By Dr. Mercola
Aspartame is an artificial sweetener used in diet soda and over 6,000 other sugar-free or "diet" products. New research1 linking aspartame to cancer in some individuals has sparked a flurry of commentary, including an "apology" from Brigham and Women's Hospital, a Harvard University teaching facility, for promoting the results2.
I first found out about the study when ABC News contacted me and requested that I provide them with a comprehensive analysis of this 40-page study within an hour. Fortunately, I have extensively reviewed this topic and was able to provide their requested review.
Funding was provided by grants from the National Institutes of Health (NIH) and the National Cancer Institute (NCI).
The Harvard hospital originally sent out a press release with the headline: "The truth isn't sweet when it comes to artificial sweeteners." Alas, just half an hour before the release of the study, the hospital suddenly got cold feet, issuing the following statement:
"Upon review of the findings, the consensus of our scientific leaders is that the data is weak, and that BWH Media Relations was premature in the promotion of this work. We apologize for the time you have invested in this story."
According to Erin McDonough3, senior vice president of communication and public affairs, this was "the first time something like this had ever happened in her 25 years of working in media relations."
NBC News stated4:
"Not all science deserves publicity. Some is not done well. Some comes to equivocal conclusions and serves solely to alert other researchers of the need for further study. The research... about a potential cancer from aspartame falls squarely in that second category. If such a study does get attention, it can often increase the confusion and anger that many people feel about science in general – and the study of possible risks and benefits of our diet, in particular."
None of this surprises me. After all, can you imagine the liability the food and beverage industries, not to mention virtually every public health agency in the US, would face were there convincing evidence that aspartame is carcinogenic? They simply cannot afford such evidence to be accepted.
But make no mistake about it, this study is of great importance because it's the most comprehensive and longest human study — spanning 22 years — that has ever looked at aspartame toxicity. The study evaluates the effect between aspartame intake and cancer, and they found a clear association between aspartame consumption and non-Hodgkin's Lymphoma and leukemia.
Ignoring First Long-Term Human Study Would Be a MAJOR Mistake
This is the first large-scale observational human study to report an association between aspartame consumption and blood cancers. The long-term nature of this study is really crucial because one of the primary tricks companies use to hide the toxicity of their products is short-term tests.
As the study mentions, the longest study prior to this one was only four and half months, far too short to reveal any toxicity from chronic exposure. Unfortunately, because there are so many of these short-term trials, they get away with saying that aspartame is one of the most studied food additives ever made and no health concerns have ever been discovered. The beverage industry was quick to respond5 to the study saying aspartame has been "deemed safe for decades by the world's leading toxicologists."
Well, they simply didn't look long enough! But the average person does not realize that all those industry-funded studies were so pathetically short, and the media doesn't inform them of this fact either. Hence, people are easily misled.
A number of animal studies have clearly documented the association between aspartame and cancer, as the study points out. But what most researchers do not appreciate is that humans are the only animals that do NOT have the protective mechanism to compensate for methanol toxicity. So evaluating methanol toxicity in animals is a flawed model for testing human toxicity.
This is due to alcohol dehydrogenase (ADH). In humans, methanol is allowed to be transported in the body to susceptible tissues where this enzyme, ADH, then converts it to formaldehyde, which damages protein and DNA that lead to the increased risk of cancer and autoimmune disease.
Interestingly, the previous AARP Diet and Health Study, which did not find an association with aspartame and cancer, used fruit juice as the control. Most are unaware that canned or bottled fruit juice is loaded with methanol that dissociates from the pectin over time and can actually cause similar problems as aspartame. This does not occur in freshly consumed fruits and vegetables, only ones that are bottled or canned. Hence no major difference could be discerned between the aspartame and the control group.
Why Was Aspartame More Toxic in Men than Women?
The health statistics for nearly 48,000 men and over 77,000 women over the age of 20 were reviewed for the featured study. They found that men who consumed more than one diet soda per day had an increased risk of developing multiple myeloma and non-Hodgkin's lymphoma. Interestingly enough, this association was not found in women.
Leukemia was associated with diet soda intake in both sexes.
One hypothesis for the difference between the sexes is that men have a higher activity of the enzyme ADH, as I mentioned earlier, which metabolizes methanol and converts it to formaldehyde. More formaldehyde circulating in your blood would naturally have more opportunity to cause greater damage.
While the findings from this study add credible evidence that consuming aspartame over a long period of time can pose significant health risks, it also demonstrates that our understanding of the precise mechanism of harm is still lacking and needs to be investigated further, as it's unclear why the women in this study didn't experience the same increased rates of cancer.
