Eating Walnuts Daily Lowered Bad Cholesterol and May Reduce Cardiovascular Disease Risk

Eating about ½ cup of walnuts every day for two years modestly lowered levels of low-density lipoprotein (LDL) cholesterol, known as “bad cholesterol,” and reduced the number of total LDL particles and small LDL particles in healthy, older adults, according to new research published today in the American Heart Association’s flagship journal Circulation.

Walnuts are a rich source of omega-3 fatty acids (alpha-linolenic acid), which have been shown to have a beneficial effect on cardiovascular health.

“Prior studies have shown that nuts in general, and walnuts in particular, are associated with lower rates of heart disease and stroke. One of the reasons is that they lower LDL-cholesterol levels, and now we have another reason: they improve the quality of LDL particles,” said study co-author Emilio Ros, M.D., Ph.D., director of the Lipid Clinic at the Endocrinology and Nutrition Service of the Hospital Clínic of Barcelona in Spain. “LDL particles come in various sizes. Research has shown that small, dense LDL particles are more often associated with atherosclerosis, the plaque or fatty deposits that build up in the arteries. Our study goes beyond LDL cholesterol levels to get a complete picture of all of the lipoproteins and the impact of eating walnuts daily on their potential to improve cardiovascular risk.”

In a sub-study of the Walnuts and Healthy Aging study, a large, two-year randomized controlled trial examining whether walnuts contribute to healthy aging, researchers evaluated if regular walnut consumption, regardless of a person’s diet or where they live, has beneficial effects on lipoproteins.

This study was conducted from May 2012 to May 2016 and involved 708 participants between the ages of 63 and 79 (68% women) who were healthy, independent-living adults residing in Barcelona, Spain, and Loma Linda, California.

Participants were randomly divided into two groups: active intervention and control. Those allocated to the intervention group added about a half cup of walnuts to their usual daily diet, while participants in the control group abstained from eating any walnuts. After two years, participants’ cholesterol levels were tested, and the concentration and size of lipoproteins were analyzed by nuclear magnetic resonance spectroscopy. This advanced test enables physicians to more accurately identify lipoprotein features known to relate to the risk of cardiovascular disease.

The two-year study had a 90% retention rate (632 participants completed the study). Complete lipoprotein analyses were available in 628.

Among key findings of all study participants:

  • At 2 years, participants in the walnut group had lower LDL cholesterol levels – by an average of 4.3 mg/dL, and total cholesterol was lowered by an average of 8.5 mg/dL.
  • Daily consumption of walnuts reduced the number of total LDL particles by 4.3% and small LDL particles by 6.1%. These changes in LDL particle concentration and composition are associated with a lower risk of cardiovascular disease.
  • Intermediate Density Lipoprotein (IDL) cholesterol also decreased. It is known that IDL cholesterol is a precursor to LDL and refers to a density between that of low-density and very-low-density lipoproteins. In the last decade, IDL cholesterol has emerged as a relevant lipid cardiovascular risk factor independent of LDL cholesterol.
  • LDL cholesterol changes among the walnut group differed by sex; in men, LDL cholesterol fell by 7.9% and in women by 2.6%.

“While this is not a tremendous decrease in LDL cholesterol, it’s important to note that at the start of the study all our participants were quite healthy, free of major non-communicable diseases. However, as expected in an elderly population, close to 50% of participants were being treated for both high blood pressure and hypercholesterolemia. Thanks in part to statin treatment in 32%, the average cholesterol levels of all the people in our study were normal,” Ros said. “For individuals with high blood cholesterol levels, the LDL cholesterol reduction after a nut-enriched diet may be much greater.”

“Eating a handful of walnuts every day is a simple way to promote cardiovascular health. Many people are worried about unwanted weight gain when they include nuts in their diet,” Ros said. “Our study found that the healthy fats in walnuts did not cause participants to gain weight.”

The major limitation of this investigation is that both participants and researchers knew who was and was not eating walnuts. However, the study did involve two very different populations with distinct diets. “The outcomes were similar in both groups, so we can safely apply the results of this study to other populations,” Ros said. More research is also needed to clarify the different LDL results in men and women.

According to the American Heart Association, walnuts are especially high in omega-3 fatty acids, the same heart-healthy fat found in oily fish. A serving size is a small handful or 1.5 ounces of whole nuts or 2 tablespoons of nut butter.

