PLEASE NOTE: Extensive photographs and study documenting the following items will be added as time allows after the main study text is finished. Those photos to be added are of apparatus, supplies, utensils, and will demonstrate methods used to further decrease plastic contamination in intervention foods whose surfaces were potentially contaminated by contact with plastic packaging.
All water consumed and/or used for cooking, washing, drinking or used to irrigate self-grown plants will be obtained from a commercial device using a solid-block carbon filter and certified by NSF for reduction of BPA and phthalates. One such device is the Aquaversa filter from Multipure which uses a carbon block filter that lists BPA among its contaminant reduction list. The list does not mention phthalates. However, the list does cover many chemical with similar phenolic structures.
If study funds are available, it would be valuable to determine BPA and phthalate levels in the water water before the filter and afterwards.
In addition, independently published research indicates that other types of carbon filters are effective in reducing many harmful compounds including organic chemicals.
- Effects of activated carbon types and service life on removal of endocrine disrupting chemicals: amitrol, nonylphenol, and bisphenol-A.
- Adsorption characteristics of selected pharmaceuticals and an endocrine disrupting compound—Naproxen, carbamazepine and nonylphenol—on activated carbon
- Bisphenol A Removal from Water by Activated Carbon. Effects of Carbon Characteristics and Solution Chemistry, Environmental Science and Technology, 39 (16) (2005), pp. 6246-6250
Only locally roasted and ground beans will be used.
Provider will be selected on the smallest amount of plastic involved. Beans and grounds will be handled with metal or glass only and packed in glass jars.
Beans will be ground in a mill with no plastic components.
The beans will be prepared using either an all glass and stainless steel French press or a stainless steel percolator with all metal parts.
Also acceptable is the Moka pot-style espresso maker or a pour-over, glass and metal coffee maker with water from an all metal tea kettle. All metal wire basket for grounds must be used, no filter paper.
If an automatic drip system can be located with no plastic ever touching the water or coffee stream, that will be obtained and used.
The weakest links in drip coffee makers that appear to be all glass and/or metal usually lies in plastic tubing that connects the heating element to the water reservoir, the hot water application tube, and the filter basket.
No tea will be allowed. Like spices, the extensive harvest, curing, processing, and packaging offers many contamination routes.
Also like spices, the tiny fragments that compose tea increase the surface area capable of acquiring chemical contamination.
Highly processed. Not allowed in the study diet.
No commercial juices allowed. Highly processed. Not allowed in the study diet.
Freshly prepares using no plastic contact. In general, whole fruits are a healthier alternative to juices.
Beer and wine
No commercial products allowed. All are extensively processed using plastic.
All food items will be sourced from the provider. All provider locations will be personally visited and inspections made of their premises, equipment and processes.
Beef, lamb, chicken, pork, fish
Minimum standards: Organic certification, no plastic in growing, harvesting, handling, or packaging. All animals must be free-range.
Even if allowed by exceptions to organic regulations: No commercial fertilizers, pesticides, or recycled wastewater irrigation are allowed in this study. No irrigation of pasture and feeding areas is preferred. Drinking water from well or municipal water only. No PVC or other plastics.
Beef and lamb must be grass-fed and comply with AGA Statement of Best Practices.
Preference given to non-irrigated pasturing. For welfare of animals, supplemental hay is allowed but must come from non-irrigated pasture.
Possible source: Crowd Cow
Must be humane.
Solid cuts of meat only. No sausage or ground meat.
Slaughter to avoid all plastic contact unless absolutely vital for health and hygiene. Nitrile gloves.
Finished cuts to be placed in glass containers covered with aluminum foil (not in contact with meat) and finally sealed with a plastic lid.
Beef, lamb & goat
Lean cuts (minimum marbling) on beef and lamb. Lower fat content helps minimize lipophilic content.
Visible fat to be removed before cooking to minimize lipophilic concentration.
Skin to remain on chicken, to be removed before cooking to minimize lipophilic concentration. Breasts only for chicken.
Not included in the study diet.
Diet and subsequent flesh contamination are extremely hard to control or monitor.
Study note: An exception was made for organic, un-smoked bacon because the intervention diet needed to include a version of the all-American bacon cheeseburger. An exception was also made to use organic sliced ham (minimal water, no preservatives) in a ham and cheese sandwich.
Same water, feed, and pasturing requirements as beef, lamb, and goat.
Udder and teat cleaning and treatments for animal welfare and human hygiene must be examined for plastic exposures and contamination minimized.
Milking must be done preferably by hand or using milk machines certified as BPA and phthalate-free. Nitrile gloves to be used. All collected milk must be in stainless steel vessels. Filtering stages cannot use polymer filters. Separation, homogenization (if any) and pasteurization must be plastic free. Glass containers must be used for bottling of milk.
Cream gathered during the separation process will either be used for cheese or discarded to minimize lipophilic contaminate concentration.
Cheese will be made using milk prepared as described above. Preference will be given to low- or moderate-butterfat cheeses.
The cheese process will use stainless steel in the initial heating processes. Curds will be gathered and drained in stainless-steel wire baskets. The whey will be discarded.
Drained curds will be pressed in stainless steel molds. Finished cheese will be packed in aluminum foil then placed in Ziploc-type airtight containers.
