Cardiovascular Risks Vary Across Nicotine Products

Although cigarette smoking is the most harmful form of nicotine use, all nicotine-containing products produce adverse cardiovascular effects, according to a recent review.(opens in new tab)

The research, published in Nature Reviews Cardiology, outlines how nicotine damages blood vessels at the biological level. Nicotine causes oxidative stress, inflammation, and depletion of nitric oxide, which relaxes the blood vessels. This pathway leads to endothelial dysfunction, which constricts the arteries and serves as an early marker for atherosclerosis, hypertension, and heart failure. Combustion amplifies the effects, meaning products such as cigarettes pose the greatest risk, but noncombusted products still set off similar signaling cascades.

Heated products pose the second greatest cardiovascular risk, followed by aerosol devices such as e-cigarettes, then oral nicotine products, including chewing tobacco and pouches.

The findings establish a hierarchy of cardiovascular harm for nicotine products, the researchers said, with nicotine abstinence as the only option that’s completely risk-free. They added that given the known cardiovascular toxicity and high addictive potential of nicotine, products containing the substance should be comprehensively regulated across all delivery platforms.

Article Information

Published Online: September 18, 2026. doi:10.1001/jama.2026.14723

Earlier age at menopause may be associated with faster cognitive decline

 

Earlier age at menopause may be associated with faster cognitive decline, a study published in JAMA Network Open suggests.

The research included about 2600 older women who were enrolled in the Religious Orders Study or the Rush Memory and Aging Project, cohorts with up to 18 years of follow-up. The nuns and community-dwelling females had no known dementia at enrollment and underwent yearly clinical evaluations and neuropsychological testing. Earlier age at menopause was linked to faster declines in both global cognition and episodic memory, as well as earlier Alzheimer disease onset. In women who experienced spontaneous menopause, as opposed to surgical, earlier menopause age was also associated with faster white matter hyperintensity volume accumulation. Having experienced spontaneous menopause 5 years earlier was associated with about 15% more white matter hyperintensity volume over 10 years.

The findings indicate that menopause may have long-term connections to structural and functional neurological outcomes, the researchers said. They added that age at menopause may serve as a marker for dementia risk stratification and early intervention.

Article Information

Published Online: September 18, 2026. doi:10.1001/jama.2026.14722

Caffeine and Cardiovascular Disease: A Scientific Statement From the American Heart Association

The recent scientific statement on the topic from the American Heart Association (AHA):

Abstract:

Caffeine is one of the most commonly consumed drugs in the world. It is found in various naturally occurring substances and can be ingested in a synthetically derived pure form. The majority of human subject–based research is observational and has focused on beverages and foods that contain caffeine. 

The relationships between caffeine and cardiovascular risk factors and diseases are complex, exhibiting heterogeneity depending on the nature of the caffeine consumed and individual-level propensities. Acute versus chronic caffeine-associated cardiovascular effects are often different. Most studies suggest an inverse J-shaped relationship between consumption of naturally occurring caffeinated products and blood pressure. 

Data on relationships between caffeine and diabetes are not consistent, but habitual coffee consumption has been associated with a lower risk of incident type 2 diabetes. Whereas no clear relationship between caffeine and blood lipids is evident, unfiltered coffee raises low-density lipoprotein cholesterol. Caffeine, studied primarily in the context of coffee, has been shown either to have no relationship or to be associated with a lower risk of coronary artery disease and heart failure. 

Randomized controlled trial data among regular caffeinated coffee drinkers showed that caffeinated coffee decreases the risk of atrial fibrillation occurrence but increases the frequency of premature ventricular contractions. Data are fairly consistent that moderate caffeine consumption, again studied primarily in the setting of coffee consumption, was associated with a lower risk of stroke. 

Data on high doses of caffeine such as that found in energy drinks are limited and generally suggest cardiovascular harm. 

Commentary

Might caffeine be good for the cardiovascular system? It depends, a recent scientific statement on the topic from the American Heart Association (AHA) concluded.

As far as caffeine is concerned, it depends on the source and the amount. And as far as caffeine consumers are concerned, it depends on their genetic makeup and health.

“It’s not as simple as all good or all bad,” explained cardiologist Gregory Marcus, MD, MAS, first author of the new statement and a JAMA associate editor.

