Will Being a Vegetarian Save the Planet - Part VI: What about my health?

Being vegetarian is great and all… but where do you get your protein from?

This was a common question that was levied against me when I was in my vegetarian phase. If mankind has one great leveller it's that everyone has an opinion about diet. We’ve all found ourselves thinking about what we eat: is it healthy? Am I getting the right calories and nutrition? Can I lose/gain weight? Diet matters, and that’s why I think so many people asked me this question. Many of you may be familiar with the concept that being vegetarian is healthier for you, others may have concerns about getting enough protein and nutrition. Besides, didn’t I open this series discussing how meat aided us in our evolution and increase in stature? If any of you are considering changing your meat consumption for the environment, you should know what the effect would be on your health.

Is being a vegetarian healthier?

 Coronary heart disease is caused by fatty deposits in the arteries, but is meat a cause?

The idea that being vegetarian is healthier for you can likely be traced back to some large inter-country studies that looked at associations between diet and coronary heart disease (CHD). In 1980, Keys published a large study looking at seven countries, their varying diets, and the incidence of coronary heart disease[1]. The study showed that the biggest predictor of CHD was intakes of butter, lard, margarine, and... you guessed it, meat. Japan in particular, had very low incidence of CHD, and it had correspondingly low meat intakes. This correlation was attributed to levels of saturated fats of which meat has relatively large amounts(1).

Of the seven countries chosen, France was a glaring exception. Why glaring? Well France, at the time, had one of the highest intakes of saturated fat but also very low CHD incidence. This became known as the French paradox[2]. A large part of this fat was coming from meat for the French as well; per capita availability of meat in France was 101kg/per capita in 2002, which ranked them the 15th highest in the world[3]. To add to the French paradox Spain and Japan started to rapidly increase their meat consumption, yet the amount of heart disease didn’t change, even with increases in cholesterol and obesity[4-6].

Meta-analyses

Clearly things are a little bit more complicated than they first appear. The trouble with studies like this is there are so many different variables it’s difficult to work out what is the causative one and what are merely correlative. We need to then look at many studies together: a meta-analysis. In a meta-analysis of 20 studies it was shown that red meat was not associated with CHD, however processed meat was strongly associated[7]. They also found that total meat intake had a moderate correlation with CHD. The issue then could be the type of meat we eat and the amounts, not meat necessarily.

Indeed, one of the largest studies following over half a million Americans over 10 years found that it was only in people with the highest meat intakes that had higher risks for heart disease[8]. What was a high intake? Over 55kg/year was considered high for men and around over 40kg/year for women. But what does that actually mean? Well to give you an idea, let’s look at my own meat intake.

What is high consumption?

I would consider myself quite a high consumer of meat, after being vegetarian for several years I seemed to leap to the other end of the spectrum. For context, I consume on average ~3000 calories a day, I’m average size in weight and height (178cm/5'10" and 75kg/165lb) and I’m a man. Over the past 13 months I have bought food every 17.5(±1.4) days. I always buy the same amount of meat each time (because I’m a boring fuck), which is 750g of beef, 1kg of chicken and 1.27kg of fish(2). These raw amounts correspond to a couple of packets of fish, 8 tins of tuna, a pack of mince and 5 large chicken breasts. If you do some mathematical wizardry (a.k.a. basic maths) you find that I eat 36kg of meat per year or 62kg if you include fish, add a few extra kilos on to there for when I eat out and you get around 40kg for meat alone and 70kg in total (including fish).

This level of intake would put me in the high category, however fish was not associated with heart disease. In fact, due to my high white meat (chicken and fish) intake according to the study I would be at a lower risk of cancer and total mortality than the general population[8]. So again, it looks like things are a little more complicated.

If you look at other risk factors associated with meat then you find that risks of stroke are uncertain, although there is some evidence of an association with processed meat, but only in men[9,10]. Red meat also increases the risk of breast cancer in women[11] and it may also increase the risk of colorectal cancer in both genders, along with processed meat[12,13], but again eating in moderation or eating white meat instead should alleviate this effect.

