Why Some High-Fiber Diets Cause Gas — And What to Do About It

If you want to reduce bloating when eating a high-fiber diet, try making it carbohydrate-rich rather than protein-rich, new study findings suggest.

Bloating is a common side effect that discourages many people from adopting a high-fiber diet.

For the study, researchers analyzed data from a clinical trial involving 164 participants who followed heart-healthy, high-fiber diets. The participants were about 40% more likely to report bloating while following diets rich in plant proteins than on carbohydrate-rich regimens.

The findings were recently published online in the journal Clinical and Translational Gastroenterology.

High-fiber diets are believed to cause bloating by increasing certain populations of healthy, fiber-digesting gut bacteria. They produce gas as a byproduct. These findings suggest that carbs and proteins change the gut bacteria population (microbiome).

“It’s possible that in this study, the protein-rich version of the diet caused more bloating because it caused more of a healthy shift in the composition of the microbiome,” said study co-senior author Noel Mueller. He’s an assistant professor of epidemiology at Johns Hopkins Bloomberg School of Public Health, in Baltimore.

“Notably, the protein in these diets was mostly from vegetable sources, such as beans, legumes and nuts,” he added.

The findings suggest that substituting high-quality carbs — such as whole grains — for proteins might reduce bloating and make high-fiber diets more tolerable.

However, substituting proteins for carbohydrates might make such diets less healthy, the researchers noted in a Hopkins news release.

“Bloating may be just a consequence of a healthy shift in the microbiome, so that if somebody is able to put up with the bloating caused by a high-protein, high-fiber diet, they may ultimately benefit more in other health measures,” Mueller said.

Source: HealthDay

Diets with More Fiber, Yogurt Tied to Lower Risk of Lung Cancer

Lisa Rapaport wrote . . . . . . . . .

Even among smokers, people who eat more fiber and yogurt may be less likely to develop lung cancer than those who don’t consume much of these foods, a research review suggests.

Researchers examined pooled data from 10 previous studies that included a total of almost 1.45 million adults in Asia, Europe, and the United States. After following people for an average of 8.6 years, 18,822 cases of lung cancer were documented.

Compared to people who never ate yogurt, those who consumed the most yogurt were 19% less likely to develop lung cancer, the analysis found.

People who had the most fiber in their diets, meanwhile, were 17% less likely to develop lung cancer than those who ate the least fiber.

And individuals with the highest fiber intake and highest yogurt consumption were 33% less likely than those with the lowest consumption of both to develop lung cancer, the study team reports in JAMA Oncology.

“Our study suggests a potential novel health benefit of increasing dietary fiber and yogurt intakes in lung cancer prevention,” senior study author Dr. Xiao-Ou Shu of Vanderbilt University Medical Center in Nashville, Tennessee, and colleagues write.

While the study wasn’t a controlled experiment designed to prove yogurt or fiber protects against lung cancer, it’s possible these kinds of foods might lead to changes in the gut microbiota – the bacteria living in our digestive tract – that help protect against cancer, the study authors hypothesize.

It’s also possible fiber and yogurt might help protect against inflammation, which in turn helps reduce the potential for tumors to develop, the researchers note.

Fiber-rich foods typically have lots of prebiotics, nondigestable compounds that can be fermented in the gut and serve as food for beneficial bacteria, the authors note. Yogurt has lots of those beneficial bacteria, or probiotics.

Considerable research links the gut microbiota to the immune system overall. And some recent studies have suggested that the gut microbiota may play a role in lung inflammation, the study authors point out.

The reduced risk of lung cancer associated with fiber and yogurt in the study persisted even after researchers accounted for smoking habits.

For people who never smoked, the lung cancer risk reduction associated with the highest levels of yogurt and fiber consumption was 31%, while for smokers it was 24% and for former smokers, 34%.

The researchers point out that they didn’t know what type of fiber people consumed or which types of foods they ate to get their fiber, or the type or fat content of any yogurt people ate.

They also lacked data on some other risk factors for lung cancer, including low income or limited education levels as well as any history of chronic obstructive pulmonary disorder.

Even so, the authors conclude it’s worth considering the potential protective effect of yogurt and fiber.