Marcus, who specializes in treating cardiac arrhythmias at the University of California, San Francisco, chairs the AHA’s Committee on Drugs, Alcohol, and Tobacco, which published the caffeine statement in July.

“It’s not a clinical practice guideline,” he emphasized, but a statement on “the latest and best evidence.”

And what Marcus and his coauthors concluded is bound to make a lot of people want to pour a cup of coffee or tea and toast them: moderate caffeine consumption—up to 400 mg per day, or about 3 to 5 8-oz cups of coffee—“is safe for most adults and is associated with lower risk of cardiovascular disease, including coronary heart disease, stroke, heart failure, and AF [atrial fibrillation], as well as hypertension and type 2 diabetes.” (That daily amount of caffeinated coffee is pretty close to the 2 to 3 cups found to be optimal for brain health in a study published earlier this year in JAMA; the sweet spot for caffeinated tea was determined to be 1 to 2 cups per day.)

But there are some caveats. For example, while the long-term effects of a caffeine habit on blood pressure remain unclear, they “are likely minimal, although the risk may increase with high intake, particularly among individuals with severe hypertension or heightened sensitivity…,” the statement authors noted.

Caffeine, Tea, or Coffee?

Although the title of the AHA’s scientific statement refers to caffeine—“probably the most commonly consumed drug in the world,” Marcus noted—and not specific foods or drinks that contain it, much of the research about the compound’s protective effects has involved coffee, the most widely consumed source in the US and a number of other countries and second only to tea as the most consumed source globally. And most of that research has been observational studies, which can show only correlation, not causation.

Data on caffeinated tea seem to be consistent with studies of caffeinated coffee, Marcus said. But whether caffeine deserves the credit for the health benefits or other compounds do remains to be seen, the AHA statement pointed out.

“Research priorities include disentangling caffeine from other components of the beverages such as polyphenols,” the authors wrote. Polyphenols, which are micronutrients from plants, are found in coffee and black and green tea and have robust antioxidant properties.

How coffee is prepared makes a difference in whether or not it’s heart healthy, according to the AHA statement. Of course, “[l]arge amounts of added sugar, flavored syrups, and dairy products can substantially increase caloric intake and counteract potential health benefits associated with coffee itself,” the authors noted.

In addition, drinking unfiltered coffee, such as French press, Greek or Turkish, and Scandinavian boiled coffee, has consistently raised levels of low-density lipoprotein (LDL) cholesterol in placebo-controlled randomized trials, due to the coffee bean component cafestol. But cafestol is not found in coffee made with a paper filter or in instant coffee; consumption of filtered coffee has not been found to raise LDL cholesterol in randomized trials.

The scientific statement did not touch on whether the timing of caffeine consumption made any difference. However, a 2025 study coauthored by Harvard University’s Frank Hu, MD, PhD, MPH, vice chair of the AHA statement’s writing committee, suggested that what time of day people drink coffee is tied to cardiovascular disease mortality as well as all-cause mortality.

The study, which included nearly 41 000 adults from the National Health and Nutrition Examination Survey, found that compared with people who didn’t drink coffee and those who drank it throughout the day, those who downed their joe between 4 am and 11:59 am had lower death rates about a decade later.

The finding may be due to caffeine’s effect on sleep, said senior author Lu Qi, MD, PhD, of the Celia Scott Weatherhead School of Public Health and Tropical Medicine at Tulane University. “If you drink coffee in the morning, the impact [on sleep] is less.”

Qi said coffee’s popularity is growing in his native country of China as well as in other Asian countries, where tea has long been the preferred beverage.

The Case Against Energy Drinks

Potential cardiovascular benefits from consuming natural sources of caffeine, such as coffee and tea, should not be extrapolated to synthetic products or high-dose caffeine, such as so-called energy drinks, the authors of the AHA statement cautioned.

“Indeed, although data on energy drinks are limited, available studies generally suggest cardiovascular harm,” they wrote. Energy drinks not only contain caffeine but often other legal stimulants, such as taurine and L-carnitine, and added sugars.

