If you’re taking an omega-3 fish oil or algae supplement to stave off Alzheimer’s disease and dementia, take note: A new clinical trial finds these supplements did nothing to improve memory, cognition or brain cell loss.
“Omega-3 supplements as a blunt instrument do not work,” said lead study author Dr. Hussein Yassine, the Volke Endowed Professor of Neurology at the University of Southern California’s Keck School of Medicine in Los Angeles.
“Even when we saw high levels of omega-3 in the brains of the treatment group, it did not improve cognition,” said Yassine, who directs Keck’s Center for Personalized Brain Health.
What does work? Optimizing your health with exercise, stress reduction, quality sleep and a plant-based diet while adding omega-3s from fatty fish, nuts and seeds, he said.
“In the Mediterranean, high omega-3 levels are very strong predictors of good cognition,” Yassine said. “But people in the Mediterranean are not popping supplements. They’re eating fatty fish, exercising, meeting with friends and living slowly with less stress.
“In that context, omega-3s are shining, helping the brain,” he added. “But if you eat a typical Western diet with fast food, don’t exercise, are stressed out all day from work, our study showed having more omega-3 in your brain doesn’t move the needle.”
After years of public messaging about how fish oil or algae supplements might protect against dementia, it’s time to refine our thinking, said Alzheimer’s prevention researcher Dr. Richard Isaacson, director of research at the Institute for Neurodegenerative Diseases of Florida.
“Omega-3s are absolutely critical to having optimal brain health, especially for people with the APOE4 gene, which increases the risk of developing Alzheimer’s,” said Isaacson, who was not involved in the new research. “However, this study shows they don’t work well in people who have not already optimized their health.”
CNN reached out to the Global Organization for EPA and DHA Omega-3s, which represents the omega-3 industry, but did not hear back before publication.
Why are omega-3 fatty acids essential?
Omega-3 polyunsaturated fatty acids are essential to any animal’s survival. In humans, they lower blood pressure, boost good cholesterol, maintain cell health and reduce the risk for cancer, dementia and Alzheimer’s disease.
Omega-3s are crucial for brain health. Up to 60% of the human brain is made up of lipids, or fats. Some 35% of those fats are omega-3s, experts say. Yet the body doesn’t produce omega-3s on its own. Instead, the fatty acids must be obtained from foods such as salmon, herring, mackerel, sardines, walnuts, chia seeds and flaxseeds.
Many people don’t eat enough fatty fish, seeds and nuts, so supplementation has become widespread. Fish oil supplements provide eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA. The two have different functions — EPA fights inflammation and supports heart health, while DHA is a core structural building block for the brain, eyes and central nervous system. Vegan supplements contain algal oil made from marine algae, which is also a source of EPA and DHA.
Chia, hemp and flaxseed oil capsules provide a third type of omega-3 called alpha-linolenic acid, or ALA, an antioxidant with the important job of turning food into energy. It’s also good for the heart — the risk of dying from heart disease falls by 10% for each gram of ALA eaten per day, according to the Cleveland Clinic.
Raw walnuts are an excellent source. One ounce, or about 14 walnut halves, provides 2.5 grams of ALA, nearly twice the recommended daily amount.
Walnuts also provide magnesium, manganese, copper, vitamin B6 and a host of other nutrients — a key feature of whole foods that experts say supplements can’t match.
Wild salmon, for example, contains proteins, vitamins A, D and B-12, and critical minerals such as selenium and potassium — as well as high-quality omega-3s.
“When you get omega-3s from eating fish, you’re not just getting the single nutrient; you’re getting the whole fish,” Yassine said.
“But it has to be part of a healthy lifestyle. If we take that salmon and fry it, it’s not going to count anymore. You can break the omega-3s down by frying the fish, or you can neutralize them by having french fries next to it.”
‘A drop in the ocean’
The results of the randomized, double-blind, placebo-controlled clinical trial — considered the gold standard of science — were published Thursday in The Lancet journal ebioMedicine.
The study divided 365 people without dementia between the ages of 55 and 80 into treatment and placebo groups. All had extremely low omega-3 levels and at least one risk factor for dementia, such as obesity, sedentary lifestyle, high blood pressure or cholesterol.