“For the first time to our knowledge, a potential synergistic association between fiber and yogurt intakes on lung cancer risk was observed,” the study authors write. “Although further investigation is needed to replicate these findings and disentangle the underlying mechanisms, our study suggests a potential novel health benefit of increasing dietary fiber and yogurt intakes in lung cancer prevention.”

Source: Reuters

Study: Yogurt, Fiber Can Lower Lung Cancer Risk

Madeline Farber wrote . . . . . . . . .

Eating yogurt and fiber could lower your risk of lung cancer, a new study suggests.

The report, published Thursday in JAMA Oncology, was based on an analysis of 10 studies from the U.S., Europe and Asia involving a total of about 1.4 million people. At a median follow up of eight years, researchers documented 18,822 cases of lung cancer.

After adjusting for known risk factors — such as smoking — researchers found those who ate more yogurt and fiber had a reduced risk for developing lung cancer compared to those who didn’t consume either.

More specifically, men who ate roughly three ounces of yogurt a day and women who ate about four ounces of yogurt a day had a 19 percent lower lung cancer risk compared to those who didn’t eat the probiotic-rich food. Comparatively, those who consumed the most amount of fiber were 17 percent less likely to develop the disease.

When combined, those who had the highest intakes of both had a 33 percent reduced lung cancer risk.

Fiber and yogurt also reduced the lung cancer risk for smokers, who were considered in the study to be the most susceptible.

“High consumption of fiber (prebiotics) and yogurt (probiotics) was related to a low risk of lung cancer. This association pattern was consistently seen among current, past smokers, and never smokers,” Xiao-Ou Shu, of Vanderbilt University Medical Center and the study’s senior author, told MedPage Today. “In addition to the known cardiovascular benefit of fiber and yogurt intake, physicians now have additional justification to encourage their care population to increase their consumption of these two types of [a] healthy diet.”

Speaking to The New York Times, Shu said it’s not totally clear why yogurt and fiber may reduce the risk of lung cancer.

However, “inflammation plays a major role in lung cancer, and we know that the gut microbiome plays a major role in reducing inflammation. People who eat a lot of fiber and yogurt have a healthier microbiome,” Shu said.

Source: Fox News

High Fiber Diet Associated with Reduced Cardiovascular Risk in Hypertension, Type 2 Diabetes Patients

Patients with hypertension and Type 2 diabetes who consume a high fiber diet had improvement in their blood pressure, cholesterol and fasting glucose, according to a study presented at the American College of Cardiology (ACC) Middle East Conference 2019 together with the 10th Emirates Cardiac Society Congress. The conference is Oct. 3-5 in Dubai, United Arab Emirates.

Hypertension and diabetes are major risk factors for future cardiovascular disease. Diet also plays a role in the severity of cardiovascular disease. Researchers from Care Well Heart and Super Specialty Hospital in Amritsar, India, investigated the relation between a high fiber diet and its impact on cardiovascular disease risk factors.

According to guidelines from the National Institute of Nutrition and the Indian Council of Medical Research, the recommended dietary allowance (RDA) for dietary fiber is 40gm/2000kcal. Patients in this study had Type 2 diabetes and a calorie intake of 1,200-1,500kcal, causing their RDA for fiber to be 24-30gm. The fiber intake of these patients was increased up to 20 to 25 percent from the recommended allowances for them to be consuming a high fiber diet.

The study tracked 200 participants’ fiber intake for six months and included check-ups at the start of the study, three months and six months. Participants were provided diet prescriptions, which included detailed lists of different food groups with portion sizes in regional languages. Qualified dietitians provided the information through regular counseling sessions and used audio-visual aids to ensure understanding among study participants.

The researchers tracked participants’ fiber intake several ways, including having patients send photos of their meals on WhatsApp–which not only helped in knowing their fiber intake but also helped approximate portion sizes–and telephone calls three times a week during which detailed dietary recall was taken.

“Comprehensive evaluation of etiological effects of dietary factors on cardiometabolic outcomes, their quantitative effects and corresponding optimal intakes are well-established,” said Rohit Kapoor, MD, medical director of Care Well Heart and Super Specialty Hospital and lead author of the study. “This study helps us determine three important things for this patient population. Firstly, a high fiber diet is important in cases of diabetes and hypertension to prevent future cardiovascular disease. Secondly, medical nutrition therapy and regular counseling sessions also hold great importance in treating and prevention of diabetes and hypertension. Thirdly, this type of diet in combination with medical treatment can improve dyslipidemia, pulse wave velocity, waist-to-hip ratio and hypertension.”