The AHA scientific statement overall “was very reasonable” when it came to adults, said cardiologist John Higgins, MD, MBA, a professor at UT McGovern Medical School, who was not involved in writing it.

But the statement did not specifically address an issue of great concern to Higgins: the use of energy drinks by children and teens. He published a call to action about young people’s consumption of the highly caffeinated beverages in August in The American Journal of Medicine.

In the article, he noted that children and many adolescents are smaller than adults, so “the same can is not the same dose.” Youths haven’t developed a tolerance for caffeine that comes from long-term exposure and are more vulnerable to sleep disruptions from consuming it, he wrote.

Higgins, who serves as the cardiologist for the Houston Rockets basketball team and Rice University Athletics, is especially alarmed that the Big 12 Conference in July announced a new multiyear agreement with Monster Energy, a global beverage brand.

The conference is branding football and men’s and women’s basketball with the company’s logo. Jerseys, fields, and courts will now carry that logo as well as the Big 12 Conference logo. The conference will also feature the cobranding across digital and social media channels.

“The first-of-its-kind partnership is built on the right brand and cultural alignment, with Monster Energy’s drive, edge and ambition mirroring the Big 12 Conference and its student athletes,” the conference stated in its announcement of the agreement. Interestingly, caffeine is among the stimulants banned by the National Collegiate Athletic Association.

Higgins isn’t as concerned about the effect of promoting energy drinks on hulking college football players as he is about how the branding deal will spur their young fans to try the products. Already, US youth aged 2 to 19 years regularly consume small amounts of caffeine, with soda and sweet bakery products being 2 of the top sources in 2021 to 2023, according to a July data brief from the National Center for Health Statistics.

The Canadian province of Quebec in June became the first jurisdiction in North America to restrict access to caffeinated energy drinks, in this case for children younger than 16 years. The legislation, which goes into effect in December, was sparked by the death of a 15-year-old who died from drinking a can of Red Bull in combination with medication for attention-deficit/hyperactivity disorder.

Beginning next April, the UK will implement a similar law that bans the sale of high-caffeine energy drinks to people younger than 16 years.

Start Drinking Coffee or Tea?

The AHA’s statement and research findings of possible cardiovascular benefits should not spur adults who currently don’t imbibe caffeinated coffee or tea to start drinking it, Marcus emphasized.

“There is definitely not sufficient data to recommend anyone initiate caffeine consumption” or that light tea or coffee drinkers increase their intake, he said.

Besides, Marcus noted, there is “tremendous heterogeneity in how each individual handles caffeine,” and coffee drinkers appear to self-titrate, adjusting their intake to minimize adverse effects, such as jitteriness. He and his coauthors pointed out that individuals metabolize caffeine at different rates due to variations in genetics and prior patterns of exposure to the compound.

The AHA’s scientific statement, Marcus said, represents “one broad message for the majority of people who currently enjoy drinking caffeine: naturally occurring caffeine in moderation likely is not harmful to their cardiovascular system and might be protective against some things.”

Article Information

Published Online: September 18, 2026. doi:10.1001/jama.2026.16716

Women with the lowest vitamin D levels faced the highest risk of preterm birth

 A common and often overlooked nutrient deficiency may play a bigger role in pregnancy outcomes than previously recognized. In a recent analysis published in the Journal of Perinatology, prominent neonatologist and pediatrician Carol L. Wagner, M.D., and Anjali G. Borsum, an M.D. candidate at MUSC’s College of Medicine, found that among more than 15,000 pregnancies studied at MUSC, the women with the lowest vitamin D levels faced the highest risk of preterm birth.

Drawing from a large retrospective dataset collected between 2016 and 2025 and leveraging extensive support from the South Carolina Clinical & Translational Research (SCTR) Institute, including biostatistical and regulatory guidance, clinical research infrastructure, laboratory services and Nexus data resources, Wagner and Borsum identified a strong association between profound vitamin D deficiency and earlier gestational age at delivery. Wagner credited SCTR’s comprehensive support as instrumental to the study’s success.  

Without SCTR, we as a team would never have been able to accomplish what we did. It’s a phenomenal infrastructure and an incredible gift to any researcher.”

While the team has not yet established a definitive causal relationship, the findings add to a growing body of evidence suggesting that optimizing a patient’s vitamin D status before and during pregnancy may improve both maternal and fetal health outcomes. 

