Bread is usually the first thing that gets dropped when you’re on a diet. At the same time, it’s one of the most common foods out there. I decided to take a closer look at different kinds of bread and to understand whether it’s a part of a healthy diet or whether it should be avoided altogether.
First, let’s clarify the difference between most common types of bread:
So what are the problems with bread?
1. Many articles mention that bread is low on nutrients, some even calling it “empty calories”. The explanation given is that refined flour used to make white bread is stripped of the outer layer of the wheat grain together with the majority of the vitamins and minerals. While this is true for many types of white bread, it does not apply to whole grain breads, which contain all the nutrients from the grains and are a great source of dietary fibre.
In fact, if you live in the UK, even white bread is nutritious as the key nutrients that are lost during milling, such as calcium, iron and B vitamins, are required by law to be put back into the flour. But the fibre content in white bread is still 3.5 times lower than whole grain. Fibre helps prevent digestive problems and makes you feel full for longer, which can assist with weight loss. White bread made from fortified flour could be a good alternative for those who may need to eat a lower fibre diet, such as toddlers or older people with poor appetite. I am assuming that those who are trying to gain weight would also be in this category.
Another difference is that whole grain bread has a higher phytonutrient content than white bread. Phytonutrients are chemicals produced by plants that may have health benefits such as anti-oxidant properties and protection from some types of cancer if consumed in high amounts. Unfortunately there isn’t enough scientific evidence to confirm those health claims at the moment.
2. Another reason bread is considered unhealthy is that it spikes blood sugar levels. This is where glycaemic index (GI) comes into play. It measures how much your blood sugar level increases after consuming a particular food. Many people mention lower GI when taking about the benefits of wholegrain bread but it’s only 1% lower than that of white bread.
The truth is both white and wholegrain bread have a relatively high GI, higher than Coca-Cola or a Snickers bar. But that can be misleading. Another value, called glycaemic load (GL) gives a more accurate picture of a food’s real life effect on blood sugar because it takes into account not only the GI but also the amount of carbohydrate in a food. As an example, watermelon has a high GI (80) but a serving of watermelon has so little carbohydrate (6 grams) that its GL is only 5.
If you compare GL’s of the foods mentioned above you will see why bread is a much healthier choice than candy bars and sugary drinks. On top of that, the addition of fat and protein slows down the absorption of carbohydrate so eating bread in combination with other (non-carbohydrate) foods (e.g. a sandwich) further reduces the GL and helps keep blood sugar levels under control.
3. The next issue is that bread is full of additives and preservatives. It may contain mono and diglycerides, DATEM, calcium peroxide, and ammonium sulphate, all of which are ingredients devoid of nutrition and help extend the bread’s shelf life. Another problematic item on the ingredient list is potassium bromate, a chemical added to fluff up bread and give it a tender texture, which has also been shown to cause cancer in animals and may hurt kidney function in humans. It’s banned pretty much everywhere except in the US and Japan.
UK and EU regulations prohibit the use of flour bleaching agents, but in other countries white flour is often bleached with potentially harmful chemicals to make it appear more white (yes, apparently it’s a good enough reason to add toxins to food). In order to avoid this, look for unbleached flour on the label.
Many commercially produced breads have higher amount of salt and sugar so it’s important to keep this in mind and check the label when shopping. The shorter the ingredients list on the label, the better (not too much longer than flour, water, yeast and salt).
4. Gluten has recently become a popular reason to avoid bread. Many people are opting for gluten free products but it’s not always clear why. There is a population of people with coeliac disease who have a severe autoimmune reaction to gluten that causes intestinal damage so have no choice but to avoid it completely but that is only about 1% of the population.
A larger number of people seem to be sensitive to gluten, which means they experience symptoms such as gastrointestinal distress, bloating, headaches etc that frequently improve after adopting a gluten free diet but it’s still a very small percentage of the general population. If you have such symptoms it might make sense to go gluten free for a month and see if it makes you feel better.
Aside from these examples, the majority of people don’t have any trouble processing gluten and there is no scientific evidence of any health benefits of a gluten free diet. Researching gluten has been quite fascinating and I am planning to write a separate post on that so stay tuned!
How does bread affect human health? Let’s turn to some scientific studies for the answers.
Does bread cause you to gain weight? A review article from 2015 has concluded that reducing white bread but not whole grain bread consumption is associated with lower weight gain. 14 cross-sectional US studies have found that intake of 3 servings of whole grains is associated with lower BMI (body mass index). The effect is pretty modest at ~0.5 but at the population level this translates to 5% decrease of heart problems rate. Calories in white and whole grain breads are similar, about 65-70 calories per slice. Usually, when people cut bread out of their diet they don’t replace it by anything else and that brings down the total calorie count and contributes to weight loss. The same thing would happen if you cut any food group out of your diet without replacing the calories.
A study in Norway that included 34,000 people suggests protection against chronic disease by whole grain intake. Another study that followed 43,000 men over the period of 12 years concluded that a diet high in whole grains is associated with a reduced risk of type 2 diabetes. Studies in North America and Europe have consistently shown that consumption of whole grains is associated with reduced risk of cardiovascular disease. Increasing intake of whole grains is highly recommended for improving gastrointestinal health but it has to be done gradually. Some people may experience discomfort due to high fibre contents but the symptoms will disappear once your body adapts to higher fibre levels.
Ok, so whole grains seem to be linked to many health benefits, but what about the refined grains, i.e. while bread? A large review of 135 relevant article between 2000 and 2010 has identified that the great majority found no association between refined grains intake and cardiovascular disease, diabetes, weight gain or overall mortality. Seems like white bread doesn’t have any protection against the diseases but it isn’t linked to any negative effects either.
How much bread should we eat? Dietary recommendations usually group bread with other starchy foods, such as potatoes, pasta, rice and cereal. Generally, it’s recommended to have about 6 portions of foods from this group per day and at least half of that should be whole grain. A portion is 1 slice of bread or half a cup of cooked pasta or rice.
Whole grain breads are nutritious and have been associated with multiple benefits, such as reduced risk of cardiovascular disease, diabetes and obesity, and should be a part of a healthy diet for most people. If you are opting for white bread it will not cause you any harm (provided you don’t have coeliac disease) if eaten in moderation as long as you go for the unbleached, fortified flour and little or no additives. For the healthiest bread option look for whole grains with short ingredients list.