President Trump, a fan of Diet Coke, will soon have four new flavors to choose from.

On Wednesday, Coca-Cola KO, -2.92% said it will introduce four new flavors of Diet Coke: Ginger Lime, Fiesty Cherry, Zesty Blood Orange and Twisted Mango. And they will come in tall cans the company describes as “sleek,” designed to remind consumers of a slim body. “We’re maintaining the essence of Diet Coke while modernizing the brand to invite a new generation of drinkers to try it,” the company said.

The company reportedly spent two years on plans to revamp the brand, testing more than 30 flavors before settling on the final four.

There’s a lot at stake. Diet soda sales have tumbled in recent years as consumers switched to bottled water. Bottled-water consumption in the U.S. hit 39.3 gallons per capita, according to data released this year, while carbonated soft drinks fell to 38.5 gallons, marking the first time that soda was knocked off the top spot, according to recent data from industry tracker Beverage Marketing Corp. (Soda, however, remains more expensive.)

Reaction online was mixed:

Diet Coke remains an iconic brand. A New York Times story on life inside the White House published last month said President Trump consumes a “dozen Diet Cokes” every day. Trump’s thirst for the diet drink doesn’t follow national trends. Trump once observed that he’s “never seen a thin person drinking Diet Coke.” A spokeswoman for Trump did not respond to request for comment, but a spate of recent research suggests the Commander-In-Chief may be onto something.

A plethora of studies raise questions about the safety of artificially sweetened sodas:

Does diet soda help you lose weight or confuse your body?

Researchers are divided over whether diet soda actually helps people lose weight, according to a 2017 review of trials and studies involving more than 400,000 participants and published in the peer-reviewed Canadian Medical Association Journal. Diet soda may condition the body to expect calories, according to Susan Swithers, a professor of psychological sciences and a behavioral neuroscientist at Purdue University in West Lafayette, Ind. When people drink diet soda, the body speeds up its metabolism and releases hormones to anticipate sugar and calories, she said.

However, the Calorie Control Council, a trade group for manufacturers of artificial sweeteners including sucralose and aspartame, said the latest study linking weight gain and heart disease with low calorie sweeteners paints with too broad a brush. “Obesity is a complex condition with numerous causes and associations,” a statement at the time read. Robert Rankin, president of the Calorie Control Council, said, “Individualized strategies are critical for successful body weight management and should address not only dietary preferences.”

What diseases have studies linked to artificial sweeteners?

Artificially sweetened beverages may be linked to an increased risk of stroke and dementia, according to a recent study by the American Heart Association’s peer-reviewed journal Stroke. The researchers looked at 2,888 people over the age of 45 (with a median age of 62) for stroke risks and 1,484 people over the age of 60 (with a median age of 69) for risk of dementia. After adjustments were made for age, sex, caloric intake, diet, exercise and smoking, they found that diet soda drinks “were associated with an increased risk of ischemic stroke, all-cause dementia, and Alzheimer’s disease dementia.” (The study cites correlation rather than causation.)

Another 2015 study found that older women who consume two or more diet sodas per day are 30% more likely to suffer a cardiovascular event and 50% more likely to die from related disease than women who rarely consume the drinks. Ankur Vyas, a fellow of cardiovascular diseases at the University of Iowa Hospitals and Clinics, and the lead investigator of the study, analyzed nearly 60,000 women aged 50 to 79 years. (The American Beverage Association argued that those who are overweight and already at risk for heart disease may consume more diet drinks.)

Is sucralose in Diet Pepsi safer than aspartame in Diet Coke?

In 2015, Diet Pepsi PEP, -0.87% switched from aspartame to sucralose. “Sucralose is almost certainly safer than aspartame,” said Michael F. Jacobson, executive director at the Center for Science in the Public Interest, a Washington, D.C.-based think tank. Aspartame-free Diet Pepsi is a “blunt acknowledgment” that consumers have soured on aspartame, he said. (The Food and Drug Administration has ruled that artificial sweeteners are safe and Jacobson said that even Diet Coke is likely better for you than regular soda with high-fructose corn syrup or sugar.)

Diet Coke, favored by Trump, is made with aspartame. Sucralose was accidentally discovered by U.K. scientists developing new insecticides, remains the biggest sugar substitute on the market, according to retail tracking service Infoscan Reviews and Information Resources, Inc. Aspartame is made from two amino acids, while sucralose is a modified form of sugar with added chlorine. One 2013 study found that sucralose may alter glucose and insulin levels and may not be a “biologically inert compound.” (Coca Cola did not respond to request for comment.)

SodaStream turns water into wine

Coca-Cola introduced Coca-Cola Life in the U.S. in 2014. It has about half the calories of a regular Coke, and uses both cane sugar and the natural plant sweetener Stevia, a sugar substitute that has been growing in popularity in recent years. To highlight the natural ingredient, Coca-Cola Life had a green label instead of the traditional red. Diet Coke still uses aspartame, but a July 2013 study in the journal Food and Chemical Toxicology found that aspartame does not cause health problems like cancer and cardiovascular disease.

Trump, meanwhile, does not smoke or drink alcohol, arguably two vices that are far more damaging to one’s health. And his predecessor, Barack Obama, was photographed smoking cigarettes, which are arguably far more damaging to your health.