As with most things in terms of nutrition, all of this is entirely up to the individual.
Grains are the world's largest source of food energy.
the three most commonly eaten types are wheat, rice, and, corn.
despite widespread consumption, the health effects of cereals are controversial.
Some people think they are an important part of a healthy diet, while others think they cause harm.
In the united states, health authorities recommend that women eat 5-6 servings of cereals per day and men 6-8 servings per day (1).
However, some health experts believe that we should avoid eating grains as much as possible.
As ancient diets that eliminate grains become more popular, people around the world are now avoiding grains because they think grains are unhealthy.
As often happens in the field of nutrition, there are good arguments on both sides.
This article details grains and their effects on health, examining the good and bad things.
What is a grain?
a grain ( or simply a grain ) is a small, hard, edible, dried seed that grows on grasses called grains.
they are a staple food in most countries, and to date, they have provided more food energy worldwide than any other food group.
food has played an important role in human history, and food agriculture is one of the major advances in promoting the development of civilization.
they are eaten by humans and are also used to feed and raise livestock. the grain can then be processed into a variety of different foods
today, the most commonly produced and consumed cereals are corn (or maize), rice, and wheat.
other smaller grains include barley, oats, sorghum, millet, rye, and several others.
then there's another type of food called pseudo-grains, which are not technically grains but are prepared and eaten like grains. these include quinoa and buckwheat.
foods made from cereals include bread, pasta, breakfast cereal, cereal, oatmeal, tacos, and junk food such as pastries and biscuits. grain-based products are also used to make ingredients added to a variety of processed foods.
for example, the main sweetener in the u.s. diet, high-fructose corn syrup, is made from corn.
bottom line: grains are edible dried seeds from plants called grains. they provide more food energy globally than any other food group. the most commonly eaten cereals are corn (maize), rice, and wheat.
Whole grains versus refined grains
like most other foods, not all grains are created equal.
it is important to distinguish between whole grains and refined grains.
whole grains consist of 3 main parts (2, 3):
- bran: the hard outer layer of the grain. it contains fiber, minerals and antioxidants.
- germ: a nutrient-rich core containing carbohydrates, fats, proteins, vitamins, minerals, antioxidants,s and, various phytonutrients. the germ is the embryo of a plant, the part that produces new plants.
- endosperm: the largest part of the grain, which mainly contains carbohydrates (in the form of starch) and protein.
the refined grain removes the bran and germ, leaving only the endosperm (4).
some grains, such as oats, are usually eaten whole, while others are usually refined.
many grains are mostly eaten after being crushed into very fine flour and processed into different forms. this includes wheat.
important: keep in mind that whole grain labels on food packaging can be highly misleading. these grains are usually crushed into very fine flour and should have a metabolic effect similar to their refined counterparts.
Examples include processed breakfast cereals such as "whole wheat" Froot Loops and cocoa puffs. These foods are not healthy, even though they may contain small amounts (powdered) whole grains.
bottom line: whole grains contain the bran and germ of grains, which provide fiber and a variety of important nutrients. refined grains remove these nutrients, leaving only the high-carbohydrate endosperm.
Some whole grains are nutrient-rich
while refined grains are undernourished (empty calories), whole grains are not.
Whole grains tend to be rich in a variety of nutrients, including fiber, B vitamins, magnesium, iron, phosphorus, manganese, and selenium (5, 6).
it also depends on the type of grain. some grains, such as oats and whole grains, are nutrient-rich, while others, such as rice and corn, are nutrient-poor, even whole grains.
Keep in mind that refined grains are often rich in nutrients such as iron, folic acid, and B vitamins to replace some of the nutrients lost during processing (7).
Bottom line: Refined grains are nutrient-poor, but some whole grains, such as oats and wheat, are rich in many important nutrients.
Refined grains are extremely unhealthy
Refined grains are like whole grains, except that all the good stuff is removed.
Apart from a high-carbohydrate, high-calorie endosperm that contains a lot of starch and a small amount of protein, nothing is left.
Fiber and nutrients have been removed, so refined grains are classified as "empty" calories.
Because carbohydrates have been separated from fiber and may even be ground into flour, they are now easily absorbed by the body's digestive enzymes.
For this reason, they break down quickly and cause a rapid rise in blood sugar levels when consumed.
When we eat foods that contain refined carbohydrates, our blood sugar rises rapidly and then quickly drops again. when blood sugar levels drop, we feel hungry and develop cravings (8).
Numerous studies have shown that eating these types of foods can lead to overeating and therefore weight gain and obesity (9, 10).
Refined grains have also been linked to many metabolic diseases. they cause insulin resistance and have been linked to type 2 diabetes and heart disease (11, 12, 13).
From a nutritional point of view, refined grains do not have any positive significance.
They are low in nutrients, prone to obesity, and harmful, and most people eat too much.
Unfortunately, most people's grain intake comes from refined varieties. few people in western countries eat large amounts of whole grains.
Bottom line: Refined grains are rich in carbohydrates and are quickly digested and absorbed, leading to rapid rises in blood sugar and leading to hunger and cravings. they have been linked to obesity and many metabolic diseases.
Whole grains have many health benefits
Whole foods are always preferable to processed foods. cereals are no exception.
Whole grains tend to be rich in fiber and a variety of important nutrients, which do not have the same metabolic effects as refined grains.
the truth is that hundreds of studies have linked whole-grain consumption to various beneficial effects on health (14, 15, 16):
- longevity: Harvard university studies showed that people who ate the most whole grains were 9 percent less likely to die and 15 percent less likely to die from heart disease during the study period (17).
- obesity: those who eat more whole grains have a lower risk of obesity and tend to have less belly fat (18, 19, 20, 21).
