jueves, 27 de febrero de 2014

Why is so important to eat foods rich in Choline?

Choline could be considered as another member of the B vitamin complex. Despite the fact that humans can synthesize it in small amounts, you must consume it through your diet to get enough. The need to include it in our diet was demonstrated in a study of healthy men who developed liver damage when fed a choline-deficient diet.

Choline has several vital functions in the body. It reduces chronic inflammation and lowers homocysteine (which is linked to cardiovascular diseases). In addition, it is a precursor for an important neurotransmitter involved in muscle control and memory (acetylcholine). Another of its metabolites, phosphatidylcholine, is necessary to prevent fatty liver. Choline is especially necessary during pregnancy as it is essential for fetal brain development, learning and memory; but it can improve cognitive function and memory at all ages.

Recommendations by life stage and gender

Most of us aren't meeting the recommended daily intake of choline (only 1 out of 10 americans). Given the importance of choline in conditions such as liver disease, atherosclerosis and neurological disorders, we have to try to eat more choline-rich foods to reach an adequate intake.

Adequate Intake (AI) for Choline
Life stageAgeMales
Infants0-6 months125125
Infants7-12 months150150
Children1-3 years200200
Children4-8 years250250
Children9-13 years375375
Adolescents14-18 years550400
Adults19 years and older550425
PregnancyAll ages-450
Breast-feedingAll ages-550
 Source:Food and Nutrition Board of the Institute of Medicine 

Excessive doses (over 3500 mg in adults) can cause intestinal problems, and there is also some concern that high doses can be carcinogenic.

Needs for Choline in Pregnancy and Nursing

It is known that folate is critical between the 21st and 27th days after conception, for normal embryonic development, and maternal supplementation with folic acid decreases the incidence of neural tube defects such as anencephaly or spina bifida. Now we also know that choline also play an essential role to prevent birth defects in newborns (like folate, it is also a methyl group donor), so it may one day be recommended for all pregnant women in the way folic acid is today. 

But choline is not only important during the first month of pregnancy, as it can also lower the stress hormone Cortisol in utero during the rest of the pregnancy. Babies exposed to high levels of cortisol in utero, such as might occur if a woman is under stress, anxiety or suffering from depression, have an increased risk of stress-related and metabolic disorders. A proper intake of choline could protect the baby later in life from some chronic diseases such as metabolic syndrome (type 2 diabetes, blood pressure...) but also from certain mental health disorders

The current recommendation for pregnant women is 450 milligrams of choline a day, but there is a new study that indicates that this may not be enough. This study found that the consumption of 930 mg of choline in the third trimester of pregnancy was linked to a 33% lower concentration of cortisol, compared to those who consumed 430 mg a day.

If you are lactating your requirements increase in 125 mg a day (total = 550 mg), as a substantial amount of choline is secreted in breast milk. 

Keep in mind that most prenatal vitamins do not contain choline. Check the label.

Food sources

Choline is found in a wide variety of foods. Eggs and meats are very good sources, providing up to 430 milligrams per 100 grams. Choline is found exclusively in the egg’s yolk, and two yolks contain about 250 milligrams of choline, or roughly half the recommended daily supply.
Other good sources are peanuts, milk, cauliflower... Lecithins added during food processing may increase the daily consumption of choline up to 115 mg/day.
If you are a vegan who does not consume any animal foods, you may be at risk of deficiency.

Total Choline (mg)
Beef liver, pan fried
3 ounces (about the size of a deck of cards)
Wheat germ, toasted
1 cup
1 large
Beef, trim cut, cooked
3 ounces
Brussel sprouts, cooked
1 cup
Broccoli, cooked, chopped
1 cup
3 ounces
Milk, skim
8 fl oz.
Peanut butter, smooth
2 tablespoons


You can find it as choline chloride or choline bitartrate. Phosphatidylcholine supplements provide only 13% choline, so for example, if the supplement contain 4230 mg of  phosphitidylcholine, it means that it provides 550 mg of choline.
Commercial lecithin is about 23% phosphatidylcholine, which only contains about 13% choline. Thus, lecithin supplements has less choline than the phosphatidylcholine supplements.
One of the problems with lecithin supplementation is its susceptibility to becoming rancid because of its high content in fat. That's why after opening it should be refrigerated.

