The US News & World Report magazine invites many experts in cardiovascular diseases, diabetes, nutrition, obesity and food psychology to review and rank dozens of diets each year. Among them, the Mediterranean diet has been ranked as the “Best Diet Overall” for five years in a row and ranked the first in several categories in 2022, including:
- Best Diet Overall
- Best Plant-based Diet
- Best Heart-healthy Diet
- Best Diabetes Diet
- Best Diet for Healthy Eating
- Easiest Diet to Follow
Numerous studies have proven that following the Mediterranean diet can reduce weight, protect heart and brain health, and prevent cancer, diabetes, and chronic diseases.
However, adopting a Mediterranean diet does not necessarily mean that you can get these benefits directly. It also depends on how you do it.
The four keys to the Mediterranean diet are:
- Consuming a lot of vegetables, fruits, whole grains, legumes, nuts, seeds and olive oil, and cooking with the right amount of herbs and spices
- Eating fish, seafood, poultry, dairy products and eggs in moderation (i.e. low to moderate consumption).
- Reducing the intake of sweets and red meat
- Can drink a little bit of red wine, according to personal preference
However, due to some misconceptions, using the Mediterranean diet in the wrong ways can be detrimental to our health. What are the common mistakes to avoid, and how can we consume a Mediterranean diet correctly?
Mistake 1: Overdoing it With the Vegetables
“The Mediterranean diet can be a balanced diet with a variety of foods, but many people do not pay attention to the word ‘balance’ and ignore the proportion and quantity of food,” said nutritionist Jiahuei Lee. She said with a smile that people may find it annoying to hear “balanced diet” all the time, but it is “the basics of everything.”
For instance, the United States government recommends adults to eat at least two to three cups of vegetables a day to replenish fiber and various nutrients. Although there is no upper limit to daily vegetable intake recommendation, this does not mean that eating too much will not make people feel uncomfortable.
Since vegetables contain a lot of indigestible dietary fiber, when too much is consumed, it may cause symptoms such as constipation, diarrhea, abdominal pain, and flatulence.
Dietary fiber promotes gastrointestinal motility and also increases gas emission, which can cause flatulence when dietary fiber is consumed in large quantities.
Certain vegetables are particularly prone to making gas and should be consumed in moderation. They include onions, garlic, leeks, cabbages, broccoli, snow peas, peas, and asparagus.
In addition, vegetables often contain the mineral potassium, some at very high levels. Patients with chronic kidney disease need to limit potassium intake, so they need to be careful about their choice of vegetables. This doesn’t mean they can’t adopt a Mediterranean diet, only that it requires additional vigilance regarding their potassium intake.
The medical journal Nephrology Dialysis Transplantation actually published a review that listed the Mediterranean diet as the preferred diet for patients with chronic kidney disease. In the article, the Mediterranean diet was stated to be able to significantly reduce the risk of chronic kidney disease and to reduce the risk of end-stage renal disease by 16 percent, thus improving patient survival.
Patients with chronic kidney disease can choose vegetables and fruits that are low in potassium, such as broccoli sprouts, towel gourds, white flowered gourds, wood-ear mushrooms, white radishes, purple onions, wax apples, watermelons, and apples. Or, when cooking vegetables, they can reduce the concentration of potassium and not drink the soup.
Mistake 2: Straight Olive Oil
The Mediterranean diet does not avoid fats or oils, but they have to be healthy ones, such as extra virgin olive oil, macadamia nut oil, and avocado oil. And when adding these oils into the diet, we still need to pay attention to the amount. Even for healthy oils, excessive intake will add a burden on our bodies.
The recommended daily intake of lipids and oils is 3 to 8 tablespoons (1 tablespoon is 15cc).
People who eat a Mediterranean diet are generally accustomed to using olive oil. Lee said that people all know that olive oil is good for our health, “but I have heard of people drinking it directly.” The reason is related to the myth that olive oil does not tolerate high temperatures, and that the nutrients in it will be destroyed when the oil is heated.
In fact, there has been no research to support the claim that drinking olive oil is more beneficial than using it in cooking. Tim Spector, a professor of genetic epidemiology at King’s College London, tried a one-week olive oil diet that included drinking olive oil for the sake of scientific experimentation and his book. As a result, he experienced nausea and dizziness and later abandoned the experiment.
Lee pointed out that some people drink olive oil for the sake of health benefits, and then they also use oil when they cook, so they end up consuming too much oil, which will cause a burden to their body. Therefore, it is recommended to add the oil into the meal rather than drinking it directly.
Olive oil’s smoke point, which is the temperature that will destroy its nutrition, is around 190 degrees. The cooking temperatures are usually not that high, so we can safely use olive oil as cooking oil. In addition, a recent study from Spain shows that minor constituents of extra virgin olive oil prevent fatty acid and vitamin oxidation during cooking.
In addition to olive oil, Lee suggested using a variety of edible oils alternatively, choosing ones that are rich in unsaturated fatty acids like olive oil.
