Dr. Roach: Where does diet soda fall on the vice spectrum?

Keith Roach
To Your Health

Dear Dr. Roach: I’ve never smoked, drank alcohol or used illegal drugs. My doctor says I’m in great health. My only vice is drinking diet soda, and I drink three or four cans a day. I’d like to know what you think about it. I know it’s not great for me, but I figure it’s better than the other vices.


Dear P.V.: I’m not sure “vice” is the correct term.

Compared with sugar-sweetened soft drinks, diet sodas are probably less harmful in several ways. Compared with plain water, they probably have some drawbacks. The effects vary by person, and the literature on this subject is mixed and controversial.

For your teeth, less sugar means less cavities. However, diet sodas are acidic and drinking too many can weaken the enamel on your teeth.

The effect of diet sodas on weight is complicated. Paradoxically, many people will gain weight when switching to diet soda. Scientists believe this is due to effects on the bacteria in the intestines (the microbiome). Consuming sweet beverages may also stimulate the desire for other sweets and less-healthy foods.

Some of the sweeteners in diet sodas can cause intestinal problems in susceptible people, especially diarrhea and gas. If you have no symptoms from drinking diet sodas, have no weight issues, get your teeth checked regularly and have good oral hygiene, then the risk from three or four daily cans of diet soda is modest. It’s still better to drink plain water.

Dear Dr. Roach: I have read numerous articles regarding the use of marijuana but have not seen a reference to cannabinoid hyperemesis syndrome. This is a condition that was recently identified and is increasing in frequency due to legalization and potency. I would appreciate your thoughts on this syndrome.


Dear D.L.: Cannabis use is indeed increasing, and one unusual side effect is the hyperemesis (literally, “too much vomiting”) syndrome. This most often occurs in daily users of cannabis, usually after years of use. The vomiting tends to occur in cycles: nausea, abdominal pain and vomiting, which can be severe, occur without warning and last 24-48 hours. This is followed by a recovery phase lasting weeks or months, where people feel generally well. The diagnosis can be confused with cyclical vomiting syndrome, and the correct diagnosis is often missed for years.

Physicians sometimes fail to think of the diagnosis or have never learned of it -- it was first described in 2004. Cannabis users are sometimes highly resistant to the idea that the cannabis is causing these symptoms, as they have often been using for years with no problems. Further, cannabinoids are sometimes used to relieve nausea, so the mechanism of cannabinoid hyperemesis syndrome is not understood. The patients I have seen with this syndrome -- including one yesterday, coincidentally -- often have had very extensive evaluations, such as CT scans and endoscopies.

One clue that points toward cannabinoid hyperemesis syndrome is that most people learn that taking a hot shower temporarily relieves symptoms, and they will take several hot showers or baths during the day.

During the acute phase, treatment is supportive care, sometimes including anti-nausea drugs. However, the long-term treatment is cannabis cessation. It may take months before it is clear that the symptoms have resolved with cannabis cessation. Unfortunately the risk of relapse is high if the patient returns to cannabis use.

Readers may email questions to ToYourGoodHealth@med.cornell.edu