Does Aspartame Cause Lymphoma?

The approval of aspartame has a controversial history. The Commissioner of the U.S. Food and Drug Administration (FDA) concluded that “there is a reasonable certainty that human consumption of aspartame: (1) …will not pose a risk of brain damage resulting in mental retardation, endocrine [hormonal] dysfunction, or both; and (2) will not cause brain tumors.” However, the FDA’s own Public Board of Inquiry withdrew their approval over cancer concerns. “Further, several FDA scientists advised against the approval of aspartame, citing…[the aspartame company’s] own brain tumor tests…” Regardless, the Commissioner approved aspartame before he left the FDA and went on to enjoy a thousand-dollar-a-day consultancy position with the aspartame company’s PR firm. Then, the FDA actually prevented the National Toxicology Program (NTP) from doing further cancer testing. As I discuss in my video Does Aspartame Cause Cancer? we were then left with people battling over different rodent studies, some of which showed increased cancer risk, while others didn’t.

This reminds me of the saccharin story. That artificial sweetener caused bladder cancer in rats but not mice, leaving us “to determine whether humans are like the rat or like the mouse.” Clearly, we had to put the aspartame question to the test in people, but the longest human safety study lasted only 18 weeks. We needed better human data.

Since the largest rat study highlighted lymphomas and leukemias, the NIH-AARP study tracked blood cancer diagnoses and found that “[h]igher levels of aspartame intake were not associated with the risk of…cancer.” Although the NIH-AARP study was massive, it was criticized for only evaluating relatively short-term exposure. Indeed, people were only studied for five years, which is certainly better than 18 weeks, but how about 18 years?

All eyes turned to Harvard, where researchers had started following the health and diets of medical professionals before aspartame had even entered the market. “In the most comprehensive long-term [population] study…to evaluate the association between aspartame intake and cancer risk in humans,” they found a “positive association between diet soda and total aspartame intake and risks of [non-Hodgkin’s lymphoma] and multiple myeloma in men and leukemia in both men and women,” as you can see at 2:12 in my video. Why more cancer in men than women? A similar result was found for pancreatic cancer and diet soda, but not soda in general. In fact, the only sugar tied to pancreatic cancer risk was the milk sugar, lactose. The male/female discrepancy could have simply been a statistical fluke, but the researchers decided to dig a little deeper.

Aspartame is broken down into methanol, which is turned into formaldehyde, “a documented human carcinogen,” by the enzyme alcohol dehydrogenase.The same enzyme that detoxifies regular alcohol is the very same enzyme that converts methanol to formaldehyde. Is it possible men just have higher levels of this enzyme than women? Yes, which is why women get higher blood alcohol levels than men drinking the same amount of alcohol. If you look at liver samples from men and women, you can see significantly greater enzyme activity in the men, so perhaps the higher conversion rates from aspartame to formaldehyde explain the increased cancer risk in men? How do we test this?

Ethanol—regular alcohol—competes with methanol for this same enzyme’s attention. In fact, regular alcohol is actually “used as an antidote for methanol poisoning.” So, if this formaldehyde theory is correct, men who don’t drink alcohol or drink very little may have higher formaldehyde conversion rates from aspartame. And, indeed, consistent with this line of reasoning, the men who drank the least amounts of alcohol appeared to have the greatest cancer risk from aspartame.

A third cohort study has since been published and found no increased lymphoma risk associated with diet soda during a ten-year follow-up period. So, no risk was detected in the 18-week study, the 5-year study, or the 10-year study—only in the 18-year study. What should we make of all this?

Some have called for a re-evaluation of the safety of aspartame. The horse is kind of out of the barn at this point with 34 million pounds of aspartame produced annually, but that doesn’t mean we have to eat it, especially, perhaps, pregnant women and children.


For more information on the effects of aspartame, watch my videos Aspartame and the Brain and Aspartame-Induced Fibromyalgia. Interested in learning more about the effects of consuming diet soda? See, for example:

What about Splenda? Or monk fruit sweetener? I have videos on those, too—watch Effect of Sucralose (Splenda) on the Microbiome and Is Monk Fruit Sweetener Safe?.

I also do a comparison of the most popular sweeteners on the market, including stevia and xylitol, in my video A Harmless Artificial Sweetener.

Perhaps the best candidate is erythritol, which you can learn about in my video Erythritol May Be a Sweet Antioxidant. That said, it’s probably better if we get away from all intense sweeteners, artificial or not. See my video Unsweetening the Diet for more on this.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

The Downside of Curcumin Supplements

Supplement manufacturers often fall into the same reductionist trap as the drug companies. Herbs are assumed to have only one main active ingredient, so, as the thinking goes, if you can isolate and purify it into a pill, you can boost its effects. Curcumin is described as the active ingredient in turmeric, but is it the active ingredient or just an active ingredient? It is just one of many different components—more than 300, in fact—of the whole food spice.

“Only limited studies have compared the potential of turmeric with curcumin.” Some, however, suggest turmeric, the whole food, may work even better—and not just against colon cancer cells. As I discuss in my video Turmeric or Curcumin: Plants vs. Pills, researchers at the Anderson Cancer Center in Texas pitted both curcumin and turmeric against seven different types of human cancer cells in vitro.

