- Fiber
is an essential part of a balanced diet and is beneficial for gut health,
prevents constipation, and helps people manage their weight.
- However,
less than 10% of Americans have enough fiber in their diet.
- A
new study suggests that incorporating plenty of fiber-rich foods, such as
vegetables, whole grains, fruits, and nuts, in your diet may have even
more health benefits.
- The
research found that two byproducts of fiber digestion by gut bacteria may
alter gene expression, reducing the risk of cancer.
Dietary
fiber is the part of plant foods that we cannot digest, but our gut
microbiome can. Fiber is an essential part of a healthy diet, helping
to prevent constipation, keep the gut healthy, and maintain a healthy weight.
However, few Americans
eat enough fiber, with research suggesting that as few as 1 in 20 people meet
the adequate intake of 14g of fiber per 1,000 kcal each
day.
A new study has reinforced advice that you should
incorporate plenty of fiber-rich foods in your diet. Researchers found that
when gut bacteria break down plant fiber, they produce two compounds that act
on genes to help prevent the growth of cancers.
The study is published
in
Dr.
Eamon Laird, Assistant Lecturer in Human Nutrition at Atlantic
Technological University Sligo and Adjunct Assistant Professor Trinity College
Dublin, Ireland, who was not involved in the study, commented:
“This is a well-run and
comprehensive cell study with good methodologies but limited in scope — there
are further questions to ask with many cell line variations and also real-life
scenarios — the typical diet and lifestyle will have major effects, and it is
unknown if these compounds still display these potential effects in the field,
so to speak.”
Gut bacteria
convert fiber into anti-cancer compounds
The gut microbiome is
made up of many millions of bacteria and other microorganisms that help us
digest what we eat. Although people cannot digest plant fiber, our gut bacteria
break it down into molecules that we can then use.
One type of molecule
these microbes produce from fiber is short-chain
fatty acids (SCFAs). SCFAs are essential for modulating immune
responses and may help prevent the formation of tumors in the gut.
In this study, the
researchers investigated the effects of two SCFAs, propionate and butyrateTrusted Source,
that are produced by gut bacteria, on healthy and colon cancer cells. Previous
studies have suggested that propionate may moderate appetite and can reduce
cholesterol, and that butyrate may help regulate inflammation and immune
responses and protect against colorectal cancer.
“The
research focuses on short-chain fatty acids (SCFAs) like propionate and
butyrate, which are produced when gut bacteria break down dietary fiber. These
SCFAs can influence the activity of both cancer-promoting (proto-oncogenes) and
cancer-suppressing (tumor-suppressor) genes by modifying histones, the proteins
that help package DNA. By making the DNA more accessible, SCFAs can turn
certain genes on or off, depending on the cell type and conditions.”
— Şebnem
Ünlüişler, Genetic Engineer and Chief Longevity Officer at the London Regenerative
Institute, who was not involved in the study.
Fatty acids
change how genes work
The researchers found
that both propionate and butyrate altered gene expression in several isolated
human cell types: healthy cells and treated colon cancer cells. Similar effects
were seen in cells in the intestines of living mice.
Importantly, these epigenetic changes
occurred in genes that regulate the differentiation and multiplication of
cells, as well as genes controlling programmed cell death, or apoptosis. All
these processes are important for controlling or disrupting the rapid cell
growth and proliferation that is characteristic of cancers.
Ünlüişler told Medical
News Today that one of the most interesting findings was how butyrate
works in cancer cells:
“It blocks enzymes
called histone deacetylases (HDACs), leading to changes in DNA packaging that
can slow down cancer cell growth or even trigger their [the cancer cells’]
death.”
Laird emphasized that,
as a cell study, this “is on the bottom part of the evidence pyramid.”
“I would like to see
this in real life — for instance large-scale observational studies measuring
indicators of these markers and then risk of cancer and disease followed by the
gold standard of randomized controlled trials before we start implementation of
the findings. […] Is there a benefit or other effects in cells being treated
for cancer?” he told Medical News Today.
“What about those
with Crohn’s disease or other conditions that cannot
tolerate high fiber — what is the effect of these compounds then? There is
still a lot more to investigate,” he said.
More reasons
to increase fiber intake
On average, in the U.S.,
adults eat around 17g of fiberTrusted Source per
day, which is less than 50% of the required amount for men and not quite 70% of
that for women. In the UK, the average fiber intake is around 60% of the daily
30g recommended by the British Dietetic Association.
“Regardless
of the findings from this study, we should be aiming for the [UK]
recommendations of 30 grams of fiber per day every day. Unfortunately, few
people actually meet these recommendations. The findings of the study add to
the already known evidence base that fiber is crucial for health both in terms
of human health and the gut microbiome which directly affects our colonic [gut]
health.”— Eamon Laird
To increase fiber
intake, it is important to include a wide variety of plants in your diet,
eating the skins of those with edible skins. Good sources of plant fiber include:
- fruits, such as avocados, apples, pears and
raspberries
- nuts and seeds
- vegetables, particularly legumes, potatoes, sweet
potatoes, broccoli, and squashes
- whole grain foods, such as freekeh, bulgur wheat,
and brown rice.
Ünlüişler welcomed the findings, telling MNT: “Eating enough fiber increases SCFA production in the gut, which may help prevent colorectal cancer by supporting healthy gene regulation. It’s a clear reminder of how closely diet and health are linked. [It] opens exciting doors for using diet and gut health to influence gene activity and prevent disease.”
No comments:
Post a Comment