Why vitamin D might matter in pregnancy

Vitamin D is a vital nutrient that is known primarily for helping the body to absorb calcium and maintain normal bone, muscle, nerve and immune health. But as Wagner and fellow MUSC basic and translational scientist Bruce W. Hollis, Ph.D., discovered in earlier randomized controlled trials, vitamin D acts as a building block for hormones that play an important role in pregnancy. 

“Vitamin D impacts literally thousands of genes in the body,” said Wagner. Research suggests that vitamin D helps the development of the placenta, the temporary organ that grows in a pregnant woman to nourish the fetus. It also appears to help support healthy immune function and may reduce the risk of serious complications like preeclampsia and gestational diabetes. 

One crucial function vitamin D seems to serve is helping the mother’s immune system to adapt to pregnancy. Because a baby in utero contains genetic material from both parents, the mother’s body must learn to tolerate something that is partially foreign. Vitamin D may help to regulate that process, supporting a healthy pregnancy and fetal development. 

Beyond pregnancy: Vitamin D’s broader health role

According to Wagner and Borsum, vitamin D may shape long-term health more than immediate outcomes. Some of the effects of deficiency may begin early in development, altering how genes function and potentially influencing the baby’s health for years, or even decades, to come.

Even outside of pregnancy, vitamin D deficiency is far more common than many people realize. Modern lifestyles often limit time spent outdoors, reducing the body’s ability to produce vitamin D from sunlight. At the same time, food sources provide only a small portion of the vitamin D most people need. As a result, many individuals do not reach healthy vitamin D levels. 

Some groups are at higher risk for deficiency, including people with darker skin, those who work indoors, individuals who regularly use sunscreen and people with limited mobility or chronic health conditions that keep them inside. 

The team stresses that sunscreen remains essential for protecting against skin cancer. However, people with limited sun exposure may benefit from discussing their vitamin D levels and potential supplementation with their health care provider. 

“We have to balance the importance of sunshine and vitamin D with the risk of skin cancer,” said Borsum. “But this further emphasizes the vast role vitamin D plays.”

Emerging research suggests that vitamin D helps to regulate thousands of genes throughout the body, particularly those involved in immune function. Low levels have been associated with autoimmune diseases such as lupus and multiple sclerosis as well as certain cancers. 

Challenges of turning research into practice and future directions

Despite growing evidence supporting the importance of vitamin D, Wagner said changing clinical practice can be difficult. Unlike prescription medications, vitamin D is inexpensive, widely available and cannot be patented, which means there is less commercial impetus to promote its use. “No one’s going to make billions off of this,” Wagner explained. “So, it then becomes a public health issue.”

As researchers continue to build evidence about the role of vitamin D in pregnancy and overall health, Wagner and Borsum see the next steps as educating health care providers, continuing to investigate vitamin D’s long-term effects and increasing public awareness. 

“We learn about vitamin D’s role in bone health, but no one teaches us about the various roles in pregnancy, especially this relationship with preterm birth we are uncovering,” Borsum explained. “I always tell my friends and family who are thinking about becoming pregnant to make sure they are sufficient!”  

As researchers continue to uncover vitamin D’s far-reaching effects, Wagner and Borsum hope the growing body of evidence will encourage more conversations about a nutrient that may shape health across generations.

Poor sleep in one partner can affect both partners’ diets

 

Poor sleep is known to lead to poor diet quality. But as a new Concordia-led study of co-habitating couples shows that poor sleep can affect not only an individual’s food choices, but their partner’s choices too. Because couples that sleep together very often eat together, one partner’s unhealthy food choices can have a ripple effect on the eating habits of the other partner, the researchers say.

The study, published in the journal Annals of Behavioural Medicine, found that poor sleep was linked to a reduced ability to stick to healthy eating goals. People who slept poorly reported making less effort to eat well and feeling less confident in their ability to maintain healthy eating habits. The partner who slept well reported similar effects.

In other words, sleep is not just an individual health issue, according to corresponding author Jean-Philippe Gouin, a professor in the Department of Psychology.

