What science really says about the health benefits of freezing bread

Several recent TikToks have claimed that freezing bread actually makes it healthier. Some of them mention that there is research that supports the claims. But is this food advice as good as social media influencers suggest?

The science behind it is really solid, if a bit confusing. But the actual health effects are not as significant as imagined.

When the bread is baked, transform the moist, bubbly dough into a soft, fluffy loaf. The heat from the oven, combined with the water in the dough, causes the starch in the flour to expand and gelatinize. The same thing happens when flour is added to a sauce and cooked until it thickens.

These gelatinized starches are easier to digest, which makes the glucose (sugars) contained in these starches easier for our cells. This is true of many freshly cooked starchy foods, especially those low in fiber or made with finely ground flour, such as white bread or potatoes.

Some evidence suggests that this type of quickly available glucose could increase insulin levels right after a meal. Although insulin is important because it helps our cells use glucose for energy (or store it for energy later), too much insulin could make you feel hungrier and possibly even and all weight gain.

But when foods containing these gelatinized starches are cooled, the expanded starches shrink, becoming what is known as resistant starch. These collapsed starches are harder for the enzymes in our digestive tract to break down, which means it’s also harder for our cells to take up the sugar these starches contain. This means that resistant starches are less likely to cause a spike in blood sugar and insulin after eating them.

The degree to which resistant starch can form depends on the baking temperature of the bread and whether it is then refrigerated or frozen. The rate of shrinkage is almost twice as fast in the freezer as it is in the refrigerator, which means that more resistant starch will form.

Also, freezing the bread traps water to keep it fresher and softer than if you had stored it in the fridge, where it will lose water, causing the bread to harden.

Should you freeze your bread?

A study of ten healthy people looked at the effect of freezing white bread and then toasting it. They compared store-bought loaves with homemade bread.

For samples of homemade bread, freezing and thawing the bread reduced the amount of blood sugar that rose by 31% over two hours. Interestingly, toasting fresh bread also reduced the rise in glucose by 25%.

This effect was even greater when the homemade bread was frozen, thawed and then toasted, reducing the blood sugar response by 39%. This effect could help with hunger, as glucose and insulin levels will not rise as much after eating the frozen bread.

But when using commercial, store-bought white bread, freezing before toasting did not improve the body’s blood sugar response. This could reflect the different ways in which commercial bread is made compared to homemade bread. The ingredients used or the way the bread is cooked and then cooled can reduce the effect of freezing on the formation of resistant starch. The evidence is not entirely clear.

Other, more recent research has also shown similar results. So while some of the studies are small, the effect of freezing bread seems consistent and thoroughly researched in the lab.

But it is worth noting that these effects only exist for a couple of hours after eating the bread. So while freezing bread before eating it may help lower blood sugar levels at one meal (and also have a small effect at the next meal), the long-term effects on appetite, weight gain or the risk of certain diseases (such as type 2). diabetes) is not known and is likely to be very small.

Resistant starch can be found in many other cooked and refrigerated starchy foods, including potatoes, pasta, and some (but not all) types of rice. Basmati rice, in particular, seems to form more resistant starch than fluffier types of rice (like arborio rice).

In addition to being more difficult to break down than freshly cooked starch, resistant starch provides nutrients to the microbes that live in our colon. This helps maintain a healthy balance of bacteria in our gut. These bacteria release chemicals into the cells lining the colon that help us maintain a healthy metabolism.

Resistant starch has also been shown to help insulin work better by slightly increasing insulin sensitivity. This can help our bodies use blood sugar more efficiently, which is linked to better health as it can be used more effectively as fuel by our muscles.

The benefits of resistant starch may even extend to other aspects of our metabolism, as it can also help lower cholesterol. This effect is thought to be caused by short-chain fatty acids produced by gut bacteria when they ferment resistant starches. Lower cholesterol levels can mean a lower risk of heart disease.

Although these changes may seem quite dramatic, they are short-term, so their effects on our long-term health are more modest. But that doesn’t mean you shouldn’t still freeze your bread. Putting a loaf of bread in the freezer can reduce food waste with the added bonus of some small health benefits.

This article was originally published on The Conversation by Duane Mellor at Aston University. Read the original article here.