Seed oils are made by extracting oil from the seeds of various plants, such as:

• Sunflower
• Rapeseed (also known as canola oil)
• Sesame
• Grape
• Flax
• Soybean
• Safflower

These oils are versatile and many are budget-friendly choices in the kitchen. Most have a neutral flavour and a high smoke point, which means they can handle high cooking temperatures – like when you’re frying or roasting – without breaking down or producing unpleasant flavours or potentially harmful compounds. This makes them a safer and more reliable option for everyday cooking.

A particular benefit of seed oils is that they are high in unsaturated fat – the type we should eat more of – and low in saturated fat, which we should eat less of. This makes them a healthier alternative to animal fats like butter and ghee.

Importantly, seed oils provide essential omega-6 fats, which our bodies can’t make so we need them from our diet. These fats support healthy skin, and help build and maintain our cells.

Seed oils and inflammation

You may have seen claims that seed oils cause inflammation. This is mainly because they contain an omega-6 fat called linoleic acid, which can be converted in small amounts into another fat called arachidonic acid – a compound involved in the body’s inflammatory response.

Some people worry that eating too much omega-6 could compete with omega-3 fats, which support heart and brain health, and have anti-inflammatory properties. The concern is that both fats share some pathways in the body, so too much omega-6 may reduce the impact of omega-3s and promote inflammation.

But research doesn’t support this idea. In fact, studies show that people who eat more linoleic acid – the type found in seed oils – often have lower levels of inflammatory markers in the body. Instead of cutting back on omega-6, it’s more important to focus on getting enough omega-3s in your diet by eating oily fish (like salmon), green leafy vegetables (like brussels sprouts) and nuts (like walnuts).

What about cancer risk?

When it comes to cancer, there’s no strong evidence to show that seed oils increase risk. What matters most is your overall diet – we recommend you eat a diet rich in fruit, vegetables, wholegrains, pulses, nuts, seeds and lean proteins like fish and chicken to support your long-term health and reduce cancer risk.

Seed oils in processed foods

Seed oils can be found in ultra-processed products like:

• shop-bought salad dressings
• mayonnaise
• cakes
• biscuits
• crisps
• sweet and savoury pastries

These foods are typically high in salt and sugar, and low in fibre, vitamins and minerals – not ideal for our health.

In fast food restaurants, oils may be reheated multiple times at very high temperatures, which can produce potentially harmful compounds. Most of us don’t cook like that at home.

But it’s important to remember – seed oils themselves aren’t the problem. The real issue is the overall quality of the processed foods that contain them. It’s these foods that are linked to a higher risk of obesity, heart disease, type 2 diabetes and some cancers.

That’s why one of our Cancer Prevention Recommendations is to limit fast food and processed foods that are high in saturated fat, salt and sugar.

So, should I avoid seed oils?

Not at all – and there’s no need to fear them. Seed oils can be part of a healthy, balanced diet. They’re low in saturated fat, provide essential omega-6 fats and offer useful nutrients like vitamins E and K, which support immune health and normal blood clotting.

As with all fats, it’s about using them wisely. They’re high in calories, so stick to small amounts – a teaspoon or a light spray is often all you need. Seed oils are versatile in the kitchen, perfect for roasting, stir-fries, baking, homemade salad dressings or as a healthier alternative to butter or ghee.

• Report provides further clarity on dietary and lifestyle pattern (DLP) recommendations for breast and colorectal cancer prevention following a comprehensive review of 170 global studies
• Adopting a healthy DLP could also have important environmental and societal benefits, say report authors, and more can be done by policymakers to support adopting a healthy, cancer preventative DLP adoption globally

World Cancer Research Fund (WCRF) International has released a major new report on DLPs and their role in cancer prevention – out today (9 April 2025).

Today’s report emphasises that studying DLPs together, rather than looking at single foods or behaviours, can help researchers and the public to better understand how all these factors together play a role in reducing cancer risk.

An independent panel of experts reviewed the available global evidence on dietary and lifestyle patterns and breast and colorectal cancer. The evidence – which was judged to be strongly associated with cancer risk – was used to develop our new recommendation of a cancer preventative DLP.

The term “plant-based diets” has become popular in recent years. These types of diets, which are traditional for some parts of the world (eg in Asia and the Mediterranean region), are rich in vegetables and fruits, plant oils (mainly olive oil), and fish, but consumption of meat and dairy products is traditionally low. Numerous studies have shown that these types of diets are beneficial for human health.