“People with a sleep-deprived partner were essentially saying they have less confidence in their ability to follow a healthy diet, so they engage in less effort to do so,” Gouin says. “This is likely because the sleep-deprived partner was more likely to expose them to highly palatable and calorie-dense food: things like crackers, chips, chocolate or candies.”

Self-reported habits reveal gender differences

The study followed 204 couples living together in Canada over three months. Both partners completed questionnaires about their sleep and diet at the beginning of the study, after one month, and after three months. Participants also kept a daily diary for the first 14 days, in which they recorded different aspects of their efforts to eat healthily.

The participants were, on average, 42 years old. At least one person in each couple was overweight or obese (meaning they had a body mass index of 25 or over) and trying to improve their diet or physical activity. Nearly 96 per cent of participants said they were actively trying to change their diets.

Overall, participants’ diet quality improved modestly during the study, while sleep quality did not change significantly. Women reported healthier diets and stronger efforts to maintain healthy eating habits than men, but the researchers found no evidence that gender changed the way one partner’s sleep affected the other’s diet.

The researchers caution that the study does not prove that poor sleep causes unhealthy eating. Since the study was observational and relied on participants to self-report, the researchers say future studies could use more objective measures to track sleep and diet. Examples include examining factors such as household food choices, meal planning, partner support and conflict.

Treating sleep as a shared concern

The team says the findings could point to a possible new approach to improving dietary habits. Treatments that improve sleep, such as cognitive behavioural therapy for insomnia, could be studied as a couple-based health intervention.

If improving one partner’s sleep also improves the other partner’s ability to maintain healthy eating habits, then treating sleep as a shared concern could offer benefits for both people, they explain.

“We need to consider the social contexts in which poor eating habits are taking place,” Gouin says. “That can involve asking how a partner is influencing one’s eating behaviour, whether intentionally or not.”

“If we want to make changes that are long-lasting, both partners need to work together to change the home and food environment so that it is easier to maintain healthier habits over time,” he says.

The study was led by Maegan Dymarski, Concordia PhD candidate. Tamara Cohen (University of British Columbia), Noémie Carbonneau (Université du Québec à Trois-Rivières) and Kaberi Dasgupta (McGill University) also contributed.

The study was funded by a Social Sciences and Humanities Research Council of Canada (SSHRC) Insight Grant.

Read the paper: “Dyadic associations between sleep quality, diet-related self-regulation, and diet quality in couples”

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Healthy eating linked to slower biological aging

 A study by DZNE finds that healthy eating is associated with slower biological aging—and that there is more than one way to eat healthily. The researchers examined ten dietary patterns considered healthy, including the Mediterranean, Nordic, and a plant-based diet, as well as the DASH diet, which is designed to help lower blood pressure. All were linked with slower biological aging, with age-related changes in the DNA serving as markers. These results, based on data from DZNE’s Rhineland Study and confirmed with data from an independent study, are published in the journal Nature Communications. 

“Our study suggests that healthy eating goes hand in hand with slower biological aging. The effects are not massive, but they are measurable and relevant for prevention. By slowing the aging process, the risk of age-related diseases such as dementia or cardiovascular disorders can be reduced. Thus, healthy eating contributes to healthy aging,” says Prof. Monique Breteler, Director of Population Health Sciences at DZNE and head of the Rhineland Study. “Importantly, there is probably no single ‘correct’ diet. According to our data, various dietary patterns are associated with slower aging, some more, some less. That is an encouraging finding, because it leaves room to tailor healthy eating to personal and cultural preferences, budget and taste.” 

Molecular Aging Measures 

For their analysis, the researchers evaluated blood samples and dietary habits from about 7,500 women and men: This included 6,470 participants of DZNE’s Rhineland Study in Bonn—where the findings were initially made—and 1,034 participants of the EPIC-Potsdam Study of the German Institute of Human Nutrition Potsdam-Rehbrücke (DIfE), where the key results were independently confirmed.  

From blood, the team determined chemical modifications in the DNA, known as “DNA methylation patterns”, which influence gene activity and thus biological mechanisms. Since these molecular markers change systematically over the course of life, they are considered indicators of biological aging. 