Nearly 50% had at least one copy of the APOE4 gene — a group that will be the mostly likely to benefit from supplementation because their brains struggle to process fats efficiently, Isaacson said.
The treatment group received a high dose omega-3 algae supplement (2,000 milligrams of DHA) each day for 24 months. The control group took a placebo for the same period. Both groups also took a vitamin B complex.
All participants underwent MRI brain scans, blood draws and cognitive testing at various points throughout the study.
Testing showed levels of omega-3s in red blood cells climbed from 4.9% to 11% in those taking the supplement. Measures of DHA levels in cerebrospinal fluid, which surrounds the brain, rose by an average of 17% after six months, confirming the omega-3 reached its intended target. The same increases were seen in people with an APOE4 gene, thought to benefit most from supplementation.
Despite evidence that levels of omega-3 had risen in the brains of people who took the supplement, there were no improvements in cognition or the size of the hippocampus, the brain’s memory center.
“In fact, there was no real difference between people taking an omega-3 supplement and those taking a placebo,” Yassine said.
The results show that omega-3 supplementation is like a “drop in the ocean” for people who don’t exercise, eat an ultraprocessed food diet and are overweight with signs of chronic disease, Isaacson said.
“What I’m telling my patients is that if a person with one or more copies of the APOE4 genetic variant has low blood levels of omega-3s and is overall healthy, they can still protect against Alzheimer’s and dementia risk by eating fatty fish twice a week and taking a high-quality omega-3 supplement,” he said. “But if they have an unhealthy lifestyle like the population in this study, an omega-3 supplement just isn’t going to work.”

NEED TO KNOW
Caroline Fonjock underwent emergency surgery after a boil on her leg turned out to be necrotizing fasciitis
The rare flesh-eating disease can kill soft tissue quickly and is fatal in about 1 in 5 cases
Fonjock hopes sharing her story will help others recognize the deadly condition earlier
A mom was left vomiting “black tar” and needing emergency surgery after a boil on her leg turned out to be an aggressive case of necrotizing fasciitis — commonly called the flesh-eating disease.
Social worker Caroline Fonjock, 45, first noticed a lesion at the top of her inner thigh in April 2021, but dismissed it as a boil, nothing more, according to a report from Cambridge University Hospitals. But within 36 hours, the mom of two was vomiting “black tar,” she told BBC, as the boil turned into a “hardened tube” and spread down her leg.
Fonjock was rushed to the hospital, where she says she was told she needed emergency surgery, multiple skin grafts, and could end up spending a year in the hospital, due to the aggressive case of necrotizing fasciitis.
The mom from the English town of Haverhill said doctors told her, “If you don’t do this, you’ll be dead by morning.”
Necrotizing fasciitis is a rare bacterial infection that can be deadly in about 1 in 5 patients, according to the U.S. Centers for Disease Control. It’s dubbed the “flesh-eating disease” because it quickly kills the body’s soft tissue found around muscles, nerves, fat, and blood vessels, and it can turn lethal in a short period of time. Immediate medical attention and often surgery to remove the affected tissue is crucial for survival.
Her husband, Lionel, told the BBC that he had never heard of the disease — and now had to tell their daughters that “it’s a possibility mum might not come back home.”
During the surgery, doctors removed a large portion of Fonjock’s leg. The damage, she told the outlet, looked “like roadkill,” and she spent two weeks in a medically induced coma in the ICU.
The road to recovery wasn’t easy: She struggled with infections, organ failure, and couldn’t speak, due to a collapsed trachea. Fonjock also lost her fine motor skills, and struggled to communicate on a dry-erase board her friend brought to the hospital.
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“I was so desperately in distress. I couldn’t write,” she says. “It was a really terrifying moment.”
Fonjack’s case is included in a report, published in Journal of Plastic, Reconstructive & Aesthetic Surgery, on factors that influence outcomes in cases of necrotizing fasciitis, as Fonjock has a history of infections and diabetes. Still, she says she doesn’t know how she may have been infected with the bacteria.
