An 80-something patient came in for an annual visit recently and was worried that recent memory lapses might be symptoms of Alzheimer’s disease. This patient, like several others in my practice, has taken cognitive tests annually for more than a decade.

With each passing year, I see and hear the patient’s spiral of worry: Am I getting more forgetful? Perhaps it feels like “Where are my keys?” and “Where did I leave my wallet?” have become common refrains. These are simple memory lapses, an experience most people have throughout their lives, but they can be troubling as we get older. Are they signs of Alzheimer’s? Or signs of that other dreadful A-word … aging?

Year after year, for 10 years, in fact, this patient’s cognitive tests had come back normal. Until this year, when a blood test was positive for biomarkers for Alzheimer’s — triggering a further sense of panic. But here’s the problem: Science can’t yet tell us whether a positive test means the patient has an early stage of the disease. The only new data point was that this patient, so long dreading this day, had positive biomarkers showing increased risk for the disease. This person may not develop full-blown Alzheimer’s for five years or 20 years or ever. So did running that test have any benefit?

There is a sense of urgency in the medical community to classify a positive biomarker test as “Stage One Alzheimer’s Disease.” This is part of a larger desire to appear aggressive in fighting the disease, which for so long had no tests and no course of treatment.

I get that, and I understand why so many older patients fear Alzheimer’s, but I disagree with doctors whose response is to test early and often — and to diagnose Stage One Alzheimer’s based solely on biomarkers.

That categorization is potentially dangerous to patients, an unnecessary source of middle-of-the-night stress that can be deeply damaging to the very quality of life this person seeks to retain.

Such worries have become more widespread recently as the biomarker blood tests, marketed by companies like Quest and Labcorp, became commercially available so that patients could pay for them out of pocket. Previously, they were only used by clinicians in studies.

There’s an understandable impulse behind the medical community’s push to test lots of people. The more the disease is diagnosed, the more individuals will be identified for future treatments, and there is no doubt we need to improve recognition of early dementia, especially in medically underserved populations.

At the same time, pharmaceutical companies need more clinical trials — and also more patients — to develop new drugs to add to the array that already exists, such as Leqembi. In an aging nation with 7 million people already diagnosed with Alzheimer’s, we need these drugs, badly, but there’s no denying that profit lurks in the background as a motive here as well.

Although there are good reasons to test lots of people and gather a larger pool of patients who might have early stage Alzheimer’s, I think the cost to specific individuals can be just too great.

Candidates for clinical trials should not be identified based on positive blood tests from a clinical setting, but rather through carefully conducted research studies that have proper counseling and disclosure protocols.

More than 40% of individuals over 80 who take a biomarker test for Alzheimer’s will test positive. And it’s natural that many of them then will fixate on the worst-case scenarios and live their lives with a sense of worry and dread.

Patients who’ve tested positive come to me and bluntly state, “I have Alzheimer’s.” I see the scared look on their faces. Reaching this conclusion based on the biomarkers is like diagnosing cancer without doing a biopsy. The danger is real: Half of the patients who actually do have Alzheimer’s experience some sort of depression, and so do quite a few who think they have it — or worry they are sure to get it.

A positive blood biomarker test could also lead to significant mental and financial damage, with unnecessary and expensive procedures like an MRI, a PET scan or a spinal fluid test. Some people don’t like to hear this, but in many cases simple lifestyle changes like exercise, more rest and healthier eating could improve cognitive function. This is the recommendation I make to all my patients regardless of their Alzheimer’s risk.

For now, the biomarker test should be taken only if you are truly showing signs of Alzheimer’s disease. Here are some ways to tell: If a loved one is experiencing noticeable changes from their baseline mental abilities — such as losing track of time and place or struggling to find words — that can be a sign. Personality changes and new mood symptoms are other warning signs. Still, these symptoms should be distinguished from the slow and steady decline we will all experience.

If you do have symptoms, then yes, it could be time for biomarker tests, but only after thorough cognitive testing and a complete review of your medical history. That medical history could show other conditions such as sleep apnea that can influence memory. Lifestyle changes or treatments of those other conditions could resolve the troubling symptoms.

My stance on widespread testing will be different when doctors have more tools available to predict and treat Alzheimer’s and can offer constructive advice after a blood test comes back positive.

When someone has a cancerous tumor, surgeons remove it as soon as possible and start a treatment plan. When someone tests positive for the gene that indicates risk for a certain type of cancer, we monitor carefully.

A positive Alzheimer’s biomarker test, on the other hand, leads to no changes in clinical management when there are no cognitive symptoms. Prevention trials and improved predictive biomarkers for Alzheimer’s disease will change that, but we’re not there yet.

In the meantime, doctors’ oath to “do no harm” should mean we avoid overdiagnosing Alzheimer’s and fueling needless anxiety.

Keith Vossel is a professor of neurology at UCLA.