The study found that curcumin kicks tush against breast cancer cells, but turmeric, the whole food, kicks even more. In addition to breast cancer, the researchers found that turmeric was more potent compared to curcumin against pancreatic cancer, colon cancer, multiple myeloma, myelogenous leukemia, and colorectal cancer cells, “suggesting that components other than curcumin can also contribute to anti-cancer activities.”

Most clinical studies treating diseases in people have used curcumin supplements, as opposed to turmeric, but none has tried using turmeric components other than curcumin, even though curcumin-free turmeric exhibits anti-inflammatory and anticancer activities.

“Although curcumin is believed to account for most activities of turmeric, research over the past decade has indicated that curcumin-free turmeric”—that is, turmeric with the so-called active ingredient removed—“is as effective as or even more effective than curcumin-containing turmeric.” There are turmerones, for example, in turmeric, which may exhibit both anticancer activities, as well as anti-inflammatory activities, but these turmerones are processed out of curcumin supplements. So, I assumed this review would conclude by stating we should stop giving people curcumin supplements and instead just give them the whole food spice turmeric, but instead the researchers proposed that we make all sorts of different turmeric-derived supplements!


That’s quite a rebut to reductionism. For more on this flawed nutritional philosophy, see my video Reductionism and the Deficiency Mentality.

Similar videos in this vein include:

Interested in learning more about turmeric and cancer? See:

And for more on turmeric and everything else:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Best Food for MGUS to Prevent Multiple Myeloma

Multiple myeloma is one of our most dreaded cancers. It’s a cancer of our antibody-producing plasma cells, and is considered one of our most intractable blood diseases. The precursor disease is called monoclonal gammopathy of undetermined significance (MGUS). When it was named, it’s significance was undetermined, but now we know that multiple myeloma is almost always preceded by MGUS. This makes MGUS one of the most common premalignant disorders, with a prevalence of about 3% in the older white general population, and about 2 to 3 times that in African-American populations.

MGUS itself is asymptomatic, you don’t even know you have it until your doctor finds it incidentally doing routine bloodwork. But should it progress to multiple myeloma, you only have about four years to live. So, we need to find ways to treat MGUS early, before it turns into cancer. Unfortunately, no such treatment exists. Rather, patients are just placed in a kind of holding pattern with frequent check-ups. If all we’re going to do is watch and wait, researchers figured they might as well try some dietary changes.

One such dietary change is adding curcumin, the yellow pigment in the spice turmeric. Why curcumin? It’s relatively safe, considering that it has been consumed as a dietary spice for centuries. And, it kills multiple myeloma cells. In my video Turmeric Curcumin, MGUS, & Multiple Myeloma, you can see the unimpeded growth of four different cell lines of multiple myeloma. We start out with about 5000 cancer cells at the beginning of the week, which then doubles, triples, and quadruples in a matter of days. If we add a little bit of curcumin, growth is stunted. If we add a lot of curcumin, growth is stopped. This is in a petri dish, but it is exciting enough to justify trying curcumin in a clinical trial. And six years later, researchers did.

We can measure the progression of the disease by the rise in blood levels of paraprotein, which is what’s made by MGUS and myeloma cells. About 1 in 3 of the patients responded to the curcumin with dropping paraprotein levels, whereas there were no responses in the placebo group. These positive findings prompted researchers to commence a double-blind, randomized, controlled trial. The same kind of positive biomarker response was seen in both MGUS patients, as well as those with so-called “smoldering” multiple myeloma, an early stage of the cancer. These findings suggest that curcumin might have the potential to slow the disease process in patients, delaying or preventing the progression of MGUS to multiple myeloma. However, we won’t know for sure until longer larger studies are done.

The best way to deal with multiple myeloma is to not get it in the first place. In my 2010 video Meat & Multiple Myeloma, I profiled a study suggesting that vegetarians have just a quarter the risk of multiple myeloma compared to meat-eaters. Even just working with chicken meat may double one’s risk of multiple myeloma, the thinking being that cancers like leukemias, lymphomas, and myelomas may be induced by so-called zoonotic (animal-to-human) cancer-causing viruses found in both cattle and chickens. Beef, however, was not associated with multiple myeloma.

There are, however, some vegetarian foods we may want to avoid. Harvard researchers reported a controversial link between diet soda and multiple myeloma, implicating aspartame. Studies suggest french fries and potato chips should not be the way we get our vegetables, nor should we probably pickle them. While the intake of shallots, garlic, soy foods, and green tea was significantly associated with a reduced risk of multiple myeloma, intake of pickled vegetables three times a week or more was associated with increased risk.

For dietary links to other blood cancers, see EPIC Findings on Lymphoma.

The turmeric story just never seems to end. I recommend a quarter teaspoon a day:

Why might garlic and tea help? See Cancer, Interrupted: Garlic & Flavonoids and Cancer Interrupted, Green Tea.

More on the effects of NutraSweet in Aspartame and the Brain and acrylamide in Cancer Risk From French Fries.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Image Credit: Sally Plank / Flickr. Image has been modified.