How much meat should I eat?

Tofu, while funny looking, is a source of complete protein and a mainstay for many vegetarians and vegans.

It looks as if moderate meat intakes, with low amounts of red and processed meat may be absolutely fine health wise. Indeed, it appears that there is no difference in health outcomes for vegetarians and moderate meat-eaters[14-17]. That ‘no difference’ is key too, as with a properly planned vegetarian diet you can be just as healthy as any meat eater(3). Even for the most restrictive vegan diets(4), and in the highest at risk populations, children or pregnant women, you can be perfectly healthy with proper planning[17,19,20]. You would require proper planning as plants do not contain complete proteins, and those they do have are harder to absorb (although mushrooms, quinoa and soybeans do have complete proteins)[21].

In fact, if you’re suffering from high cholesterol and blood pressure vegetarianism may be beneficial for you[22]. There have also been some reports of longevity gains for vegetarians[23], but if all other conditions are the same (e.g. activity levels) these gains seem to disappear[17].

Both the contrasting ideas of vegetarianism being healthier and being less healthy appear then to be ill-founded if you take a close look at the research. Certainly, meat does seem to have negative health consequences if consumed in excess with lots of processed and red meats, likely due to fat and possibly iron content[24], but moderate intakes with high levels of white meat seem to be as healthy as vegetarian diets. Vegetarian diets as well, even the more extreme solely plant based vegan diets, are healthy if properly planned.

In which case, what do moderate intakes look like? If we look at my diet again, we have daily intakes of 99.8g of meat or 172.2g if you include fish. The WHO recommends around 0.83g protein per kilogram bodyweight per day[21]. For me then, at 75kg, I would need to eat 62.25g protein a day(5). 94% of protein from meat is digestible(6) so I would need just over a third of what I eat now. That’s also not including the dairy and plant protein that I eat. Realistically I could probably eat about 10% of the meat I eat now and be fine – around 3 large chicken breasts every two weeks.

For health and for the environment it may be better to reduce meat consumption. Moderate meat intakes have low health impacts and vegetarianism can be equally as healthy. What you eat is up to you, but it’s worth thinking about your meat intake, especially if you’re a high-consumer, like me.


Next time I'll be discussing ethics, I'm sure this will cause NO PROBLEMS AT ALL. Help...

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Footnotes

(1) This may be an unfair accusation of meat. Sure, generally, it does have high levels of unsaturated fat, but this can vary hugely depending on the cut and the breed. Something like chicken has very little fat at all[14].

(2) If you’re wondering how I know this, I do all my food shopping online and so can easily go back and track what I’ve bought and when.

(3) Those that ate eggs and dairy wouldn’t even have to worry about planning – they have access to complete proteins.

(4) In the spirit of this article I must add that there is some evidence that veganism may be worse for the environment than vegetarianism due to the low-calorie content of plants and thus higher intakes to meet calorie demands, at least in the US[18]

(5) For the average 50kg woman it would be around 42g per day.

(6) This is compared to around 85% for cereals, >80% for beans and 77% for plant proteins

1.         Ancel Keys. Seven countries. A multivariate analysis of death and coronary heart disease: Harvard University Press; 1980.

2.         S de Renaud, Michel de Lorgeril. Wine, alcohol, platelets, and the French paradox for coronary heart disease. The Lancet. 1992;339(8808):1523-6.

3.         FAOSTAT. Statistics of the Composition of the Agricultural Area of the World. Statistics Division, Food and Agriculture Organization of the United Nations, Rome, Italy 2014 [Available from: http://www.fao.org/faostat/en/ - data/RL/visualize.14/02/17

4.         Lluís Serra-Majem, Lourdes Ribas, Ricard Tresserras, Joy Ngo, Llufs Salleras. How could changes in diet explain changes in coronary heart disease mortality in Spain? The Spanish paradox. The American journal of clinical nutrition. 1995;61(6):1351S-9S.