California air quality regulators late Friday approved tougher rules to encourage use of lower-carbon fuels, overriding objections that the action would lead to higher gasoline prices for motorists.

On an 12-to-2 vote, the California Air Resources Board approved amendments to the state’s Low Carbon Fuel Standard, or LCFS, which aims to shift California’s fuel dependence away from gasoline and toward lower-carbon fuels such as biodiesel, hydrogen and electricity.

The board members voting for the plan, some looking bleary-eyed by the end of the 12-hour meeting, said the new rules were needed to move the state closer to its goal of no longer burning fossil fuels.

“From a climate perspective, this is absolutely necessary,” said board member Hector De La Torre.

Dean Florez, a former Democratic state lawmaker, was one of two board members to vote no. He said one of his concerns was that the plan would make driving more expensive in a state that already has the second-highest pump prices in the nation after Hawaii.

“I’m just kind of wondering how we can in all good conscience, say that … somehow we’re not a cause of this,” Florez said.

Of the 14 voting members on CARB’s board, 12 were appointed by Gov. Gavin Newsom and confirmed by the state Senate. Florez was appointed by the state Senate. De La Torre was appointed by the state Assembly.

California Air Resources Board staffers estimated last year that the new rules could raise the price of a gallon of gas by as much as 47 cents next year. By 2040, the added cost to the price per gallon could be $1.80, staff members estimated in their 2023 document.

Since then, and again Friday, CARB officials asserted that those estimates were flawed and that they no longer believe the action will boost gas prices.

“Any claims that LCFS is responsible for high gas prices is misleading at best and not supported by the data,” Dillon Miner, CARB’s staff air pollution specialist, told the packed auditorium in Riverside on Friday.

Those assurances were met with skepticism by some speakers during the seven-hour public hearing.

Assemblymember Tom Lackey (R-Palmdale) told the board that residents of his district, many of whom were lower-income, often drove 100 miles a day.

“This is all about survival, financial survival,” Lackey said. “We simply cannot afford this.”

Nearly 13,000 Californians signed a petition written by Republican state senators that asked the board to postpone the vote until CARB provided information on how much the amendments would increase gas prices.

Even some Democrats spoke out about how the amendments could raise gas prices, which would especially burden low-income people who must drive to their jobs.

“I represent a working-class rural district that is largely dependent on agricultural jobs,” Assemblymember Esmeralda Soria (D-Merced) wrote in a Thursday letter to CARB Chair Liane Randolph. “It is these working families that can least afford even a modest increase in fuel prices.”

Many speakers at the public hearing urged the board to reject the amendments for reasons that did not involve the price of gasoline.

Some said they lived in the Inland Empire where the meeting was held. They spoke about how the pollution from trucks and other vehicles was continuing to harm the health of their families. They said they believed the program was benefiting companies by allowing them to continue to pollute and that the board should do more to support electric vehicles.

Environmentalists told the board they were disappointed that the amendments favored fuels such as renewable diesel that is made from food crops including soybeans and canola. Such biofuels result in turning land that was once used to grow food into that producing fuel.

Gary Hughes at BiofuelWatch told the board the plan would be “a driver of global deforestation” as more land was used to grow plants for the biofuel. “These fuels are not a climate solution,” he said.

Because of the LCFS, California now accounts for nearly all renewable diesel consumption in the U.S. Most of that fuel is not made in California but trucked in from other states or imported, mostly from Singapore.

“These dirty fuels are wolves in sheep’s clothing,” Nina Robertson of Earthjustice told the board.

Supporters of the amendments included dozens of executives from the producers of alternative fuels and electric vehicles, as well as other companies that have been financially benefiting from the program.

Steve Lesher of Shell U.S.A. told the board that the LCFS had prompted the oil company to invest in hydrogen and biofuel production, as well as electric vehicle charging stations. He called the program an “investment attractor.”

The LCFS program was created in 2009 under Republican Gov. Arnold Schwarzenegger. CARB says the program has resulted in more than 30 billion gallons of petroleum being displaced by low-carbon fuels. The program, the agency said, has also helped California reduce its greenhouse gas emissions by 20%.

The state uses a carbon-trading market to encourage producers to make the alternative fuels. Producers that don’t meet the state’s low carbon standard must buy credits from those who do, which pushes companies to develop cleaner options.

Under the current program, fuel producers had to reduce the carbon intensity of their fuels by 20% of the levels in 2010 by 2030.

The proposal approved Friday increased the carbon-intensity reduction target in 2030 to 30%. And the target would leap to 90% in 2045.

As the standard tightens, the cost of the credits is expected to rise. Critics say this cost will be passed on to consumers.

CARB officials say that isn’t correct. They say there is no direct relationship between the fuel credit prices and the cost of gas at the pump. And they say data show that the current fuel standard, before the amendments approved Friday, has added just 10 cents to the price of a gallon of gas.

