Professor Richard Lampitt, of the UK's National Oceanography Centre, who was not involved in the research, told CNN that it was hard to assess the significance of ingestion rates without understanding the associated health risks.
These tiny particles can originate from a variety of sources, including artificial clothes fibers, microbeads found in some toothpastes, or bigger pieces of plastic which gradually break into smaller pieces when they're thrown away and exposed to the elements.
"In water it's mostly fibres which could come from industrial activities", he said.
Becoming carriers for other toxins that enter the body: microplastics generally repel water and will bind to toxins that don't dissolve, so microplastics can bind to compounds containing toxic metals such as mercury, and organic pollutants such as some pesticides and chemicals called dioxins, which are known to causes cancer, as well as reproductive and developmental problems.
"And there are no filtration systems for bottled water that could filter out those sub-micron phase particles".
The research compiled 52 studies investigating the plastic ingestion and found that on average, people around the world ingest about 2,000 microplastic particles a week.
Of the consumables studied, those with the highest recorded plastic levels included shellfish, beer and salt.
Dr Palanisami said microplastics were an emerging contaminant and there was little specific data for Australia, but he would expect ingestion rates to be lower there due to lower seafood consumption rates and a cleaner environment.
According to an article published in the International Journal of Environmental Research and Public Health, our understanding of the potential human health effects from exposure to microplastics 'constitutes major knowledge gaps'.
"What is the real impact?"
People worldwide swallow around five grams of microplastics per week, or around 250 grams a year, says the University of Newcastle's No Plastic in Nature report. The research also found that the largest source of ingesting microplastics was via drinking water.
Prakash-Mani said a global treaty on plastics and reduction targets from companies and governments was needed to tackle the issue.
"We can not just remove it", said Kavita Prakash-Mani, global conservation director at WWF International.
"Since 2000, the world has produced as much plastic as all the preceding years combined, a third of which is leaked into nature", the report said.
It said 104 million metric tons of plastic could be released into the environment by 2030 unless drastic action is taken.