“We applied three different approaches, so-called epigenetic clocks, to read biological aging from DNA methylation,” explains Juliana Tavares, a doctoral researcher at DZNE and lead author of the current publication. “To this end, we leveraged state-of-the-art technology, which allowed us to cover about 850,000 sites in the DNA. This is roughly twice as many as in most previous studies.” 

Healthy Eating: Different for Everyone 

The researchers also matched every participant’s eating habits against the recommendations of each of the ten diets studied. Adherence was quantified and graded using a scoring system based on how closely individuals followed each dietary pattern. “One and the same person could therefore rank high on one diet score and low on another. In other words: People who ate healthily by one standard were often not the same people who ate healthily by another. According to our data, hardly anyone counts as a healthy eater by every standard at once,” says Tavares. 

However, across the board, higher diet quality was associated with slower biological aging. This applied to all of the ten diets examined. “While there are measurably differences between the diets, they are modest in absolute terms. It’s the big picture what matters,” says Tavares. “In summary: When it comes to slowing down the aging process, there isn’t just one healthy diet, but indeed a whole repertoire of possible diets with a positive effect.”  

One result was particularly noteworthy: the association between diet quality and slower biological aging was most pronounced in smokers, even though smokers were by no means eating healthier than non-smokers. The biological explanation is still open. “Smoking is very harmful to health,” says Tavares, “One explanation for our findings might be that there is just more health benefit to gain for smokers by eating healthy because of the enormous detrimental effects of smoking.” 

Shared Biological Pathways 

Although each dietary pattern was associated with its own distinct set of DNA methylation sites, the biological mechanisms involved showed substantial overlap. “More than 70 percent of the affected biological pathways were shared across all diets. These involve cell structure, cell signaling and metabolism—processes central to aging and chronic disease. Therefore, it is understandable that the dietary patterns we examined were all linked with a slowing of biological aging,” says Tavares. “A few pathways were diet-specific, and they matched each diet’s main objectives: heart-related pathways were unique to the DASH diet, and pathways related to cognition and memory were unique to the so-called MIND diet, which aims to support brain health. You don't need a perfect diet — that may be the most practical message here. But moving forward, the diet-specific pathways point to future research on targeted dietary interventions. This could be helpful in designing targeted health recommendations.” 

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4-6 servings of wholegrain each day reduces risk factors for cardiovascular disease

 High wholegrain diet lowers body weight, cholesterol, blood sugar and blood pressure

Eating four to six servings of wholegrain each day reduces several major risk factors for cardiovascular disease, according to a new study published in the European Heart Journal [1] today (Wednesday).

 

The study is a systematic review and meta-analysis, meaning it brings together the results of all existing research in this area. It includes data from 87 clinical trials that tested the effects of eating wholegrain food on risk factors for cardiovascular disease.

 

It shows that eating a diet rich in wholegrain food is likely to prevent heart disease by reducing body weight, blood pressure and the levels of cholesterol and glucose in the blood.

 

The research was led by Dr Helda Tutunchi from Tabriz University of Medical Sciences, Iran. She said: “Although higher wholegrain intake has long been linked to better heart health in population studies, clinical trials have produced mixed findings. This left an important practical question unanswered: how much whole grain should people eat to meaningfully improve cardiovascular health? To address this, we systematically combined and analysed all available randomised controlled trials to identify the amount of whole grain associated with the greatest benefits.”

 

The analysis included more than 6,500 people from trials conducted across Asia, Europe, the United States, Canada, Australia, and Brazil It showed that eating more wholegrain reduced people’s body weight, waist circumference and blood pressure, as well as reducing the levels of total cholesterol and low-density lipoprotein cholesterol (LDL or ‘bad’ cholesterol), triglycerides, glucose and interleukin-6 (a sign of inflammation) in people’s blood.

 

These benefits could be seen in people eating 30 to 40 grams of wholegrain per day (dry weight), but the greatest benefits were found in people eating 60 to 100 grams per day. This corresponds to four to six servings of wholegrain daily, for example, a bowl of oatmeal, a sandwich made with wholegrain bread, and a serving of brown rice.

 

Dr Tutunchi said: “This is the largest and most comprehensive meta-analysis of randomised controlled trials on wholegrain intake and cardiovascular risk factors. Unlike previous reviews, we looked specifically at how much wholegrain people need to eat to get the greatest benefits. We also evaluated the certainty of the evidence and found high-certainty evidence for improvements in several outcomes, including body weight, waist circumference and total cholesterol.