Source: American Heart Association

Starchy Snacks May Increase CVD Risk; Fruits and Veggies at Certain Meals Decreases Risk

Can starchy snacks harm heart health? New research published today in the Journal of the American Heart Association, an open access journal of the American Heart Association, found eating starchy snacks high in white potato or other starches after any meal was associated at least a 50% increased risk of mortality and a 44-57% increased risk of CVD-related death. Conversely, eating fruits, vegetables or dairy at specific meals is associated with a reduced risk of death from cardiovascular disease, cancer or any cause.

“People are increasingly concerned about what they eat as well as when they eat,” said Ying Li, Ph.D., lead study author and professor in the department of nutrition and food hygiene at Harbin Medical University School of Public Health in Harbin, China. “Our team sought to better understand the effects different foods have when consumed at certain meals.”

Li and colleagues analyzed the results of 21,503 participants in the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2014 in the U.S. to assess dietary patterns across all meals. Among the study population, 51% of participants were women and all participants were ages 30 or older at the start of the study. To determine patient outcomes, researchers used the U.S. Centers for Disease Control and Prevention’s National Death Index to note participants who died through December 31, 2015, due to CVD, cancer or any cause.

Researchers categorized participants’ dietary patterns by analyzing what types of food they ate at different meals. For the main meals, three main dietary patterns were identified for the morning meal: Western breakfast, starchy breakfast and fruit breakfast. Western lunch, vegetable lunch and fruit lunch were identified as the main dietary patterns for the mid-day meal. Western dinner, vegetable dinner and fruit dinner were identified as the main dietary patterns for the evening meal.

For snacks, grain snack, starchy snack, fruit snack and dairy snack were identified as the main snack patterns in between meals. Additionally, participants who did not fit into specific meal patterns were analyzed as a reference group. The researchers noted that the Western dietary pattern has higher proportions of fat and protein, which is similar to many North American meals.

Participants in the Western lunch group consumed the most servings of refined grain, solid fats, cheese, added sugars and cured meat. Participants in the fruit-based lunch group consumed the most servings of whole grain, fruits, yogurt and nuts. Participants in the vegetable-based dinner group consumed the most servings of dark vegetables, red and orange vegetables, tomatoes, other vegetables and legumes. Participants who consumed starchy snacks consumed the most servings of white potatoes.

According to their findings:

  • Eating a Western lunch (typically containing refined grains, cheese, cured meat) was associated with a 44% increased risk of CVD death;
  • Eating a fruit-based lunch was associated with a 34% reduced risk of CVD death;
  • Eating a vegetable-based dinner was associated with a 23% and 31% reduction in CVD and all-cause mortality, respectively; and
  • Consuming a snack high in starch after any meal was associated with a 50-52% increased risk of all-cause mortality and a 44-57% increased risk in CVD-related mortality.

“Our results revealed that the amount and the intake time of various types of foods are equally critical for maintaining optimal health,” said Li. “Future nutrition guidelines and interventional strategies could integrate optimal consumption times for foods across the day.”

Limitations to this study include that dietary data was self-reported by participants, which may lead to recall bias. And, although the researchers controlled for potential confounders, other unmeasured confounding factors cannot be ruled out.

Source: American Heart Association

High Glycemic Index Diet May Up Risk for Cardiovascular Disease, Death

Diets with a high glycemic index are associated with an increased risk for cardiovascular disease and death, according to a study conducted on five continents published online Feb. 24 in the New England Journal of Medicine.

David J.A. Jenkins, M.D., Ph.D., from the University of Toronto, and colleagues examined data from 137,851 participants between the ages of 35 and 70 years living on five continents to examine the association between glycemic index and cardiovascular disease. Dietary intake was determined using country-specific food-frequency questionnaires, and glycemic index and load were estimated based on consumption of seven categories of carbohydrates.

During a median follow-up of 9.5 years, there were 8,780 deaths and 8,252 major cardiovascular events. The researchers found that a diet with a high glycemic index was associated with an increased risk for a major cardiovascular event or death after performing adjustments comparing the lowest with the highest glycemic-index quintiles, both among those with and without preexisting cardiovascular disease (hazard ratios, 1.51 and 1.21, respectively). A high glycemic index was also associated with an elevated risk for death from cardiovascular causes. The results with respect to glycemic load were similar for participants with cardiovascular disease at baseline, but not for those without preexisting cardiovascular disease.

“I have been studying the impact of high glycemic diets for many decades, and this study ratifies that the consumption of high amounts of poor quality carbohydrates is an issue worldwide,” Jenkins said in a statement. “Diets high in poor quality carbohydrates are associated with reduced longevity, while diets rich in high quality carbohydrates such as fruit, vegetables, and legumes have beneficial effects.”

Source: HealthDay

Study: How Air Pollution May Increase the Risk of Cardiovascular Disease

Julie Cunningham wrote . . . . . . . . .