Danny Cullenward, a climate economist in San Francisco and senior fellow at the Kleinman Center for Energy Policy at the University of Pennsylvania, estimated in an October report that under the new rules, the 2025 cost could be as high as 65 cents a gallon.

“It’s absolutely irresponsible and unacceptable that this board has chosen to ignore how its policies will impact gas prices,” state Sen. Rosilicie Ochoa Bogh (R-Yucaipa) said in a statement. “How can they possibly vote to approve it if they don’t even know what it will do to Californians at the pump?”

More than half of Californians and nearly 75% of U.S. residents live in communities where fluoride has been added to drinking water to prevent tooth decay, an intervention hailed by the U.S. Centers for Disease Control as one of the 20th century’s greatest public health achievements.

Yet should Donald Trump be elected to a second term, water systems will be immediately directed to end this practice, according to supporter Robert F. Kennedy Jr.

“On January 20, the Trump White House will advise all U.S. water systems to remove fluoride from public water,” Kennedy posted Saturday on the social media platform X.

Kennedy described the mineral, which occurs naturally in all fresh water supplies, as an “industrial waste” associated with a variety of health risks.

On Sunday, Trump told NBC News that he had not discussed the fluoride proposal with Kennedy, “but it sounds OK to me.” Reached for comment Monday, a campaign spokesperson told The Times that while Trump “has received a variety of policy ideas, he is focused on Tuesday’s election.”

Kennedy’s statement follows a September ruling from a federal judge in California that could have major effects on the long-standing public health intervention, but that multiple dentists and pediatricians say is based on a flawed reading of the available science.

In his X post, Kennedy tagged Michael Connett, the lead attorney representing the plaintiff in that lawsuit, the advocacy group Food & Water Watch.

In late September, U.S. District Judge Edward Chen ordered the U.S. Environmental Protection Agency to take further unspecified steps to regulate fluoride in drinking water.

In his ruling, Chen cited a literature review by the U.S. National Toxicology Program that found associations between exposure to high levels of fluoride and lower IQ levels in children.

Though he could not “conclude with certainty that fluoridated water is injurious to public health,” Chen wrote, he still determined that it posed an “unreasonable risk” of harm. His ruling did not specify what exactly the EPA should do about that.

The American Dental Assn. and American Academy of Pediatrics issued a joint statement of concern after the ruling, saying that there were major limitations in the study Chen cited. The groups pointed out that the study found low IQ associations only at fluoride concentrations more than double those of the current recommendation of 0.7 milligrams per liter.

“There is nothing about the current decision that changes my confidence in the safety of optimally fluoridated water in the U.S.,” said Dr. Charlotte W. Lewis, a member of the AAP Section on Oral Health, at the time. “Water fluoridation is a public health policy based on a solid foundation of evidence.”

In California, scientifically shaky skepticism of fluoridated water has been around almost as long as the stuff has been coming out of the taps.

In 1952, San Francisco and Antioch became the first communities in California to supplement naturally occurring levels of fluoride in their drinking water, after a raft of studies showing that the mineral made teeth enamel stronger and more resistant to acid. Within a decade, cavities in 6-year-olds’ permanent teeth had dropped by 84%.

The U.S. Public Health Service in 1962 recommended a fluoridation level of 0.7 to 1.2 mg per liter in drinking water supplies. (In 2015 the service revised its recommendation to 0.7 mg per liter — a sweet spot that maximized the dental health advantages while reducing the risk of tooth discoloration associated with excess fluoride exposure.)

Yet as the number of communities in California voting to fluoridate their water grew, so did complaints from skeptics who pushed debunked theories about fluoride’s link to cancer, AIDS and other conditions, according to a history by UC San Francisco oral biology professor Ernest Newburn.

Despite California’s early leadership in water fluoridation, it now ranks 39th among U.S. states in the percentage of the population covered by fluoridated water systems, with 57.5% of residents living in covered communities, according to the United Health Foundation. (Kentucky leads the board with 99.9% coverage.)

An exploratory study published this year found associations between prenatal exposure to fluoride and an increased risk of neurobehavioral problems at age 3 in a cohort of 229 Los Angeles-area children.

The American Dental Assn., the American Academy of Pediatrics and others have pushed back on the study, citing concerns about the methods used to evaluate both child IQ and maternal fluoride levels.

“It is irresponsible of the authors, based on this study, to suggest that recommendations be changed on the beneficial use of fluoride to prevent dental problems,” said Howard Pollick, a professor at the UC San Francisco School of Dentistry, shortly after the study was published.

A larger study published last year followed more than 2,000 children in Australia over five years and found no associations between prenatal fluoride exposure and behavioral development problems.

Both Trump and Kennedy have said publicly that longtime anti-vaccine activist Kennedy will probably have a prominent role in health policy in a second Trump administration.

“I’m gonna let him go wild on health. I’m gonna let him go wild on the food. I’m gonna let him go wild on medicines,” Trump told supporters during a rally at Madison Square Garden last month.

The Associated Press contributed to this report.