Now, five years after her life-threatening health crisis, Fonjock has since re-learned how to walk and talk, says she feels “blessed” to have been saved “in the middle of the night” by emergency surgery.
“The scar, while not pretty, is better than losing a limb, or worse,” she says, adding that she hopes her story can help others identify the rare, but very deadly, illness. “I am certainly not one to seek the limelight about my health issues, but I am very happy to share my story alongside this research if it helps doctors – and perhaps patients – recognize this condition at an earlier stage.”

I am going to talk about how fast shingles vaccines reverse dementia across 4 papers. Turns out the effect is near instant. But before I do that, let us agree on some facts about the nature of the evidence used to make these claims.
Fact: Observational studies and even “natural” experiments have methodologic challenges.
People who get a vaccine and those who don’t are different.
If you see a doctor, you are more likely to get a diagnosis. Show me a healthy person, and I will show you someone who hasn’t gotten enough tests.
Diagnoses change over time. A dementia diagnosis in 2017 and 2018 may not be the same thing. Doctors may become more or less disease aware. They may be incentives to add diagnoses to the chart to make more money. They may code the same exact forgetful elderly man differently* based on a single calendar date.
Doctors may consciously or unconsciously offer more preventive care to people who appear well.
The medical record aka “chart” doesn’t truly capture how well people look.
Here are some other facts, which I don’t think can be disputed
There has been no truly successful treatment for dementia. We have a few drugs with effects so abysmally poor, we can debate if they work at all. Dementia is not a disease with a series of advances. It seems like we barely understand it biologically.
This is despite huge financial investments.
Dementia is a slow process that takes years to manifest. By the time you forget who you are, you have likely had symptoms for a long time.
With this background, lets turn to a scientific hypothesis:
What if the shingles vaccine reduces dementia?
I am willing to consider this hypothesis. Maybe less episodes of shingles— which is debilitating— and you get less dementia. Probably would take a few years or maybe a decade to see the benefit, if true. Powering a randomized trial for this would be gargantuan. Observational studies or natural experiments are probably useless due to the challenges with the data and endpoint adjudication, but that never stops a scientist up for promotion.
Now let us look at the 4 papers:
“Experts” offer a series of papers making ludicrous claims. They argue because the claim is consistently ludicrous— it must be true— rather than the same sources of bias plague the literature. The earth is flat because it looks flat when you look around in every direction.
In annals of IM this week.
Wait, if you get ADMITTED to a nursing home—in less than a year—maybe as soon as 200 days—you get less dementia because of the Shingles vaccine. Within 3 years there is a 5% ABSOLUTE reduction in dementia. This vaccine must go inside neurons and repair them. It is what Ponce De Leon was looking for. A huge effect size that is also rapid.
In the JAMA paper, by 100 days, the shingles shot is already halting dementia. I don’t have dementia— at least I think I don’t— if I get 3 doses, I will probably be able to build Anthropic or Space X in a week— the brain benefit is so rapid.
The Wales paper doesn’t include K-M time to event plots. Sad. Why omit data when it will be so amazing? The US data is great. Obviously it confirms that the effect is near immediate.
And it includes a hazard function— thank you!— which makes it easier to see the fast action of the shingles vaccine. It makes Tums look slow acting.
Wait, what if this is true for every vaccine given to adults. What if the effect is not just shingles vaccines, but all vaccines. Perhaps they are miraculous as a class.
Check out this meta-analysis— it is true. Every vaccine prevents dementia!
Which is more likely?
Shingles vaccines (and maybe all sorts of other vaccines) instant act to reverse dementia. Even though nearly no drug in 50 years has achieved this. Despite tremendous effort and hundreds of billions of dollars. And this discovery just so happens to occur at a contentious time when vaccine science has taken on a left-right political bent, and coincidentally all the liberal outlets know the truth, while the conservative outlets spread misinformation (Option 1)…. or
The speed of the result is preposterously fast, the pretest probability abysmally low, and the desire to deceive ourselves astronomically high. (Option 2)
Future steps
Write to the annals of internal medicine and ask the editors to make the authors provide a Kaplan-Meier (time to event plot) of all cause mortality. (falsification endpoint)
Write to the Wales/ nature editors and ask for a time to event plot for dementia.
