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Obesity and Cancer: 5 Eye-Opening Statistics

Written by Andrew Le, MD

UpdatedDecember 11, 2024

Obesity has become a significant risk factor for cancer, with numerous studies revealing disconcerting trends linking excess weight to increased cancer incidence globally. Research has shown connections between being overweight and obesity and a wide range of cancer types across different demographics and populations.

This article will analyze the statistics and findings demonstrating the impact of the obesity epidemic on cancer rates. Also, the growth in obesity-associated cancer over time, as well as differences based on factors like age, gender, and location.

🔑 Key Takeaways

  • Obesity-related cancer rates increased by 7% in the US from 2005-2014, with over 684,000 cases reported annually. The majority affected were aged 50 and over.
  • Over 1 in 20 cancer cases in the UK are caused by overweight and obesity, linked to 13 different cancer types through mechanisms like inflammation and hormone changes.
  • High BMI surpasses tobacco as the leading risk factor for disease burden in many high-income countries. In 2012 alone, over 100,000 US cancer cases were attributed to excess weight.
  • People with cardiovascular disease, along with high BMI, saw a 17% increase in cancer risk, especially for bowel, breast, and liver cancers, per an IARC study.
  • While obesity showed a small protective effect for premenopausal breast cancer in European women, it substantially raised the risk for postmenopausal women globally.
  • The rate of cancers tied to obesity rose 7% from 2005-2014 in the US, except for colorectal cancer, which fell 23% thanks to screening.
  • Breast cancer after menopause and colorectal cancer are the most common obesity-linked cancers in women and men, respectively, in the US. Over 90% of these cases occur in those over 50.

Understanding Obesity and Cancer

Obesity refers to an excessive accumulation of body fat that poses health risks. It is clinically defined as having a Body Mass Index (BMI) over 30 kg/m2. Obesity has been linked to an array of health complications, including:

On the other hand, cancer encompasses diseases characterized by uncontrolled cell division and growth. Cancerous cells can invade surrounding tissues and metastasize to distant body areas. Many genetic, environmental, and lifestyle factors trigger mutations that enable cells to become cancerous. If left untreated, cancers can be fatal.

💡 Did You Know?

Obesity can induce specific physiological changes, such as chronic inflammation, elevated insulin levels, insulin-like growth factors, and alterations in sex hormones. These alterations can potentially contribute to the development of cancer. The greater the weight gain and its maintenance, the higher the risk of cancer becomes. To learn more about their connection, check out our article about obesity and cancer.

As rates of obesity continue rising globally, understanding its relationship to cancer becomes ever more crucial. Now, let’s explore the statistics and trends of the connection between obesity and cancer.

Statistics and Trends

Much research highlighted the impact of obesity on cancer incidence across different regions and demographics.

These findings are significant as they underscore the need for public health initiatives to reduce obesity rates to potentially lower cancer risks. Here are some key findings from various studies to understand the extent of this issue.

1. The CDC found a 7% increase in obesity-related cancers in the US from 2005 to 2014, with over 684,000 cases annually, mainly affecting individuals aged 50 and older. (CDC)

The Centers for Disease Control and Prevention (CDC) in the US reports that obesity is linked to an increased risk of various cancers. From 2005 to 2014, most cancers associated with overweight and obesity increased in the US, while cancers related to other factors decreased.

During this period, the rate of new cancers associated with overweight and obesity increased by 7%, except for colorectal cancer, which decreased by 23% due to screening tests. More than 684,000 obesity-associated cancers occur in the US each year, including over 210,000 among men and 470,000 among women.

Breast cancer after menopause is the most common obesity-associated cancer among women, while colorectal cancer is the most common among men. More than 90% of new obesity-related cancers occur in individuals who are 50 years old or older​.

2. Overweight and obesity are the second leading cause of cancer in the UK, contributing to over 1 in 20 cancer cases, linked to 13 cancer types due to various mechanisms. (Cancer Research UK)

Cancer Research UK has found that overweight and obesity are the second biggest cause of cancer in the UK, causing more than 1 in 20 cancer cases. The risk of cancer increases with the amount of excess weight and the duration of being overweight.

Overweight and obesity have been linked to 13 different types of cancer, including:

  • Breast cancer
  • Bowel cancer
  • Pancreatic cancer
  • Esophageal cancer
  • Gallbladder cancer
  • Endometrial cancer
  • Ovarian cancer
  • Liver cancer
  • Kidney cancer
  • Upper stomach cancer
  • Myeloma
  • Meningioma
  • Thyroid cancer

The mechanisms include increased levels of growth hormones, inflammation, and sex hormones, which can lead to an increased risk of cancer.