It's possible that there is some hormonally mediated protection against the adverse effects of aspartame in women, in addition to men having higher ADH activity, but the study was not designed to answer that question.
All in all however, I believe the study offers significant supporting evidence of the danger that "diet" drinks and foods pose. Many have indeed been injured by aspartame — there are more adverse reports to the FDA on aspartame than all other food additives combined. It's also widely known how massive industry and government collusion at the FDA was ultimately responsible for its approval after it failed to be approved for many years.
Although the authors' summary conclusion mentions they do not rule out the possibility of chance for this association, it's worth noting that this is because they could not offer a conclusive explanation for the difference between the sexes.
I carefully reviewed this study in its entirety, and found it to be extremely well executed. While the mechanism responsible for the difference between the sexes for certain cancers need to be studied further, a biological mechanism for cancer from aspartame does exist, which I'll review in a moment. Furthermore, it was the reviewers of the study that pushed back during the editing process, insisting that it should be made clear that chance was a plausible explanation for the findings6.
Lead researcher Eva Schernhammer, MD, DrPH stated in the original press release (which has since been removed):
"The sex difference we observed deserves consideration. There are many possible explanations in this, one being chance, however these differences could be related to a yet-to-be-discovered risk factor for lymphoma and leukemia, which are associated with soda consumption in men, but not women."
Methyl Alcohol — The Root of the Problem with Aspartame
Aspartame is primarily made up of aspartic acid and phenylalanine. The phenylalanine has been synthetically modified to carry a methyl group, which provides the majority of the sweetness. That phenylalanine methyl bond, called a methyl ester, is very weak, which allows the methyl group on the phenylalanine to easily break off and form methanol. This is in sharp contrast to naturally-occurring methanol found in certain fruits and vegetables, where it is firmly bonded to pectin, allowing the methanol to be safely passed through your digestive tract.
If the methyl alcohol is broken off from the phenylalanine, as easily happens when drinks sweetened with it are exposed to higher temperatures, it no longer tastes sweet. This is precisely what happened to most of the diet soda sent to the Middle East for US troops. They received non-sweet sodas that were loaded with dangerous levels of methanol, which can be toxic when it's in this already broken down state.
Methanol acts as a Trojan horse; it's carried into susceptible tissues in your body, like your brain and bone marrow, where the ADH enzyme converts it into formaldehyde, which wreaks havoc with sensitive proteins and DNA. All other animals, on the other hand, have a protective mechanism that allows methanol to be broken down into harmless formic acid...
According to aspartame expert Dr. Woodrow Monte, there's a major biochemical problem with methanol in humans, because of the difference in how it's metabolized, compared to all other animals. This is why toxicology testing on animals is a flawed model. It doesn't fully apply to humans.
Both animals and humans have small structures called peroxisomes in each cell. There are a couple of hundred in every cell of your body, which are designed to detoxify a variety of chemicals. Peroxisome contains catalase, which help detoxify methanol. Other chemicals in the peroxisome convert the formaldehyde to formic acid, which is harmless, but this last step occurs only in animals.
When methanol enters the peroxisome of every animal except humans, it gets into that mechanism. Humans do have the same number of peroxisomes in comparable cells as animals, but human peroxisomes cannot convert the toxic formaldehyde into harmless formic acid.
So again, to recap: In humans, the methyl alcohol travels through your blood vessels into sensitive areas, such as your brain, that are loaded with alcohol dehydrogenase (ADH), which converts methanol to formaldehyde, and since there's no catalase present, the formaldehyde is free to cause enormous damage in your tissues.
Saccharin and Aspartame Cause Greater Weight Gain than Sugar
In related news, a study published on October 19 in the journal Appetite7, found that compared with sucrose (regular table sugar), saccharin and aspartame caused greater weight gain in adult rats, and this weight gain was unrelated to caloric intake. The underlying mechanism was not determined.
However, a number of studies have already shown that consuming artificial sweeteners breaks the connection between a sweet sensation and a high-calorie food, thereby changing your body's ability to regulate intake naturally. In a similar 2008 study8, rats that ate yogurt sweetened with an artificial sweetener consumed more calories, gained more weight, and put on more body fat than rats that ate yogurt sweetened with sugar. Other studies, too, have shown that eating artificial sweeteners might hinder your body's ability to estimate calorie intake, thus boosting your inclination to overindulge.
