The “National Center for Biotechnolgy information”, an American governmental research center, published in their “National Library of Medicine”, different studies / researches checking the hygiene of wooden compared to plastic cutting boards.

The below results, prove beyond any doubt that wooden cutting boards are far superior to plastic. Not only for treating your precious knives much better than plastic ones (especially the end grain ones as we have explained in detail in our cutting boards section), but even more importantly for hygienic reasons.

As stated below:

“Cutting boards are commonly perceived as important fomites in cross-contamination of foods with agents such as Salmonella spp., despite the lack of supporting epidemiological data. A variety of woods and plastics have been used to make work surfaces for cutting. In general, wood is said to dull knives less than plastic, and plastic is seen as less porous than wood. Research to model the hypothetical cross-contamination has been done in a variety of ways and has yielded a variety of results.

At least some of the work with knife-scarred plastic indicates that the surface is very difficult to clean and disinfect, although this may vary among the polymers used. High-density polyethylene, which is most used in commercial applications, has been shown to delaminate in response to knife scarring. Wood is intrinsically porous, which allows food juices and bacteria to enter the body of the wood unless a highly hydrophobic residue covers the surface. The moisture is drawn in by capillary action until there is no more free fluid on the surface, at which point immigration ceases.

Bacteria in the wood pores are not killed instantly, but neither do they return to the surface. Destructive sampling reveals infectious bacteria for hours, but resurrection of these bacteria via knife edges has not been demonstrated. Small plastic cutting boards can be cleaned in a dishwasher (as can some specially treated wooden boards), but the dishwasher may distribute the bacteria onto other food-contact surfaces. Most small wooden boards (i.e., those with no metal joiners in them) can be sterilized in a microwave oven, but this should be unnecessary if accumulation of food residues is prevented. However, 2 epidemiological studies seem to show that cutting board cleaning habits have little influence on the incidence of sporadic salmonellosis. Further, one of these studies indicated that

use of plastic cutting boards in home kitchens is hazardous, whereas use of wooden cutting boards is not.

https://pubmed.ncbi.nlm.nih.gov/16640304/

The microbiology of Plastic and wooden cutting boards was studied, regarding cross-contamination of foods in home kitchens. New and used Plastic (four polymers plus hard rubber) and wood (nine hardwoods) cutting boards were cut into 5-cm squares (“blocks”). Escherichia coli (two nonpathogenic strains plus type O157:H7), Listeria innocua , L. monocytogenes , or Salmonella typhimurium was applied to the 25-cm² block surface in nutrient broth or chicken juice and recovered by soaking the surface in nutrient broth or pressing the block onto nutrient agar, within 3-10 min or up to ca. 12 h later.

Bacteria inoculated onto Plastic blocks were readily recovered for minutes to hours and would multiply if held overnight. Recoveries from wooden blocks were generally less than those from plastic blocks, regardless of new or used status; differences increased with holding time. Clean wood blocks usually absorbed the inoculum completely within 3-10 min. If these fluids contained 10³-10⁴ CFU of bacteria likely to come from raw meat or poultry, the bacteria generally could not be recovered after entering the wood. If ≥10⁶ CFU were applied, bacteria might be recovered from wood after 12 h at room temperature and high humidity, but numbers were reduced by at least 98%, and often more than 99.9%. Mineral oil treatment of the wood surface had little effect on the microbiological findings.

These results do not support the often-heard assertion that Plastic cutting boards are more sanitary than wood.

https://pubmed.ncbi.nlm.nih.gov/31113021/

Lets see some more…

“Talking about the wooden cutting board, it is a renewable resource and is more durable. Most people prefer using it since it doesn’t scar as easily as plastic. Not only do wood boards last longer, they also help in keeping the knives stay sharp for a longer time. Wood boards don’t make the blades blunt as quickly as plastic boards. Wood shows the ability to halt the growth of and kill bacteria on its surface. Both new and used wooden cutting boards maintain this ability equally well.

As stated in a study conducted at the University of Wisconsin they tested which surface was better by using bacteria known to produce food poisoning namely Salmonella, Listeria and Enterohemorrhagic E.coli. These bacteria were placed on cutting boards made from seven different species of trees and four types of plastic.

All the wooden boards consistently outperformed the plastic”. (read more  )

The same study results were also published in The New York Times

https://www.nytimes.com/1993/02/10/health/wooden-cutting-boards-found-safer-than-plastic.html