Warning for pregnant women: In some stores you can only find choline supplements which include Inositol, which has been documented to cause uterine contractions because it has an intimate relationship with oxytocin, a key uterine stimulator, making it potentially dangerous for the risk of causing miscarriage.

jueves, 23 de enero de 2014

Superfoods broadcast's script

Today we are talking about super-foods. You've probably heard that certain foods have special properties to promote health and to stave off chronic diseases such as cancer or heart disease, boost immunity or fight against ageing process. But what qualities need a food to be considered as super?

First of all I must say that there isn't such a thing as a superfood; we should use instead the term "healthy choice". There isn't even a legal or scientific definition of superfood. In my opinion marketing is taking advantage of the motivation that consumers have to buy products which provide health and wellness. That's why we continually hear of new superfoods popping out in the market. We all want to believe that eating this kind of foods will give our bodies the health kick we need to ward off illness and ageing, and we think that if we eat that food once, twice or even three times a day we can forget about the rest of the diet. However, this can have an unwanted outcome; for example, you may eat a lot of nuts or olive oil a day because they have fats that protect your heart, but they are so fattening that may provide you with all the calories you need a day making you overweight, so instead of making you healthier they are having the opposite effect. It also does not make sense to me to eat berries frequently to prevent cancer or ageing so you don't have to make the effort of stopping smoking, do more exercise or have a plant-based healthy diet.
This is the reason why, instead of eating super foods, we should focus on having a super diet based on a variety of nutritious foods, including plenty of fruits, vegetables, whole grains, legumes, nuts, seeds or other foods dense in nutrients; and we should limit the intake of saturated or trans fats, as well as salt, sugar, and we have to try to achieve and maintain a healthy weight and do exercise regularly. This is the only way to reach an optimal health. So we have to keep in mind that a single food, no matter how "ultra-healthy" it is, it’s not a magic bullet that makes up for a crappy diet.

Lately I’m reading a lot about the properties that flavonoids have. Why are they so important?

Eating high levels of flavonoids, including anthocyanins and other compounds (found in berries, tea, and cocoa) are associated with lower insulin resistance and better blood glucose regulation. Findings published last tuesday in the Journal of Nutrition reveal that high intakes of flavonoids could offer protection from type 2 diabetes.

Another study also found that these food groups lower inflammation which, when chronic, is associated with diabetes, obesity, cardiovascular disease, and cancer.

What are the most popular superfoods?

They change from time to time, but currently the most “trendy” foods that we think that superpower our diet are fruits, especially berries like blueberries or citrus fruits like oranges, lemons or pomegranate, which can lower blood pressure in the short-term, as well as reduce the oxidative stress. Vegetables as broccoli, pumpkin, tomatoes, and dark leafy vegetables like spinach or kale; tree nuts as walnuts, foods rich in omega-3 fatty acids such as salmon; foods rich in fiber capable of lowering the cholesterol levels such as the one found in oats and beans; soy because of its isoflavones; and of course, probiotic foods like yogurts.

Does really dark chocolate have healthy properties or it’s just an excuse invented by somebody with a sweet tooth who doesn’t want to have any regrets after eating it?

I’m also the kind of person who uses the excuse of the healthy benefits of some foods to eat them as much as I want… But jokes apart, it is true that dark chocolate have a high amount of antioxidants known as flavonoids which can lower blood pressure by increasing the elasticity of the blood vessels, so it helps to protect your heart. But not all chocolates do the trick, it must have over a 60% of cocoa content, so the darker, the better; and in addition it will have a lower amount of fat and sugar.

Most of the superfoods are characterised for being rich in antioxidants. Why are they so important?

There are highly reactive toxic free radicals that we create as part as normal metabolism, like oxygen free radicals because, although we need to breathe oxygen to live, it produces metabolic byproducts which are very harmful. Our body produces some types of antioxidants to block these free radicals, but it cannot make some antioxidants which are essential for us, that's why we need to eat them with the food, for instance: vitamins C and E. There are other compounds which are also antioxidants that our body cannot produce like beta-carotene, lycopene and lutein, which we get from plant-foods. And there is a large class called polyphenols that include flavonoids found in green tea, red wine or dark chocolate. There are thousands of these compounds in our diet, and you can't get all the antioxidants you need in a single food, that's why we need to eat a variety of foods.

The foods that contain the highest amount of antioxidants are fruits like berries. Blueberries are the most popular among the berries because they are packed with anthocyanins, which have the property of inhibiting the growth of cancerous human colon cells, as well as kill them off. Other antioxidants found in blueberries can prevent and reverse age-related diseases like cancer, diabetes, and heart disease.

