Another busy year for clinical research has come and gone. What are the most important findings from 2019? Here is our overview of some of the most noteworthy studies of the year.
"Medicine is of all the Arts the most noble," wrote the Ancient Greek physician Hippocrates — whom historians call the "father of medicine" — over 2,000 years ago.
Advances in therapeutic practices have been helping people cure and manage illness since before the time of Hippocrates, and, today, researchers continue to look for ways of eradicating diseases and improving our well-being and quality of life.
Each year, specialists in all areas of medical research conduct new studies and clinical trials that bring us a better understanding of what keeps us happy and in good health, and what factors have the opposite effect.
And, while each year, experts manage to overcome many obstacles, challenges old and new keep the medical research field buzzing with initiatives.
Reflecting on how research has evolved over the past decade, the editors of the reputable journal PLOS Medicine — in a recent editorial — emphasize "ongoing struggles" with infectious diseases, as well as growing tensions between two approaches in medical research. These approaches are the effort of finding treatments that are consistently effective in large populations versus the notion of "precision medicine," which favors therapy that we closely tailor to an individual's very personal needs.
But how has clinical research fared in 2019? In this special feature, we look at some of the most prominent areas of study from this year and give you an overview of the most noteworthy findings.
Friends or foes?
The medication we take — as long as we follow our doctors' advice — is meant to help us fight off disease and improve our physical or mental well-being. But can these usually trusty allies sometimes turn into foes?
Most drugs can sometimes cause side effects, but more and more studies are now suggesting a link between common medication and a higher risk of developing different conditions.
In March this year, for instance, experts affiliated with the European Resuscitation Council — whose goal is to find the best ways to prevent and respond to cardiac arrest — found that a conventional drug doctors use to treat hypertension and angina may actually increase a person's risk of cardiac arrest.
By analyzing the data of more than 60,000 people, the researchers saw that a drug called nifedipine, which doctors often prescribe for cardiovascular problems, appeared to increase the risk of "sudden cardiac arrest."
Project leader Dr. Hanno Tan notes that, so far, healthcare practitioners have considered nifedipine to be perfectly safe. The current findings, however, suggest that doctors may want to consider offering people an alternative.
Another study, appearing in JAMA Internal Medicine in June, found that anticholinergic drugs — which work by regulating muscle contraction and relaxation — may increase a person's risk of developing dementia.
People may have to take anticholinergics if some of their muscles are not working correctly, usually as part of health issues, such as bladder or gastrointestinal conditions, and Parkinson's disease.
The research — that specialists from the University of Nottingham in the United Kingdom led — looked at the data of 58,769 people with and 225,574 people without dementia.
It revealed that older individuals — at least 55 years old — who were frequent users of anticholinergics were almost 50% more likely to develop dementia than peers who had never used anticholinergics.
But, while common drugs that doctors have prescribed for years may come with hidden dangers, they are, at least, subject to trials and drug review initiatives. The same is not true for many other so-called health products that are readily available to consumers.
Such findings says the study's lead researcher, Prof. Carol Coupland, "highlight the importance of carrying out regular medication reviews."
In 2019, we have celebrated 50 years since someone first successfully sent a message using a system that would eventually become the internet. We have come a long way, and now, we have almost everything within reach of a "click and collect" order.
This, unfortunately, includes "therapeutics" that specialists may never have assessed, and which can end up putting people's health — and lives — in danger.
In August, the Food and Drug Administration (FDA) issued a warning against an allegedly therapeutic product that was available online, and which appeared to be very popular.
The product — variously sold under the names Master Mineral Solution, Miracle Mineral Supplement, Chlorine Dioxide Protocol, or Water Purification Solution — was supposed to be a kind of panacea, treating almost anything and everything, from cancer and HIV to the flu.
Yet the FDA had never given the product an official assessment, and when the federal agency looked into it, they saw that the "therapeutic" — a liquid solution — contained no less than 28% sodium chlorite, an industrial bleach.
"[I]ngesting these products is the same as drinking bleach," which can easily be life threatening, warned the FDA's Acting Commissioner Dr. Ned Sharpless, who urged people to avoid them at all costs.
The heart and its tributaries
Many studies this year have also been concerned with cardiovascular health, revisiting long held notions and holding them up to further scrutiny.
For instance, a study in the New England Journal of Medicine in July — which involved around 1.3 million people — suggested that, when it comes to predicting the state of a person's heart health, both blood pressure numbers are equally important.
When a doctor measures blood pressure, they assess two different values. One is systolic blood pressure, which refers to the pressure the contracting heart puts on the arteries when it pumps blood to the rest of the body. The other is diastolic blood pressure, which refers to the pressure between heartbeats.
So far, doctors have primarily taken only elevated systolic blood pressure into account as a risk factor for cardiovascular disease.
However, the new study concluded that elevated systolic and diastolic blood pressure are both indicators of cardiovascular problems.
