Salt by Jay Mann NZ PhD (Biochemistry)

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Must We Eliminate Sodium from our Diets? I very much fear that the current eat-no-salt recommendations will induce lots of guilt but have very little effect on heart disease and stroke. (Did eat-no-fat succeed in preventing obesity?) Salt-fear, resulting in maternal iodine deficiency, is already putting newborn New Zealand babies at risk of permanent brain damage. Nutrition is a complex problem not aided by simple-minded formulas and knee-jerk mental attitudes. There is enormous evidence that by eating more potassium than sodium, most if not all of the damage from salt (sodium) can be prevented. (Excess sodium not affects not only blood pressure but also bone loss.) The evidence includes both short-term studies where potassium supplements were given for a month or so, and long-term studies where lifetime diets of hundreds of thousands of people were matched with their deaths from heart disease, stroke, and other causes. Consistently, high potassium intake was found to reduce or eliminate sodium damage. This evidence has been available for years, published in reputable peer-reviewed journals and summarised by such agencies as the US Center for Disease Control and the American Heart Association. Yet I have never seen any publicity that emphasizes the logic of eating high-potassium foods such as potatoes, silver beet, oranges, bananas, and sweet corn. The publicity machine has locked itself into a rigid anti-salt mode. After all, why give consumers the good news about potassium, when it’s much more rewarding to make us guilt-ridden for not overriding our inbuilt biological urge to eat salty foods. As a simple target, we should aim for twice as much potassium as sodium. For instance, 100 g of McDonald’s much-maligned chips contains 576 mg potassium and 233 mg sodium, a K:Na ratio of 2.5. For athletic young men who will burn off any excess fat from these chips, they are a healthy food! (People with kidney disease have to avoid potassium. That is not the case for most of us.) If you try to buy groceries with high levels of potassium, you will be dismayed at how many food manufacturers do not list the levels of this important nutrient. So much for any claims that they are genuinely concerned with our health!

Sheryl: Jay Mann is a professional plant biochemist. Since his retirement from Crop and Food CRI in 1993, he has been a consultant, preparing reviews on topics as diverse as ways to lower blood cholesterol, feedstuff composition, chicken flavour, and industrial use of enzymes. Food for people has been a lifelong interest. I met Jay many years ago when he was a speaker at a Skeptics Conference I was attending. He has written a book called “How to Poison your Spouse the Natural Way – A Kiwi Guide to Safer Food” Website: We called in to see him on our recent visit to NZ. 

Book Review from the web: One of the great myths of alternative medicine and the health food industry is that natural things are better than artificial or synthetic things because natural is natural and Mother Nature wouldn’t want to hurt us. Wouldn’t she just? Plants and animals have had many millions of years to evolve ways of protecting themselves against predators and competitors for resources. Humans have had about 100,000 years of hunting and gathering to evolve natural resistance and about 10,000 years of agriculture to breed out the nastiness, and these times are just not long enough to make much difference. We are surrounded by plants and animals which can do us great harm if we are not careful about what we eat, and also by a myriad of fungi which delight in making safe foods unsafe. The book is divided into three sections – “Dangers we should worry about but don’t”, “Things we worry about but need not”, and “Things we ought to know”. The first section is about the dangers out there which are often ignored because “natural is safe” or simply because people don’t know any better. Some of the warnings are well recognised, such as the dangers of rhubarb leaves and anything to do with oleander plants. Others, such as the dangers of moulds, are often ignored because they are secondary to the main event. An example would be a herbal medicine which is harmless if the herbs are kept dry but which can become deadly if it becomes mouldy through bad handling or storage. If you want to be really scared, think about saxitoxin and tetrodotoxin in seafood which can paralyse someone to the point where bystanders think that they are dead but which leave the victim fully conscious and aware of what is happening. This is the stuff of horror movies. The second section deals with irrational fears about chemicals. Much of the hysteria about genetically-modified foods, additives, preservatives and other ways man interferes with nature is based on ignorance or fear of the unknown. This is not to say that we should not be careful, but if you are eating in an Asian restaurant you probably should be more worried about zearalenone in the corn and chicken soup or aflatoxin in the sate than about the MSG in the sweet and sour sauce. The third section of the book gives a good explanation of how to interpret research and statistics, as well as some good advice about exercise. Some of this book will make you think very carefully about what you put into your mouth and some of it will reassure you, but I recommend it to anyone who wants to find out the reality of food dangers and safety.

Sheryl:  Jay passed away in 2019.