My understanding is that the NIH is planning on commissioning a randomized trial on this question. Encourage them to do so. (Equipoise is in the population of individuals who would do it, if and only if, this claim were true).
If there is a betting market on this trial, get a shingles shot to boost brain health before you vote.
Conclusion
The media coverage of this topic is deeply concerning. As I wrote recently in Sensible medicine, the media is unable to cover health and medicine without in house expertise in clinical trial appraisal. The status quo is untenable.
Coming soon, let me discuss that whole body ultrasound 😉
PS, if you enjoy these analyses, please subscribe
*say before or after a 2024 election

The basic training facility for the Air Force in San Antonio, Texas, is experiencing a flu outbreak following the end of mandatory vaccination for all service members.
As of Wednesday, there are at least 159 known cases among recruits and two hospitalizations at Joint Base San Antonio, two sources familiar with the matter told ABC News. One source told ABC News the number of cases and hospitalizations may be higher.
The outbreak comes after Defense Secretary Pete Hegseth announced in April that the annual flu vaccine would be optional for all U.S. military personnel, both active and reserve.
Previously, the flu vaccine was mandatory, but the new policy is in line with a previous change of making the COVID-19 vaccine optional.
The Pentagon has granted the military services exceptions to the policy, so the flu vaccine can be required in certain cases.
An Air Force spokesperson confirmed the outbreak to ABC News and said in a statement that over the last three weeks there has been a “localized influenza outbreak among trainees at Basic Military Training.”
“Medical professionals and Public Health officials have implemented mitigation measures to isolate and treat symptomatic trainees to reduce further exposure and continue to monitor the situation,” the statement read. “Medical personnel are also monitoring trainees who were in close contact with sick members in case they become symptomatic.”
The spokesperson said symptomatic trainees are receiving “the appropriate care” including antiviral medications such as Tamiflu.
“Once they are cleared by medical professionals they will return to training,” the statement said.
Earlier this year, when Hegseth ended mandatory vaccination, he referred to the policy as “overly broad and not rational.”
“Our new policy is simple: If you, an American warrior entrusted to defend this nation, believe that the flu vaccine is in your best interest, then you are free to take it; you should. But we will not force you,” Hegseth said.
The sources told ABC News that there is 40% flu vaccination rate among recruits at the San Antonio base since the mandate was lifted. Previously, the rate was nearly 100%.
Chief Pentagon spokesman Sean Parnell told ABC News that the Defense Department recently granted exceptions to the policy for the Army, Navy, Air Force, National Security Agency (NSA) and Defense Health Agency (DHA) through the Under Secretary of Defense for Personnel and Readiness.
“The decisions were based upon thorough risk assessments and are designed to maximize operational readiness, lethality, and force generation, while safeguarding at-risk populations,” Parnell said. “The Army, Navy, Air Force, NSA, and DHA are responsible for implementing the [exceptions to the policy]. The Department remains committed to the health and readiness of our warfighters and civilian personnel.”
The annual flu vaccine is currently recommended to everyone over 6 months old between September and the start of November. Although the typical flu season ends by February or March, people can become infected at any time.
People who travel internationally or live in group settings are at higher risk of transmitting and acquiring infectious diseases.
Public health specialists have warned that military members may suffer unnecessary complications from the flu after the vaccination mandate was ended and fear that severe cases will continue to climb in subsequent flu seasons if preventive vaccinations aren’t given to those most at risk.
Evidence has shown that young recruits are much more vulnerable to severe infection from influenza compared to other service members, though lower than the general population due to the military having historically high immunization rates.
A study published last year by the Defense Health Agency found that from the 2010-2011 to the 2023-2024 flu seasons, the highest rate of influenza hospitalizations among active service members were among those under the age of 25, especially young recruits.
The flu vaccine has been required for the military since 1945, at the end of World War II, partly tied to the threat of biological warfare use by rival nations and as well as the devastation that the flu pandemic of 1918-1920 wreaked on U.S. troops, according to a 2022 analysis from Wright State University in Ohio and the U.S. Air Force.