When choosing cooking oil, many people will buy olive oil in transparent glass bottles or plastic containers, which are cheaper. In fact, it is best to store olive oil in dark glass bottles, because such bottles insulate the oil from light to prevent rapid oxidation. Furthermore, the use of plastic containers and cans is a concern due to the release of plasticizers.
The oxidation process of oil and grease will produce lipid peroxides, which are quite unstable and will continue to disintegrate and produce more and more free radicals in the process of oxidation and deterioration of oil and grease. Free radicals are unstable factors that can damage cells and cause aging and many chronic diseases, such as cardiovascular disease, cataracts, and cancer.
Some people may also choose large containers of inexpensive blended oil for financial reasons. This kind of cooking oil, which blends different vegetable oils in different proportions, also contains higher unsaturated fatty acids, but the larger containers of oil are prone to oxidation and spoilage if they are not used up quickly. Therefore, if you have a lot of family members who often cook, you can choose blend oils, but you have to finish them quickly.
Mistake 3: Red Wine
One of the characteristics of the Mediterranean diet is the consumption of a glass of red wine at meals. The health benefits of red wine are thought to be related to resveratrol, a polyphenol.
However, academicians who promote the Mediterranean diet do not necessarily recommend people to drink wine, due to its alcohol content.
Dr. Chih Hao Lin, neurologist and director of the Brain Stroke Center at Lin Shin Hospital in Taiwan, is against people drinking red wine or other alcoholic beverages. He pointed out that after analyzing the advantages and disadvantages of drinking alcohol, it is found that alcohol does not have much benefit to the body and also reduces the quality of sleep.
Drinking too much alcohol can cause fatty liver and damage the brain. One study found that alcohol causes atrophy of the hippocampus, which is mainly responsible for memory and spatial orientation navigation.
Once alcohol reaches the liver, it further turns into a carcinogen, increasing the risk of many cancers. In 2020, more than 740,000 of all new cancer cases worldwide were attributed to alcohol consumption, of which about 100,000 were caused by light and moderate alcohol consumption.
So is it okay to drink a small amount of alcohol? The Lancet, a top international medical journal, gave us the answer: after a systematic review of alcohol consumption and its health effects in 195 countries from 1990 to 2016, it was found that the safe intake of alcohol is 0.
Lee said that people who don’t drink to begin with should not start drinking red wine when they adopt the Mediterranean diet. Or, they can cook with red wine, such as making beef bourguignon. However, although alcohol content diminishes with cooking time, even after long cooking times, such as two and a half hours, there will still be 5 percent of alcohol remaining in the dish.
If you want to supplement resveratrol, you can just eat grapes or blueberries with deep purple or dark red skins, or even have a glass of grape juice.
Mistake 4: Fruit Consumption Timing and Amount
Many people have the misconception that fruits with a refreshing taste are low in calories, so they eat a lot of them with relish. Lee reminded us that we should pay special attention to the amount of fruit consumption.
Clinically, there have been people, who seldom consumed sweets or sugary drinks ending up with high blood lipids, fatty liver, or weight loss failure, due to their excessive fruit consumption and fructose intake.
Epidemiological studies have shown that high fructose intake is associated with independent risk factors for obesity, non-alcoholic fatty liver disease, type 2 diabetes, chronic kidney disease, cardiovascular disease, and cognitive decline.
Furthermore, it is best to eat fruits after meals and to avoid turning them into fruit juice. Some studies have pointed out that eating some food before eating fruits can activate the small intestine’s ability to metabolize fructose, which has a protective effect on the liver. However, the study emphasized that if we eat too many fruits (high-dose of fructose) or drink fruit juice (the fructose release rate in the intestines is relatively high), it may still lead to fatty liver.
Mistake 5: Protein Preparation
High-quality protein can be found in beans, fish, eggs, and meat, in descending order of protein quality. White meat (e.g. poultry) is of higher quality than red meat (e.g. beef and pork), and the latter should be consumed no more than twice a week.
Whether it is plant-based protein or animal-based protein, we should avoid preparing it with high-temperature cooking.
Some people enjoy eating fried and grilled fish, but this can deplete the health benefits of fish oil and even spoil it. Moreover, the proteins in meat are easily denatured at high temperatures, and beans are also suspected of producing carcinogens after being processed at high temperatures.
Mistake 6: Starch Intake
As staple food sources, whole grains and cereals, such as brown rice, germ rice, pearl barleys, oats, rye, buckwheat, quinoas, wheats, barleys, and millets, are all familiar to us.
These grains provide the body with various nutrients and starch. Starch can be a source of energy for the body, but too much starch intake can still cause high blood sugar and high blood cholesterol.
However, there are many ingredients that look like vegetables, but are actually whole grains, which can make people accidentally consume too much starch. Such food items include corn, taros, pumpkins, yams, lotus roots, sweet potatoes, potatoes, red beans, green beans, broad beans, and chestnuts.
In addition, whole grains such as brown rice are high in phosphorus, so patients with chronic kidney disease who need to limit phosphorus should keep and eye on the amount they consume. Fortunately, plant-based sources of phosphorus are not fully absorbed by the body, and studies have shown that only 40 percent to 60 percent of phosphorus in plant-based foods is absorbed.