Forget an al-desko salad – eating a whole wheat sandwich every day for lunch reduces your risk of colorectal cancer by 17 percent, a new study claims.
In fact, the Harvard researchers say, the more you eat the lower the risk.
The study, a collaboration with the World Cancer Research Fund, is the first to link whole grains with lower cancer risk.
But they warn you should skip the bacon and opt for a veggie or fish filling instead, since their research also showed processed meats undo all the benefits.
Harvard researchers have found that a daily dose of whole wheat bread, paired with fish like tuna (pictured) or a vegetarian filling can lower your risk of colorectal cancer by 17 percent
In the US, colorectal cancer is the third most common cancer among both men and women, with an estimated 371 cases diagnosed each day.
The American Institute for Cancer Research estimates that 47 percent of US colorectal cancer cases could be prevented each year through healthy lifestyle changes.
‘Colorectal cancer is one of the most common cancers, yet this report demonstrates there is a lot people can do to dramatically lower their risk,’ said Dr Edward Giovannucci, lead author of the report and professor of nutrition and epidemiology at the Harvard TH Chan School of Public Health.
‘The findings from this comprehensive report are robust and clear: diet and lifestyle have a major role in colorectal cancer.’
The new report evaluated the scientific research worldwide on how diet, weight and physical activity affect colorectal cancer risk.
The report analyzed 99 studies, including data on 29 million people, of whom over a quarter of a million were diagnosed with colorectal cancer.
The report concluded that eating approximately three servings (90 grams) of whole grains daily reduces the risk of colorectal cancer by 17 percent.
It adds to previous evidence showing that foods containing fiber decreases the risk of this cancer.
There was strong evidence that physical activity protects against colon cancer – but not rectal cancer.
For physical activity, people who are more physically active have a lower risk of colon cancer compared to those who do very little physical activity.
The report found other links between diet and colorectal cancer that were visible but not as clear.
Links to lowering risk of colorectal cancer was with fish and foods containing vitamin C, such as oranges, strawberries and spinach.
There was limited evidence that risk increases with low intake of both non-starchy vegetables and fruit.
A higher risk was observed for intakes of less than 100 grams per day (one cup) of each.
‘Many of the ways to help prevent colorectal cancer are important for overall health,’ Giovannucci said.
‘Factors such as maintaining a lean body weight, proper exercise, limiting red and processed meat and eating more whole grains and fiber would lower risk substantially.
‘Moreover, limiting alcohol to at most two drinks per day and avoidance or cessation of smoking also lower risk.’
According to Alice Bender, director of Nutrition Programs, the research all points to the power of a plant-based diet.
‘Replacing some of your refined grains with whole grains and eating mostly plant foods, such as fruits, vegetables and beans, will give you a diet packed with cancer-protective compounds and help you manage your weight, which is so important to lower risk,’ she said.
‘When it comes to cancer there are no guarantees, but it’s clear now there are choices you can make and steps you can take to lower your risk of colorectal and other cancers.’