Diet Soda, Sugar Substitutes, and Brain Trickery

Lindsey asks: "Are diet drinks really all that bad for you? I've heard stuff about the 'sugar' in them being addicting."

Great question! The arguments about this have been all over the place over the past 20 years, ever since sugar substitutes really began taking off, so this is a hefty topic. The most common charges against diet soda (or other beverages sweetened with sugar substitutes) are:

• Diet soda can cause an increased risk of type II diabetes, metabolic syndrome (high blood pressure, abdominal obesity, and other health issues), heart attack, and stroke.

• Diet soda contains aspartame and other artificial sweeteners which cause: cancer, headaches, depression, nausea, mood swings, kidney problems, liver problems, respiratory problems, skin irritation, gastrointestinal distress... and pretty much anything else you can think of.

• The sweeteners in diet soda are more addicting than normal sugar, and actually cause people to gain weight rather than lose weight.

Some of these claims are (partly) true, others false, some misleading, and most simply unknown. Here's what I found after researching each claim individually.


Claim #1: Diet soda can cause an increased risk of type II diabetes, metabolic syndrome, heart attack, and stroke.

First off, diet soda has never been found to cause any of these conditions. Correlations have been found, but as we know, that doesn't necessarily imply causation.

That said, a study published by the American Diabetes Association in 2009 showed that daily consumers of diet soda had a 67% increased incidence of type II diabetes compared to non-consumers. Although the study focused on diet beverages, it also accounted for consumers of sugar-containing beverages, but did not find the same correlation in those consumers.

That same study also looked at metabolic syndrome; here the researchers found the daily consumers of diet soda had a 36% increased incidence of metabolic syndrome compared to the other groups, but after adjusting the data for other factors, the correlation turned out to be statistically insignificant. On the flip side, a later study led by the University of North Carolina at Chapel Hill showed that consumers of the typical "Western" diet (fast food, lots of carbs, fat, salt, and sugar), in addition to diet beverages, were at a much higher risk for metabolic syndrome than their healthy-eating, non-diet-soda-consuming counterparts. So what do the conflicting conclusions mean? Probably not very much for diet soda. Both studies strongly suggest that overall diet--not a single type of beverage--is what truly impacts one's risk for metabolic syndrome.

So what about heart attack and stroke? A study published in the Journal of General Internal Medicine in 2012 found increased incidence of heart attack and stroke in daily consumers of diet soda (compared to those who drank none). No increased risk was found for consumers of regular soft drinks or those who drank diet beverages less than daily. However, researchers noted that drinkers of diet soda tended to be heavier, suggesting that those who consume diet soda are trying to lose weight--rather than diet soda causing them to be overweight and thus increasing their risks of heart attack and stroke. More studies are needed, but once again, overall diet is the main factor here.


Claim #2: Diet soda contains aspartame and other artificial sweeteners which cause [insert health problem here]

This claim is much more difficult to support or refute because the data is almost eerily lacking or insufficient. I could write a whole separate post about the controversy surrounding artificial sweeteners, but for the purposes of this one, I'll just mention a few general concerns about aspartame, the most commonly used sweetener in diet beverages. (This information comes from an article at MedicineNet, which gives a great, balanced overview of aspartame and other sweeteners while providing an accurate list of sources.)

A survey of  166 studies regarding human safety and aspartame revealed some unsettling information: 100% of the research conducted or funded by Nutrasweet industry (prime producer of aspartame) confirmed the product's safety... while 92% of the independently funded studies reported various health problems associated with it. One study conducted on 40 patients with depression was actually cut short because of how severe the reactions were in the first 13 patients tested. Another study reported that migraine sufferers experienced increased frequency and intensity of their headaches due to aspartame. Other suggested symptoms of the sweetener include nausea, abdominal pain, diarrhea, fatigue, and seizures. Cancer, of course, has been the most common concern, but although many more studies are still needed, the information currently available more strongly supports that aspartame consumption does not contribute to cancer.

While food safety organizations around the world stand by aspartame as a safe product, once again, more studies are needed.


Claim #3: The sweeteners in diet soda are more addicting than normal sugar, and actually cause people to gain weight rather than lose weight.