I’m thinking of drinking more tea to get more antioxidants, which tea would you recommend to me?

I would recommend green tea because although in overall it has the same amount of antioxidants than the black tea, green tea have a specially powerful antioxidant known as ECGC. There have been more than 100 studies focusing on this natural substance and its anti-cancer benefits.

I would also like to mention the white tea because like black and green tea, it is also derived from Camellia sinensis, thus, it shares many of the same chemical properties and health effects of tea. This tea contains the most antioxidants because it retains a higher amount of catechins, which are a group of polyphenol antioxidants present in fresh tea leave and due to the process the white tea is made, it’s the tea with the highest amount of these substances which have been found to reduce cholesterol, decrease blood pressure, and improve the function of blood vessels, thereby decreasing the risk of cardiovascular disease.

I usually add beetroot to my salads because I’ve heard it’s good for your heart. Is it also due to the antioxidants?

It’s true that beetroot is an ally of your heart, but for a different reason. It contains high levels of nitrate which is converted by the body into nitric oxide which can lower blood pressure and also reduce the blood clotting.

After the foods rich in antioxidants, the superfoods more popular are those that can lower the cholesterol. But do they really work?

According to an important study publicated in 2003 in “The journal of the American Medical Association” a diet that include soy fiber, protein from oats and barley, almonds and margarine from plant sterols lowers the cholesterol levels as much as statins, the most widely prescribed cholesterol medicine.

But these nutrients have other additional health benefits. For example, fiber has the bonus of reducing the risk of cancer, it slows down the absorption of sugar and helps to manage your weight by making you feel full sooner and longer.

I use soy sauce very frequently in my cooking, can it also help to reduce my cholesterol?

I’m afraid that soy sauce doesn’t count, you should eat tofu, soy milk or edamame to do the trick.

Is it true that drinking red wine offer protection against heart disease?

Red wine has been associated with numerous health benefits, including a lower rate of heart disease. Studies have shown that drinking small to moderate amounts of red wine daily (which is from 1 to 3 standard drinks) may help protect middle-aged and older adults against heart disease. However, before you uncork that bottle of red wine, remember that alcohol is addictive. Heavy drinking can lead to high blood pressure, heart disease, stroke, obesity and liver failure.
Due to the harmful health and social consequences of alcohol consumption, adults who do not drink alcoholic beverages should not start even though there are some potential heart health benefits.

What is the scientific evidence behind the media's superfood claims?

Although there are many studies that have shown that certain foods have health-promoting properties, most of those results can not be applied to real diets. For example, they tend to use very high concentrations of those nutrients, what is not realistically attainable in the context of a normal diet. On top of that, the physiological effects of many of these foods are often short-term. So if you want to get the benefits they have, you should consume them in huge amounts. And this could be counter-productive for certain foods such as red wine because of its alcohol or cocoa in the form of dark chocolate which would boost intake of not only their healthy flavonoids but also of other nutrients that we should limit in our diet like sugar or saturated fats.

Another problem with the studies about superfoods is that they are done mainly on animals like rats, or in vitro with human cell cultures, and there is no guarantee that these nutrients will have the same effects in people when consumed in a normal diet where we combine nutrients, which can modify the absorption of certain compounds. For instance, the beta-carotene in carrots and spinach, is more readily absorbed when eaten together with a source of fat such as olive oil or any other salad dressing.

What is the truth behind the publicity of the Superfoods?

There are some foods which have a better nutrient profile than others, but we have to remember that what really counts is how we eat them on the context of our diet. So if you eat them several times a day but then you fill the rest of your diet with fast food or pre-cooked food you are not going to prevent any disease.

Sometimes the media publicite processed products as superfoods, but I wouldn't put a fortified potato chips in the superfoods list because it should be always a real unprocessed food. Another example would be the bread made from enriched wheat flour publicized as a whole grain. But actually It’s the germ and bran of the whole grain you’re after because it’s in there where you can find all the nutrients a grain product has to offer, like magnesium, chromium or folate, And when you purchase processed grains like bread made from enriched wheat flour, you don’t get these.

Can you give us another example of a superfood which claims are false or misleading?

