At a recent community event, I met a New Yorker whose story left me a bit unsettled. She told me how her husband had passed away from something called MASH — metabolic dysfunction-associated steatohepatitis. “I’d heard of steatotic liver disease [formerly known as fatty liver disease] before my husband was diagnosed,” she said, “but didn’t realize how serious it could be. I’d heard of cirrhosis, but we weren’t big drinkers, so I never thought we would have to worry about it. When I started researching metabolic dysfunction-associated steatotic liver disease [MASLD, formerly known as non-alcohol related fatty liver disease] after his death, I discovered how big a problem it is, so I don’t understand why people aren’t regularly checked for it.”

Her words hit me hard.

We may live in one of the most health-conscious cities in the world, but we remain silent in the face of a public health threat–MASLD and MASH. These liver diseases are estimated to affect 1 in 3 adults, and tens of thousands of our young people, yet most remain undiagnosed.

Just take a look at the NYC Department of Health and Mental Hygiene’s recent “HealthyNYC” campaign, which aims to increase New Yorkers’ life expectancy to over 83 years by 2030. Although it has made great strides in tackling chronic diseases like heart disease, stroke and diabetes–more than 30,000 New Yorkers died from these conditions in 2021 alone–MASLD and MASH are not mentioned in the plan.

Now, don’t get me wrong. The health department’s focus on the former issues is well-placed. This is not an “either-or” scenario. Rather, the HealthyNYC campaign is incomplete. Metabolic diseases like MASH are known to be strongly associated with cardiovascular diseases, obesity, type 2 diabetes, and hypertension—all of which the city is already battling. The missing piece of the puzzle is recognizing that MASLD and MASH are part of the same spectrum of diseases that we’re trying to fight as a city.

Obesity, for instance, has been steadily rising across the United States—from 13% in 1960 to a staggering 42% today. In New York City alone, approximately 2 out of every 3 adults are either obese (29.1%) or overweight (34.5%). These trends make MASLD an inevitability for many, and yet, the disease remains largely underdiagnosed and untreated. If New York City’s health department is serious about increasing life expectancy, it must integrate these liver diseases into its broader non-communicable disease (NCD) framework.

Some might argue that adding MASLD and MASH to the city’s health agenda would complicate an already massive workload. But this doesn’t have to be the case. In 2023, the 76th World Health Assembly approved an updated list from the World Health Organization containing 58 interventions, of which 28 were considered “best buys” on the basis of cost-effectiveness and feasibility of implementation. The list was intended as a guide to implement the WHO Global Non-communicable Disease Action Plan and focus predominantly on four main NCD risk factors (i.e., physical inactivity, unhealthy diet, tobacco, and alcohol) and four disease areas (i.e., cardiovascular disease, diabetes, chronic respiratory disease, and cancer). Interestingly, these WHO’s best buys for NCD prevention already align with interventions that could help address these liver diseases. In a Lancet Gastroenterology Hepatology Comment, we reported that 19 out of WHO’s 28 recommended interventions were directly applicable to MASLD and MASH. This means the groundwork is already laid—the city just needs to build on it.

Furthermore, the NYC Department of Health and Mental Hygiene would not be alone in addressing the issue immediately. Other health institutions have already spurred local action to raise visibility of the public health threat and pursue possible partnerships and solutions. In May 2024, the CUNY Graduate School of Public Health and Health Policy sponsored and launched the MASH Cities initiative in New York, kicking off what would be the beginning of a city-by-city platform to build knowledge, collaboration and awareness among city officials, community and industry leaders, and healthcare providers. More recently, the renowned Icahn School of Medicine at Mount Sinai hosted an open-to-the-public debrief event on the first-ever United Nations General Assembly side-event on MASLD/MASH, which was convened by the Economist Impact. The latter event welcomed a fireside chat from two health ministers (Mexico and Qatar), a panel discussion with leading experts from across the NCD field, and three newly-drafted, actionable policy briefs for the United States, Germany and Japan. Our health department doesn’t have to start from scratch. It can leverage existing networks and resources within the city to spark positive, real change when it comes to MASLD/MASH.

But here’s the real crux: the NYC healthcare system would benefit if the health department were to understand that inaction today would mean higher costs tomorrow, in more ways than one. We already know that the economic burden of MASLD in the U.S. is over $100 billion annually, and this number is expected to grow. From 2021 to 2040, the combined medical and societal costs of MASH alone may reach over $300 billion per year. In other words, for New Yorkers, we wouldn’t just be talking about the possibility of rising healthcare costs in an already overburdened healthcare system. It would also entail heavy physical and emotional strains due to a higher prevalence of untreated (yet preventable) liver diseases. NYC-based healthcare providers don’t need a reminder of this fact. They deal with the reality of MASLD/MASH in their clinical practice, everyday, even though the health department has the capabilities and expertise to take action that would prevent pushing the healthcare system and its users to the brink.

We cannot afford to ignore this any longer. The NYC Department of Health and Mental Hygiene has an opportunity to pivot now and incorporate MASLD and MASH into their strategy. This will increase their chances of achieving their 2030 life expectancy goal. New Yorkers deserve a health system that anticipates all major future challenges, not just reacts to them after the fact. We deserve a system that’s proactive, not just good enough.

Tackling this underrecognized public health threat will be the key to a healthier, longer life for all New Yorkers. We have the tools, the knowledge, and the partnerships to make it happen. Now, let’s update the HealthyNYC plan to meet the needs of this metropolitan city.