Cancer prevention and COVID-19

Responding to the COVID-19 pandemic as it evolves and changes

27 April 2020

The COVID-19 pandemic has immediate and long-term implications for a range of factors that can influence an individual’s risk of developing cancer – especially for those in vulnerable and low-income populations, and those facing a rapid loss of income. While the pandemic presents immediate health risks, it is also changing our food consumption patterns and our levels of physical activity, potentially impacting on the longer-term health of populations.

The World Health Organization has highlighted that people with pre-existing medical conditions and non-communicable diseases (NCDs), such as cancer, appear to be more at risk of developing severe COVID-19 symptoms after catching the virus. There is also some preliminary evidence that people living with obesity also have worse health outcomes1-3.

Diet, immunity and COVID-19

Living with overweight and obesity increases the risk of at least 12 different types of cancer. So a healthy, balanced diet is vital for good health, but especially so during and after infection. As shown by World Cancer Research Fund’s (WCRF) Cancer Prevention Recommendations, a healthy diet, alongside physical activity, is key to maintaining a healthy immune system. There is also evidence to show that people affected by obesity can have an impaired immune response or immune function, making them more vulnerable to infections. Not only does a healthy diet provide ongoing support to the immune system, but as part of a healthy lifestyle it can help reduce around 40 per cent of cancers, as highlighted in WCRF’s Third Expert Report, Diet, Nutrition, Physical Activity and Cancer: a Global Perspective.

The wider consequences of COVID-19

However, the very measures designed to keep us safe from COVID-19, such as lockdowns, have the unintended consequence of affecting our diet and physical activity levels. This often affects the poorest and most vulnerable disproportionately, due to the lack of access to quality, affordable, healthy food. The pandemic has caused food supply disruption, stockpiling and production issues, and spikes in food prices. This has led to an increased reliance on highly processed, long shelf life, calorie-rich foods and has reduced access to fresh fruit and vegetables. In addition, nutrition-specific community measures designed to address problems of malnutrition might be suspended to focus health resources on COVID-19.

All of these changes can contribute to weight gain, the long-term effects of which can have an impact throughout the life course, starting for example with the suspension of a number of different health services, for example maternal health services such as breastfeeding support services. For children, having been breastfed reduces their risk of being overweight or obese in childhood and adulthood, decreasing their risk of many cancers in later life.

There are also health risks due to reduced physical activity and increased sedentary behaviour due to movement restrictions and physical distancing measures. In America, time spent on streaming platforms such as Netflix, YouTube and Amazon Prime grew by 34 percent over two weeks at the beginning of March 2020, with collective usage going from 116.4bn minutes the week of 2 March to 156.1bn in the week of 16 March.

WCRF’s expert panel found strong evidence that greater screen time is a convincing cause of weight gain, overweight and obesity in children – an issue that could be exacerbated in the crisis. Increased screen time also increases exposure to advertising, which, research shows, affects the dietary intake of children4. However, for many stuck inside with no access to gardens or other outdoor spaces, active video games or exercise videos may be their best chance for physical activity.

Changes to the food environment

The food and drink industry have been quick to offer products and services to overcome physical distancing or offer “comfort” in a time in crisis. However, many of these products are high in salt, fat and sugar. In managing the immediate crisis, there are risks that the enforcement of regulations could be relaxed, loopholes exploited, and businesses start using new tactics to promote unhealthy products in times of economic crisis and uncertainty.

To ensure populations continue to access and consume healthy diets and can be physically active during the pandemic, governments should:

  • Recognise that the food system and health system are intrinsically linked.
  • Ensure healthy and affordable food is available for all, especially for those who are more vulnerable to COVID-19, are from low-income households, or rely on social protection.
  • Continue advancing obesity and NCD prevention policies that are in development.
  • Encourage the food and drink industry to offer healthy and affordable food.
  • Run campaigns to promote healthy food preparation and consumption.
  • Maintain surveillance on policies and industry actions that may undermine access to healthy diets, and ensure that policies relating to healthy diets are still enforced and that regulations are not exploited (especially in relation to children).
  • Tackle misinformation about COVID-19 and promote the importance of high quality and trustworthy news sources, especially around diet, nutrition and physical activity.
  • Deliver mass communication campaigns and messaging on how to remain physically active while physically distancing.