 

“However, most of the trials we included were relatively short, with an average duration of about eight weeks. As a result, we cannot determine whether these benefits are maintained over the long term. In addition, relatively few studies evaluated very high wholegrain intakes, above 140 grams per day, so the effects at those intake levels remain uncertain.

 

“Our findings provide a practical indication of the amount of wholegrain that may be needed to achieve meaningful improvements in cardiovascular risk factors. Increasing wholegrain intake is a relatively simple, accessible and affordable dietary strategy that can complement other lifestyle and medical interventions.

 

“We found that most benefits occur at intakes of approximately 60 to 100 grams per day, toward the upper end of current dietary recommendations. These findings do not necessarily call for major changes to existing guidelines, but they support public health strategies that help people increase their whole-grain intake and move toward the higher end of current targets.

 

“One important finding is that whole grains may benefit cardiovascular health through several modest improvements acting together, rather than through one large effect on a single risk factor. We observed improvements across multiple pathways, including blood lipids, blood pressure, glucose regulation, body fat and some markers of inflammation. Although the change in each individual risk factor was generally modest, improving several risk factors simultaneously could contribute to a greater reduction in long-term cardiovascular risk. However, the included trials did not assess cardiovascular events directly, so longer-term studies are needed to confirm this.”

 

In an accompanying editorial [2] Dr Cecilie Kyrø from the Danish Cancer Institute, Copenhagen, and colleagues said: “More than half a century ago, Sir Denis Burkitt and colleagues proposed that the refining of staple carbohydrates, with the accompanying removal of cereal fibre (i.e. from whole to refined grains), underpinned a broad spectrum of ‘Western’ diseases via effects on stool bulk, transit time, and the colonic milieu. Whole grains refer to cereal grains where the three main parts— bran, germ, and endosperm—are all retained in the same proportions as in the intact kernel, whether consumed as whole kernels, flakes, or milled into flour and used in bread and other foods.

 

“A meta-analysis of trials investigating the effect of whole grains on cardiometabolic risk markers by Naghshi et al. is published in this issue of the European Heart Journal and includes 87 trials of 6529 study participants in total. The meta-analysis shows high-certainty evidence for reductions in body weight, waist circumference, total cholesterol. and interleukin-6 (IL-6), and moderate-certainty evidence for improvements in LDL cholesterol, triglycerides, systolic blood pressure, fasting plasma glucose, and insulin resistance (HOMA-IR).

“Importantly, the meta-analysis includes dose–response analyses, addressing differences in whole-grain intake between trials and providing quantitative evidence to inform food-based dietary guidelines. Overall, intakes of 60–100 g/day dry weight (∼4–6 servings) were found to be clearly related to relevant cardiometabolic improvements.

 

“For clinicians, the message from Naghshi et al. is reassuringly simple: encouraging patients to replace refined grain foods with minimally processed whole grains is likely to yield modest but meaningful improvements in body weight, waist circumference, and blood lipids, perhaps particularly in individuals with type 2 diabetes. At the population level, even small shifts in these markers can translate into substantial reductions in cardiometabolic events. Adding evidence from research into other disease endpoints indicates that the beneficial effects of whole- grains foods even go substantially beyond cardiometabolic disease.

 

“The dose–response analyses by Naghshi et al. suggest that intakes of around 60–100 g/day whole grains (∼4–6 servings) are needed to achieve measurable cardiometabolic benefits. Current US dietary guidelines recommend 2–4 servings of whole grains per day within an overall pattern that emphasizes ‘real food’ and reduced intake of ultra-processed products. While this is an important step in the right direction, the trial evidence indicates that higher whole-grain intakes than presently recommended in some guidelines may be optimal for cardiometabolic health.

 

“From a policy perspective, the challenge is to make minimally processed whole-grain staples accessible, affordable, and culturally acceptable, while avoiding a drift towards ultra-processed products that merely add whole grains to otherwise highly processed formulations.”

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Journal

European Heart Journal

DOI

10.1093/eurheartj/ehag519