It’s estimated that between 20% and 40% of Army and Navy personnel fell ill, with more than 26,000 deaths among U.S. soldiers during the 1918-1920 flu pandemic.
After researchers noticed the effectiveness of the vaccine fading, the mandate was withdrawn in 1949. This was later found to be caused by abrupt and major changes to the flu virus — and the mandate was reinstated in the early 1950s after the changes became “clearer and combatable,” according to the analysis.

Cases of a devastating STI are on the rise and newborns are at high risk for deadly complications.
The deadly and entirely preventable disease has claimed the lives of 42 babies in Australia, and a spike in cases in the US has experts worried about a potential uptick in domestic deaths.
Across the US, syphilis cases have risen sharply over the past decade. In states like New York, infections have increased fivefold since 2013, reflecting a broader nationwide trend.
Last month, several California counties reported particularly alarming rates.
Even more concerning, federal data shows congenital syphilis — when the infection is passed from a pregnant mother to her baby — has skyrocketed by 700% compared to roughly ten years ago.
“As a physician and former public health official, I have never been more concerned about those rates of congenital syphilis,” Jeffrey D. Klausner, a clinical professor of medicine at the Keck School of Medicine of the University of Southern California, wrote in an op-ed for STAT this week.
Left untreated, congenital syphilis can lead to miscarriage, premature birth, skeletal abnormalities, neurological problems, developmental delays, stillbirth or infant death shortly after birth.
In 2024, the CDC reported nearly 4,000 new cases of congenital syphilis, the highest case number since the mid-1950s.
In Australia, the disease has been the cause of 42 infant deaths in the past decade and a source of infection for countless others, leading the country’s Chief Medical Officer to deem it a “communicable disease incident of national significance.”
“It worries us a lot. It’s 100% important not to allow it to spread and to become endemic,” University of Adelaide Emeritus Professor Maciej Henneberg told the outlet.
Syphilis is spread by vaginal, anal or oral sex. Symptoms typically emerge 10 to 90 days after exposure, starting with a painless sore at the site where the bacterium Treponema pallidum enters the body.
The sore can heal on its own in three to six weeks, even as the infection persists.
In the next stage of infection, symptoms can include a rash, fever, fatigue, sore throat, swollen lymph nodes and hair loss.
If not addressed, it can devastate the brain, heart, and nervous system, leading to blindness, paralysis, and even death.
Syphilis is typically diagnosed with a blood test.
Despite progress in reducing other sexually transmitted infections like chlamydia and gonorrhea, congenital syphilis has continued to climb year after year in the US.
By 2024, it marked 12 consecutive years of increases, reaching its highest level since 1994.
According to the CDC, most cases of congenital syphilis are the result of pregnant women not being tested for syphilis or not being properly treated when they test positive.
Lack of insurance or access, fear of immigration detention, substance use and mental health problems can all create barriers to proper prenatal care and testing.
Even among women who do receive appropriate prenatal care, only 80% are tested for syphilis.
The disease can be effectively treated — and cured — with antibiotics such as penicillin, particularly when caught in its early stages.
“It is entirely preventable, so even if a pregnant person got syphilis, we can totally treat that pregnant person, and then the baby will not be at risk any longer,” Dr. Kelly Hosking, director of sexual health and blood-borne viruses strategy and policy for NT Health, told ABC News Australia.
In 2024, in response to rising syphilis rates, New York implemented a new requirement for syphilis screening.
Pregnant women must now be tested for syphilis at their first prenatal appointment, in their third trimester (between weeks 28 and 32), and at delivery.
Still, Klausner says there is more that can be done on a national scale to treat and prevent congenital syphilis, including making rapid point-of-care tests and same-day injectable penicillin treatment available in clinics and testing locations.
Klausner also underscored the importance of integrating prenatal care and substance abuse treatment to ensure high-risk populations have access to testing and treatment.
“Dead babies have no voice, and the families devastated by congenital syphilis are too stigmatized to speak up,” he said. “Physicians and those who care about children’s health must loudly advocate and demand attention from our public health leaders.”