3. High BMI is a leading risk factor for disease burden in high-income countries, with over 100,000 cancer cases attributed to it in 2012, including various cancer types. (Plos)

This longitudinal study from the US found that high BMI is a leading risk factor for disease burden in high-income countries, surpassing the decreasing disease burden attributable to tobacco smoking.

Approximately 70% of adults in the US are considered overweight, and 36% are obese. The study linked overweight and obesity with an increased risk and mortality from cancer and other chronic diseases such as type 2 diabetes and cardiovascular disease.

In the US, more than 100,000 cancer cases were attributed to high BMI in 2012 alone. Cancers linked to high BMI include postmenopausal breast cancer, adenocarcinoma of the esophagus, and pancreatic, colorectal, renal, endometrial, ovarian, and gallbladder cancer.

Specific Cancer Risk Factors

The connection between specific risk factors and cancer incidence has been the subject of extensive research, emphasizing how various factors influence the likelihood of developing certain cancers.

Understanding these relationships is crucial for both prevention and early detection. Below are some key findings.

4. High BMI in individuals with cardiovascular diseases increases cancer risk by 17%, especially for bowel, breast, and liver cancers. (IARC)

A study by the International Agency for Research on Cancer (IARC) revealed that high BMI increases cancer risk by 17% for individuals with cardiovascular diseases.

This multinational study involving over 577,000 adults investigated the association between BMI, cardiometabolic, and cardiovascular diseases. It found that people with excess weight, obesity, and cardiovascular diseases are more likely to develop cancer, particularly of the bowel, breast, and liver.

5. Obesity is associated with a significantly increased risk of breast cancer in post-menopausal women across continents, while pre-menopausal European women show a slight protective effect. (PubMed)

A comprehensive study investigated the relationship between obesity and breast cancer risk in women, examining both pre-menopausal and post-menopausal groups across different continents. The research analyzed 102 studies, with 48 focused on pre-menopausal women and 67 on post-menopausal women.

For pre-menopausal women, the results indicated that obesity had a slightly protective effect against breast cancer. However, this protective association was statistically significant only among European women.

In contrast, among post-menopausal women, the study found a substantially increased risk of breast cancer associated with obesity. This risk was observed consistently across different continents, including among Asian, North American, African, and European women.

The level of heterogeneity was higher in the post-menopausal group, suggesting that the association between obesity and breast cancer risk was more pronounced in this population.

📔 Related Article:

For additional statistical insights on weight management, feel free to explore our collection of articles:

Final Thoughts

As overweight and obesity levels continue to climb worldwide, the burden of associated cancers will likely escalate as well.

The data underscores the urgent need for public health strategies aimed at curbing obesity rates to mitigate obesity-related cancer risks. Population-level lifestyle changes promoting a healthy diet and regular exercise can help reverse this trend at the source. Screening and early detection also remain vital for improved outcomes.

Additionally, a better understanding is required of the intricate biological pathways linking obesity and cancer to identify targeted prevention and treatment options. As the research continues to reveal the multifaceted relationship between excess body weight and cancer, addressing the obesity crisis must become a priority in cancer control. Lifestyle and policy efforts to reduce obesity can ultimately save lives by reducing cancer incidence and mortality.

FAQs on Obesity and Cancer

What are the key components of an effective weight loss program?

An effective weight loss program typically includes a balanced diet, regular physical activity, and behavioral changes. It should be tailored to an individual's health status and lifestyle preferences.

Is BMI a good indicator of body fat?

While BMI is not a perfect measure of body fat, it is a helpful guide for most adults. However, it isn't appropriate for certain groups, such as professional athletes. For children, BMI is adjusted for age and gender.​

Can obesity affect cancer screening and management?

Yes, obesity can lead to difficulties in cancer screening and management. For instance, women who are overweight or obese have an increased risk of cervical cancer compared to women of healthy weight, likely due to less effective cervical cancer screening in these individuals​.

What is the most common obesity-associated cancer in women? In men?

Among women, breast cancer after menopause is the most common obesity-associated cancer. In men, colorectal cancer is the most common obesity-associated cancer​​.

What can individuals do to reduce the cancer risk associated with obesity?

Individuals can reduce their cancer risk by maintaining a healthy weight, engaging in regular physical activity, and following a balanced diet. These lifestyle changes can help lower the risk of obesity-related cancers. It's also essential to participate in recommended cancer screenings

What are some good weight loss programs?

When looking for a good weight loss program, it's essential to find one that offers personalized support and is tailored to your needs. A great example is Korb, which provides customized nutrition plans, fitness guidance, and expert advice. Korb's programs are designed to help you achieve sustainable weight loss and improve your overall health, making it an excellent choice for those seeking a comprehensive and personalized approach.