It’s normally associated with flatulence and bloating.
But research increasingly shows dietary fiber is a life saver and one of nutrition’s unsung heroes.
Just 24 grams per day – the equivalent of around five portions of fruit per day- has been linked to a 30 percent lower risk of colon cancer.
Yet nine out of 10 Americans get fewer than the recommended 30g of fiber in their daily diets – a statistic that believe is helping fuel an explosion of colorectal cancer cases in younger adults.
The above graph shows how rates of colon cancer have risen among adults aged 20 to 49. Scientists say more than 40 percent of diagnoses are among those aged 45 to 49 years old. The graph shows rates of colon cancer per 100,000 people in younger adults by stages
Scientists argue that the power of fiber cannot be overstated.
Jerlyn Jones, a registered dietitian based in Atlanta, told DailyMail.com: ‘We don’t get enough fiber, and the more fiber that we have in our diet the lower our chances of having certain types of disease, especially heart disease, which is prevalent in the US, along with type two diabetes and certain cancers on average.’
Fiber is a type of carbohydrate that the body cannot fully digest, unlike fats and proteins. It passes through most of the digestive system relatively intact.
It’s essential for digestive health, prevents constipation, tamps down ‘bad’ LDL cholesterol, and because it’s not easily absorbed by the body and digests slowly, keeps you feeling fuller for longer.
Fiber can also help control blood sugar levels. Because the body does not fully digest it, there is a slower and more gradual release of sugar into the bloodstream, preventing rapid spikes, which can lead to type 2 diabetes, inflammation, and weight gain.
Yes, fiber can cause gas and potentially embarrassing flatulence, ‘that could also be some a reason why a lot of people might may not want to introduce more fiber into their diet,’ Ms Jones said, but stressed that the micronutrient’s benefits outweigh any downsides.
Dietary fiber helps regulate the gut’s delicate balance of good bacteria. It’s broken down in the gut into metabolites, breakdown products that provide energy for cells that line the colon and prevent inflammation – a leading precursor to cancer.
Fiber is also well known to help constipated people in the restroom.
It helps stool move through and exit the gut more quickly by softening stool and absorbing water, making passing it easier.
By speeding up this transit time, potentially harmful substances, including carcinogens, have less time to interact with the gut lining and prevent cancerous changes in the colon.
Eating a fiber-rich diet is also a dietitian-recommended way to manage weight. Fiber slows down the digestion and absorption of nutrients, which means food stays in your stomach longer and you feel full for a longer period.
It also adds more volume to your food without adding calories, which helps to fill up your stomach, which then sends signals to the brain that you’re full.
A growing body of research has pointed to the anti-cancer benefits of fiber. A 2010 study from Oxford University reported that eating an average of 24 grams per day of dietary fiber reduces colorectal cancer risk by 30 percent compared to people who eat around 10 grams.
A 2011 analysis published in the British Medical Journal of more than two dozen studies into fiber’s effects on cancer risk concluded that for every 10 grams of fiber added to one’s diet, the risk of colorectal cancer drops by 10 percent.
Those researchers added: ‘These findings thus have important public health implications. Our results provide further support for public health recommendations to increase the intake of dietary fibre in the prevention of colorectal cancer.’
Dr Suneel Kamath, a GI oncologist at the Cleveland Clinic, told DailyMail.com that maintaining a health, fiber-rich diet is ‘very important’ for staving off colorectal cancer or prevent it from recurring.
The above table shows the most common signs of colorectal cancer in young people, according to a study in JAMA Network Open
Fiber is broken down in the gut into metabolites, byproducts that provide energy for cells that line the colon and prevent inflammation – a leading precursor to cancer.
When the diet is rich in meat and fat but low in fiber, the gut bacteria produce a different range of metabolites, including hydrogen sulfide, ammonium compounds, and bile acids.
Dr Patrick, who runs a podcast called FoundMyFitness, said that dietary fiber’s protective effect ‘might be attributed to fiber’s impact on the gut microbiome by producing short-chain fatty acids or SCFAs.