Note: Ziploc claims to be BPA free but has not addressed phthalates. It is also unknown whether “BPA free” means a switch to a Bisphenol analog such as BPS.
Fruits & vegetables
All vegetables and fruits must come fresh from an organically-certified source irrigated by well water or suitably filtered tap water.
Recycled municipal wastewater (increasingly used for food crops) is unacceptable.
All irrigation must also be done using metal containers. No plastic drip lines or emitters
No commercial fertilizer can be used.
No pesticide can be applied including substances that are approved for organic use unless they have been examined for — and free of — adjuvants, surfactants, and other auxiliary chemicals that may have endocrine-disrupting or other harmful effects.
The soil in which plants are grown cannot come from a source that uses commercial fertilizer amendments, or biosolids (sludge from municipal sewage treatment plants) which is also increasingly used on food crops.
The vegetables must be harvested and processed by hand without using polymer gloves other than nitrile. No conveyor belts, plastic tubs, or containers are allowed.
Vegetables must be placed in a glass or steel container for delivery, not in a plastic bucket or in cardboard. Phthalates are commonly used in the inks on paper and cardboard and are found in recycled paper, cardboard, and packaging materials.
Salad dressings will be made with lemon or other citrus juices, not vinegar.
Bread and cereal
Bread will be sourced directly from a baker who has ground the grain without any plastic contact including utensils, dough rising pans or wrapping. Paper for wrapping cannot be recycled because of phthalate inks commonly used in packaging printing.
Plain bread without seeds, nut, spices, or other components such as raisins may be allowed.
Corn-based foods must be from non-GMO corn raised organically and fried in oil which is similarly organic and non-GMO in origin. It is unknown at this time whether such healthier alternative is available.
Commercially produced cereals are not allowed on this diet due to extensive processing involved. Rolled oats may be allowed if as suitable source can be found.
Given the lipophilic nature of BPA, phthalates and many other harmful environmental chemicals, finding an acceptable source of edible oils is one of the most difficult.
This is aggravated by the fact that producing edible oils requires many processing steps to separate the desired lipids from the pulp and aqueous portions of the source fruit, nut or seed.
Because of its local ready availability, this diet will use first cold press olive oil.
Locally produced olives will, ideally, be non-irrigated.
The Olive fruit fly is endemic in California and other wine producing regions around the world. There are a variety of methods for controlling infestations including baits, traps, attractant strips and certified organic pesticides such as Spinosad and Surround. (UC Pest Management Guidelines).
Despite their organic-certified status, both Surround and Spinosad contain toxic chemicals and proprietary chemicals whose identities are trade secrets and not disclosed. Because of this, olives treated with these are unacceptable.
Untreated olives or those produced in groves using baits, traps, or attractant strips are acceptable.
Olives undergo a washing process — a water rinse — before pressing. There are many other stages, some of which commonly use plastic components in the process.
Visits will be made to determine which oil press minimizes the use of plastic components.
Nuts & Spices
Almonds will either be hand-shelled or obtained from a commercial processor directly from the shelling process before encountering plastic materials in the processing and packaging processes. Slight contact with plastic may be encountered as almond nuts exit the sheller into glass or metal containers.
We will grow our own spices except for whole black/green/red peppercorns which will be ground in a glass, ceramic, or metal peppermill.
Spices will be irrigated with carbon-filtered water.
Spices will be diced with a knife on a wooded cutting board or ground in a grinder without contact with plastic.
Sugar and sweeteners
No refined sugar or sugar substitutes will be allowed in this diet. Sugar undergoes extensive processing from harvest to store and has too many possible contamination sources to be allowable.
Acceptable is raw, organic, unprocessed honey from blossom sources distant from non-agricultural regions where pesticides, fungicides, and herbicides are applied.
Candy, snacks, protein- & meal-replacement bars
Highly processed. Not allowed in the study diet.
We will avoid products known to have GMO ingredients.
While the debate on potential negative effects has not reached a scientific consensus, the debate over the significance of regulatory limits and low levels (nano-and picomolar) parallels earlier work done on endocrine disruptors.
GMO ingredients raise two issues for this study:
(1) GMO crops are designed to withstand levels of pesticides such as glyphosate which would kill non-GMO plants. As such, glyphosate is becoming common in foods sold in the marketplace
Rubio F, Guo E, Kamp L (2014) Survey of Glyphosate Residues in Honey, Corn and Soy Products. J Environ Anal Toxicol 4: 249. doi: 10.4172/2161-0525.1000249
Glyphosate residues in Swiss market foods: monitoring and risk evaluation Otmar Zoller , Peter Rhyn, Heinz Rupp, Jürg A. Zarn & Christoph Geiser Pages 83-91 | Received 14 Sep 2017, Accepted 17 Dec 2017, Accepted author version posted online: 28 Dec 2017, Published online: 23 Jan 2018
(2) Evidence is accumulating that GMO plants may not be as safe as initially warranted. Zdziarski, I.M., Carman, J.A. and Edwards, J.W. (2018) Histopathological Investigation of the Stomach of Rats Fed a 60% Genetically Modified Corn Diet. Food and Nutrition Sciences, 9, 763-796. https://doi.org/10.4236/fns.2018.96058