Modern food is packed with additives, many of which most of us aren't even aware of. Scientific evidence increasingly shows that these substances are having a myriad of adverse effects on the health of global populations. This is quite ironic given the fact that The World Health Organisation (WHO) defines food additives as 'substances added to food in order to maintain or improve its safety, freshness, taste, texture or appearance'1.
While food additives are often required by governing bodies to be listed on labels, the quantities are not. Even if they were, they would probably be something most overlook, instead paying more attention to the nutritional information such as calories, protein, carbohydrate and fat content that we've been taught to examine when dieting.
As evidence of the potential dangers of food additives mounts, the latest findings, gleaned from a two-phase study of both mice and humans, have uncovered a strong link between the addition of one particular food additive and a lack of physical exercise2.
Adult activity rates dangerously low
According to statistics, less than 5% of the adult United States population engages in the recommended 30 minutes of daily exercise3. That is a frightening statistic that may be a contributing factor to increasing obesity rates (it is estimated that approximately 39.8% of the population is clinically obese4) and resultant elevated risk of developing obesity-related conditions such as type 2 diabetes, heart disease, stroke and certain cancers.
Efforts to explain sedentary lifestyles
Research efforts to explain just why adults are increasingly leading such sedentary lifestyles abounds. New findings published by researchers led by Dr Wanpen Vongpatanasin at the University of Texas Southwestern Medical Center reveals that a common food additive, inorganic phosphate, may be a contributing factor.
What is inorganic phosphate and why is it a potential health risk?
Phosphate is a derivative of phosphorus, an essential mineral used in the production and repair of bones and teeth, it also aids nervous system function and is used by the body to enable muscle contraction. Dietary phosphorus occurs in organic (natural) form in both animal and vegetarian proteins, while inorganic (synthetic) phosphate is generally derived from food additives.
Inorganic phosphate is added to everything from processed meats to tinned fish, baked goods, soft drinks and more. This is done in order to preserve freshness and enhance flavour.
The difference between the two forms of phosphate comes down to the way they are absorbed in the body. Organic phosphate is incompletely absorbed by the body, while inorganic (synthetic) phosphate is fully absorbed5, which means that there is more circulating in the system.
Generally, healthy kidneys regulate the amount of phosphate present in the blood and filter out excess via the urine. However, those suffering from kidney disease may have difficulty flushing excess phosphate out of the body, which is harmful to health and increases the risk of mortality.
Even in healthy individuals, excess phosphate is associated with an elevated risk of cardiovascular related events and death.
Phosphate's influence on physical activity
In the study led by Dr Vongpatanasin, researchers initially fed two groups of healthy mice the same diet with one exception – one group was given additional phosphate in amounts equivalent to those consumed by adults in the United States.
According to the researchers, 25% of adults consume between three and four times more phosphate than the recommended guidelines. After 12 weeks, the body weight of the mice on the phosphate enriched diet was not altered, but the rodents exhibited lower activity rates and exercise intolerance, spending less time on the treadmill and displaying decreased cardiac fitness.
The mice also experienced impaired fatty acid metabolism and displayed changes in key genes that facilitate fat and cell metabolism.
In the second phase of the study, 1,600 healthy adults wore fitness trackers for a week, allowing researchers to monitor their activity levels. Findings revealed that those with higher blood phosphate levels also led more sedentary lifestyles and spent less time engaging in physical exercise at a moderate to vigorous pace.
From these findings the researchers concluded that a high intake of dietary phosphate may be a significant contributor to declining exercise rates in the general population. They also called for further research and studies to define the health impact of modified phosphate in food.
Commenting on the study's findings, Dr Vongpatanasin said that he believed it was time for people to push the food industry to detail just how much phosphate is really going into food, however he noted that this was something that would require further research to be enforced by the appropriate governing bodies.
How to reduce inorganic phosphate intake
While there is no need to reduce organic phosphate in your diet due to the fact that this is incompletely absorbed by the body, reducing the intake of inorganic phosphate found in food additives which is fully absorbed by the body, is highly beneficial and may not only improve overall health but also the capacity for physical exercise.
This can be done by examining food labels and avoiding (or at least limiting) intake of those that mention any of the following:
- Aluminium phosphate
- Dicalcium phosphate
- Hexametaphosphate
- Monocalcium phosphate
- Phosphoric acid
- Polyphosphate
- Pyrophosphate
- Sodium phosphate
- Sodium polyphosphate
- Sodium tripolyphosphate
- Tetrasodium phosphate
- Tricalcium phosphate
- Trisodium phosphate
When it comes to selecting food items, cutting down on, or eliminating the following is advisable:
- Processed (enhanced meats like ham, sausages and chicken products) and fast food
- Breakfast (cereal) bars
- Sodas, iced teas, flavoured waters and bottled coffee beverages
- Non-dairy creamers
References
1. Food additives. Who.int. https://www.who.int/news-room/fact-sheets/detail/food-additives. Published 2018. Accessed January 10, 2019.
2. Peri-Okonny P, Baskin K, Iwamoto G et al. High-Phosphate Diet Induces Exercise Intolerance and Impairs Fatty Acid Metabolism in Mice. Circulation. 2019. doi:10.1161/circulationaha.118.037550
3. Facts & Statistics. HHS.gov. https://www.hhs.gov/fitness/resource-center/facts-and-statistics/index.html. Published 2017. Accessed January 10, 2019.
4. Adult Obesity Facts | Overweight & Obesity | CDC. Cdc.gov. https://www.cdc.gov/obesity/data/adult.html. Published 2018. Accessed January 10, 2019.
5. Ritz E, Hahn K, Ketteler M, Kuhlmann M, Mann J. Phosphate Additives in Food. Deutsches Aerzteblatt Online. 2012. doi:10.3238/arztebl.2012.0049