Landmark cancer prevention report puts forth a blueprint to reduce the risk of cancers

The American Institute for Cancer Research (AICR) and the World Cancer Research Fund (WCRF) recently issued an evidence-based blueprint for healthy living that could prevent nearly half of all cancer cases.

This is the 3^rd report in the series of expert reports Diet, Nutrition, Physical Activity, and Cancer: A Global Perspective, and updates the two previous comprehensive reports, which were published in 1997 and 2007.

The report has distilled evidence of 30 years of research into 10 recommendations that could help prevent cancer by lifestyle modification. The report is based on a review of data from 51 million people, including 3.5 million cancer cases in 17 cancers.

The evidence shows that a modification in your diet, staying physically active, having a healthy body weight and other health-related choices can prevent 12 cancer diagnoses. These include breast, colorectal, pancreatic, endometrial, ovarian, prostate, liver, gallbladder, kidney, bladder, stomach and esophageal cancers.

In 2012, an estimated 14.1 million new cases of cancer occurred worldwide, with nearly 1 in 6 deaths due to cancer.

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“The evidence is clear that making changes to diet and exercise and maintaining a healthy weight cuts cancer risks, regardless of age. The message may not be glamorous, but these changes can save your life,” said Kelly Browning, Chief Executive Officer of AICR.

The ten recommendations are:

1) Maintaining a healthy weight is the most important thing you can do to reduce your risk of cancer. Aim to be in the lower end healthy Body Mass Index (BMI) range.

2) Be physically active-incorporate physical activity as a part of your daily life. Walk more and sit less, for maximum health benefits, aim for 150 minutes of moderate, or 75 minutes of vigorous, physical activity a week.

3) Eat a diet rich in vegetables, fruits, whole grains, and beans. AICR recommends a plant-based diet that forms at least two-thirds of your plate.

4) Limit the intake of fast food. There is strong evidence that consuming "fast-foods" and a "Western-type" diet are causes of weight gain, overweight and obesity, which are linked to 12 cancers. Glycemic load also increases the risk for endometrial cancer.

5) Limit red meat and avoiding processed meat - red meat includes beef, pork and lamb and processed meat includes ham, bacon, salami, hot dogs, sausages.

6) Limit consumption of sugar-sweetened beverages- Whenever you feel thirsty drink water or unsweetened beverages.

7) Limit alcohol consumption- alcohol in any form is a potent carcinogen. It's linked to 6 different cancers. The best advice for those concerned about cancer is not to drink.

8) Do not take the supplement for cancer prevention-Aim to obtain nutrition from diet instead of popping the supplements. The panel doesn’t discourage the use of multivitamins or specific supplements for those sub-sections of the population who stand to benefit from them, such as women of childbearing age and the elderly. But, dietary supplements will not avoid cancer.

9) Mothers, please breastfeed your baby- There is a strong evidence that breastfeeding your baby protects against breast cancer later in life.

10) If you are already diagnosed with cancer, you should follow the nutritional advice from an appropriately trained professional. For breast cancer survivors, there is persuasive evidence that nutritional factors and physical activity reliably predict important outcomes from breast cancer.

The report emphasizes the need for knowledge about the link between lifestyle and cancer. In a 2017 AICR Cancer Risk Awareness Survey more than 50% of the population who responded was not aware of the link between obesity and cancer.

The report provides robust evidence for healthcare professionals and government officials to advise the patients about healthy eating and making policies that make healthy eating more affordable.  

AICR today launched Cancer Health Check – an easy-to-use tool, which shows how your lifestyle stacks up against known cancer risks and outlines the changes you can make to follow AICR’s evidence-based Cancer Prevention Recommendations.

ACIR News Release

Cancer Health Check – an easy-to-use tool

Diet, Nutrition, Physical Activity, and Cancer: A Global Perspective, the Second Expert Report

Ob/Gyn Updated Facebook page

Here is a video about AICR 10 recommendations for cancer prevention.

