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
https://safe.org.nz/growing-compassion. If you have concerns, talk to your doctor or a nutritionist with experience in plant-based diets.

Jennifer Riley

SAFE, Eat Kind Coordinator

References 

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.