Diet Sodas – How Many Can We Drink?

Margarita FolkPosted by

Questions and anxieties about drinking too many diet sodas (containing aspartame) came up in our family recently. The main concern was whether it caused cancer. After a brief search, I found two authoritative sources that agreed with each other on overlapping points. One was on the web site for the American Cancer Society and the other was a recent paper in Food and Chemical Toxicology by Renwick and Nordmann1. While aspartame is included in many diet products as a sucrose (sugar) replacement, I wanted to know how many diet sodas is considered safe to drink each day.

The American Cancer Society web site gave a brief history of aspartame. In 1981, the US Food and Drug

Administration (FDA) approved its use in a variety of foods including cold breakfast cereals, chewing gum, dry drink mixes, instant tea and coffee, gelatins, puddings, fillings, non-dairy toppings, and as a tabletop sweetener. It was approved in 1983 for use in carbonated beverages and carbonated beverage syrups. Today it is found in even more food products. Two units of the United Nations, the World Health Organization (WHO) and the Food and Agriculture Organization (FAO), through their Joint Expert Committee on Food Additives (JECFA), recommend Acceptable Daily Intake (ADI) levels for many food additives. The ADI is the amount of an additive that, if eaten every day for the rest of a person's life, would be considered safe. Animal studies in the 1970s found that rats could eat 4 grams of aspartame per kilogram of body weight without showing health problems. To be safe, the JECFA divided this dose by 100, and set the Acceptable Daily Intake of aspartame for humans at 40 milligrams per kilogram of body weight. The FDA has now increased acceptable daily intake of aspartame for humans to 50 milligrams per kilogram of body weight per day.

OK, given the amount of aspartame in a typical can of diet soda (~ 180 mg), we can estimate the number of diet sodas that corresponds to 50 mg / kg body weight per day. Assuming we are not consuming aspartame in any other form, the maximum number of diet sodas per day depends on our weight: 6.3 (50 lb), 8.8 (70 lb), 11.4 (90 lb), 13.9 (110 lb) 16.4 (130 lb), 18.9 (150 lb), 21.5 (170 lb) and 24.0 (190 lb). So, basically, we may need to monitor the number of diet sodas that kids consume but the upper limits for adults seem to be well above the number they would want to drink.

Research into the safe consumption limits for aspartame is ongoing. As recently as April 2007, the FDA found no reason to alter its previous conclusion that aspartame is safe as a general-purpose sweetener in food (at 50 mg / There is one exception to this limit that has been well documented. People born with a rare genetic disorder called
phenylketonuria (PKU) can not break down (metabolize) the amino acid phenylalanine. This amino acid occurs naturally and is found in aspartame. PKU is usually detected in babies by a routine blood test at birth. People with the disorder are placed on a phenylalanine-restricted diet and must avoid aspartame. Regarding cancer, the American Cancer Society concluded that current evidence does not demonstrate any link between aspartame and an increased risk of cancer.

The Renwick paper 1 assessed the findings of a recent animal study on aspartame at the Ramazzini
Institute (Soffritti et. Al., Environmental Health Perspectives, 114, p. 374-385, 2006), which claimed that aspartame was a "multi-potential carcinogen". The European Food Safety Authority (EFSA) did a comprehensive evaluation (EFSA Journal, 356, p. 1-44, 2006) of this study and reached the conclusion that the data presented do not provide evidence of a carcinogenic potential from aspartame and that there was no reason to revise the FDA allowance (then 40 mg /, now 50 mg /

The Renwick paper also assessed the potential benefits of sucrose (sugar) replacements. In theory, replacing sucrose (4 kcal / g) by a low-calorie sweetener (aspartame) should allow the pleasure of ingesting sweet-tasting foods and drinks to be retained while decreasing energy intake, but the issue is complex. Sucrose fulfills roles in food other than sweetness and its removal from solid food requires the introduction of other ingredients, which might add calories back into the food. However, for beverages the main function of sucrose is to impart sweetness, so it can be replaced more readily with a reduction in calories. In the past, questions have been raised about whether intense sweeteners increase appetite or result in a craving for sweetened foods, but these suggestions have been disproved (Rolls, International Journal of Obesity 53, 872-878, 1991). In contrast, a number of intervention studies have shown that replacing sucrose with aspartame in the diet of those trying to reduce their weight results in an increased weight loss
(De la Hunty et al., British Nutrition Foundation Nutrition Bulletin 31, 115-128. 2006).

So, the evidence after 25 years of aspartame consumption is that the risk of a health hazard is vanishingly low within the FDA allowance (except if you are on a phenyalanine-restricted diet) and that lowering our energy intake by sucrose replacement helps in weight reduction and management.

1 AG Renwick and H. Nordmann, "First European Conference on Aspartame: Putting safety and benefits into perspective. Synopsis of presentations and conclusions, Food and Chemical Toxicology, vol. 45, pp. 1308-1313, 2007.

Source by Bob Klassen