Christine Cairns Fortuin, Mississippi State University

Evolution has fostered many reproductive strategies across the spectrum of life. From dandelions to giraffes, nature finds a way.

One of those ways creates quite a bit of suffering for humans: pollen, the infamous male gametophyte of the plant kingdom.

In the Southeastern U.S., where I live, you know it’s spring when your car has turned yellow and pollen blankets your patio furniture and anything else left outside. Suddenly there are long lines at every car wash in town.

Even people who aren’t allergic to pollen – clearly an advantage for a pollination ecologist like me – can experience sneezing and watery eyes during the release of tree pollen each spring. Enough particulate matter in the air will irritate just about anyone, even if your immune system does not launch an all-out attack.

So, why is there so much pollen? And why does it seem to be getting worse?

2 ways trees spread their pollen

Trees don’t have an easy time in the reproductive game. As a tree, you have two options to disperse your pollen.

Option 1: Employ an agent, such as a butterfly or bee, that can carry your pollen to another plant of the same species.

The downside of this option is that you must invest in a showy flower display and a sweet scent to advertise yourself, and sugary nectar to pay your agent for its services.

Option 2, the budget option, is much less precise: Get a free ride on the wind.

Wind was the original pollinator, evolving long before animal-mediated pollination. Wind doesn’t require a showy flower nor a nectar reward. What it does require for pollination to succeed is ample amounts of lightweight, small-diameter pollen.

Why wind-blown pollen makes allergies worse

Wind is not an efficient pollinator, however. The probability of one pollen grain landing in the right location – the stigma or ovule of another plant of the same species – is infinitesimally small.

Therefore, wind-pollinated trees must compensate for this inefficiency by producing copious amounts of pollen, and it must be light enough to be carried.

For allergy sufferers, that can mean air filled with microscopic pollen grains that can get into your eyes, throat and lungs, sneak in through window screens and convince your immune system that you’ve inhaled a dangerous intruder.

Plants relying on animal-mediated pollination, by contrast, can produce heavier and stickier pollen to adhere to the body of an insect. So don’t blame the bees for your allergies – it’s really the wind.

Climate change has a role here, too

Plants initiate pollen release based on a few factors, including temperature and light cues. Many of our temperate tree species respond to cues that signal the beginning of spring, including warmer temperatures.

Studies have found that pollen seasons have intensified in the past three decades as the climate has warmed. One study that examined 60 location across North America found pollen seasons expanded by an average of 20 days from 1990 to 2018 and pollen concentrations increased by 21%.

That’s not all. Increasing carbon dioxide levels may also be driving increases in the quantity of tree pollen produced.

Why the Southeast gets socked

What could make this pollen boost even worse?

For the Southeastern U.S. in particular, strong windstorms are becoming more common and more intense − and not just hurricanes.

Anyone who has lived in the Southeast for the past couple of decades has likely noticed this. The region has more tornado warnings, more severe thunderstorms, more power outages. This is especially true in the mid-South, from Mississippi to Alabama.

Since wind is the vector of airborne pollen, windier conditions can also make allergies worse. Pollen remains airborne for longer on windy days, and it travels farther.

To make matters worse, increasing storm activity may be doing more than just transporting pollen. Storms can also break apart pollen grains, creating smaller particles that can penetrate deeper into the lungs.

Many allergy sufferers may notice worsening allergies during storms.

The peak of spring wind and storm season tends to correspond to the timing of the release of tree pollen that blankets our world in yellow. The effects of climate change, including longer pollen seasons and more pollen released, and corresponding shifts in windy days and storm severity are helping to create the perfect pollen storm.

Christine Cairns Fortuin, Assistant Professor of Forestry, Mississippi State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Jean Wactawski-Wende, University at Buffalo

Women make up more than 50% of the population, yet before the 1990s they were largely excluded from health and medical research studies.

To try to help correct this imbalance, in 1991 the National Institutes of Health launched a massive, long-term study called the Women’s Health Initiative, which is still running today. It is the largest, longest and most comprehensive study on women’s health ever conducted in the U.S. It also is one of the most productive studies in history, with more than 2,400 published scientific papers in leading medical journals.

On April 20, 2025, the Department of Health and Human Services told the study’s lead investigators it plans to terminate much of the program’s funding and discontinue its regional center contracts. On April 24, after pushback from the medical community, HHS officials said the funding had been reinstated. But the reversal was never officially confirmed, so the study’s lead investigators – including me – remain concerned about its future.

I am a public health researcher who has studied chronic disease prevention in women for nearly 40 years. I have been centrally involved with the Women’s Health Initiative since its inception and currently co-direct one of its four regional centers at the University at Buffalo.

The project’s findings have shaped clinical practice, prevention strategies and public health policies across the U.S. and the world, particularly for older women. In my view, its loss would be a devastating blow to women’s health.