Participants on a high fiber diet experienced significant improvement in several cardiovascular risk factors, including a 9 percent reduction in serum cholesterol, 23 percent reduction in triglycerides, 15 percent reduction of systolic blood pressure and a 28 percent reduction of fasting glucose. The researchers found a high fiber diet is inversely related with cardiovascular risk factors and plays a protective role against cardiovascular disease.

Source: EurekAlert!

More Proof High-Fiber Diets Help Prevent Cancers, Heart Disease

Alan Mozes wrote . . . . . . . . .

A large, new analysis helps confirm that eating lots of grains, vegetables and fruit lowers your risk of dying early from cancer or heart disease.

When compared with those who consume very little fiber, people at the high end of the fiber-eating spectrum saw their risk for dying from heart disease, stroke, type 2 diabetes and/or colon cancer plummet by 16 to 24 percent, investigators reported.

The team also concluded that more is definitely more: For every additional 8 grams of dietary fiber a person consumes, the risk for each of those illnesses was found to fall by another 5 to 27 percent.

“The health benefits of fiber are supported by over 100 years of research into its chemistry, physical properties, physiology and effects on metabolism,” said study author Andrew Reynolds, a postdoctoral research fellow at the University of Otago in New Zealand.

“What really surprised us was the range of conditions that higher intakes of dietary fiber seemed to improve,” Reynolds added. “Heart disease, type 2 diabetes and [colon] cancers are some of the most detrimental diseases of our time.”

The conclusions follow a deep-dive into the results of 185 observational studies conducted over the last four decades, alongside the findings of another 58 clinical trials involving more than 4,600 participants.

Reynolds and his colleagues reported their work, which was commissioned by the World Health Organization, in the Jan. 10 online edition of The Lancet.

The research team noted that worldwide most people eat less than 20 grams of fiber each day, a figure that dips to just 15 grams per day among Americans. For examples of foods: 1 slice of whole wheat bread has 2 grams of fiber; 1 cup of boiled broccoli has 5 grams; 1 medium orange has 3 grams, and 1 cup of cooked black beans has 15 grams.

But investigators found that taking in 25 to 29 grams of dietary fiber per day is just an “adequate” starting point, with greater protection against premature death accruing more heartily to those who routinely consume even greater amounts of fiber.

For example, every additional 15-gram bump in daily whole grain intake was found to curtail an individual’s overall risk of early death — as well as their risk of early death from heart disease — by between 2 and 19 percent.

What’s more, the researchers found little evidence that eating more dietary fiber was in any way risky.

And even for those whose diets have for years largely sidestepped fiber, Reynolds suggested it’s never too late to start embracing fiber’s benefits.

“We saw this from the trials where participants were asked to increase their fiber intakes,” he said. “When considering all the trials of increasing fiber intakes, those participants that did reduced both their body weight and the total cholesterol in their blood, two important predictors of disease.”

That thought was seconded by Dr. Gerald Bernstein, program coordinator for the Friedman Diabetes Institute at Lenox Hill Hospital in New York City.

“I do not think there is a time to start that is not beneficial,” he said. “Of course, combined with some exercise and calorie control the benefits become exponential.”

As to the New Zealand study results, Bernstein observed that “none of this is surprising.” But he suggested that the findings “should lead to a change in dietary recommendations.”

That thought was seconded by Lona Sandon, program director and associate professor in the department of clinical nutrition for the school of health professions at the University of Texas Southwestern Medical Center at Dallas.

“This is just one more that supports and further solidifies the recommendations registered dietitian nutritionists have been making for years,” said Sandon.

“It’s never too late to start on a healthy diet,” she said. “Sure, you may have missed out on some health prevention years and therefore your risk will not be as low as someone who has been eating whole grains all their life. But you have nothing to lose by giving a healthy diet a try.”

Source: HealthDay

Read also:

Fiber: It’s Not Just for Adults . . . . .

High intake of dietary fiber and whole grains associated with reduced risk of non-communicable diseases . . . . .

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