What is a Preservative-Free Diet?
Preservative-free diets are globally seen as the new food craze. Preservatives are chemicals that are added into foods to prevent spoiling. They improve appearance and preserve the nutritional quality of the food item. Some examples of preservatives include benzoic acid, calcium sorbate and antioxidants like butylated hydroxy anisole. There are natural preservatives such as sugar, salt and citrus juice.
Preservative-free foods are a choice that an individual makes based on potential health concerns over preservatives. It includes using fresh vegetables, dried legumes and lean meats such as fish, chicken and other poultry. Additionally, it may also involve using pre-packaged foods with fewer preservatives e.g. bagged rice, quinoa, buckwheat, salads, cut vegetables and fruits tray(2).
Why Do We Use Preservatives?
There are many reasons for adding preservatives but whole foods typically do not contain any. Preservatives are added to increase the shelf life of food items, inactivate food ageing and combat the discolouration (as seen in the browning of apples for example)(2).
Types of Preservatives: Natural vs Synthetic
Natural methods of preservation include boiling, freezing, pasteurising and the addition of natural agents such as sugar, alcohol with sugar, salt, alcohol by itself, and vinegar are used for preventing bacterial growth(1).
Synthetic or chemical preservatives include sodium benzoate, benzoic acid, sodium sorbate, potassium sorbate, and sodium nitrate which preserves amino acids and vitamins. Harmful effects include sulfite activity in fruits causing side effects like headaches and palpitations, nitrates and nitrites in cured meats can cause stomach cancer, and also benzoates used as antimicrobial agents are associated with skin rashes and asthma(5).
The Arguments for going Preservative free
Improvement in asthma and other inflammation based conditions following removal of preservatives
People who suffer from rhinitis, eczema, asthma and urticaria have been shown to benefit from preservative free foods as they can accelerate symptoms when ingested. These include azo dyes, benzoates, and sulphur dioxide containing foods. Intake of processed food like grains, red meat and desserts are known to be triggers for asthma(5).
Some evidence suggests preservatives containing nitrites and nitrates can cause cancer
They naturally occur in foods of plant origin like raw spinach, beets and celery and lettuce which contain high amounts of nitrates. Processed meats such as beef and other red meats are sources of nitrites due to preservatives added in the curing process. These nitrates and nitrites convert into nitrosamine compounds which have evidence for being carcinogenic to humans, however experts are unable to create a definite correlation(6). It is advisable to use plant derived nitrates for preservation of meat.
How to go preservative free?
The first step is to check the label for additives. You need to scan the entire ingredients list for ascorbic acid, added colour and sulphur dioxide. The first ingredient is usually the one with the largest quantity while the last ingredient is the smallest. In addition to food preservatives, there are also additives that one must watch out for. These include food colouring, artificial sweeteners, vitamins and minerals. For instance, high fructose corn syrup is a highly dangerous artificial sweetener added to soft drinks. It is worth your while to list all the preservatives that you want to avoid like propionates, nitrates, Glycerine, Xanthan gum, modified corn or corn starch, pectin and agar(3).
Choosing whole foods like unprocessed varieties of grains, fruits, vegetables, raw nuts and seeds is a good second step in this diet. Meat and seafood that are minimally processed, yoghourts without fruits, cheese without heavy processing. Typically, food stores stock processed foods in the main aisles and the perimeter or to the walls contain only unprocessed and preservative free foods.
Learn to identify common preservatives used when buying food
One must scan the entire ingredient list(1). This checklist of items can help you zero in on the preservatives that need to be eliminated from your diet:
Propionates, ascorbic acid, and nitrates for preserving and maintaining foods fresh.
Glycerin is added to maintain moisture for preventing drying of foods
Xanthan gum for thickening foods
Pectin and Agar agar for thickening and stabilising.
Modified corn and corn starch for adding bulk to food
Buy Organic
Labels can be misleading. 100% organic foods are not preservatives free as there are about 45 preservative items that can be added to these. All natural foods can also be misleading as some of them still contain artificial sweeteners and preservatives.
Cook as much as you can from scratch yourself
It is advisable to buy meat and seafood as uncooked varieties and cook them from home. Deli meat stores should be avoided and turkey can be bought whole and sliced by oneself. Shredded cheese contains preservatives so alternatively you can buy a block of cheese and grate it manually. With this home cooked diet, you can more easily control calories, sugar, salt, and preservative intake. For example, salad dressing, sauces and marinades can be prepared fresh and stored at home. Frozen food can be made simply by freezing fruits and vegetables at home, provided they are washed first(3)(4).
Summary
Preservative rich foods can exacerbate diseases like asthma, urticaria and eczema.Common chemicals include nitrates that are extremely harmful for the health so one can be on the lookout for the item on the ingredient list when buying groceries. In order to avoid these kinds of ingredients, it is better to read the labels before buying food as well as home cooking meals.
References
- Center for Food Safety, Applied Nutrition. Overview of Food Ingredients, Additives & Colors [Internet]. U.S. Food and Drug Administration. FDA; [cited 2022 Jun 27]. Available from: Fda
- What you Need to Know about Preservatives - Unlock Food [Internet]. Unlockfood.ca. 2022 [cited 21 March 2022]. Available from: Unlockfood
- Freedman BJ. A dietary free from additives in the management of allergic disease. Clin Allergy. 1977 Sep;7(5):417-21. doi: 10.1111/j.1365-2222.1977.tb01472.x. PMID: 589776.
- Karwowska M, Kononiuk A. Nitrates/Nitrites in Food—Risk for Nitrosative Stress and Benefits. Antioxidants. 2020;9(3):241.
- Asthma and food allergies [Internet]. Gov.au. [cited 2022 Jun 27]. Available from: Betterhealth
- Rushlow A. Is there a connection between food preservatives and cancer? [Internet]. Cure Today. 2014 [cited 2022 Jun 27]. Available from: Curetoday