The fact that aspartame is NOT a dieter's best friend has been known by scientists for some time. The problem is this news has not received the necessary traction in the media...
For example, a study from 19869, which included nearly 80,000 women, found that those who used artificial sweeteners were significantly more likely than non-users to gain weight over time, regardless of initial weight. According to the authors, the results "were not explicable by differences in food consumption patterns," and concluded that:
" The data do not support the hypothesis that long-term artificial sweetener use either helps weight loss or prevents weight gain."
Another more recent study with the telling title of Gain Weight by "Going Diet?" Artificial Sweeteners and the Neurobiology of Sugar Cravings, published in 201010, found that epidemiologic data suggest artificially sweetened foods and beverages do not reduce weight. Quite the contrary:
"Several large scale prospective cohort studies found positive correlation between artificial sweetener use and weight gain. The San Antonio Heart Study examined 3,682 adults over a seven- to eight-year period in the 1980s.
When matched for initial body mass index (BMI), gender, ethnicity, and diet, drinkers of artificially sweetened beverages consistently had higher BMIs at the follow-up, with dose dependence on the amount of consumption... Saccharin use was also associated with eight-year weight gain in 31,940 women from the Nurses' Health Study conducted in the 1970s.
Similar observations have been reported in children.
A two-year prospective study involving 166 school children found that increased diet soda consumption was associated with higher BMI Z-scores at follow-up, indicating weight gain. The Growing Up Today Study, involving 11,654 children aged 9 to 14 also reported positive association between diet soda and weight gain for boys. For each daily serving of diet beverage, BMI increased by 0.16 kg/m2... A cross-sectional study looking at 3,111 children and youth found diet soda drinkers had significantly elevated BMI."
Are Your Health Problems Related to Artificial Sweeteners?
Many people belatedly realize they've been suffering reactions to one artificial sweetener or another. If you suspect an artificial sweetener might be to blame for a symptom you're having, a good way to help you weed out the culprit is to do an elimination challenge. It's easy to do, but you must read the ingredient labels for everything you put in your mouth to make sure you're avoiding ALL artificial sweeteners. To determine if you're having a reaction to artificial sweeteners, take the following steps:
- Eliminate all artificial sweeteners from your diet for two weeks.
- After two weeks of being artificial sweetener-free, reintroduce your artificial sweetener of choice in a significant quantity (about three servings daily). Avoid other artificial sweeteners during this period.
- Do this for one to three days and notice how you feel, especially as compared to when you were consuming no artificial sweeteners.
- If you don't notice a difference in how you feel after re-introducing your primary artificial sweetener for a few days, it's a safe bet you're able to tolerate it acutely, meaning your body doesn't have an immediate, adverse response. However, this doesn't mean your health won't be damaged in the long run.
- If you've been consuming more than one type of artificial sweetener, you can repeat steps 2 through 4 with the next one on your list.
Let me make it abundantly clear that even though you may not show immediate signs of any noticeable reaction after consuming artificial sweeteners, please don't make the mistake of telling yourself "they must be OK for me". I strongly urge you to avoid them at all costs. They are toxic to all humans and will not help you in any way, shape, or form.
Also, if you do experience side effects from aspartame, please report it to the FDA (if you live in the United States) without delay. It's easy to make a report — just go to the FDA Consumer Complaint Coordinator page, find the phone number for your state, and make a call reporting your reaction. There's no telling just how many reports they might need to receive before taking another look at aspartame's safety and reconsidering their stance. But I CAN tell you, the more reports they get, the more likely that is to happen. So if you suspect you have experienced an adverse reaction from aspartame (or any other drug or food additive), please take a moment to make this important call.
Are there ANY Safe and Healthy Alternatives to Sugar?
The best strategy is to lower your use of sugar and eat right for your nutritional type and make sure you have enough high quality fats. Once your body has the proper fuel, your sweet cravings will radically diminish and you will be satisfied without them. If you still have cravings it is a strong suggestion you need to further refine your attempt to identify the right fuel for your body. My free Nutritional Plan can help you do this in a step by step fashion.
If you need a sweetener you could use stevia or Lo Han, both of which are safe natural sweeteners. Remember, if you struggle with high blood pressure, high cholesterol, diabetes or extra weight, then you have insulin sensitivity issues and would benefit from avoiding ALL sweeteners.
If you're having trouble weaning yourself off soda, try Turbo Tapping. Turbo Tapping is a clever use of the Emotional Freedom Technique (EFT), specifically designed to resolve many aspects of an addiction in a concentrated period of time.