What is organic food? Is it safer or more nutritious than conventionally farmed food? What food safety tips should we follow?

• What is organic food?
• Should we be concerned about the chemicals used in conventional farming?
• What about antibiotics and growth hormones given to farm animals?
• What about nutrition?
• Are organic tomatoes better for you?
• The pros and cons of organic milk
• Food safety tips
• Conclusions 

What is organic food?

Organic food is the product of a farming system which avoids the use of man-made fertilisers, pesticides, growth regulators and livestock feed additives. Irradiation and the use of genetically modified organisms (GMOs) or products produced from or by GMOs are generally prohibited by organic legislation.

Department for Agriculture and Rural Affairs (DEFRA)

 

 

Organic fruit and vegetables

Organic crops are grown using:

• natural fertilisers, such as manure or compost, rather than chemical fertilisers.
• traditional methods of controlling weeds – such as crop rotation (growing different crops in succession on each piece of land, rather than just the same crop each time), tilling the soil (turning it over and breaking it up), and hand weeding – instead of using herbicides.
• birds, insects, and traps, against pests and diseases rather than using insecticides and fungicides. 

Organic meat

Organic meat comes from animals that are:

• fed organic food and given access to the outdoors.
• fed a balanced diet and kept in clean housing.
• moved onto different pieces of land to graze, rather than staying in one place (this ‘rotational grazing’ minimises disease).
• not given antibiotics, growth hormones, or medication (as they often are in conventional modern farming).

 

 

There is not enough strong evidence available to prove that eating organic provides health benefits over eating regular foods. Healthline, Sept 2021

 

 

Should we be concerned about the chemicals used in conventional farming?

Many people are concerned about the potential health risks of consuming chemicals from the fertilisers, pesticides and insecticides used to grow food in conventional farming.

It is also worth noting that organic crops may have been grown on land previously farmed conventionally and so can still contain pesticides up to 20 years later, albeit at a reduced level. 

‘We screened 100 fields under organic and conventional management: pesticides were found in all sites, including 40 organic fields.’ Environmental Science and Technology

 

To put this in context, a 2021 study of three European countries found that organic soils contained 70–90% lower residue concentrations of pesticides than corresponding conventionally managed soils.

However, the UK Health and Safety Executive reports, ‘If used correctly, authorised pesticides should not pose a risk to the health of people.’ 

 

What about antibiotics and growth hormones given to farm animals?

People are sometimes also concerned about the antibiotics, growth hormones and medication in the meat from animals reared on conventional farms.

A 2012 review by Stanford University of the available evidence found that there was no evidence of significant benefit for organic food in most areas. The review did note, however, that:

…the risk for isolating bacteria resistant to three or more antibiotics was higher in conventional than in organic chicken and pork (risk difference, 33%) … Consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.

Meanwhile, a 2017 comprehensive review of the evidence carried out by several European researchers and published in the Environmental Health journal concluded that:

Of greater concern is the prevalent use of antibiotics in conventional animal production as a key driver of antibiotic resistance in society; antibiotic use is less intensive in organic production. 

 

What about nutrition?

Nutrient content

Research at the London School of Hygiene and Tropical Medicine was published in the American Journal of Clinical Nutrition. It analysed 162 articles published in the scientific literature between 1958 and 2008 The review found no evidence that organic and conventional foods differ significantly in their nutrient content.

Antioxidants and heavy metals

In contrast, a study led by Newcastle University, published in the British Journal of Nutrition in 2015, suggested a more positive picture for organic food. According to Professor Carlo Leifert:

This study demonstrates that choosing food produced according to organic standards can lead to increased intake of nutritionally desirable antioxidants and reduced exposure to toxic heavy metals. 

However, the study’s methodology has been criticised. A possible conflict of interest has also been identified, as the study was part-funded by the Sheepdrove Trust, a British charity that funds research which is in favour of organic farming.

Nutrition and medical health

The 2017 comprehensive review by European researchers cited earlier, notes some differences in the composition of organic versus conventional crops, dairy products and perhaps meats, but it concludes, ‘However, these differences are likely of marginal nutritional significance.’

Conversely, a systematic review of the evidence, published in 2020, reported:

Significant positive outcomes were seen in longitudinal studies where increased organic intake was associated with reduced incidence of infertility, birth defects, allergic sensitisation, otitis media [infection of the middle ear], pre-eclampsia [a condition that causes high blood pressure during pregnancy and after labour], metabolic syndrome, high BMI, and non-Hodgkin lymphoma [a type of cancer of the lymphatic system].

The researchers who carried out this review declared that they were associated with an organic food research centre, but they stated that their review had remained objective, transparent, and reproducible. 

One challenge for researchers – which may help to explain the sometimes different findings – is that farming practices and their effects differ depending on country, region, year, and season, and between and within organic and conventional systems.

 

Are organic tomatoes better for you?

While most scientific evidence appears to show no clear nutritional advantage for organic foods, there is one possible exception.

According to a 10-year study conducted by the University of California-Davis and published in 2007, organic tomatoes had significantly higher levels of two compounds: the antioxidant quercetin, which may protect against lung cancer (79% higher), 
and kaempferol, a flavonol compound which may have a beneficial effect on Alzheimer’s (97% higher).

Meanwhile, a study published in 2013 noted that tomatoes from organic farming contained higher concentrations of compounds contributing to fruit nutritional quality such as vitamin C and phenolic compounds.

 

The pros and cons of organic milk

A 2016 review of published research confirmed that organic milk has higher levels of omega-3 but lower levels of iodine. Iodine helps maternal thyroid functioning and children's neurocognition, and milk is the principal contributor to iodine intake. While the role of omega-3 in physical health is well established, there may also be mental-health benefits as well.

A 2021 study concluded:

Raw milk from organic farms is more valuable [than milk from conventional farms], especially in terms of the content of health-promoting compounds, including vitamins, fatty acids, whey proteins, and minerals. This applies to organic dairy products as well, mainly cheese and yoghurt. However, the hygienic quality of the raw milk, and often the products as well, raises some concerns.

So people should consider whether the benefits of organic milk outweigh the hygiene/health risks for their particular circumstances. 

 

Food safety tips

The Mayo Clinic offers the following safety tips, whatever type of food you are eating: 

Recommendation	Comments
Select a variety of foods from a variety of sources	This will give you a better mix of nutrients and reduce the likelihood of you being exposed to a single pesticide.
Buy fruits and vegetables in season when possible	Get the freshest produce.
Read food labels carefully	Some organic products may still be high in sugar, salt, fat or calories.
Wash and scrub fresh fruits and vegetables thoroughly under running water	Washing helps remove dirt, bacteria and traces of chemicals from the surface of fruits and vegetables (although washing may not remove all pesticide residues). You can also peel fruits and vegetables, although peeling can mean losing both fibre and nutrients.

 

 

 

 

Conclusions

Current research suggests:

• In general, organic foods are no more nutritious than conventionally farmed foods.
• However, organic tomatoes may be more nutritious than their non organic counterparts.
• Pregnant and young women who drink organic milk, and who are already iodine-deficient, should ensure adequate iodine intake from other sources.
• The levels of pesticide used when growing non organic food are controlled by governments.
• Levels of pesticide on the surface of food can be reduced by thorough washing.
• Eating organic foods may reduce overall exposure to pesticide residues and to antibiotic-resistant bacteria.

Reviewed and updated by Andrea Cannas and Michael Baber, February 2023. Next review date January 2027.