5.         Yoshinori Koga, Ryuichi Hashimoto, Hisashi Adachi, Makoto Tsuruta, Hiromi Tashiro, Hironori Toshima. Recent trends in cardiovascular disease and risk factors in the seven countries study: Japan.  Lessons for Science from the Seven Countries Study: Springer; 1994. p. 63-74.

6.         A Keys. Lessons for Science from the Seven Countries Study. 1994.

7.         Renata Micha, Sarah K Wallace, Dariush Mozaffarian. Red and processed meat consumption and risk of incident coronary heart disease, stroke, and diabetes mellitus. A systematic review and meta-analysis. Circulation. 2010.

8.         Rashmi Sinha, Amanda J Cross, Barry I Graubard, Michael F Leitzmann, Arthur Schatzkin. Meat intake and mortality: a prospective study of over half a million people. Archives of internal medicine. 2009;169(6):562-71.

9.         Susanna C Larsson, Jarmo Virtamo, Alicja Wolk. Red meat consumption and risk of stroke in Swedish women. Stroke. 2011;42(2):324-9.

10.       Susanna C Larsson, Jarmo Virtamo, Alicja Wolk. Red meat consumption and risk of stroke in Swedish men. The American journal of clinical nutrition. 2011;94(2):417-21.

11.       Valerie H Taylor, Monali Misra, Som D Mukherjee. Is red meat intake a risk factor for breast cancer among premenopausal women? Breast cancer research and treatment. 2009;117(1):1-8.

12.       Teresa Norat, Annekatrin Lukanova, Pietro Ferrari, Elio Riboli. Meat consumption and colorectal cancer risk: dose‐response meta‐analysis of epidemiological studies. International journal of cancer. 2002;98(2):241-56.

13.       Susanna C Larsson, Alicja Wolk. Meat consumption and risk of colorectal cancer: a meta‐analysis of prospective studies. International journal of cancer. 2006;119(11):2657-64.

14.       Vaclav Smil, Kazuhiko Kobayashi. Japan's Dietary Transition and Its Impacts: MIT Press; 2012.

15.       E Ginter. Vegetarian diets, chronic diseases and longevity. Bratisl Lek Listy. 2008;109(10):463-6.

16.       Timothy J Key, Paul N Appleby, Elizabeth A Spencer, Ruth C Travis, Andrew W Roddam, Naomi E Allen. Mortality in British vegetarians: results from the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford). The American journal of clinical nutrition. 2009;89(5):1613S-9S.

17.       Vaclav Smil. Should We Eat Meat? Evolution and Consequences of Modern Carnivory: Wiley-Blackwell; 2013.

18.       Christian J Peters, Jamie Picardy, Amelia F Darrouzet-Nardi, Jennifer L Wilkins, Timothy S Griffin, Gary W Fick. Carrying capacity of US agricultural land: Ten diet scenarios. Elementa. 2016;4.

19.       Ann Reed Mangels. Vegetarian diets in pregnancy.  Handbook of Nutrition and pregnancy: Springer; 2008. p. 215-31.

20.       LT Ho-Pham, BQ Vu, TQ Lai, ND Nguyen, TV Nguyen. Vegetarianism, bone loss, fracture and vitamin D: a longitudinal study in Asian vegans and non-vegans. European journal of clinical nutrition. 2012;66(1):75-82.

21.       WHO/FAO/UNU. Protein and amino acid requirements in human nutrition. World health organization technical report series. 2007(935):1.

22.       Anand M Saxena. The vegetarian imperative: JHU Press; 2011.

23.       Pramil N Singh, Joan Sabaté, Gary E Fraser. Does low meat consumption increase life expectancy in humans? The American journal of clinical nutrition. 2003;78(3):526S-32S.

24.       Nadia M Bastide, Fabrice HF Pierre, Denis E Corpet. Heme iron from meat and risk of colorectal cancer: a meta-analysis and a review of the mechanisms involved. Cancer prevention research. 2011;4(2):177-84.