Vaguely implied by many studies and specifically explored in this 2008 study is the idea that diet soda is more "addicting" than regular soda because our brains aren't as satisfied with artificial sweeteners as with regular sugar. Functional MRI (fMRI) brain scans showed that while both artificially sweetened and sugar-containing beverages lit up the brain's reward system, the normal sugar did so more completely. This may be one reason why some diet soda drinkers don't lose weight--even if their tastebuds can't tell the difference in sweetness, their brains can, thus making them crave more sweet foods or beverages and consume more calories. (Of course, there's the other suggestion that some diet soda drinkers may just be making poorer dietary choices in general because they think diet beverages will help negate some of those choices.)



So to answer your question...

Your choice of beverage is obviously a personal decision, but hopefully it can be an informed one, too. Before researching this I was wary about aspartame because of the general concerns I had heard over the years. I also don't like the taste, and since I rarely drink soda, I've mostly just avoided the diet versions all together. But until more data is available on potential health risks, the old standby in nutrition advice is probably best: "Enjoy in moderation!"




Duffey, Kiyah J, Lyn M Steffen, Linda Van Horn, David R Jacobs, and Barry M Popkin. "Dietary patterns matter: diet beverages and cardiometabolic risks in the longitudinal Coronary Artery Risk Development in Young Adults (CARDIA) Study." American Journal of Clinical Nutrition 95.4 (2012): 909-915. Print.

Frank, Guido K W, Tyson A Oberndorfer, Alan N Simmons, Martin P Paulus, Julie L Fudge, Tony T Yang, and Walter H Kaye. "Sucrose activates human taste pathways differently from artificial sweetener." NeuroImage 39.4 (2008): 1559-1569. ScienceDirect.com. Web. 3 July 2012.

Friedrich, Cathe. "Diet Soda." Photo. Cathe.com 1 July 2012. 3 July 2012 <http://cathe.com/the-diet-soda-dilemma>.

Gardener, Hannah, Tatjana Rundek, Matthew Markert, Clinton B Wright, Mitchell S V Elkind, and Ralph L Sacco. "Diet Soft Drink Consumption is Associated with an Increased Risk of Vascular Events in the Northern Manhattan Study.." Journal of General Internal Medicine Online before Print (2012): 1-7. PubMed. Web. 3 July 2012.

Kovacs, Betty, and William C Shiel. "Artificial Sweeteners: Side Effects, Cancer Risk, Weight Gain and Pros and Cons of Sugar Substitutes." MedicineNet. MedicineNet, 13 Dec. 2010. Web. 3 July 2012. <www.medicinenet.com/artificial_sweeteners/article.htm>.

Nettleton, Jennifer A, Pamela L Lutsey, Youfa Wang, João A Lima, Erin D Michos, and David R Jacobs. "Diet Soda Intake and Risk of Incident Metabolic Syndrome and Type 2 Diabetes in the Multi-Ethnic Study of Atherosclerosis (MESA)." Diabetes Care 32.4 (2009): 688-694. Diabetes Care. Web. 3 July 2012.

10 Tips for Hungry College Students

William asks: “How can college students (like us) eat healthier on a college student budget and without a lot of time to prepare food?”

This challenge of finding healthy, easy (and fast), affordable ways to eat as a college student always used to look like this in my brain:

Thankfully, that big question mark in the middle isn’t as mysterious as I once thought. Here are some tips for having the best of all three worlds—and as you might notice, none of them are particularly “big.” As with anything related to everyday lifestyle, the biggest differences usually happen by trying little changes and sticking to the ones that work for you. 

1. Canned is not banned from a healthy diet

While it’s true that canning vegetables results in a loss of nutrients, it’s often overlooked that normal cooking of the fresh varieties can result in the same amount of nutrient loss (or greater, depending on the cooking method). Commercially canned produce is usually processed within hours of picking, just like frozen produce, optimizing their nutrient content before they experience any losses from canning or cooking. While fresh produce is always ideal, the fact is that after the amount of time it spends between harvesting and reaching your grocery store, the nutrient content has already been a bit compromised anyway. The other usual concern about canned veggies is an increase in sodium, but this can be alleviated if needed by choosing a low-sodium version or by thoroughly rinsing your canned veggies before consuming.

2. Rice goes with everything

Rice is cheap, nutritious, and I can’t think of any dish I’ve combined it with that I didn’t personally like. It’s easy to prepare, too, but if waiting for water to boil drives you crazy (it happens), try making a big batch on a weekend and storing it in your refrigerator for easy re-heating. Both white and brown rice are great sources of vitamins and minerals (primarily B vitamins, magnesium, selenium, and iron), as well as carbohydrates for energy. Brown rice is also a particularly good source of fiber.

