Lifestyle Changes to Reduce Cancer Risk: What the Research Shows

Brian McCloskey and Brad Power January 18, 2023 “Every couple of years, we do a cancer risk factor awareness survey and about half of the people are unaware of most of these strong risk factors like alcohol, obesity, low physical activity, and diet.” – Nigel Brockton, PhD “The immune system is important because then you're using a system against a system, rather than one tool against one target.” – Nigel Brockton, PhD “There is a huge difference between what can be recommended at the population level (the predominant role of AICR) versus what can be assessed to be potentially beneficial at the individual level (clinical guidance and patient choice).” – Nigel Brockton, PhD

Advanced cancer patients are looking for every edge they can find to enhance their immune system and general health to fight their disease. In a diagnosis that can arrive "out of the blue", it is important to have agency and make a difference in things they can do, such as follow a healthy diet, reduce stress, get sleep, and exercise. But what is the science that shows the potential impact of these and other lifestyle factors on patient outcomes?

A patient's medical team is usually focused on testing and treatment options with surgery, radiation, or drugs. Where should patients look to get advice on these other lifestyle factors? How should a patient (and caregivers) think about the potential impact? What should an active and engaged patient do?

As a cancer survivor (Ewing sarcoma) and Vice President of Research at the American Institute for Cancer Research’s (AICR), Nigel Brockton, PhD, is uniquely positioned to share the scientific evidence regarding diet, nutrition, body weight and physical activity as they relate to cancer risk and survivorship.

The AICR was formed to try and distinguish evidence from opinion because patients were fatigued and confused by the changing messages about what was healthy. Dr. Brockton outlined the evidence about cancer risk generally and about prostate cancer specifically, and he explained the future direction of research on a global scale with AICR’s international colleagues.

What does the science show about the potential impact of lifestyle factors on cancer outcomes?

The AICR recommends in general that you should be at a healthy weight, be physically active, eat a diet rich in whole grains, vegetables, fruits and beans, limit consumption of fast and processed foods, limit consumption of red and processed meats, limit consumption of sugar sweetened drinks, limit alcohol consumption, and don't take supplements for cancer prevention. There are reasons to take supplements, but cancer prevention isn't one of them.

In some cancers, some of these supplements can interfere with the action of treatments. They can cut both ways. If exercise were a pill, we'd give it to everyone. As long as you are capable of doing it, that is probably one of the strongest medicines, and it's based on evidence. Immune benefits seem to come more from high intensity workouts. Specific cancers have specific recommendations.

For example, in colorectal cancer there is strong evidence for five factors that decrease your risk: whole grains, foods containing fiber, dairy products, calcium supplements, and physical activity, and five that increase your risk: red meat, processed meat, alcoholic drinks, adult body fatness, and attained height. In prostate cancer the only strong evidence is increased risk from adult body fatness, specifically for advanced prostate cancer.

There is limited, suggestive evidence that dairy products, diets high in calcium, low plasma alpha-tocopherol concentrations (Vitamin E), and low plasma selenium concentrations increase cancer risk. You can substantially reduce your cancer risk by changing your behavior. About half of people are unaware of strong risk factors like alcohol, obesity, low physical activity, and diet, or that coffee is beneficial.

People often think that it's genetics and pesticides and things, but they account for a fairly low proportion of cancers. The cancer treatments that you receive could be bad for your cancer, but they are also bad for the rest of your body. The more you can do to maintain your resilience, the better off you are. The call is for action, not perfection.

The more of these recommendations you follow, the lower your cancer risk, and the better your outcomes. But any of these you address will be beneficial. How should advanced cancer patients think about adopting lifestyle, nutrition, and exercise guidelines? You can think about cancer like a bathtub which fills up with water (cancer risk). We're all born with a certain amount of water in our cancer bathtub.

There's a leaky tap that adds water (cancer risk) over our lifetimes. Although we can never stop that leaky tap, we can reduce the flow by adopting healthy behaviors and avoiding unhealthy behaviors. How do we know when our bathtub is getting full? We know through diagnostic tests. It’s never too late to adopt healthy behaviors and slow the flow, and it's also never too early. It's pretty difficult to remove the water.

We don't have evidence yet for the reversibility of cancer risk. What is the evidence for future cancer treatments, especially immunotherapies? The future of cancer treatment, although it's been very disappointing so far in prostate cancer, is immunotherapy. Prostate cancer tends to be a very immune cold tumor. The immune system doesn't respond to them. Males, particularly older males, tend to have poor immune systems.

A lot of lifestyle factors have an impact on the immune system. If the immune system is already compromised, then immunotherapy is not going to be able to function. If you're giving immunotherapy as a last-ditch attempt, after you've wrecked somebody's immune system with chemotherapy, the immunotherapy has less of a chance. This is not sci-fi anymore because with melanoma they've shown some really good results with mRNA vaccines.

How should advanced cancer patients make decisions between treatments based on solid, evidence-based research and those that are based on solid scientific theories, but for which there is no randomized clinical trial evidence (and may not be for many years)?

Given the complexity of cancer treatment options and the unique context of each case, particularly in advanced disease, being your own advocate and engaging in collective advocacy is hugely valuable. Oncologists are well trained, but it is impossible for one person to assimilate the entire ever-expanding field.

Tumor boards seek to exploit a group to optimize treatment approaches for individual cases, but you are the best advocate for optimal approaches for YOU!