On the other hand, diets of affluent western societies have changed significantly during the past 60 years towards a diet that is rich in meat, refined carbohydrates, sugar, and saturated fats. This type of diet is not only associated with a higher risk of chronic diseases such as cardiovascular diseases, diabetes and several types of cancer, but it also has a strong impact on our planet’s climate.

Production of animal products such as meat and dairy needs more energy than the production of plant products, hence, by reducing our consumption of animal products, we can save significant amounts of energy. For example, in Switzerland, about 30% of environmental impacts are due to food production, transportation and consumption (PDF).

An international group of nutrition scientists has proposed a diet that meets most nutrition requirements, while simultaneously taking sustainability and planetary health into account. This diet is often called the “EAT-Lancet Reference Diet” or “Planetary Health Diet”. It’s mainly plant-based, meaning that carbohydrates come from whole grains, proteins are mainly from legumes (such as beans, lentils, peas, but also soy food and peanuts), and fats are mostly unsaturated plant oils. Animal products are not forbidden, but their consumption is recommended to be limited.

Our research group at the University of Zurich, in collaboration with colleagues from other universities, was interested as to whether this type of diet, which is thought to reduce the damaging impact of food on our environment, also has beneficial effects on our health, particularly regarding the risk of cancer.

To try to answer our question, we needed a dataset in which the food consumption of the participants was assessed, but in which participants were also followed up for a number of years so that we could know how many of them were diagnosed with cancer. The UK Biobank is a large cohort in the UK that includes more than half a million people. Using data from this large cohort, we have examined how closely people were following the recommendations of the EAT-Lancet Reference Diet in 2005–07, and how many of them had been diagnosed with cancer until 2019.

Sustainability lowers cancer risk, too

When we compared those participants whose diet was closest to the EAT-Lancet Reference Diet with those who ate a less sustainable diet, we saw that an environmentally friendly diet was indeed associated with a lower risk of cancer. Better adherence was linked to a 10% lower cancer risk. However, we did not see a particularly strong protective effect for a specific type of cancer.

The results of our study are consistent with those of other groups trying to answer the same research question using different data sets. This strengthens our conclusions that a planet-healthy, plant-based diet can promote health.

In fact, plants are excellent sources of most of the essential vitamins and minerals in our diet. When a plant-based diet is balanced, products of animal origin are only needed in moderation to provide us with the few essential vitamins that cannot be found in plant sources (eg vitamin B12).

Greater focus should be given to exploring different plant-based foods, as well as on how to prepare plant foods – in particular legumes – so that more people are able to cook and enjoy these types of foods. Consumers, researchers and cooks need to team up to develop climate-friendly recipes. In Switzerland, we have published the first cookbook that only contains climate-friendly recipes. And recently World Cancer Research Fund developed Budget-friendly recipes: Good for you, good for the planet.

• Dr Nena Karavasiloglou, a researcher, was formerly a Postdoc at the University of Zurich. Dr Sabine Rohrmann is at the University of Zurich. Read more about their grant funded by World Cancer Research Fund, including papers published from this grant.

At an event to mark World Cancer Day, the Health and Social Care Secretary, Wes Streeting, announced the development of a National Cancer Plan for England.

He also launched of a new, world-leading trial that is testing AI tools to diagnose breast cancer cases earlier. More than 700,000 women are expected to take part.

Breast cancer is the most common type of cancer in women, with more than 59,000 people being diagnosed in the UK in 2021.

Alongside this, Streeting announced a new initiative called the UK Collaborative for Cancer Clinical Trial Research, which will help to maximise opportunities for the UK to lead in clinical research.

It is being hosted by the Association of Medical Research Charities, of which World Cancer Research Fund is a member.
Responding to the launch of the Government’s consultation on the National Cancer Plan for England, World Cancer Research Fund’s Executive Director of Research and Policy Dr Giota Mitrou, said:

“Around 40% of cancer cases can be prevented by making our lives and the environment we live in healthier.

“We therefore warmly welcome the UK Government’s consultation on the National Cancer Plan for England and commitment to publishing the Plan this year. Marking a pivotal opportunity to shift the dial from sickness to prevention, the Government must ensure the Plan is truly transformative and achieves a step change in cancer prevention so that more people can live free of cancer.

“The launch of a new UK Collaborative for Cancer Clinical Research also provides a welcome focus to maximise opportunities for cancer research. As a member of the Association for Medical Research Charities leading this work, we stand ready to share our expertise on research in cancer prevention and survivorship.

