What Is Aspartame and How Does It Affect Your Health?

Aspartame is a synthetic sweetener made from two ingredients:

1. Aspartic acid: This is a nonessential amino acid naturally found in the human body and various foods. Amino acids are the building blocks of proteins, and aspartic acid plays a role in producing hormones and supporting the nervous system. It can be found in foods like meat, fish, eggs, soybeans, and peanuts.

2. Phenylalanine: This essential amino acid is present in most protein-rich foods but is not produced naturally by the body. It must be obtained from the diet. Phenylalanine is used by the body to produce proteins, brain chemicals, and hormones. It’s found in foods such as lean meats, dairy products, nuts, and seeds.

The combination of these two ingredients creates a substance that is around 200 times sweeter than regular sugar. Just a small amount can make food taste very sweet, with minimal calories.

The Claims Surrounding Aspartame

Several online sources claim that aspartame (sold under brand names like Equal and NutraSweet) can cause various health problems, including:

• Multiple sclerosis (MS)

• Lupus

• Seizures

• Fibromyalgia

• Depression

• Memory loss

• Vision issues

• Confusion

The FDA approved aspartame as a safe sweetener for general use in 1981 and for use in carbonated beverages in 1983. According to the FDA, extensive studies support its safety.

However, at the time of approval, some scientists voiced concerns based on an animal study that suggested potential negative effects on brain development and health. They noted that these adverse effects might only occur with very high aspartame consumption.

A safety board concluded that the amount of aspartame needed to trigger these issues would be extremely difficult for a human to consume. The study’s methodology was also considered flawed, and the sweetener was deemed safe.

The American Cancer Society points out that the FDA has set an “acceptable daily intake (ADI)” of 50 milligrams per kilogram of body weight per day. This amount is roughly 100 times lower than the level at which health problems were observed in animal studies.

Potential Risks and Side Effects of Aspartame

Since the approval of aspartame, various scientific studies have investigated its potential health effects. Here’s what we’ve learned:

Immune System and Oxidative Stress:
A 2017 review concluded that aspartame could impact the immune system, potentially leading to oxidative stress and inflammation. This review suggested that aspartame could affect multiple organs, including the brain, heart, liver, and kidneys. Additionally, aspartame could disrupt the balance of the gut microbiota, which plays a key role in overall health.

Some researchers believe aspartame may interfere with glucose tolerance and insulin levels, particularly for people with diabetes, and have called for further research on its long-term effects.

Phenylketonuria:
The FDA warns that individuals with phenylketonuria (PKU), a rare genetic disorder, should avoid aspartame. Those with PKU have difficulty metabolizing phenylalanine, one of aspartame's components. If consumed, phenylalanine can accumulate in the body and cause brain damage. The FDA advises people with PKU to monitor their intake of phenylalanine from all sources, including aspartame.

Mood Changes:
Some studies suggest aspartame could potentially affect mood disorders like depression. An older study found that aspartame seemed to worsen symptoms in people with a history of depression, though it did not have this effect on those without such a history.

A 2014 study found similar results, with participants consuming a high-aspartame diet reporting more irritability and feelings of depression.

A 2017 review of studies examining aspartame and neurobehavioral health also suggested that phenylalanine might interfere with the production of "feel-good" neurotransmitters, such as serotonin and dopamine. The review also linked aspartame to oxidative stress and higher cortisol levels, which could impact mood and overall well-being.

Cancer Risk:
Some animal studies have suggested a connection between aspartame and cancers like leukemia. For instance, a 2007 study found that rats exposed to low doses of aspartame daily had a higher chance of developing cancer. However, the methodology of this study was criticized, and a 2019 review found no evidence of a link between aspartame and cancer.

The American Cancer Society states that there is insufficient evidence to conclude that aspartame causes cancer in humans.

Multiple Sclerosis (MS) and Lupus:
According to the National MS Society, the theory that aspartame is linked to MS has been debunked. Similarly, the Lupus Foundation of America does not believe that aspartame consumption causes lupus.

Headaches:
Some studies have suggested that aspartame could trigger headaches in certain individuals. However, a 1987 study found no increased incidence of headaches among people who consumed aspartame compared to those who took a placebo. A small 1994 study did suggest that some people might be sensitive to aspartame and experience headaches, but the study’s design was later criticized.

Seizures:
In a 1995 study, researchers tested 18 individuals who claimed aspartame triggered seizures. They found that even at a high dose of 50 mg, aspartame did not cause seizures more frequently than a placebo. Similar findings were noted in a 1992 animal study.

Fibromyalgia:
In 2010, two patients reported that eliminating aspartame from their diet helped alleviate fibromyalgia symptoms. However, no experimental evidence supports this claim, and a later study found no impact on fibromyalgia pain from removing aspartame.

Should You Avoid Aspartame?

While aspartame may cause issues for people with phenylketonuria or those with mood disorders, there is no solid evidence suggesting that it increases the risk of conditions like MS, lupus, seizures, cancer, or fibromyalgia.

Several reputable organizations, including the FDA, the Joint Expert Committee on Food Additives, the United Nations Food & Agriculture Organization, the European Food Safety Authority, and the World Health Organization, all consider aspartame to be a safe sugar substitute.

However, due to public concern, many food and drink manufacturers have opted to avoid aspartame in their products. If you’re concerned about sensitivity to aspartame, make sure to read food and beverage labels and choose products without it.