Its authors emphasize that the large amount of data they had access to painted a "convincing" picture in this respect.
"This research brings a large amount of data to bear on a basic question, and it gives such a clear answer."
Lead researcher Dr. Alexander Flint
At the same time, a slightly earlier study, appearing in the European Heart Journal in March, emphasizes that having high blood pressure may not mean the same thing for everyone, and while doctors may associate it with adverse outcomes in some, this does not hold for all populations.
The study's first author, Dr. Antonio Douros, argues that "[w]e should move away from the blanket approach of applying the recommendations of professional associations to all groups of patients."
Dr. Douros and team analyzed the data of 1,628 participants with a mean age of 81 years. The researchers found that older individuals with lower systolic blood pressures actually faced a 40% higher risk of death than peers with elevated blood pressure values.
"[A]ntihypertensive [blood pressure lowering] treatment should be adjusted based on the needs of the individual," the study's first author advises.
When it comes to protecting heart health, 2019 studies have shown that diet likely plays an important role. Thus, research in the Journal of the American Heart Association in August showed that people who adhered to plant-based diets had a 32% lower risk of death that researchers associate with cardiovascular disease than those who did not.
People who ate plant-based foods also had a 25% lower risk of all-cause mortality, according to this study.
And another study — from April in the journal Nutrients — warned that people who follow a ketogenic diet, which is high in fats and low in carbohydrates, and who decide to take a "day off" from this commitment every now and again, may experience blood vessel damage.
Ketogenic — or keto — diets work by triggering ketosis, a process in which the body starts burning fat instead of sugar (glucose) for energy. But "cheat days" mean that, for a brief interval, the body switches back to relying on glucose.
"[W]e found [...] biomarkers in the blood, suggesting that vessel walls were being damaged by the sudden spike in glucose," notes first author Cody Durrer.
Our diets, ourselves
In 2019, the topic of how our food choices influence our health has remained popular among researchers and readers alike.
And this year's studies have certainly reflected the widespread interest in the link between dietary choices and well-being.
One intriguing study — in Nature Metabolism in May — pointed out that protein shakes, which are popular among individuals who want to build muscle mass, may be a threat to health.
Fitness protein powders, the study authors explain, contain mostly whey proteins, which have high levels of the essential amino acids leucine, valine, and isoleucine.
The research — in mice — suggested that a high intake of these amino acids led to overly low levels of serotonin in the brain. This is a key hormone that plays a central role in mood regulation, but which science also implicates in various metabolic processes.
In mice, the heightened levels of leucine, valine, and isoleucine, which caused excessively low serotonin, led to obesity and a shorter life span.
So, if too much of certain types of protein can have such detrimental effects on health, what about fiber? Dietary fiber — present in fruit, vegetables, and legumes — is important in helping the body take up sugars little by little.
But how much fiber should we consume? This is the question that a study commissioned by the World Health Organization (WHO) — and appearing in The Lancet in January — sought to lay to rest.
The research took into account the findings of 185 observational studies and 58 clinical trials, covering almost 40 years.
It concluded that to lower their death risk, as well as the incidence of coronary heart disease, stroke, type 2 diabetes, and colon cancer, a person should ideally consume 25–29 grams of fiber per day.
"Fiber-rich whole foods that require chewing and retain much of their structure in the gut increase satiety and help weight control and can favorably influence lipid and glucose levels," explains one of the authors, Prof. Jim Mann.
On the other hand, several studies from this year draw attention to just how detrimental foods that are not 100% natural can be. A small trial, whose results came out in Cell Metabolism in May, showed that processed food leads to abrupt weight gain — but not for the reasons we may think.
The study authors said they were surprised that when they asked participants to eat either an ultraprocessed food diet or a nonprocessed food diet — whose caloric contents the researchers matched perfectly — the people who ate processed foods rapidly gained more weight than the ones who ate the nonprocessed foods.
The researchers blame this on the speed with which individuals end up eating processed foods, in particular. "There may be something about the textural or sensory properties of the food that made [participants] eat more quickly," says study author Kevin Hall, Ph.D.
"If you're eating very quickly, perhaps you're not giving your gastrointestinal tract enough time to signal to your brain that you're full. When this happens, you might easily overeat," he hypothesizes.
And more research in mice — from Scientific Reports in January — found that emulsifiers, which are a common additive present in many products from mayonnaise to butter, could affect gut bacteria, leading to systemic inflammation.
What is more, the impact on the gut could even influence processes that occur in the brain, increasing anxiety levels. "[W]e [now] know that inflammation triggers local immune cells to produce signaling molecules that can affect tissues in other places, including the brain," explains co-lead researcher Prof. Geert de Vries.
While some of the studies that made the headlines in 2019 were conclusive, many encourage further research to confirm their findings or further investigate the underlying mechanisms.
Stepping into the next decade, this much is clear: The wheels of medical research will keep on turning for better health across the globe.