“Overall, the Government’s announcement is a huge step in the right direction. We look forward to working with the Health Secretary and others to make the Plan a reality.”

This study was funded by Wereld Kanker Onderzoek Fonds based in the Netherlands, as part of the World Cancer Research Fund International network.

Here is our year in numbers

1 shared vision to stop preventable cancer

Estimated figures show that approximately 40% of cancers could be prevented by modifying key risk factors such as smoking, poor diets, obesity, low physical activity levels, and alcohol consumption.

Our Research Interpretation team have worked hard to deepen our understanding of the factors influencing the risk of developing, and the chance of surviving, a cancer.

5 CUP Global Panel meetings on the risk factors cancer incidence and survivorship

We have met with our CUP Global Expert Panel (a group of world-renowned independent experts from a variety of disciplines) to discuss the scientific evidence that early life body measurements affect later risk of developing breast cancer, as well as the evidence of the impact of physical activity, diet and adiposity (fatness) has on quality of life after a colorectal cancer diagnosis.

We have also formulated new recommendations for the public on the impact of various dietary lifestyle patterns on cancer incidence, following our discussions with the CUP Expert Panel.

99 associations reviewed by the CUP Global experts

There are many modifiable factors that may be associated with developing cancer, or worsen cancer prognosis after diagnosis. This year, we reviewed 99 of them from across the cancer survivorship and cancer incidence evidence.

2 reports published on cancer survivorship

This year, we released 2 reports that summarise the complex evidence on diet, nutrition, physical activity and body weight for people living with and beyond breast and colorectal cancers. Drawing on that evidence and additional inputs from experts, health professional and patients, we produced practical guidance for patients.

We now recommend that, “after a breast cancer diagnosis, people are physically active. However, physical activity should be increased under the supervision of healthcare professionals”. We also outline recommendations for future research, as lots remains to be done in this field.

9 peer-reviewed papers; 5 published, 4 under review.

Five CUP Global peer-reviewed papers have been published this year in academic journals, to share our findings with the scientific community.

Three of them reported on the impact of sedentary behaviour, body fatness, or dietary factors and supplement use after a colorectal cancer diagnosis, while a 4th paper summarised the strength of this evidence. Our CUP Global findings on the effect of dietary and lifestyle patterns and breast cancer incidence were also published in 2024.

Another 4 manuscripts are under peer review. They report on the latest CUP Global work, including the effect of both dietary and lifestyle patterns and early life body size on colorectal cancer risk.

1 new gateway on Health Open Research

Keeping our work transparent is important. A benefit of having a gateway on a site such as Health Open Research is that it allows a central space for us to hold our research outputs and makes them openly available to everyone interested in our work. Check it out here!

16 conferences and events dissemination events

Professor TH Lam speaking at the Chinese Anti-Cancer Conference

Our CUP Global findings were presented on many occasions and to various audiences (the scientific community, health professionals, the public, students and our supporters) across the globe this year.

• At both the World Cancer Congress during a symposium, a rapid firerapid-fire session and a symposium, the 4th Nutrition and Cancer Conference, the Oncology Professional Care conference, and the Chinese Anti-Cancer Conference.
• Throughout 8 lectures at UCL, ICL, and Oxford Brookes, and a 3-day course at Wageningen University & Research
• During a webinar hosted by Breast Cancer Now
• At 2 WCRF supporters’ events in Manchester and Exeter

1 European Code Against Cancer

We contributed to the development of the European Code Against Cancer, an initiative of the European Commission to inform people about key risk factors for cancer.

2 strengthened methodologies

• We have strengthened the way we draw on our collaborators’ expertise when exploring the biology underpinning the link between diet, nutrition, physical activity and body weight, and cancer. This will deepen our understanding of how nutrition-related factors operate inside the human body to influence the onset of cancer.
• CUP Global is also now equipped with a new way of identifying what evidence, among all the research being produced globally, is worth looking at to best strengthen or expand our recommendations for cancer prevention and survival. We have identified 6 topics whose influence on cancer risk will be explored further within CUP Global:
  1. ultra processed foods,
  2. tea,
  3. coffee,
  4. sugary drinks (including artificial sweeteners),
  5. soy (isoflavones) and
  6. sedentary behaviour.

Looking forward to 2025

We will keep disseminating our CUP Global outputs on cancer survivorship dietary lifestyle patterns and on our imminent early life anthropometry findings. This is to ensure that the public, patients, health professionals, researchers and policymakers are informed about actions they can take. We are looking forward to presenting some of this work at the International Congress of Nutrition in Paris, in August 2025.

