More and more manufacturers are enriching foods with additives, such as vitamins or lactic acid bacteria. Such yogurts, drinks or snacks should be healthy. Is that correct? Or do they even harm?
Probiotic yogurt, margarine with healthy fatty acids , drinks with additional minerals : more and more products of this type can be found in supermarkets today. The most common additives are lactic acid bacteria, plant sterols, omega-3 fatty acids and folic acid. Such foods are called functional food by experts because they promise additional benefits. You should be healthy.
Consumers should take a critical look at this promise. Only a few manufacturers can prove the added health value with scientific studies. It is also questionable whether anyone needs these added substances at all.
Functional foods, nutritionists warn, seem to be more of a clever advertising strategy in order to be able to sell the fortified foods more expensively. The German Nutrition Society (DGE) emphasizes: Functional foods cannot compensate for nutritional errors. They should therefore only be used in addition to a varied diet with regular fruit, vegetables and whole grain cereal products.
Lactic acid bacteria
Yogurts, cream cheese or sourdough bread can be enriched with live lactic acid bacteria. Manufacturers advertise that these foods strengthen the immune system, regulate digestion , maintain the intestinal flora and protect against diseases. That is why such probiotics are healthy.
Studies have shown some of the health effects of these foods, while other effects have only been investigated by scientists in model and animal experiments.
One thing is certain: lactic acid bacteria contribute to maintaining a healthy intestinal flora. They are resistant to the aggressive digestive juices of the stomach, to a large extent they reach the intestine alive and ensure a good climate there. They promote the growth of useful intestinal bacteria and displace the less good ones.
After antibiotic therapy, they help to rebuild the normal intestinal flora. The same applies after suffering from diarrhea. However , studies have not yet been able to prove whether probiotics can prevent cancer and allergies , as manufacturers occasionally claim.
Healthy bacteria in normal curd too
Lactic acid bacteria only settle in the intestine for a few days. If the microorganisms are to help digestion over the long term, you have to keep buying probiotic foods.
Live lactic acid bacteria, which are contained in normal yoghurt, curdled milk or buttermilk, work just as effectively – provided the milk products have not been heat-treated. Because heat kills the living microorganisms. The DGE therefore recommends consuming low-fat, acidified milk products every day. By the way, lactic acid bacteria also live in fresh sauerkraut.
Extra food for the helpful microorganisms
Often producers enrich their drinks and desserts with indigestible carbohydrates , for example with inulin or with oligofructose. They enter the large intestine unchanged. There they serve as food for the lactic acid bacteria, as a result these bacteria multiply well.
Such additives are called prebiotics: they achieve the same goal as probiotics, but in an indirect way. Because the body can only tolerate a limited amount of indigestible carbohydrates, caution is advised with prebiotic foods: If the body is given too much inulin, diarrhea is at risk.
In the EU there are margarines, salad dressings and dairy products that are fortified with plant sterols. These so-called phytosterols have a similar structure to cholesterol and are supposed to prevent too much dangerous LDL cholesterol in the blood.
How do they do that? Researchers believe that when you eat phytosterols, less food cholesterol is absorbed from the intestines. Many studies show: Plant sterols actually help to lower cholesterol levels. Few people do not respond to them at all.
A question of the dose
But be careful: the benefits of phytosterol-containing foods are controversial. Because even if they can help lower cholesterol, there is no study that shows that consuming them helps prevent heart attacks.
What’s more, some people with a genetic disorder ingest high amounts of these phytosterols through the intestines, so that they get into the bloodstream – which normally rarely happens. The concentration of these sterols in their blood is then particularly high, which could be associated with an increased risk of heart attack.
Overall it can be said that the data situation is very unclear. Therefore, a phytosterol-containing margarine is only suitable, if at all, for people who already have a slightly elevated cholesterol level. Under no circumstances should they be eaten preventively.
Do not use several products at the same time
It shouldn’t be more than three grams of phytosterols per day anyway. Nutritionists recommend a maximum of 1.6 to two grams per day, which corresponds to around 20 grams of a phytosterol-containing margarine. And those who already use this margarine should avoid other phytosterol-containing foods, such as milk or yoghurt.
People taking cholesterol-lowering medication should ask their doctor whether they should be getting any extra plant sterols from their diet at all. Incidentally, an appropriately fortified margarine does not replace a healthy, low-cholesterol diet with a few saturated fatty acids and lots of fruit, vegetables, whole grain products and vegetable oils. Those affected should not do without it under any circumstances, not even if they are taking medication.
Omega-3 fatty acids
Numerous scientific studies prove: Natural omega-3 fatty acids have a positive effect on health. They help to reduce high triglyceride levels or high blood pressure and can prevent arteriosclerosis, including those of the coronary arteries.
Many food manufacturers therefore enrich products with omega-3 fatty acids, for example bread, eggs, margarine or soft drinks. It has been scientifically proven: Omega-3 fatty acids work when they are taken as capsules or when they are in the hen’s egg. They occur naturally in oily fish such as salmon, mackerel or herring or in some vegetable oils, especially rapeseed oil. Walnuts are also a good source.
To increase the intake of omega-3 fatty acids, the DGE therefore recommends eating high-fat fish regularly, about once or twice a week, and also using vegetable oils, especially rapeseed oil.
Folate – that’s the name of the natural form of the vitamin, folic acid is the name of the synthetic form – is a class B vitamin . It is said to protect against cardiovascular diseases. However, this has not yet been clearly scientifically proven.
Folate is found in abundance in many foods, for example in oranges and orange juice, in grapes, tomatoes, green vegetables, whole grain products or in meat, including in liver, as well as in dairy products and eggs. Nevertheless, the DGE regards it as a so-called critical nutrient: Many people of all ages consume too little folate. A folate deficiency is rarely seen, however.
The Federal Institute for Risk Assessment recommends women who want to have children, pregnant and breastfeeding women, to take a preparation with folic acid. This can prevent deformities in newborns, such as an open back, or a miscarriage.
Some table salts are fortified with folic acid. Some scientists are calling for flour to be fortified with the B vitamin , as is done in the USA or Switzerland. Other scientists are critical of this.
Whether folic acid is harmful has not been researched
It is not clear whether the additional intake of folic acid increases the number of twin births. It is also unclear whether folic acid taken in addition promotes the growth of cancer precursors, for example in the colon.
Studies show that high doses of folic acid can mask a deficiency in vitamin B12 . The problem particularly affects older people who cannot easily absorb vitamin B12 from food.
Anyone who buys drinks that are fortified with the vitamin combination ACE – provitamin A and vitamins C and E – should be critical. The added amounts of vitamins often exceed the daily dose recommended by nutritionists several times over.
The excess of vitamins C and E is not a cause for concern. It becomes problematic with provitamin A , beta-carotene. Because artificial beta-carotene is suspected of promoting bone fractures and increasing the risk of lung cancer in smokers. Some studies confirm this connection, others could not prove it.
Energy drinks have dubious benefits
The demand for energy drinks is great. The advertised stimulating effect of the drinks is questionable. The caffeine content often corresponds to that of a cup of coffee and the other invigorating ingredients are substances that the body also produces, such as taurine. The benefits and risks of energy drinks have not yet been researched in scientific studies.
The Federal Institute for Risk Assessment warns of possible dangers. For those who drink alcohol in addition to the energy drinks, the mixture can be health-critical: Coffee and alcohol mutually reinforce their effects.
Guarana drinks contain a lot of caffeine, plus theobromine from cocoa beans and theophylline, obtained from the leaves of the tea bush – all substances have a stimulating effect. When children drink guarana, they can become temporarily cranky and nervous, perhaps even anxious.