Lower protein diet may lessen risk for cardiovascular disease

February 3, 2020

Science Daily/Penn State

A plant-based diet may be key to lowering risk for heart disease. Penn State researchers determined that diets with reduced sulfur amino acids -- which occur in protein-rich foods, such as meats, dairy, nuts and soy -- were associated with a decreased risk for cardiovascular disease. The team also found that the average American consumes almost two and a half times more sulfur amino acids than the estimated average requirement.

Amino acids are the building blocks of proteins. A subcategory, called sulfur amino acids, including methionine and cysteine, play various roles in metabolism and health.

"For decades it has been understood that diets restricting sulfur amino acids were beneficial for longevity in animals," said John Richie, a professor of public health sciences at Penn State College of Medicine. "This study provides the first epidemiologic evidence that excessive dietary intake of sulfur amino acids may be related to chronic disease outcomes in humans."

Richie led a team that examined the diets and blood biomarkers of more than 11,000 participants from a national study and found that participants who ate foods containing fewer sulfur amino acids tended to have a decreased risk for cardiometabolic disease based on their bloodwork.

The team evaluated data from the Third National Examination and Nutritional Health Survey. They compiled a composite cardiometabolic disease risk score based on the levels of certain biomarkers in participants' blood after a 10-16 hour fast including cholesterol, triglycerides, glucose and insulin.

"These biomarkers are indicative of an individual's risk for disease, just as high cholesterol levels are a risk factor for cardiovascular disease," Richie said. "Many of these levels can be impacted by a person's longer-term dietary habits leading up to the test."

Participants were excluded from the study if they reported having either congestive heart failure, heart attack or a reported change in diet due to a heart disease diagnosis. Individuals were also omitted if they reported a dietary intake of sulfur amino acids below the estimated average requirement of 15 mg/kg/day recommended by the Food and Nutrition Board of the National Academy of Medicine.

For a person weighing 132 pounds, food choices for a day that meet the requirement might include a medium slice of bread, a half an avocado, an egg, a half cup of raw cabbage, six cherry tomatoes, two ounces of chicken breast, a cup of brown rice, three quarters of a cup of zucchini, three tablespoons of butter, a cup of spinach, a medium apple, an eight inch diameter pizza and a tablespoon of almonds. Nutritionists collected information about participants' diets by doing in-person 24-hour recalls. Nutrient intakes were then calculated using the U.S. Department of Agriculture Survey Nutrient Database.

After accounting for body weight, the researchers found that average sulfur amino acid intake was almost two and a half times higher than the estimated average requirement. Xiang Gao, associate professor and director of the nutritional epidemiology lab at the Penn State University and co-author of the study, published today (Feb. 3) in Lancet EClinical Medicine, suggested this may be due to trends in the average diet of a person living in the United States.

"Many people in the United States consume a diet rich in meat and dairy products and the estimated average requirement is only expected to meet the needs of half of healthy individuals," Gao said. "Therefore, it is not surprising that many are surpassing the average requirement when considering these foods contain higher amounts of sulfur amino acids."

The researchers found that higher sulfur amino acid intake was associated with a higher composite cardiometabolic risk score after accounting for potential confounders like age, sex and history of diabetes and hypertension. They also found that high sulfur amino acid intake was associated with every type of food except grains, vegetables and fruit.

"Meats and other high-protein foods are generally higher in sulfur amino acid content," said Zhen Dong, lead author on the study and College of Medicine graduate. "People who eat lots of plant-based products like fruits and vegetables will consume lower amounts of sulfur amino acids. These results support some of the beneficial health effects observed in those who eat vegan or other plant-based diets."

Dong said that while this study only evaluated dietary intake and cardiometabolic disease risk factors at one point in time, the association between increased sulfur amino acid intake and risk for cardiometabolic disease was strong. She said the data supports the formation of a prospective, longitudinal study evaluating sulfur amino acid intake and health outcomes over time.

"Here we saw an observed association between certain dietary habits and higher levels of blood biomarkers that put a person at risk for cardiometabolic diseases," Richie said. "A longitudinal study would allow us to analyze whether people who eat a certain way do end up developing the diseases these biomarkers indicate a risk for."

https://www.sciencedaily.com/releases/2020/02/200203141501.htm

Suggested move to plant-based diets risks worsening brain health nutrient deficiency

Suggested move to plant-based diets risks worsening brain health nutrient deficiency

And UK failing to recommend or monitor dietary levels of choline, warns nutritionist

August 29, 2019

Science Daily/BMJ

The momentum behind a move to plant-based and vegan diets for the good of the planet is commendable, but risks worsening an already low intake of an essential nutrient involved in brain health, warns a nutritionist in the online journal BMJ Nutrition, Prevention & Health.

To make matters worse, the UK government has failed to recommend or monitor dietary levels of this nutrient -- choline -- found predominantly in animal foods, says Dr Emma Derbyshire, of Nutritional Insight, a consultancy specialising in nutrition and biomedical science.

Choline is an essential dietary nutrient, but the amount produced by the liver is not enough to meet the requirements of the human body.

Choline is critical to brain health, particularly during fetal development. It also influences liver function, with shortfalls linked to irregularities in blood fat metabolism as well as excess free radical cellular damage, writes Dr Derbyshire.