The information and opinions expressed on this website or platform, or during discussions and presentations (both verbal and written) are not intended as health care recommendations or medical advice by Cancer Patient Lab/Prostate Cancer Lab, its principals, presenters, participants, or representatives for any medical treatment, product, or course of action.

You should always consult a doctor about your specific situation before pursuing any health care program, treatment, product or other course of action that might affect your health.

Meeting Notes The information and opinions expressed on this website or platform, or during discussions and presentations (both verbal and written) are not intended as health care recommendations or medical advice by Cancer Patient style Choices to Reduce Your Cancer Risk” Meeting Notes The information and opinions expressed on this website or platform, or during discussions and presentations (both verbal and written) are not intended as health care recommendations or medical advice by Cancer Patient Lab/Prostate Cancer Lab, its principals, presenters, participants, or representatives for any medical treatment, product, or course of action.

SUMMARY KEYWORDS cancer, people, evidence, prostate cancer, recommendations, immune system, question, research, diet, exposures, colorectal cancer, factors, chemotherapy, risk factor, studies, exercise, risk, treatment, nigel, beneficial SPEAKERS Nigel Brockton, Rick Stanton, Amit Gattani, Brad Power, Brian McCloskey Brad Power 00:03 Today we're going to have a session with Nigel Brockton talking about research on lifestyle, nutrition, and exercise, and how they can help in cancer treatment.

But before we do that, I want to read our standard disclaimer so that everyone knows that this is not medical advice and that if you say anything, or if you have your camera on, it all will be made public in a Zoom recording and a transcript. Please note that the information and opinions shared on this website or platform or during this discussion or presentations are not intended as medical advice.

It is important to consult with a healthcare professional about your specific situation before making any decisions related to your health. I like to point out that it's a ChatGPT version for those of you who know about ChatGPT, which took the legal words and made them a little simpler and clearer. Nigel is going to start with a few slides, and then we'll open it up for discussion.

Nigel, if you could start by introducing yourself and the story you started telling me it would be perfect. There's someone named Wendy Fantl who is an ovarian cancer survivor and a scientist at Stanford. When we find people who are cancer survivors themselves, it really gives them a special perspective which is consistent with who we are and what we're up to.

Brad was asking me how I got into this line of work before we went live. I was eight years old when I decided I wanted to be a marine biologist. I stuck with that single mindedly until I had a degree in marine biology. But on the way to getting a degree in marine biology at 18, I was diagnosed with Ewing Sarcoma in the soft tissue of my jaw. This was in 1989 when there was zero information about cancer.

In fact, people wouldn't even say the word “cancer”. And it's quite amazing to see the societal change that I've lived through. Even between 1989 to 1992 when I had my recurrence, people had started to be able to say the word "cancer," but it wasn't common. I was working in a bar, or an English pub, and I was reading a book on chemotherapy. In those days, there were no layperson books. This was a book for doctors.

Somebody asked me to put the book away because it had the word "cancer" on it. The fact that we now have these forums to have these kinds of discussions currently shows there's almost too much information. One of the roles for AICR is to cut through to what we know. There's been some pretty massive changes. I had a recurrence, and I went through nine months of intensive treatment. I've been cancer free since I finished treatment in March of 1993.

This will be 30 years next month. ” because there are very few recurrent Ewing sarcoma survivors. I have no disclosures to report. Who of you are familiar with the American Institute for Cancer Research before I popped on your radar? No? Good. That means I'm talking to a new audience and sharing our message. I've been following AICR since I started my PhD in 1997 when the first expert report was published.

Certainly, from a research and clinical perspective, AICR WCF (World Cancer Fund) is seen as the global experts on diet, nutrition, physical activity and cancer prevention survival. I'm not sure how many of you followed this back in February when they relaunched the Cancer Moonshot? I was frustrated. " Part of what I'm going to present here is that we have lots of ways to prevent it. Here's a little bit of a history, or context, in terms of AICR.

AICR was 40 years old in 2022. The way we think about cancer has changed dramatically over that period. When people were looking at the causes of cancer in the 1980s, it was all about external carcinogens. " There was some progress on that front, some mechanistic insights, but when we got into the 2000s, it was more about looking at metabolic factors and endogenous factors, obesity, and inflammation.

Those became the causative factors that people were looking at. Now as they move into and through the 2010s, it was the host, and the microbiome and metabolism. Now, we really are in the era of immune responses and the interplay with tumors, which is a particular issue for prostate cancer. How we think about diet has changed. It was all about single nutrients and these magic bullets. I'm sure you've heard the beta carotene story.

My mother was duly giving me beta carotene tablets when I was going through treatment. She was well-meaning, but that's what people thought it was to be anti-cancer. In lung cancer, the risk of lung cancer increased for smokers. Then it was about looking at the genes that regulate and metabolize these nutrients.

Then as we got into the 2020s, it was really looking more at whole foods and dietary patterns, and the big interest now concerns the time of eating. It's not just what you eat, but how and when you eat. Back in the 80s, when the first lifestyle recommendations were released from AICR, there was quite a lot of pushback. We were seen as snake oil salesmen. There was nothing you could do personally to be effective in cancer prevention.

Then we moved to strong evidence into the 2000s when the first expert report was in 1997. That summarized the evidence and made some conclusions, but really strong evidence occurred in the 2000s. Since the early 2010s, the research showed the benefits of adhering to the recommendations. Now the application of those recommendations and the evidence to support benefits in survivorship, both in quality of life and survivorship.

Basically, the reason that AICR was formed was to try and distinguish evidence from opinion because the consumer is fatigued and confused by the changing messages.