Does avoiding meat in pregnancy cause substance abuse in adolescents?


It’s World Vegetarian Month and there have been lots of stories about the benefits of adopting a plant-based diet. That said, there are occasionally news articles that give us pause and have the potential to make us question our decision to cut out animal products.

In one study, researchers claim to have found a link between substance abuse at age 15 and a vegetarian diet on the part of the child’s mother during pregnancy (1). Despite the sensational headlines, it’s far from clear that avoiding meat in pregnancy “causes” substance abuse in teens.

The research was based on a long-running study in the UK called the Avon Longitudinal Study of Parents and Children. Researchers asked almost 10,000 teenagers about their use of alcohol, cannabis and tobacco, and about half responded. They also looked at the dietary records of the teens’ mothers who had filled out a survey during their pregnancy.

The study found that children of women who ate the most meat in pregnancy were less likely to be users of alcohol, cannabis and tobacco at age 15, compared to children of those who ate little or no meat.

The researchers speculate that this could be because women who don’t eat meat might have low levels of vitamin B12, however we can’t know that diet was the cause. That’s because researchers did not actually assess whether any of the women had a B12 deficiency. Instead researchers relied on women’s self-reported food intake and a generalisation about B12 levels at a population level. It is likely that other facts are contributing to the findings.


Substance abuse is a complicated problem and it is unlikely that one factor such as maternal diet in pregnancy could have caused it. There are some other weaknesses in how the study was conducted. For example, the study only looked at teens’ self-reported substance use status at a moment in time. This snapshot doesn’t provide any clues as to motivations or habits. More research is needed before we can make conclusions about what causes substance abuse.

The findings do not mean that vegetarian pregnant women need to start eating meat.

Well-planned diets free from animal products are appropriate no matter your age or life stage. It is important to get all the nutrients you need in pregnancy (including iron, vitamin B12 and calcium). Rest assured you can easily get the nutrients you need during pregnancy without eating meat or other animal products, though some women choose to take supplements (3).

The study does serve as a reminder that pregnant women need to ensure they are getting the nutrients they and their growing baby need. The ideal human diet should be composed of 80% carbohydrates, 10% fat and 10% protein. It is plant-based, in forms as close to their natural state as possible. Eat a variety of vegetables, fruits, raw nuts and seeds, beans and legumes, and whole grains.


And we’re not the only ones who think so. Studies from around the world are showing that a global dietary shift to completely plant-based diets would be best for the environment and human health (4). A recent study found that increased fruit consumption during pregnancy is associated with improved cognitive development in children and strongly recommends fruit consumption as part of a prenatal diet (5). Another study found that vegans reported less anxiety and stress than people that ate meat (6).

There’s also mounting evidence that eating animal products can be harmful for a growing foetus, just look at fish as an example. New Zealand’s “pristine” waters aren’t exempt from the pollutants like polychlorinated biphenyls (PCBs), dioxin, chlordane, DDT and mercury that accumulate in fish and shellfish.

Classified as a carcinogen by the International Agency for Research on Cancer, in humans’ mercury exposure can cause irreversible damage to the cardiovascular and central nervous systems, brain damage and memory loss, and can damage a foetus (7).

Dioxins are also carcinogens that have been shown to cause liver damage, weight loss, skin rashes and reduce immune function – exposure is particularly dangerous during foetal development and early childhood. High intakes of fish during pregnancy increases the risk of being overweight and obese in childhood (8).

World Vegetarian Month is the perfect opportunity to learn more about eating well and raising children on a compassionate diet free from animal products. Learn more by visiting our web page If you have concerns, talk to your doctor or a nutritionist with experience in plant-based diets.

Jennifer Riley

SAFE, Eat Kind Coordinator



  1. Hibbeln JR, SanGiovanni JP, Golding J, et al. Meat Consumption During Pregnancy and Substance Misuse Among Adolescent Offspring: Stratification of TCN2 Genetic Variants. Alcoholism: Clinical & Experimental Research. Published online October 4 2017.
  2. Craig WJ, Mangels AR, American Dietetic Association. Position of the American Dietetic Association: vegetarian diets. Journal of American Dietetic Association 2009 Jul; 109(7): 1266-82.
  3. Piccoli GB, Clari R, Vigotti FN, Leone F, Attini R, Cabiddu G, Mauro G, Castelluccia N, Colombi N, Capizzi I, Pani A, Todros T, Avaginina P. Vegan-vegetarian diets in pregnancy: danger of panacea? A systematic narrative review. BJOG: An international journal of obstetrics and gynaecology. 2015 Apr; 122(5): 623-33.
  4. Springmann M, Godfray HC, Rayner M, Scarborough P. Analysis and valuation of the health and climate change cobenefits of dietary change. Proceedings of the National Academy of Science of the United States of America. 2016 April 12; 113(15):4146-51.
  5. Bolduc FV, Lau A, Rosenfelt CS, Langer S, Wang N, Smithson L, Lefebvre D, Alexander RT, Dickson CT, Li L, Becker AB, Subbararo P, Turvey SE, Pei J, Sears MR, Mandhane PJ, and the CHILD Study Investigators. Cognitive enhancement in infants associated with increased maternal fruit intake during pregnancy. EBioMedicine. 2016 Jun; 8:331-340.
  6. Beezhold B, Radnitz C, Rinne A, DiMatteo J. Vegans report less stress and anxiety than omnivores. Nutritional Neuroscience. 2014 Nov 21; 18(7):289-296.
  7. World Health Organization. Mercury and health: Fact Sheet. World Health Organization. 2017 Mar.
  8. Stratakis N, Roumeliotaki T, Oken E, et al. Fish intake in pregnancy and child growth: A pooled analysis of 15 European and US birth cohorts. JAMA Pediatrics. 2016; 170(4):381-390.



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