3. Meat is tough (hopefully not literally)

Depending on your personal preference for meat dishes and how often to have them, fitting them into a college student budget could be difficult or not a big deal. I’m not a red meat lover, so I usually buy frozen bags of tilapia or chicken, which tend to be less expensive per serving than fresh beef or pork. If you prefer the latter, here’s a tip: if you have time to cook the meat within a day or two (whether to eat right away or put cooked portions in the freezer), look for packages with an early “sell by” date—many stores mark down meats that are closest to this date just to get them off the shelves. Also, ground meats are incredibly easy to freeze in portions, either cooked or raw.

4. Take some responsibility off your peanut butter

As I just mentioned, meat doesn’t have to be eliminated from your diet because of price, so the stereotype of the college student who has peanut butter at least twice a day for protein doesn’t have to be true. But aside from meat, beans are a fantastic source of protein—especially when combined with rice. The amino acids in beans and the amino acids in rice (the building blocks of protein) are incomplete; however, they complement each other, meaning a meal with both items will give you a perfect protein boost. And fortunately for us, canned or dried beans are about the cheapest items to put in the pantry. (Canned chicken and fish are also handy protein sources.)

5. Crockpots are your friends

If you can’t find a used crockpot or afford a new one right now, try asking for one for Christmas. Seriously. Delicious, satisfying, comforting, home-cooked food is literally as easy as throwing ingredients into a pot and letting it simmer all day while you’re in class.

6. Apps are also your friends

It turns out buying fresh produce can be pretty complicated. First there’s choosing the “best” item (and what looks best on the outside may not be tastiest on the inside), storing it properly for max freshness, then eating it in time before it spoils. One iOS app I use often is Produce Guide. Can’t remember if kiwis are supposed to be firm or a little squishy? The kiwi entry in the guide will tell you, along with helpful information on when it’s in season (i.e. when it will be cheapest), how to store it, how long it will last, and some basic nutrition information.

7. Try something new / looks can be deceiving

This tip primarily comes from an experience I had with lettuce. (So exciting!!! Right?) I used to buy heads of iceberg lettuce because it was cheap, and I could tear it and wash it for easy salad from the fridge. I mostly ignored the pre-washed, pre-cut, pre-boxed/bagged selections of lettuce on the other end of the aisle because they were more expensive, and the “easy” factor just wasn’t enough to make up for price in my mind. But then I noticed this variety, a box of a few smaller, different heads of lettuce that not only looked more flavorful and healthy, but really wasn’t that much more expensive. So I gave it a try—as it turned out, this type of lettuce actually lasted almost twice as long in my refrigerator, provided more edible portions than the iceberg heads, and again, was more nutritious.

8. Roommates can help

Buying staple items in bulk can help cut costs, especially if those items are used by your whole household. I have some friends who all split the cost of a Sam’s Club membership so they could all save money on items like frozen chicken, pasta, rice, cereal, milk, coffee, and household supplies like toilet paper, paper towels, and laundry detergent. A basic membership is $40 a year, so if you live in a house of 4, that’s only $10 a year each—a cost easily made up for in one or two shopping trips.

9. Buy local

I’m not sure how far “local” extends for our area in Abilene, but I’ve noticed two or three offerings of local produce at our Walmart most times I visit. (United and Albertson’s probably offer some as well, maybe more, but I don’t know.) I usually buy the local oranges—they’re fresher (and thus more nutritious), tastier, and cheaper. And it’s always great to help support local growers.

10. Potato power

Potatoes sometimes get such a bad rap for being the primary ingredient in junk food items like chips and fries that people forget how healthy they are on their own. One large baked potato (without toppings) has just under 300 calories, about 26% of your daily recommended value for fiber, high vitamin C, high potassium, and high vitamin B6—in addition to containing other vitamins and minerals, protein, and plenty of carbs. Add some low-fat cheese for a boost of calcium and flavor, any veggie of your choice, and you’ve got a filling meal in no more than 10 minutes.

I hope some of these tips provided new ideas to try in your quest for achieving the College Student Nutrition Trifecta. Please feel free to comment if anyone has any other tips to share!