‘These fatty acids inhibit the growth of pathogenic organisms, modulate inflammation, and even increase tumor cell [death].’
Sustained inflammation has been shown to ‘age’ cells and damage the lining of the large intestine, allowing the growth of cancerous cells that accumulate to form tumors.
In a 2018 study published in the journal Nutrients, researchers from Brigham Young University found that, as people age, the protective caps on the ends of chromosomes called telomeres get shorter.
But increasing fiber intake by 10 grams for every 1,000 calories daily lengthens those telomeres, which is like reducing biological age by about five years.
They did this by using data from the National Health and Nutrition Examination Survey (NHANES), which included telomere length measurements from the 1999 to 2002 cycles, which were collected as part of the survey’s health assessments.
They analyzed data from 5,674 adults and assessed telomere length using a specialized DNA analysis technique in the lab. They also analyzed the relationship between the amount of fiber consumed and telomere length, adjusting for potential confounding factors like age, sex, race, physical activity, and other lifestyle factors.
Oncologists worry not only that the majority of Americans take in far too little fiber and, overall, maintain diets that could potentially introduce carcinogens through processed foods and red meat to the gut microbiome.
Dr Kamath said: ‘What we consistently see is that rise in early onset colorectal cancer is definitely largely driven by the US, Canada, Western Europe.
‘As certain countries have gotten more wealth and then people start to eat a diet that’s more westernized, we start to see those same trends start to appear there as well.’
Foods high in fiber include fruits like apples, bananas, and berries; vegetables such as carrots, broccoli, and spinach; whole grains like brown rice and oatmeal; legumes including beans and lentils; and nuts and seeds like almonds and chia seeds.
Ms Jones’ father was diagnosed with colorectal cancer about 20 years ago. With his daughter’s advice, he reformed his diet to include the recommended amount of dietary fiber by eating a mixture of those fiber-rich foods and is now in remission.
She said: ‘Eat high fiber foods because that also feeds your good gut bacteria, which helps minimize risk of any of those illnesses and support your immune system, which also helps with any carcinogenic cells at the same time.
‘As you’re getting a variety of different food items that are high in fiber, you’re going to definitely decrease your risk of certain types of cancer, and also cholesterol levels’ which reduces inflammation and improves gut health.’
Eating these foods can also help support digestive health and keep you feeling fuller for longer.
Obesity, a condition that affects nearly 42 percent of Americans, is also considered a leading risk factor for CRC.
One study published by the NIH estimated that obesity can raise one’s risk of CRC by as much as 32 percent.
According to GI doctors at The Gastro Clinic, an ideal fiber-rich breakfast would include ¾ cup of bran cereal, which provides six grams of fiber, half a grapefruit for three grams of fiber, one egg, one cup of skim milk, a teaspoon of margarine, and a cup of decaf coffee.
THE CANCER-BUSTING, FIBER-LOADED DIET
An ideal lunch would include two slices of whole wheat bread, which provides six grams of fiber, one cup of tossed salad for three grams of fiber, two ounces of roast beef, a medium apple, which contains about three grams of fiber, and a glass of lemonade.
And for dinner, doctors recommend one baked potato with skin for three grams of fiber, three ounces of baked chicken, half a cup of broccoli for three grams of fiber, and a large glass of water.
The average American diet comprises processed foods, red meat, fats, simple carbohydrates, and just 15 grams of fiber a day.
In early 2023, the American Cancer Society (ACS) reported that 20 percent of diagnoses in 2019 were in patients under 55, roughly double the rate in 1995.
With the threat of excess deaths due to CRC in younger adults looming closer by the year, both the US Preventive Services Task Force (USPSTF) and the Multisociety Task Force on Colorectal Cancer, two organizations that offer preventive health guidelines, now advise that most Americans begin colorectal cancer screening at age 45—five years earlier than before—and continue to get screened regularly until age 75.
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Read more at DailyMail.co.uk