Dr.ª Ana Rita Horta
 

Nutritionist

Dr.ª Marina Augusto Estévão

Nutritionist

Dr.ª Soraia Santos
 

Nutritionist

Think outside the box…

Of food myths

HPA Magazine 6

Food, and consequently diets, both have a major role in our health, especially in certain chronic situations, such as hypertension, diabetes or hypercholesterolemia.
This principle arises from the assessment of many and diverse studies, which have contributed to our better understanding of the relationship between nutrition, nutrients and health. Nevertheless, a lot of unfounded beliefs still persist in this context.
We challenged our nutritionists to deconstruct some of these myths. See if you still believe them.

DO EGGS INCREASE CHOLESTEROL AND THE RISK 
OF DEVELOPING CARDIOVASCULAR DISEASE?
For decades, eggs have been considered to be “villains”, because eating them would allegedly raise the levels of blood cholesterol, therefore increasing the risk of cardiovascular disease. But over the past few years, this notion has changed, as countless studies have proved exactly the opposite: eggs have a heart-protecting, anti-inflammatory, antioxidant effect and even act as a neural protector.
Eggs are a source of animal protein and are considered to be a reference food, comparable to breast milk. They are rich in vitamins (including vitamin D, responsible for absorbing bone calcium), minerals (iron and zinc, important for the immune system), proteins (albumin, related to gaining muscle mass, regeneration of cells and maintaining immunities), as well as antioxidants (vitamin E, choline, biotin and carotenoids). Besides giving the yolk its colour, these proteins also act as anti-inflammatories and antioxidants. As to the additional content of cholesterol from eggs, except for rare exceptions (diabetes, high LDL levels), it appears that eggs do not raise the blood cholesterol in healthy people. For this reason, the American Heart Association has changed its recommendations on the consumption of eggs: “At the moment, there is no specific recommendation as to how many egg yolks a person can eat per week.” Eggs are delicious, practical and healthy. Eat them, for your health!

DOES DOING CARDIOVASCULAR EXERCISE 
ON AN EMPTY STOMACH BURN MORE FAT?
The “logic” of this myth is associated with the following principle: during the night, our organism turns to fat (fatty acids) as a source of energy (mainly if we reduce the sources of carbohydrates at dinner), and so it should supposedly be easier to use fat as fuel during exercise (on an empty stomach). Despite being a valid argument, the truth is that science does not seem to support it.
We know that physical exercise of moderate/high intensity leads to a greater use of fat after doing it, although during the activity the organism turns mainly to the carbohydrates as a source of energy. If the object of the exercise is to lose weight, it will certainly have a greater impact in the long term; “breaking down fat” in the hours after training will be greater than during exercise, especially if activity continues at the basal rate.
Another important aspect to consider when doing exercise on an empty stomach is a greater breakdown of muscle mass, because the organism needs to fall back on its reserves of glucose as a source of energy and these reserves are in the form of muscle glycogen. In sporadic sessions, it will not have much impact, but if recurring, it can represent too high a sacrifice for the muscle.
Generally speaking, doing exercise on an empty stomach does not seem to be a particularly efficient strategy for anyone trying to lose weight.

IS BREAD FATTENING?
In most cases, what is fattening is what we put on the bread (fatty cheese, sausages). These ingredients, not the bread, increase the caloric value of the sandwich. Another question is the type of bread we eat. Bread made exclusively from wheat (white bread), without added fibres, is not recommended, nor is milk bread or packaged loaves, because they contain too much sugar and saturated fats, which are bad for cholesterol. Very dark breads (mixed grain or whole grain) are rich in fibres that satisfy hunger, as they slow down digestion and avoid the feeling of permanent hunger and the desire to eat other high-calorie foods. Besides this, they help facilitate good intestinal function, control glucose and lipids, and are strong allies in the prevention and control of diabetes and dyslipidemia.

IS EATING ORANGES AT NIGHT BAD FOR YOU?
An old Portuguese proverb says, “Oranges in the morning are gold, in the afternoon silver, but at night they will kill you.” This myth probably came about by associating the vitamin C contained in oranges, which is also attributed to an excitement effect, which could interfere with a good night’s sleep. However, oranges do not have enough vitamin C to influence the nervous system in such a way. The only thing that occurs is a stimulating effect to the organism, which could occur throughout the day. This is not a reason not to eat oranges at night; they are good for you at any time of day, except if there is a specific situation such as heartburn, gastritis or acid reflux, in which case acidic foods should be avoided, especially at night.

DOES BEETROOT PREVENT ANAEMIA? 
Despite being red, beetroot has very little iron compared to red meat. Besides this, iron is more easily absorbed when it comes from foods of animal origin (shellfish, tuna, sardines, mackerel, liver and meat in general). There are also good sources of iron of vegetable origin, such as legumes (lentils, chickpeas, beans, peas), nuts or green leafy vegetables. However, the iron in these foods is more difficult to absorb. To intensify the absorption of iron from these foods, we can ingest them together with foods that are rich in vitamin C (kiwis, mangos, pineapple, strawberries, citrus fruits, parsley, coriander, chestnuts). There are other foods that inhibit the absorption of iron, as is the case with some dairy products (yoghurt or cream sauces, desserts such as ice-cream or milk puddings), whose consumption should be avoided together with foods rich in this nutrient.

DOES DRINKING WATER WITH MEALS 
CAUSE WEIGHT GAIN?
Water has no calories, does not contain fat, carbohydrates or protein, and therefore is not fattening at any time it is ingested; it only supplies a few micronutrients. It is fundamental for the functioning of the organism, and therefore should be the choice source of hydration in its natural form or in teas, infusions or unsweetened flavoured water.
The recommended daily consumption of liquids is between 1.5 to 2 litres a day, at frequent intervals and in small volumes, mainly between meals.
Drinking water in moderation with meals (around 1 glass of 200 ml) has some advantages: it moistens the food we are swallowing, helps with intestinal transit and gives a feeling of satiety.

AS MUCH FRUIT AS WE WANT?
Fruit is an important source of vitamins, fibres and antioxidants, as well as simple carbohydrates; in other words, it contains fructose, a sugar that is naturally present, is quickly absorbed, but which in excess can provoke an increase in glucose levels in the blood and increase weight. It makes no difference what time it is eaten, as it has the same type of calories before or after a meal.
The recommended daily intake is of a varied and balanced 3 to 5 pieces of fruit. Fresh fruit is preferred, one portion at a time, as this contains less sugar compared to fresh fruit juices, which contain more than one piece of fruit and therefore more calories.

COW’S MILK OR VEGETAL DRINKS?
Cow’s milk is considered to be a common food in human nutrition. Compared to other vegetal drinks, such as soy, wheat, almond or rice drinks, cow’s milk has a lower energetic value (skim milk = 34 Kcal/100 ml, or 85 Kcal/250 ml cup), high quality protein and a greater bioavailability for absorbing calcium, phosphorus and zinc. Its fat content is variable (skim milk = 0.2 g/100 ml, or 0.5 g/250 ml cup), and does not contain any additional sugar or, in some types, any lactose.
Cow’s milk integrates dietary and nutritional recommendations throughout the cycle of life, and therefore should only be excluded for reasons of pathological situations, intolerance or food allergy. 
The recommended quantities are 1 – 2 dairy products per day, with 1 product equivalent to: 1 cup of milk (250 ml) or 1 liquid yoghurt (180 ml) or 2 yoghurts (125 g each) or 1 slice of cheese (30 g) or fresh cheese (50 g) or cottage cheese (100 g), with low fat content (<30% of fat content).