Tiny particles of air pollution — called fine particulate matter — can have a range of effects on health, and exposure to high levels is a known risk factor for cardiovascular disease. New research led by investigators at Massachusetts General Hospital (MGH) reveals that fine particulate matter has a detrimental impact on cardiovascular health by activating the production of inflammatory cells in the bone marrow, ultimately leading to inflammation of the arteries. The findings are published in the European Heart Journal.

The retrospective study included 503 patients without cardiovascular disease or cancer who had undergone imaging tests at MGH for various medical reasons. The scientists estimated participants’ annual average fine particulate matter levels using data obtained from the U.S. Environment Protection Agency’s air quality monitors located closest to each participant’s residential address.

Over a median follow-up of 4.1 years, 40 individuals experienced major cardiovascular events, such as heart attacks and strokes, with the highest risk seen in participants with higher levels of fine particulate matter at their home address. Their risk was elevated even after accounting for cardiovascular risk factors, socioeconomic factors, and other key confounders. Imaging tests assessing the state of internal organs and tissues showed that these participants also had higher bone marrow activity, indicating a heightened production of inflammatory cells (a process called leukopoiesis), and elevated inflammation of the arteries. Additional analyses revealed that leukopoiesis in response to air pollution exposure is a trigger that causes arterial inflammation.

“The pathway linking air pollution exposure to cardiovascular events through higher bone marrow activity and arterial inflammation accounted for 29% of the relationship between air pollution and cardiovascular disease events,” says co–first author Shady Abohashem, MD, a cardiovascular imaging fellow at MGH. “These findings implicate air pollution exposure as an underrecognized risk factor for cardiovascular disease and suggest therapeutic targets beyond pollution mitigation to lessen the cardiovascular impact of air pollution exposure.”

Co–first author Michael Osborne, MD, a cardiologist at MGH, explains that therapies targeting increased inflammation following exposure to fine particulate matter may benefit patients who cannot avoid air pollution. “Importantly, most of the population studied had air pollution exposures well below the unhealthy thresholds established by the World Health Organization, suggesting that no level of air pollution can truly be considered safe,” he says.

Source: Massachusetts General Hospital

Gut Microbiome Data May be Helpful in Routine Screening of Cardiovascular Disease

Using artificial intelligence to analyze the bacteria in a person’s gut microbiome shows promise as a new screening method for cardiovascular disease (CVD), according to preliminary research to be presented Sept. 10-13, 2020, at the virtual American Heart Association’s Hypertension 2020 Scientific Sessions. The meeting is a premier global exchange for clinical and basic researchers focusing on recent advances in hypertension research. The full study published simultaneously today in Hypertension, an American Heart Association journal.

Recent studies have found a link between gut microbiota, the microorganisms in human digestive tracts, and CVD, which is the leading cause of mortality worldwide. Gut microbiota is highly variable between individuals, and differences in gut microbial compositions between people with and without CVD have been reported.

“Based on our previous research linking gut microbiota to CVD in animal models, we designed this study to test whether it is possible to screen for CVD in humans using artificial intelligence screening of stool samples,” said Bina Joe, Ph.D., FAHA, the study director, Distinguished University Professor and Chairwoman of the department of physiology and pharmacology at the University of Toledo in Toledo, Ohio. “Gut microbiota has a profound effect on cardiovascular function, and this could be a potential new strategy for evaluation of cardiovascular health.”

Researchers used data from the American Gut Project (an open platform for microbiome research based in the United States) to analyze microbial composition of stool samples with state-of-the-art machine learning modeling. Nearly 1,000 samples were analyzed, and approximately half of the samples were from people with CVD. The model was able to identify different clusters of gut bacteria that could potentially help identify individuals with existing CVD and without CVD.

Among the bacteria identified:

  • Bacteroides, Subdoligranulum, Clostridium, Megasphaera, Eubacterium, Veillonella, Acidaminococcus and Listeria were more abundant in the CVD group.
  • Faecalibacterium, Ruminococcus, Proteus, Lachnospira, Brevundimonas, Alistipes and Neisseria were more abundant in the non-CVD group.

“Despite the fact that gut microbiomes are highly variable among individuals, we were surprised by the promising level of accuracy obtained from these preliminary results, which indicate fecal microbiota composition could potentially serve as a convenient diagnostic screening method for CVD,” Joe said. “It is conceivable that one day, maybe without even assessing detailed cardiovascular function, clinicians could analyze the gut microbiome of patients’ stool samples with an artificial machine learning method to screen patients for heart and vascular diseases.”

Source: American Heart Association


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