- type 2 diabetes: people who eat more whole grains have a lower risk of developing diabetes (22, 23, 24).
- heart disease: people who eat more whole grains have a 30 percent lower risk of heart disease, the world's biggest killer (25, 26, 27, 28).
- colon cancer: in one study, consuming 3 servings of whole grains per day was associated with a 17% lower risk of colorectal cancer. many other studies have found similar results (29, 30, 31).
It may seem impressive, but keep in mind that most of these studies are observational in nature. they can't prove that whole grains cause a reduced risk of disease, only that people who eat whole grains are unlikely to get them.
that being said, there are also controlled trials (true science) that show that whole grains can increase satiety and improve many health indicators, including indicators of inflammation and heart disease risk (32, 33, 34, 35, 36, 37, 38).
bottom line: numerous studies have shown that people who eat the most whole grains have a lower risk of obesity, heart disease, diabetes, colon cancer, and tend to live longer. this is supported by controlled trial data.
Some cereals contain gluten, which can cause problems for many people
gluten is a protein found in grains such as wheat, spelled wheat, rye, and barley.
many people are intolerant to gluten. this includes people with celiac disease, a severe autoimmune disease, and people who are sensitive to gluten (39).
celiac disease affects 0.7-1% of people, while numbers for gluten sensitivity range from 0.5-13% and mostly around 5-6% (40, 41).
so, overall, probably less than 10% of the population is sensitive to gluten. in the united states alone, this is still equivalent to millions of people and should not be taken lightly.
this is a serious burden of disease attributable only to one food (wheat).
Some grains, especially wheat, are also rich in FODMAP, a carbohydrate that causes indigestion in many people (42, 43).
however, just because gluten can cause problems for many people, that doesn't mean "grains" are bad, as many other whole grain foods are gluten-free.
this includes rice, corn, quinoa, and oats (for people with celiac disease, oats need to be labeled "gluten-free" because trace amounts of wheat are sometimes mixed in during processing).
Bottom line: Gluten is a protein found in a variety of grains, especially wheat, and can cause problems for people who are sensitive to it. however, many other bowls of cereal are naturally gluten-free.
Grains are high in carbohydrates and may not be suitable for people with diabetes
The carbohydrate content of cereals is very high.
For this reason, they can cause problems for people who can't tolerate a lot of carbohydrates in their diet.
This is especially true for people with diabetes, who tend to do well with low-carb diets (44).
When diabetics consume large amounts of carbohydrates, their blood sugar spikes unless they take medications such as insulin to lower their blood sugar.
Therefore, people with insulin resistance, metabolic syndrome, or diabetes may want to avoid eating grains, especially refined grains.
However, not all grains are the same in this regard, and some of them (e.g., oats) may even be beneficial (45, 46).
A small study showed that eating oatmeal every day lowered blood sugar levels in people with diabetes and reduced insulin requirements by 40%. （47）
While avoiding all grains may be a good idea for people with diabetes (because of carbohydrates), whole grains are at least "less bad" than refined grains (48).
Bottom line: Cereals are high in carbohydrates, so they're not suitable for people on low-carb diets. people with diabetes may not tolerate large amounts of grains because they contain a lot of carbohydrates.
Grains contain antinutrients, but it is possible to degrade them
A common argument against grains is that they contain anti-nutrients (49).
Antinutrients are substances in food, especially plants, that interfere with the digestion and absorption of other nutrients.
This includes phytic acid, lectins, and many other substances.
Phytic acid can bind minerals and prevent them from being absorbed, while lectins can cause damage to the intestines (50, 51).
However, it is important to remember that antinutrients are not specific to grains. They are also found in a variety of healthy foods, including nuts, seeds, legumes, tubers, and even fruits and vegetables.
If we're going to avoid all foods that contain antinutrients, there's not much to eat.
That being said, traditional preparation methods, such as soaking, germination, and fermentation, degrade most of the anti-nutrients. （52, 53, 54)。
Unfortunately, most of the grains consumed today have not been processed by these methods, so they may contain a lot of anti-nutrients.
even so, the fact that food contains antinutrients doesn't mean it's bad for you. every food has its pros and cons, and the benefits of real, whole foods often far outweigh the harmful effects of antinutrients.
Bottom line: Like other plant foods, grains tend to contain antinutrients such as phytic acid, lectins, etc. these can be degraded using preparation methods such as soaking, germination, and fermentation.
Some grain-free diets have health benefits
Several studies have been conducted on grain-free diets.
This includes low-carb diets and paleo diets.
The original diet did not eat grains in principle, but a low-carbohydrate diet eliminated grains due to their high carbohydrate content.
Many studies have been low in carbohydrates and paleo suggest that these diets can lead to weight loss, reduction in belly fat, and major improvements in various health indicators (55, 56, 57).
These studies often change a lot of things at the same time, so you can't say that just removing the grain is good for your health.
But they do make it clear that diets don't need to include grains to stay healthy.
On the other hand, we have done a lot of research on the Mediterranean diet, which includes cereals (mainly whole grains).
The diet in the Mediterranean can also cause significant health benefits, reducing the risk of heart disease and premature death (58, 59).
According to these studies, both a diet that includes and does not include cereals can be compatible with good health.
Conclusion:
As with most things in terms of nutrition, all of this is entirely up to the individual.
If you love grains and feel good about eating them, there doesn't seem to be any good reason to avoid them as long as you primarily eat whole grains.
On the other hand, if you don't like grains or they make you feel bad, then there's no harm in avoiding them.
Grains are not essential, and there is no nutrient in them that other foods cannot obtain.
At the end of the day, grains are good for some people, but not good for others.
If you like grains, eat them. if you don't like them, or if they make you feel bad, avoid them. it's that simple.