foods? For these items, the benefits of buying organic go beyond just pesticide residue. We're talking about antibiotic use, animal welfare and nutritional differences, all of which are more tightly regulated under organic standards.
“When it comes to meat and dairy, while the UK does not allow the use of growth hormones in any farming system, organic or conventional, organic standards still go further," says Clarissa. “Organic meat and dairy come from animals raised on organic feed, without the use of routine antibiotics, and under higher animal welfare standards." There can also be nutritional benefits too. “Organic dairy, for example, has been shown to contain higher levels of omega-3 fatty acids,” she adds.
When it comes to packaged goods (like cereals, snacks, sauces or ready meals) the organic label can still carry weight, but the benefits really depend on the ingredients. Choosing organic here can mean fewer artificial additives, no genetically modified ingredients and stricter rules around processing. However, it’s still important to check the labels. Just because something is organic doesn’t always mean it’s healthier. Organic biscuits are still biscuits at the end of the day. Instead look at focusing on ingredient quality and transparency, and prioritise organic for products with wholefood ingredients like grains, oils or dairy.
Going fully organic isn’t always realistic, but with a few smart strategies, you can still cut down on pesticide exposure and make informed choices. “For non-organic produce, a simple and effective way to reduce pesticide residues is to soak fruits and vegetables in a 1% bicarbonate of soda (baking soda) solution for around 15 minutes, followed by a thorough rinse. Research has shown that this method can significantly lower the levels of pesticide residue remaining on the surface.”
When organic options are limited or expensive, strategic swapping can also help. “With my clients, I recommend screenshotting or writing notes of the Dirty Dozen list and foods with very thin skins (or those you eat with the skin on) and aiming to buy those foods organic. Or if the price point is too high, to swap to an alternative. For example, swap pears for apples, or choose avocados or bananas with thicker skins. For everything else, base your decisions on price and availability and then soak and wash if you have time.” In other words, prioritise where it counts, be flexible where you can and don’t underestimate the power of a good rinse.
Buy organic for fruits and veggies with thin skins or eaten raw, as they tend to have the highest pesticide residues.
The ‘Clean Fifteen’ are thick-skinned or pest-resistant produce like avocados and onions and are generally safer to buy non-organic.
Organic meat, dairy, and packaged goods offer added benefits like better animal welfare, no routine antibiotics and higher nutritional quality.
Soaking produce in a 1% baking soda solution for 15 minutes can effectively reduce pesticide residues when organic isn’t available.
Use the Dirty Dozen list to prioritise organic purchases and swap expensive items for safer alternatives with thicker skins, while washing all produce thoroughly.
This article is for informational purposes only, even if and regardless of whether it features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice. The views expressed in this article are the views of the expert and do not necessarily represent the views of Healf
This article is for informational purposes only, even if and regardless of whether it features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice. The views expressed in this article are the views of the expert and do not necessarily represent the views of Healf
Samantha Nice is a seasoned wellness writer with over a decade of experience crafting content for a diverse range of global brands. A passionate advocate for holistic wellbeing, she brings a particular focus to supplements, women’s health, strength training, and running. Samantha is a proud member of the Healf editorial team, where she merges her love for storytelling with industry insights and science-backed evidence.
An avid WHOOP wearer, keen runner (with a sub 1:30 half marathon) hot yoga enthusiast and regular gym goer, Samantha lives and breathes the wellness lifestyle she writes about. With a solid black book of trusted contacts (including some of the industry’s leading experts) she’s committed to creating accessible, well-informed content that empowers and inspires Healf readers.