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Dear Doctor: French fries are absolutely one of my favorite foods, but because of their calorie content, I try to limit them to twice a week. Now I just read that eating them even that rarely is linked to a higher risk of death. Just how problematic are a couple of servings of fries each week?

Dear Reader: In my younger days, I also loved french fries. It didn't take me long to figure out that potatoes fried in oil were not the healthiest of foods, so I gave them up. I didn't rely on any studies to make this decision, but the research to which you're referring raises some interesting questions about the potential risks of potatoes, especially fried potatoes.

The study, published recently in the American Journal of Clinical Nutrition, assessed 4,400 people who were at high risk of osteoarthritis of the knees. All participants filled out a food questionnaire; two of the questions were about consumption of fried potatoes and un-fried potatoes. Fried potatoes included french fries, hash browns and tater tots.

Participants were then divided into sub-groups, depending on how often they ate potatoes: less than once a month, two to three times a month, once a week, twice per week or, lastly, three or more times per week. Over the eight years of the study, 236 people died. People who ate fried potatoes twice a week had almost double the risk of death, compared to people who ate fried potatoes less than once a month. Those who ate fried potatoes three or more times per week had more than twice the risk of death, compared to the group who ate the fewest fried potatoes. The authors did not find a correlation between death risk and un-fried potatoes.

Note that there were significant limitations to this study. One is that it was relatively small. Second, the authors did not make mention of other foods that participants ate, such as processed meats, trans fats or sodas. So to take fried potatoes in isolation -- and then draw conclusions -- is difficult. Lastly, the groups who ate the fewest fried potatoes included a greater proportion of women, who have a lower death rate within any given time frame as compared to men.

That said, let's assume the data are reliable. If so, why are fries so risky? A 2016 study combined data from three large trials with a total of 199,181 people. In that analysis, three servings per week of french fries correlated with a 19 percent increased risk of diabetes. This increased rate of diabetes was also seen in two other studies. Further, a 13-year Swedish study found a 22 percent increase in the cardiovascular death rate among people who ate fries -- not other fried potatoes -- three days per week. Something to consider: At the time of these studies, fries may have contained greater amounts of trans fats, which have been associated with increased death rates.

The research correlating fries and death rate is not perfect, but there does appear to be a correlation. I would recommend decreasing your intake. Now I have to convince my kids to do the same.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

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