Prioritising health-promoting food policies

Before the pandemic we already had a global epidemic of overweight and obesity. Governments could be presented with a ticking health time-bomb of rising overweight and obesity rates, and a greater burden of disease, once the pandemic subsides if healthy diets and physical activity are not prioritised.

Indeed, this pandemic could provide the pivotal moment to refocus on prevention, reshape policy, and increase action to reduce rising rates of overweight and obesity.

To achieve this, we urge governments to, as soon as viable, take a longer-term view and:

  • Promote affordable and accessible healthy foods to all.
  • Adopt a comprehensive approach, as outlined in the NOURISHING framework, to policymaking to ensure policy coherence between food and health.
  • Promote increased physical activity in policy development processes.
  • Seek international cooperation and coherence between food policy and health.

These are very difficult times. Despite these challenges, WCRF commends the World Health Organization for its leadership and coordination of the pandemic response. The World Health Organization has played, and continues to play, a critical role in protecting people’s health and we urge the international community to maintain support for the WHO.


1COVID-19 Surveillance Group, Characteristics of COVID-19 patients dying in Italy: report based on available data on March 20th, 2020. Rome, Italy: Instituto Superiore Di Sanita; 2020.
2Bhatraju PK, Ghassemieh BJ, Nichols M, et al. Covid-19 in critically ill patients in the Seattle region — case series. N Engl J Med. DOI: 10.1056/NEJMoa2004500.
3CDC COVID-19 Response Team. Preliminary Estimates of the Prevalence of Selected Underlying Health Conditions Among Patients with Coronavirus Disease 2019 – United States, February 12-March 28, 2020. MMWR Morb Mortal Wkly Rep. 2020;69(13):382–386. Published 2020 Apr 3. doi:10.15585/mmwr.mm6913e2
4Russell SJ, Croker H, Viner RJ (2019). The effect of screen advertising on children’s dietary intake: A systematic review and meta-analysis. Obes Rev

COVID-19 resources

WCRF does not take responsibility for the resources or the information contained.

COVID-19 and cancer

Union of International Cancer Control

Cancer Council Australia

American Cancer Society

Canadian Cancer Society

COVID-19 and NCDs

Guidance on COVID-19 and NCDs: World Health Organization

Calls to action from NCD civil society: Non-Communicable Disease Alliance

Response to COVID-19: Non-Communicable Disease Alliance

Resources relevant to NCDs: Non-Communicable Disease Alliance

COVID-19 and obesity

Will the Covid-19 pandemic increase obesity rates? International Development Studies

COVID-19 and obesity: World Obesity Federation

COVID-19 and obesity policy statement: World Obesity Federation

COVID-19 and Obesity Webinar Series 1 – The collision of two pandemics: COVID-19 and obesity: World Obesity Federation

COVID-19 and Obesity Webinar Series 2 – People at the Centre: Obesity, COVID-19 and the Patient Perspective: World Obesity Federation

COVID-19 and Obesity Webinar Series 3 – Children, Obesity and COVID-19: Risks and recommendations for the most vulnerable populations: World Obesity Federation

COVID-19 and Obesity: European Association for the Study of Obesity

COVID-19 and healthy diets

Food and nutrition tips during self-quarantine: World Health Organization

COVID-19 and physical activity

Physical activity in quarantine: WHO EURO

COVID-19 and food and nutrition policy

[Blog] Healthy diets for human resilience in the age of COVID-19: Nutrition Connect

[Policy and Research] A new global research agenda for food: Nature

[Blog] The COVID-19 Crisis and Food Systems: addressing threats, creating opportunities: GAIN

Food Environments in the COVID-19 Pandemic: United Nations Standing Committee on Nutrition

A resource list on Food Systems and Nutrition responses: United Nations Standing Committee on Nutrition

COVID-19 & Nutrition Advocacy Talking Points: International Coalition on Advocacy for Nutrition (ICAN)

Latest news and views on COVID-19 and food systems: Nutrition Connect

COVID-19 – Policy tools: FAO