I would like to make a warning about the açaí scams. There are several companies that sell açaí supplements as part of a multi-level marketing scheme. Marketers of these products make unfounded claims. They state that açaí and its antioxidant qualities provide a variety of health benefits, none of which has scientific confirmation to date. False claims include reversal of diabetes and other chronic illnesses, as well as expanding size of the penis and increasing men´s sexual virility. But the truth is that it has less content in polyphenols and lower antioxidant potency if we compare it with others 11 varieties of frozen juice pulp, scoring even lower than strawberries, grapes, mango or acerola.

I see superfoods are not as miraculous as we think, but can they be harmful?
Some people shouldn’t have too much of certain superfoods. For example people who have a family history of breast cancer shouldn’t consume extra soy because of its estrogenic effect. There are other people who are more vulnerable to the toxic effect of alcohol, so they shouldn’t drink red wine regardless how good it seems to be.

But the real problem with the promotion of the superfoods is that they can be misleading in the sense that they can distract you from the true message that is to have a diverse and balanced diet.

If you could only add to your diet one kind of superfood which one would you choose?

I would probably choose a food with anti-inflammatory properties like blueberries or a food high in omega-3 fatty acids; as inflammation is a key driver of all chronic diseases.

Blueberries have this quality because they are packed with potent antioxidants and bioflavonoids, and moreover they also have a high content in vitamin C and potassium. So their benefits go beyond their capacity of lowering your risk of heart disease.

And you can find the omega-3 fatty acids in wild cold-water fish such as salmon, sardines, herring, mackerel or other fatty fish. They can help to ease inflammatory diseases like arthritis as well as reduce the risk of cardiovascular disease, and recent studies show evidence that they can also help with memory loss and Alzheimer's disease and reduce depression as well.

I’d also like to point out that omega-3 fatty acids are essential for the developing brain and vision, so pregnant and breastfeeding women should take these supplements. But if you're pregnant avoid the fish liver oils like cod liver oil, because its high concentration in vitamin A can harm your baby, so choose fish oil instead, and don’t eat fish high in mercury such as shark, swordfish, tilefish and king mackerel.
My favourite source of omega-3 fatty acids is salmon. But stay away from the breaded and deep fried variety… they don’t count in your goal of 6-9 ounces of fish per week.

These healthy fatty acids are not exclusive to fish, they can also be found in vegetarian sources such as seaweed, flaxseeds, walnuts and fortified eggs.

What is the final thought you want us to keep in mind?

We should increase the intake of superfoods, but without forgetting the rest of the diet and to keep an overall healthy lifestyle. The only way we can take advantage of the health properties of the superfoods is when we replace not so healthy choices by these foods. For example, for a double health whammy, replace sugary sodas with tea, or choose nuts as a snack instead of potato chips.

In conclusion, when it comes to ensuring a balanced nutrient intake of good health, we need to increase the range of nutritious foods as opposed to focusing on a diet based solely on one or a handful of foods claimed to be "super". Importantly, this should include a greater quantity and variety of fruits and vegetables.

Click here if you would like to listen to the broadcast.

martes, 7 de enero de 2014

Do Electronic Muscle Stimulators really work?

You might have seen ads for electronic muscle stimulators (EMS) claiming they will tone, firm, and strengthen abdominal muscles, help you lose weight, or get rock hard abs. But according to FDA, while these devices may temporarily strengthen, tone, or firm a muscle, no electronic muscle stimulator device alone will give you “six-pack” abs. 

Applying electrical current to muscles may cause muscles to contract. Stimulating muscles repeatedly with electricity may eventually result in muscles that are strengthened and toned to some extent but will not, based on currently available data, create a major change in your appearance without the addition of diet and regular exercise.

At this time, FDA is not aware of scientific information to support many of the promotional claims being made for numerous devices being widely promoted on television, infomercials, newspapers, and magazines.

Doctors may use electrical muscle stimulators for patients who require muscle re-education, relaxation of muscle spasms, increased range of motion, prevention of muscle atrophy, and for treating other medical conditions which usually result from a stroke, a serious injury, or major surgery. Again, the effect of using these devices is primarily to help a patient recover from impaired muscle function due to a medical condition, not to increase muscle size enough to affect appearance.

Warning: FDA has received reports of shocks, burns, bruising, skin irritation, and pain associated with the use of some of these devices. So it is very important that these devices be properly designed, manufactured, and labeled with clear and complete instructions for use and that anyone using them follows the instructions carefully.