Book review: An Apple a Day, Dr J. Schwarcz

Dr Joe Schwarcz, “An apple a day. The myths, misconceptions, and truths about the food we eat”. Review by Paola Bassanese.


Reading this book should be made compulsory to anyone studying nutrition. As a holder of an ITEC Diet and Nutrition Diploma myself, I have been literally “fed” factually weak information about food. In the ITEC course we analysed a number of food theories and approaches and, whilst we all knew that none of these theories were the absolute truth, we progressed on to quote from and follow these theories when we came to applying what we studied to creating our clients’ nutrition plans.

We were quick at criticising “fad diets” but wholeheartedly approved of dogmatic nutritional approaches that stipulated that gluten, dairy and sugar are better avoided to preserve good health. Furthermore, candida was the all-encompassing cause of modern illnesses and we all suffer from it to various degrees. Some nutrition advisors have thriving practices and clinics on the back of anti-candida diets and supplements.

Unfortunately, such approaches, diets and theories did not receive enough scientific scrutiny. Schwarcz, winner of the American Chemical Society’s Grady-Stack Award, often cited the Nurses’ Health Study from Harvard University which analysed food questionnaires from 76,000 nurses starting from 1984.

This study was particularly useful to evaluate the link between food and diseases. For example, if the nurses had a diet rich in fibre from pulses they were 25% less likely to develop breast cancer. Those who were getting vitamin K from leafy vegetables were 30% less likely to have hip fractures.

Schwarcz launched into an attack against those “alternative health practitioners”  who “prescribe” alkalising diets based on the theory of “acidity” in the body. He went on to explain that our bodies have been designed to keep the same level of pH in the blood at 7.4 no matter what food or drink is ingested. Therefore, one cannot “manipulate” their blood pH with diet, as simple as that. I have been guilty of believing this “blood acidity” theory and accompanying diet because it is paraded as a well known “fact” in nutrition studies and followed by many practitioners.

The complementary health sector is somewhat flawed (and often criticised) because of its scant reliance on scientific data. Most practitioners are “accused” of relying on anecdotal evidence rather than hard facts. Each year new diets and books launching new nutrition theories are published and unfortunately us practitioners simply broadcast, market and recommend these books without applying some due diligence.

Schwarcz’s book still has some gaps in its analysis and fails to address vegan and raw food diets which currently enjoy a “holier than thou” status. The book does mention the risks associated with a diet based on red meat and processed foods but it also looks at the benefits of tofu although studies on soy products showed that they only lower cholesterol by 3%.

Schwarcz also dug at detox diets which he deemed to be meaningless because our bodies are constantly detoxing automatically without the need for external intervention or dietary changes. He did admit that simple, low-calorie diets may bring a sense of wellbeing but there is no scientific double-blind study which can prove detox diets have any impact on wellbeing. What the author is highly critical of is the belief that a detox will un-do all the dietary sins committed during the year. Short term solutions won’t work but a good old-fashioned balanced healthy diet will.

The truth is that there is no perfect diet and Schwarcz advised to adopt common sense as a better way to solve food dilemmas. Fresh fruit and vegetables, pulses, fibre from oats and flaxseed, eggs, fish, poultry are all fine as long as foods are rotated without fixating on one food group alone (eg protein only).

Science may take all the fun out of the food equation but one thing is certain: our grandmothers were right when they said an apple a day keeps the doctor away.