Should we switch to plant-based proteins?

While New Zealand was in lockdown, I had ample opportunity to think about life, the universe and everything.  Specifically, I was thinking about plant-based protein as human food.  Recently, meals at home have exposed me a variety of new dishes and some of these were plant-based.  I’m setting out these thoughts in the hope that they will stimulate conversation between readers.

First, there is a strong drive from some members of the community to change from eating animal proteins to eating plant-based protein meals.  Some of this is a concern for the welfare of animals and some is ideological.  Probably the primary driver is health, but the second driver is sustainability and environmental concerns around our planet and its long term health.  Is it really more healthy to eat only plant proteins?  Is it truly better for the environment?  There is concern that rivers and waterways are being polluted by our raising of animals for meat and milk, but will the production of plant proteins result in greater use of fertiliser and hence increase runoff?  Methane emissions will decrease, but growth of legumes may ultimately result in increased nitrate leeching. Of course, traditional farming mixed plants and animals - the vegetables etc. were grown on land fertilised by animal manure, but if we no longer raise animals, that cycle will be eliminated. 

What is the point of trying to reproduce the taste, appearance and texture of products such as burgers, but using plant proteins?  Really, that is just a sop to confirmed meat eaters.  As I understand it, The Impossible Burger is more expensive to produce than the meal it is trying to emulate.  Is there going to be resistance to the use of colours and flavours to simulate animal products?  The key ingredient that gives the Impossible Burger its meaty taste and makes it bleed like meat when cut is soy leghemoglobin, derived from genetically engineered yeast.  Production of the yeast by fermentation requires inputs of industrially manufactured, chemically synthesised ingredients.  The safety of these inputs will be subject to regulatory approval and their use will not be universally accepted.  Ikea is introducing a non-meat version of its traditional Swedish meatball  and claims that conversion of about 20 per cent of its meatball sales to plant balls would mean around 8 per cent reduction of the climate footprint for the food business at Ikea.  Meanwhile, KFC has announced that it is collaborating with 3-D Bioprinting Solutions to develop chicken nuggets made with cultured chicken cells and plant material.  The thinking of food technologists and new product developers is way ahead of the general population.

We all require iron in our diets, young or pregnant women particularly.  The recommended daily allowance for vegetarians is 1.8 times higher than for people who eat meat. This is because heme iron from meat is more bioavailable than non-heme iron from plant-based foods, and meat, poultry, and seafood increase the absorption of non-heme iron. This is just one aspect of changing from eating animal protein to exclusively plant-based protein.  There is any amount of information on the Internet regarding iron requirements and sources, but caution is required before believing everything!

I really have no answers for these questions, but I think that the proponents of moving to an exclusive plant protein diet haven’t thought it through.  Here are some questions that I’d like answered:

Does New Zealand have sufficient agricultural land to produce all the plant protein we need to feed the population, assuming that we all move to consuming it?  Much of our farming is on hill country.  This is not suitable for crop production.

Will the energy inputs for food production increase or decrease?  We will need diesel to harvest the crops and energy to dry some of the products.  With the shutdown of the Tiwai Point Aluminium smelter, there may be an opportunity to divert some of the surplus electricity to processing of plant proteins, but will that be enough or even practical?

What of our exports?  In 2019, dairy, eggs and honey earned NZ$16.3 billion and accounted for 27.9% of total exports, while meat earned NZ$8.03 billion - 13.9% of total exports.  If meat and dairy were no longer produced here, that would be a loss of nearly 42% of our exports.  In the current post COVID-19 era, it would be hard to replace those contributions.

Lies, damned lies, and misinterpretation of the data.

I am constantly amazed by the apparent ignorance and credulity of the general public on matters of food safety and nutrition.  But should I be surprised?   Few people are lucky enough to have studied food technology, food science or nutrition.  Their main sources of information are then the popular press, magazines, television cooking shows and the all-pervasive Internet. 

Scientists and engineers know that the best sources of information are peer-reviewed papers published in international journals.  Experts in the field have read the paper and picked it apart, looking for poor experimental design, inconsistencies and faulty interpretation of data.  Believe me, I can say this with certainty from both sides of the fence: it is pretty difficult to get a paper published these days!

The other sources of information mentioned above are generally not peer-reviewed.  Articles can be published by people with no formal qualifications in the subject and are often either highly biased or downright wrong.  See:  http://foodsafetywithjaybee.blogspot.co.nz/2015/04/dangers-of-google-degree.html

Sensationalism and sycophantic following of media celebrities are what sell newspapers and magazines.  We see more food scares and wonder diet advice every month without any reference to the original research.

A few examples spring to mind:

Towards the end of October 2015, the WHO International Agency for Research on Cancer stated that processed meats, including hot dogs and sausages would be added to its list of high risk carcinogens.  Red meats were also declared a probable carcinogen.  Needless to say, this caused a furore in all the media.  A Google search, using the terms “sausages cause cancer” returned 469,000 results!  IARC classifications rank the quality of the evidence that something can cause cancer, but don’t assess the level of risk. The announcement was often quoted out of context.  For example, Discovery News baldly stated “Eating sausages, ham and other processed meats causes colon cancer”.  Other reports mentioned the increase in risk as a percentage, but did not state the base level of risk. This scare is enduring; at a barbecue recently, someone noted that I was cooking “cancer sticks”.

Coconut water appears to have been a major drink commodity this year. I have no sales figures, but the sales in 2013 were around half a billion dollars, see http://www.stuff.co.nz/life-style/well-good/75567921/how-healthy-is-coconut-water.html.  Claims for coconut water include helping with weight loss, improving skin tone and aiding digestion.   Other claims, now withdrawn, stated that it could fight kidney disease, osteoporosis and viruses.  Coconut water contains potassium, calcium, magnesium and phosphorus, which are required minerals.  As a sports rehydration drink, coconut water is definitely unsuitable - when we sweat, we lose lots of sodium.  The ratio of sodium to potassium in sweat is about 10:1, but the ratio of sodium to potassium in coconut water is around 1:3.  Where are the peer reviewed scientific studies of the value of coconut water? They are never quoted.

Critics of the hypothesis that saturated fat consumption is linked with coronary heart disease use the argument that the correlation between total saturated fatty acids and risk factors is not very good.  Unfortunately, the scientific findings have been misinterpretated by the popular press media, with the result that we are told we can eat as much saturated fat as we wish. This advice is incorrect, unethical and irresponsible, see http://nzifst.blogspot.co.nz/2015/10/the-recent-non-scientific-comments.html.

Despite all the information on food safety available, in my opinion, a large proportion of the population is still badly educated in this regard.  At an outdoor party this week (it's summer in New Zealand) I sat with a very-soon-to-be mother.  She got stuck into the soft cheese in a big way, but said that she would eat it only during the first half hour of its being unwrapped; thereafter it was to be avoided.  In fact, the cheese had been made with pasteurised milk and she was therefore probably safe in eating it, but where had she got this idea from?  I guess she had read about Listeria in soft cheeses, and believed that the bacteria could multiply as the cheese warmed up.  For reliable information on safe foods to eat during pregnancy, see:  http://www.foodsmart.govt.nz/information-for/pregnant-women/list-of-safe-food.htm

I believe that food scientists and food technologists have a duty to provide unbiased and easily digested (sorry!) information to the public in order to help educate them in food safety.  But how can we compete with big advertising budgets and the pronouncements of media celebrities?

I wish all my readers a happy, successful and safe 2016.