An imperative to invest in women’s health

The Women’s Health Initiative was established in response to a growing realization that very little medical research existed to inform health care that was specifically relevant to women. In the U.S. in the 1970s, for example, almost 40% of postmenopausal women were taking estrogen, but no large clinical trials had studied the risks and benefits. In 1985 an NIH task force outlined the need for long-term research on women’s health.

Launched by Bernadine Healy, the first woman to serve as director of the NIH, the Women’s Health Initiative aimed to study ways to prevent heart disease, cancer and osteoporosis.

Between 1993 and 1998, the project enrolled 161,808 postmenopausal women ages 50 to 79 to participate in four randomized clinical trials. Two of them investigated how menopausal hormone therapy affects the risk of heart disease, breast cancer, hip fractures and cognition. Another examined the effects of a low-fat, high-fiber diet on breast and colorectal cancers as well as heart disease. The fourth looked at whether taking calcium plus vitamin D supplements helps prevent hip fractures and colorectal cancer.

Women could participate in just one or in multiple trials. More than 90,000 also took part in a long-term observational study that used medical records and surveys to probe the link between risk factors and disease outcomes over time.

Clarifying the effects of hormone therapy

Some of the most important findings from the Women’s Health Initiative addressed the effects of menopausal hormone therapy.

The hormone therapy trial testing a combination of estrogen and progesterone was set to run until 2005. However, it was terminated early, in 2002, when results showed an increased risk in heart disease, stroke, blood clotting disorders and breast cancer, as well as cognitive decline and dementia. The trial of estrogen alone also raised safety concerns, though both types of therapy reduced the risk of bone fractures.

After these findings were reported, menopausal hormone therapy prescriptions dropped sharply in the U.S. and worldwide. One study estimated that the decreased use of estrogen and progesterone therapy between 2002 and 2012 prevented as many as 126,000 breast cancer cases and 76,000 cardiovascular disease cases – and saved the U.S. an estimated US$35 billion in direct medical costs.

Reanalyses of data from these studies over the past decade have provided a more nuanced clinical picture for safely using menopausal hormone therapy. They showed that the timing of treatment matters, and that when taken before age 60 or within 10 years of menopause, hormones have more limited risk.

Defining clinical practice

Although the Women’s Health Initiative’s four original clinical trials ended by 2005, researchers have continued to follow participants, collect new data and launch spinoff studies that shape health recommendations for women over 65.

Almost a decade ago, for example, research at my institution and others found in a study of 6,500 women ages 63 to 99 that just 30 minutes of low to moderate physical activity was enough to significantly boost their health. The study led to changes in national public health guidelines. Subsequent studies are continuing to explore how physical activity affects aging and whether being less sedentary can protect women against heart disease.

Bone health and preventing fractures have also been a major focus of the Women’s Health Initiative, with research helping to establish guidelines for osteoporosis screening and investigating the link between dietary protein intake and bone health.

One of the Women’s Health Initiative’s biggest yields is its vast repository of health data collected annually from tens of thousands of women over more than 30 years. The data consists of survey responses on topics such as diet, physical activity and family history; information on major health outcomes such as heart disease, diabetes, cancer and cause of death, verified using medical records; and a trove of biological samples, including 5 million blood vials and genetic information from 50,000 participants.

Any researcher can access this repository to explore associations between blood biomarkers, disease outcomes, genes, lifestyle factors and other health features. More than 300 such studies are investigating health outcomes related to stroke, cancer, diabetes, eye diseases, mental health, physical frailty and more. Thirty are currently running.

What does the future hold?

In addition to data amassed by the Women’s Health Initiative until now, about 42,000 participants from all 50 states, now ages 78 to 108, are still actively contributing to the study. This cohort is a rare treasure: Very few studies have collected such detailed, long-term information on a broad group of women of this age. Meanwhile, the demographic of older women is growing quickly.

Continuing to shed light on aging, disease risk and prevention in this population is vital. The questions guiding the project’s ongoing and planned research directly address the chronic diseases that Health Secretary Robert F. Kennedy Jr. has announced as national priorities.

So I hope that the Women’s Health Initiative can continue to generate discoveries that support women’s health well into the future.

Jean Wactawski-Wende, Professor of Public Health and Health Professions, University at Buffalo

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Indu Subramanian, University of California, Los Angeles

Health and Human Services Secretary Robert F. Kennedy Jr. has attracted a lot of attention for his raspy voice, which results from a neurological voice disorder called spasmodic dysphonia.

Kennedy, 71, says that in his 40s he developed a neurological disease that “robbed him of his strong speaking voice.” Kennedy first publicly spoke of the quiver he had noticed in his voice in a 2004 interview with journalist Diane Rehm, who also had spasmodic dysphonia.

In 2005, Kennedy was receiving shots of botulinum toxin, the neurotoxin that is now used in Botox as well as to treat migraines and other conditions, every four months. This first-line treatment for dysphonia helps to weaken the vocal folds that contract abnormally with this condition. He used botulinum toxin injections for 10 years and then stopped using them, saying they were “not a good fit” for him.