We won’t stop trying to further our understanding of the modifiable factors that shape the risk of developing, and the chances of surviving, cancer. With the 6 topics identified for CUP Global in 2025, we can’t wait to share findings from this research and learn more about the best way to prevent cancer.

A new study funded by World Cancer Research Fund has found that activity throughout the day, with peaks in the morning and late afternoon, correlated with an 11% reduced risk of developing colorectal (also known as bowel) cancer, compared with other patterns of exercise studied.

This study used accelerometer data (which measures movement) to analyse daily activity. It used a statistical method that examines all of the data and finds common patterns, and how those patterns might be related to the risk of colorectal cancer.

Researchers from Regensburg University utilised data from the UK Biobank, which had contacted 86,252 randomly selected individuals (56% of them women), asking them to wear accelerometers to track their movement over 1 week and following them for 5 years to monitor the development of colorectal cancer. When studying the data, researchers identified a 2-peak pattern of daily physical activity associated with reduced colorectal cancer risk.

The researchers identified 4 different patterns of physical activity throughout the day:

1. Continuous day-long activity
2. Activity later in the day
3. Early and late-day activity
4. Activity in the middle of the day and during the night

The 3rd pattern, where people were active both in the early and late parts of the day, was associated with an 11% lower risk of colorectal cancer, compared with 6% for day-long activity and no change for middle of the day and the night. Data from activity later in the day only was inconclusive. These findings held true even when considering factors such as smoking, shift work and other variables that could affect a person’s cancer risk.

Impact on sedentary lifestyles

In addition, the researchers found that a day-long activity pattern most effectively reduced colorectal cancer risk among individuals who were more sedentary. This may be because the effect of physical activity becomes more obvious when contrasted with a previously more inactive lifestyle, meaning that those who are fit and healthy are already at a reduced level of cancer risk. These findings show how beneficial physical activity can be, especially in those who are more sedentary.

Dr Helen Croker, Assistant Director of Research and Policy at World Cancer Research Fund, said:

“Being physically active is one of our Cancer Prevention Recommendations, and we know that this cuts cancer risk. These intriguing new findings offer potential for developing more specific recommendations, including patterns and timing of physical activity, for reducing cancer risk. This shows the vital importance of World Cancer Research Fund continuing to support research that expands our knowledge to inform cancer prevention going forwards.”

Prof Michael Leitzmann, Chair of the Department of Epidemiology and Preventive Medicine at the University of Regensburg, Germany, who was the lead investigator in the study, said:

“Our study highlights that not only is physical activity important for reducing colorectal cancer risk, but the timing of peak activity throughout the day could play a crucial role. By identifying specific times – early morning and late day – when physical activity is most beneficial, our findings open new avenues for targeted prevention strategies. If confirmed by future research, this could provide a simple yet impactful way for individuals to further reduce their cancer risk through the timing of their exercise.”

Read the paper

Stein, M.J., Baurecht, H., Bohmann, P. et al. Diurnal timing of physical activity and risk of colorectal cancer in the UK Biobank. BMC Med 22, 399 (2024).

More on this grant

The combined impact of physical activity, sedentary behaviour and cardiometabolic comorbidities on cancer risk and survival among cancer survivors

About the UK Biobank

The UK Biobank is a large, population-based prospective study, established to allow detailed investigations of the genetic and non-genetic determinants of the diseases of middle and old age. It has 500,000 UK participants between the ages of 40–69.

About the University of Regensburg

The University of Regensburg is a nationally and internationally renowned comprehensive university with an excellent research spectrum, an attractive range of courses and a high sense of social responsibility. The UR stands for diversity, openness to the world and shaping the future. Its research strength is demonstrated by 6 Collaborative Research Centers funded by the German Research Foundation (DFG) and 9 grants from the European Research Council.

In 2017, the Institute for East and Southeast European Studies (IOS), an affiliated institute of the UR, was the first institution in Regensburg to be accepted into the renowned Leibniz Association, followed in 2022 by the Leibniz Institute for Immunotherapy, which emerged from the Regensburg Center for Interventional Immunology. In May 2024, the Regensburg Center for Ultrafast Nanoscopy opened at the university, where the ultra-fast quantum movements of atoms and molecules are researched using innovative, high-resolution slow-motion cameras. In spring 2022, the Science Council recommended funding for the Center for Immunomedicine in Transplantation and Oncology at the UR, a center for basic research in immunomedicine.