Moderate intensity physical activity for an hour mitigates the risk of death associated with sedentary lifestyle: A Meta-analysis.

Clinical Pearls:

• Intense to moderate physical activity for 60-75 minutes’ can eliminate the effects of prolonged sitting (> 8 hours).
• This equals to brisk walking at 5.6 km/h or cycling for pleasure at 16 km/h.

The association of sedentary lifestyle and many chronic conditions and colorectal cancer is well known and physical inactivity is an important modifiable risk factors in the causation of many chronic condition.  Prolonged sitting is one of the important cause of premature mortality.

But, according to a Meta-analysis involving about a million people, intense to moderate physical activity for 60-75 minutes’ can undermine the effects of prolonged sitting. This study was published online in the Lancet on July 27, 2016.[1] Examples of physical activity were brisk walking at 5.6 km/h or cycling for pleasure at 16 km/h.

This is a second in the series of articles published on physical inactivity by Lancet, the first was published in 2012, sending a message that physical inactivity is a global pandemic killer-responsible for 5.3 million premature deaths worldwide. The number equals the deaths caused by smoking and twice the deaths caused by obesity.

This is the first harmonized meta-analysis that compares the relationship between all-cause mortality and sedentary life style and different levels of physical inactivity.

A systematic review of literature identified about 16 studies out of which 13 were identified by the researchers as providing data on sitting time and all-cause mortality.

The combined study data generated data on pool of 1,005,791 individuals from different countries, who were followed up for 2-18 years.

The study participants were divided into quartiles according to the time spent being physically active and ranged from less than 5 minutes/day to 60-75 minutes/day. The daily sitting and TV viewing time was also divided into 4 standardized protocol.

It was seen that those who very active (60-75 minutes/day), the amount of sitting time does not increase the mortality. But, the risk of death increases as the activity time decreases. WHO guidelines also recommends at least 150 minutes of physical activity per week, which is far less than what the study recommends.[2]

"A clear dose-response association was observed, with an almost curvilinear augmented risk for all-cause mortality with increased sitting time in combination with lower levels of activity," the researchers noted.

For the purpose of estimating the hazard ratio(HR), the most active individuals were used as the reference group. (HR=1).

People who exercised the least (less than 5 min/day) were at highest risk, even if they did not spend much time sitting (less than 4 h/day). In this group the hazard of premature death was 1.27. This was way higher than those group of individuals who were most active physically (60-75 min/day) but also spent more than 8 hours sitting (HR=1.04). This was very close to the referent group, which led the researchers to conclude that physical inactivity is the root cause of premature deaths, independent of the hours of sitting.

The findings of this study emphasized the importance of physical activity, even if you have a job that demands prolonged sitting.

The study also draws attention towards relationship with TV watching and premature death. Watching TV for more than 3 hours per day is associated with premature death regardless of physical activity except in the most active quartile. In this group the mortality was only increased if you watch more than 5 hours of TV. The benefit of physical activity is not very strong in people watching TV because of “residual confounding”. Dr. Ekelund points that perhaps these people have unhealthy life- style that include snacking or drinking that increases the risks.

Ekelund pointed out in a London press conference [3]  that the average amount of time adults in the United Kingdom spend watching TV is three hours and six minutes. “I don’t know if it’s too much to ask that maybe a little of those three hours be devoted to physical activity,” he said. The general rule of thumb, as Ekelund succinctly advised: “Sit less and move more, and the more the better.”

He also emphasized the message about "moving more," suggesting that people should walk as much as they can and that if they do need to sit for prolonged periods, they should break up those periods with short bursts of activity, such as walking for 5 minutes every hour.

The full Lancet podcast about the series can be heard here.

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[1] http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(16)30370-1/fulltext

[2]  http://www.who.int/dietphysicalactivity/factsheet_recommendations/en/

[3] http://press.thelancet.com/PhysicalactivityMEDIA.mp3