Fact check: Plants can't restructure their DNA if exposed to human saliva, won't turn into superfoods

Miriam Fauzia, USA TODAY
·3 min read

The claim: Plants can analyze human DNA and transform into personally customized superfoods

Eating an apple a day may keep the doctor away, but any health-conscious consumer knows to include blueberries, kale and other so-called superfoods as well. They are reported to prevent diseases like cancer and boost the immune system.

But what if you could tailor a fruit or vegetable to meet your body's specific nutritional needs? One social media post circulating on Facebook claims you can.

"If you put your saliva on the seed of an edible plant and place it in the soil, something miraculous will happen," claims a graphic in a June 29 post. "The plant will read your DNA and structure its own genetic blueprint to be a superfood based on any deficiencies that your DNA is signaling."

Since it first appeared on Facebook in July 2020, the graphic has been shared more than 4,500 times in multiple posts across the social media platform. USA TODAY has reached out to the posters for comment.

Fact check: 'Mayoreo Sauce' is not a real Heinz product

While many user responses expressed awe and an interest in trying the method out for themselves, others were unconvinced.

"Wow, just wow. You go right ahead and spit in those seeds... In the end you'll end up with the exact sort of plant it was always going to be," commented one Facebook user.

That skepticism is well founded, because this claim is nonsense.

Experts say while plants can be genetically modified, they aren't capable of modifying their DNA or discerning someone's unique nutritional needs.

No basis in science

Genetically modifying a plant involves methods far more sophisticated than simply spitting on a seed, such as using bacteria or bombarding a plant with genetic material via a device called a gene gun.

"If you were to put a human gene into a plant, (it) could read the DNA and translate it into a protein, but this is totally ridiculous that just putting your saliva on the seed can somehow change its DNA to feed you better," Maureen Hanson, a molecular biologist and professor of molecular biology and genetics at Cornell University, told USA TODAY.

Fact check: Contact with wild parsnip harmful to humans and animals

Harry Klee, eminent scholar and professor of horticultural sciences at the University of Florida, agreed, saying there was no conceivable way for a plant to take up human DNA outside of genetic engineering.

He noted the post is flawed on multiple levels. Not only is the gene modification assertion absurd, the nutritional deficiency referenced would be due to diet, not genetics.

"Your DNA has no bearing whatsoever on any kind of nutritional deficiency that you're experiencing. It's what you eat, it's how your body responds," he told USA TODAY. "The concept your DNA could transfer information into a plant is just a non-starter."

Klee did say some metabolic deficiencies could be genetically inherited, such as phenylketonuria – a rare disorder that causes the amino acid phenylalanine to build up in the body – but these again are mostly treated with specialized diets, nutritional supplements or other traditional medical treatments.

Fact check: Social media posts on Subway tuna DNA test lack context

Our rating: False

We rate the claim that plants can analyze human DNA and transform into personally customized superfoods FALSE, based on our research. Experts say there is no biological mechanism in plants to discern nutritional deficiencies someone might have that would transform their own genetics. Changing or adding nutritional value to a plant requires sophisticated genetic engineering methods.

Our fact-check sources:

Thank you for supporting our journalism. You can subscribe to our print edition, ad-free app or electronic newspaper replica here.

Our fact-check work is supported in part by a grant from Facebook.

This article originally appeared on USA TODAY: Fact check: Plants exposed to human saliva won't turn into superfoods