If you believe that cancer is a disease that strikes from nowhere with very little in your control that can prevent it, then you would be wrong on both counts. A person’s risk of cancer can be significantly lessened by simple and fairly obvious nutrition and lifestyle changes. In this podcast, I’ll explore where you should put most of your focus and spoiler alert, none of it has to do with avoiding 5G signals, GMO foods, artificial sweeteners, underarm deodorants or acid causing foods.

Cancer is a major burden of disease worldwide. And in a typical western country likely Australia, it accounts for about one-third of deaths each year. The ‘big 5’ of breast, prostate, colorectal, melanoma and lung are the most common in Australia. Yet there is good news here as the incidence rate of cancer (that’s the number of people that are diagnosed with cancer each year) has been plateauing and even showing signs of declining when you account for an ageing population that’s because age is the biggest risk factor for all cancer – the longer you live, the more likely cancer mutations have a chance to grow and propagate. And the even better news is that thanks to earlier detection and better treatments, the survivability of cancer continues to grow.

Cancer is rarely a disease that strikes out of the blue for no reason – there is a whole range of known risk factors, many of which are considered modifiable. And for this, we have what I like to call ‘the big 6’. In order of importance, it goes: smoking, excess body weight, poor diet, physical inactivity, sun exposure and alcohol.

And when we’re talking about diet and cancer risk, it should be no surprise that fruits, vegetables and wholegrains come out on top as being the best ‘cancer preventing’ foods. While some foods may be promoted as being more beneficial, there is no one single ‘superfood’ that can prevent cancer; it is a combination of good eating habits and food variety that gives the greatest benefit.

In 2018, the World Cancer Research Fund and the American Institute for Cancer Research released updated recommendations on how a person can reduce their risk of cancer. And I’ll link to this advice in the show notes https://www.wcrf.org/dietandcancer/cancer-prevention-recommendations 

The advice is hardly controversial and would not only apply for cancer but also cross over into other chronic diseases like heart disease and type 2 diabetes. 

So, here are the recommendations in a nutshell:

• Choose a diet rich in a variety of plant-based foods including fruits, vegetables, legumes and wholegrains
• Cut back on highly processed fast foods
• Limit consumption of sugar-sweetened drinks
• Take part in regular physical activity
• Be as lean as possible within the normal range of body weight
• Limit how much red and processed meats you eat
• Drink alcohol only in moderation, if at all
• Aim to meet nutritional needs through diet alone rather than through supplements
• And for women, to breastfeed if possible. That’s because lactation has favourable hormonal effects on a woman that can reduce cancer risk while for the infant, being breastfed is linked to a lower risk of later-life obesity

These guidelines are not just theoretical as there is a lot of research that informs each of them. And now we have new research that has explored how closely following these guidelines across large population groups can translate into reducing the risk of cancer. Published only in the last week in the British Journal of Cancer, a research team looked at how well following the recommendations in a group of 50,000 people from Sweden equated to a lower risk of cancer. And I’ll link to this study in the show notes. https://pubmed.ncbi.nlm.nih.gov/32210367

There were two large cohorts of Swedish men and women followed; each of which had details of recorded diet and cancer data available. To see how well each person met the recommendations for cancer prevention a scoring system (which could range from 0 right up to 8) was used to evaluate adherence to the recommendations: the higher the score, the more recommendations met.

So, what was the study conclusion? After a median of over 15 years of follow up, a higher recommendation adherence score was associated with a 12 to 15 percent lower risk of all cancer types compared to a low score. For every point a person scored, it was associated with between a 3 and 4 percent reduction in the risk of cancer. But not that many people were meeting all the recommendations with just 10 percent eating sufficient plant foods and limiting red/processed meat and fast food. And fewer than 50 percent of people met the weight and physical activity recommendations.

The link between excess weight and cancer could be from how our bodies can change hormone levels and produce chemical messengers, which in turn can increase cancer risk. High body fatness is associated with increased levels of insulin, which can promote cell growth and inhibit normal programmed cell death (called apoptosis).

Obesity is normally seen together with chronic low-level inflammation, which over time can cause DNA damage that leads to cancer. But rather than just a focus on obesity, it more important to look at where body fat is stored and it is excess body fat around the abdomen that is linked to chronic local inflammation.

While BMI can be a useful, but quite imprecise measure of overall health risks, it fails to take into account the distribution of fat throughout the body. I often say that when it comes to linking weight to health, it is much more important where the fat is than how fat you are and is. For this reason, waist circumference was developed as a simpler and potentially more accurate measure of disease risk. Waist circumference is not only a gauge of body fat, but it specifically targets the most dangerous type of fat: visceral fat. Visceral fat is metabolically active and can directly change the metabolism of certain hormones and inflammatory markers.

Summary

So there you have the recommendations. What should a person do about it? For some people, a complete lifestyle overhaul can be a difficult thing to manage in one go. Instead, focus on one change at a time like building more activity into your day and then following this up with eating five different types of fruits and vegetables with the emphasis on colour as your best guide to variety. Prevention guidelines shouldn’t be seen as a prescription for restricting your life, but a series of small changes to how you eat and live now that will build the framework for a long, healthy and cancer-free life.

So that’s it for today’s show. You can find the show notes either in the app you’re listening to this podcast on if it supports it, or else head over to my webpage www.thinkingnutrition.com.au and click on the podcast section to find this episode to read the show notes.

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I’m Tim Crowe and you’ve been listening to Thinking Nutrition.