1. Be as lean as possible without becoming underweight.
Maintaining a healthy weight is one of the most important things you can do to reduce your risk of cancer. Aim to be at the lower end of the healthy Body Mass Index (BMI) range.
Maintaining a healthy weight brings an array of health benefits. As well as making us feel better, it also means that we are less likely to develop not only cancer, but also other chronic diseases such as type 2 diabetes and heart disease.
We also know that where we store extra weight affects cancer risk. Scientists have discovered that carrying excess fat around our waists can be particularly harmful – it acts like a ‘hormone pump’ releasing estrogen into the bloodstream as well as raising levels of other hormones in the body. This is strongly linked to colon cancer and probably to cancers of the pancreas and endometrium (lining of the uterus), as well as breast cancer (in postmenopausal women).
See Recommendations 2 and 3 for strategies for weight management.
2. Be physically active for at least 30 minutes every day.
Physical activity in any form helps to lower cancer risk. Aim to build more activity, like brisk walking, into your daily routine.
As well as helping us avoid weight gain, activity itself can help to prevent cancer. Studies show that regular activity can help to keep hormone levels healthy, which is important because having high levels of some hormones can increase your cancer risk.
Physical activity may also strengthen our immune system, help keep our digestive system healthy and allow us to consume more food and more cancer-protective nutrients – without gaining weight.
If you’re not used to doing much activity, start by working toward 30 minutes of moderate activity each day – remember that anything is better than nothing. You can build up slowly until you reach your target. Shorter bouts of activity are just as beneficial. (It’s the total time that’s important.)
Research shows that to avoid weight gain, doing more activity is beneficial. For maximum health benefits, scientists recommend that we aim for 60 minutes or more of moderate activity every day, or 30 minutes or more of vigorous activity.
Moderate and Vigorous Activity
- Moderate activity is anything that gets your heart beating a bit faster and makes you breathe more deeply – like brisk walking.
- Vigorous activity means raising your heart rate so that you warm up, start to sweat and feel out of breath.
3. Avoid sugary drinks. Limit consumption of energy-dense foods (particularly processed foods high in added sugar, or low in fiber, or high in fat).
Choosing healthy foods and drinks instead of those that are high in refined carbohydrates and often in added sugar and fat (energy-dense foods) can help us avoid overweight and obesity and thereby reduce our cancer risk.
What are energy-dense foods?
Most foods provide us with energy (calories), but some foods contain more energy ounce-for-ounce than others. Energy-dense foods tend to be processed foods with sugar and fat added to improve the taste. The result is more calories per ounce.
For example, 3.5 oz. of chocolate contains 10 times more calories than the same amount of apple:
3.5 oz. of milk chocolate = 520 calories
3.5 oz. of apple = 52 calories
It can be difficult to control how much energy you are consuming if you eat a lot of energy-dense foods because you only need to eat a small amount to take in a lot of calories. It’s okay to eat energy-dense foods occasionally, or in small quantities, but try not to make them the basis of your diet. By choosing a diet based on low-energy-dense foods, you can actually eat more food but consume fewer calories.
Foods that are low in energy density, like the apple, are high in fiber and water. Most vegetables, fruits and beans fall into the low-energy-dense category. It is yet another reason to base your diet on plant-based foods.
Sugary drinks and weight gain
The expert report found that regularly consuming sugary drinks contributes to weight gain. These drinks are easy to drink in large quantities but don’t make us feel full, even though they are quite high in calories. Sugary drinks include: soft drinks like colas and juice flavored drinks. We should try to avoid these drinks.
Water is the best alternative. Unsweetened tea and coffee are also healthy options. Natural fruit juice counts as one of our recommended 5 or more daily portions of vegetables and fruits, but it does contain a lot of sugar. It’s best not to drink more than one glass a day.
4. Eat more of a variety of vegetables, fruits, whole grains and legumes such as beans.
Basing our diets on plant foods (like vegetables, fruits, whole grains and legumes such as beans), which contain fiber and other nutrients, can reduce our risk of cancer.
For good health, AICR recommends that we base all of our meals on plant foods. When preparing a meal, aim to fill at least two-thirds of your plate with vegetables, fruits, whole grains and beans.
Research shows that vegetables and fruits probably protect against a range of cancers, including mouth, pharynx, larynx, esophagus, stomach, lung, pancreas and prostate. There are many reasons why vegetables and fruits may protect against cancer. As well as containing vitamins and minerals, which help keep the body healthy and strengthen our immune system, they are also good sources of substances like phytochemicals. These are biologically active compounds, which can help to protect cells in the body from damage that can lead to cancer.
Foods containing fiber are also linked to a reduced risk of cancer. These foods include whole-grain bread and pasta, oats and vegetables and fruits. Fiber is thought to have many benefits, including helping to speed up ‘gut transit time’ – how long it takes food to move through the digestive system.
Plant foods can also help us to maintain a healthy weight because many of them are lower in energy density (calories).
5. Limit consumption of red meats (such as beef, pork and lamb) and avoid processed meats.
To reduce your cancer risk, eat no more than 18 oz. (cooked weight) per week of red meats, like beef, pork and lamb, and avoid processed meat such as ham, bacon, salami, hot dogs and sausages.
Red meat refers to beef, pork and lamb–foods like hamburgers, steak, pork chops and roast lamb. The term processed meat refers to meats preserved by smoking, curing or salting, or by the addition of preservatives. Examples include ham, bacon, pastrami and salami, as well as hot dogs and sausages.
The evidence from the expert report that red meat is a cause of colorectal cancer is convincing. This evidence is much stronger now than it was in the mid-1990s. Red meat contains substances that are linked to colon cancer. For example, heme iron, the compound that gives red meat its color, has been shown to damage the lining of the colon.
Studies also show that people who eat a lot of red meat tend to eat less plant-based foods, so they benefit less from their cancer-protective properties.
There is also convincing evidence that choosing processed meat increases the chances of colorectal cancer. The expert panel advises limiting red meat and avoiding processed meat. Studies show we can eat up to 18 ounces a week of red meat without raising cancer risk. Research on processed meat shows cancer risk starts to increase with any portion.
When meat is preserved by smoking, curing or salting, or by the addition of preservatives, cancer-causing substances (carcinogens) can be formed. These substances can damage cells in the body, leading to the development of cancer.