The primary sources of dietary choline are found in beef, eggs, dairy products, fish, and chicken, with much lower levels found in nuts, beans, and cruciferous vegetables, such as broccoli.

In 1998, recognising the importance of choline, the US Institute of Medicine recommended minimum daily intakes. These range from 425 mg/day for women to 550 mg/day for men, and 450 mg/day and 550 mg/day for pregnant and breastfeeding women, respectively, because of the critical role the nutrient has in fetal development.

In 2016, the European Food Safety Authority published similar daily requirements. Yet national dietary surveys in North America, Australia, and Europe show that habitual choline intake, on average, falls short of these recommendations.

"This is....concerning given that current trends appear to be towards meat reduction and plant-based diets," says Dr Derbyshire.

She commends the first report (EAT-Lancet) to compile a healthy food plan based on promoting environmental sustainability, but suggests that the restricted intakes of whole milk, eggs and animal protein it recommends could affect choline intake.

And she is at a loss to understand why choline does not feature in UK dietary guidance or national population monitoring data.

"Given the important physiological roles of choline and authorisation of certain health claims, it is questionable why choline has been overlooked for so long in the UK," she writes. "Choline is presently excluded from UK food composition databases, major dietary surveys, and dietary guidelines," she adds.

It may be time for the UK government's independent Scientific Advisory Committee on Nutrition to reverse this, she suggests, particularly given the mounting evidence on the importance of choline to human health and growing concerns about the sustainability of the planet's food production.

"More needs to be done to educate healthcare professionals and consumers about the importance of a choline-rich diet, and how to achieve this," she writes.

"If choline is not obtained in the levels needed from dietary sources per se then supplementation strategies will be required, especially in relation to key stages of the life cycle, such as pregnancy, when choline intakes are critical to infant development," she concludes.

https://www.sciencedaily.com/releases/2019/08/190829184143.htm

Reassessing the benefits of plant-based eating

August 29, 2017

Science Daily/European Society of Cardiology

A large dietary study from 18 countries, across seven geographic regions has found that even relatively moderate intake of fruit, vegetables and legumes such as beans and lentils may lower a person's risk of cardiovascular disease (CVD) and death.

Analysis of the Prospective Urban Rural Epidemiology (PURE) study was presented at ESC Congress today1 and published in the Lancet.

"To our knowledge, this is the first study to report on the associations of fruit, vegetable and legume intake with CVD risk in countries at varying economic levels and from different regions," said study investigator Dr Andrew Mente, PhD, from the Population Health Research Institute, McMaster University, Hamilton, Canada.

"Previous research, and many dietary guidelines in North America and Europe recommended daily intake of these foods ranging from 400 to 800 grams per day, but this is unaffordable for many people in low to middle-income countries," he explained.

"Our findings indicate that optimal health benefits can be achieved with a more modest level of consumption, an approach that is likely to be much more affordable."

Using country-specific food frequency questionnaires, PURE documented diet in 135,335 individuals, aged 35 to 70 years, from countries in North America and Europe, South America, the Middle East, South Asia, China, South East Asia and Africa.

For this analysis, investigators assessed associations between fruit, vegetable, and legume consumption at baseline and risk of CVD and mortality after a median of 7.4 years of follow-up.

Looking at the total of 5,796 deaths, 1,649 CV deaths, and 4,784 major CVD events, and adjusting for demographic, lifestyle, health, and dietary factors, the study showed greater fruit, vegetable, and legume intake was associated with lower total mortality, and non-CV mortality.

Of particular importance, an intake of 3 to 4 servings per day (equivalent to 375-500 grams per day) was just as beneficial on total mortality as higher amounts (hazard ratio [HR] of 0·78; 95% CI 0·69 to 0·88).

Looking at the dietary components separately showed that the benefits were attributable to fruit and legumes, with vegetable intake not significantly associated with improved outcomes.

Specifically, compared to fewer than three servings of fruit per week, more than 3 per day was associated with an 18% reduced risk in non-CV mortality (HR: 0·82: 95% CI 0·70 to 0·97; P-trend=0·0008), and 19% reduction in total mortality (HR: 0·81; 95% CI 0·72 to 0·93; P-trend<0·0001).

Regarding legumes, higher consumption was associated with significant reduction in both non-CV mortality and total mortality risk.

As compared with less than one serving of legumes per month, more than one serving per day was associated with an 18% reduction in non-CV mortality (95% CI 0·70 to 0·97; P-trend=0·0019) and a 26% reduction in total mortality (95% CI 0·64 to 0·86; P-trend=0·0013).

Finally, comparing vegetable preparation, the study showed a trend towards lower risk of cardiovascular disease and death with raw versus cooked vegetable intake "but raw vegetables are rarely eaten in South Asia, Africa and Southeast Asia," said Dr. Mente.

"Since, dietary guidelines do not differentiate between the benefits of raw versus cooked vegetables -- our results indicate that recommendations should emphasize raw vegetable intake over cooked."

In conclusion he said that findings from the study "are robust, globally applicable and provide evidence to inform nutrition policies. Many people in the world don't consume an optimal amount of fruit, vegetables and legumes. The PURE data add to the substantial evidence from many studies and extend them globally."

https://www.sciencedaily.com/releases/2017/08/170829091009.htm