Kennedy initially developed symptoms while in the public eye teaching at Pace University in New York. Some viewers wrote to him suggesting that he had the condition spasmodic dysphonia and that he should contact a well-known expert on the disease, Dr. Andrew Blitzer. He followed this advice and had the diagnosis confirmed.

I am a movement disorders neurologist and have long been passionate about the psychological and social toll that conditions such as dysphonias have on my patients.

Types of dysphonias

In North America, an estimated 50,000 people have spasmodic dysphonia. The condition involves the involuntary pulling of the muscles that open and close the vocal folds, causing the voice to sound strained and strangled, at times with a breathy quality. About 30% to 60% of people with the condition also experience vocal tremor, which can alter the sound of the voice.

Typically, a neurologist may suspect the disorder by identifying characteristic voice breaks when the patients is speaking. The diagnosis is confirmed with the help of an ear, nose and throat specialist who can insert a small scope into the larynx, examine the vocal folds and rule out any other abnormalities.

Because the disorder is not well known to the public, many patients experience a delay in diagnosis and may be misdiagnosed with gastric reflux or allergies.

The most common type of spasmodic dysphonia is called adductor dysphonia, which accounts for 80% of cases. It is characterized by a strained or strangled voice quality with abrupt breaks on vowels due to the vocal folds being hyperadducted, or abnormally closed.

In contrast, a form of the condition called abductor dysphonia causes a breathy voice with breaks on consonants due to uncontrolled abduction – meaning coming apart of the vocal folds.

Potential treatments

Spasmodic dysphonia is not usually treatable with oral medications and sometimes can get better with botulinum toxin injections into the muscles that control the vocal cords. It is a lifelong disorder currently without a cure. Voice therapy through working with a speech pathologist alongside botulinum toxin administration may also be beneficial.

Surgical treatments can be an option for patients who fail botulinum toxin treatment, though surgeries come with risks and can be variably effective. Surgical techniques are being refined and require wider evaluation and long-term follow-up data before being considered as a standard treatment for spasmodic dysphonia.

Dysphonias fall into a broader category of movement disorders

Spasmodic dysphonia is classified as a focal dystonia, a dystonia that affects one body part – the vocal folds, in the case of spasmodic dysphonia. Dystonia is an umbrella term for movement disorders characterized by sustained or repetitive muscle contractions that cause abnormal postures or movements.

The most common dystonia is cervical dystonia, which affects the neck and can cause pulling of the head to one side.

Another type, called blepharospasm, involves involuntary muscle contractions and spasms of the eyelid muscles that can cause forced eye closure that can even affect vision in some cases. There can be other dystonias such as writer’s cramp, which can make the hand cramp when writing. Musicians can develop dystonias from overusing certain body parts such as violinists who develop dystonia in their hands or trumpet players who develop dystonia in their lips.

Stigmas and psychological distress

Dystonias can cause tremendous psychological distress.

Many dystonias and movement disorders in general, including Parkinson’s disease and other conditions that result in tremors, face tremendous amounts of stigma. In Africa, for instance, there is a misconception that the affected person has been cursed by witchcraft or that the movement disorder is contagious. People with the condition may be hidden from society or isolated from others due to fear of catching the disease.

In the case of spasmodic dysphonia, the affected person may feel that they appear nervous or ill-prepared while speaking publicly. They may be embarrassed or ashamed and isolate themselves from speaking to others.

My patients have been very frustrated by the unpredictable nature of the symptoms and by having to avoid certain sounds that could trigger the dysphonia. They may then have to restructure their word choices and vocabulary so as not to trigger the dysphonia, which can be very mentally taxing.

Some patients with dysphonia feel that their abnormal voice issues affect their relationships and their ability to perform their job or take on leadership or public-facing roles. Kennedy said in an interview that he finds the sound of his own voice to be unbearable to listen to and apologizes to others for having to listen to it.

A 2005 study exploring the biopsychosocial consequences of spasmodic dysphonia through interviews with patients gives some insight into the experience of people living with the disorder.

A patient in that study said that their voice sounded “like some kind of wild chicken screeching out words,” and another patient said that it “feels like you’re having to grab onto a word and push it out from your throat.” Another felt like “there’s a rubber band around my neck. Someone was constricting it.” And another said, “It feels like you have a sore throat all the time … like a raw feeling in your throat.”

Patients in the study described feeling hopeless and disheartened, less confident and less competent. The emotional toll can be huge. One patient said, “I used to be very outgoing and now I find myself avoiding those situations.” Another said, “People become condescending like you’re not capable anymore because you don’t speak well.”

As conditions such as spasmodic dysphonia become better recognized, I am hopeful that not only will treatments improve, but that stigmas around such conditions will diminish.

Indu Subramanian, Clinical Professor of Neurology, University of California, Los Angeles

This article is republished from The Conversation under a Creative Commons license. Read the original article.