Tag: diet

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There are five ways to boost a student’s academic performance.

The evidence has been there. And now we have one more study which confirms that increased physical activity will boost academic performance of students. This is like icing on the cake. Besides boosting your brain power, increased physical activity will make your heart, lungs and body strong.

Earlier this month, researchers from Denver presented their research at the annual meeting of the Pediatric Academic Societies. Their conclusion: being more physically fit means kids will do better in school. They found that this can be achieved by increasing school’s physical education program to 40 minutes a day, five days a week, from 40 minutes once a week. The performance improved by about 70 per cent. Amazing!

A healthy and smart child will one day become a parent and hopefully instill the same kind of healthy attitude to the future generations. A person can workout at school, at a public or private gym or at home.

Secondly, a student needs a good night’s sleep every day to improve his academic performance. Sleep scientists say that without exception, we all need seven to eight hours of sleep to be fully capable of performing at a peak level. A competitive student would need that kind of sleep. Top performers, often need more than eight hours of sleep, plus an afternoon nap.

Sleep scientists say that we need one hour of sleep for every two we stay alert. This allows the brain to regenerate and repair itself. A student needs that to stay fresh and study more. A good night’s sleep also makes driving safe.

Thirdly, the student has to study. Without studying you don’t get the grades. So how many hours should one study? That requires time management skills. We all have 168 hours in a week to use as we wish. Common sense says that more time you spend studying better your academic performance will be.

Most universities recommend that students study at least two hours outside of class for every hour spent in class, although some recommend even more. Many students are taking 15 hours per semester, which probably means spending about 15 hours a week in class. Therefore, studying at least 30 hours a week outside of classes would be recommended. Combining the 15 hours a week in class and the 30 study hours outside of class, many students will need to plan to spend about 45 hours a week on school – about seven hours a day (source: Virginia Tech website).

Fourthly, you have to take care of examination anxiety. Recent studies have shown that students score higher after jotting down worries before a big exam. You will not choke under pressure if you write down test-related worries for 10 minutes before taking a major exam. Psychologists from University of Chicago found that this 10-minute exercise resulted in students scoring higher grades.

Finally, boost your memory and brain power with superfoods like berries (strawberries, blueberries, blackberries, cranberries), walnuts, leafy greens, fish, heart healthy fats (olive oil, canola oil, flaxseed oil and non-hydrogenated margarine), avocado, almonds, other fruits and vegetables, cereal grains, cocoa, soy foods, tea and wine.

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There are many health benefits to eating fish at least twice a week.

There are many health benefits to eating fish at least twice a week.

Remember PUFA (polyunsaturated fatty acids)? We discussed that few weeks ago. PUFA is good fat found in plant oils such as sunflower and soybean oil. It is also found in fish with omega-3 fatty acids (found in fattier fish such as tuna, mackerel and salmon).

Omega-3 fatty acids comprise of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) and alpha-linolenic acid (ALA). Fish oil contains both DHA and EPA, while some nuts (English walnuts) and vegetable oils (canola, soybean, flaxseed/linseed and olive oil) contain ALA.

Eskimos have extremely low rates of death from heart disease because they eat lot of fish. Mediterranean diet is also high in omega-3 fatty acids.

There is evidence from multiple studies supporting intake of recommended amounts of DHA and EPA in the form of dietary fish or fish oil supplements. The health benefits of omega-3 fatty acids are:

1. lowers triglycerides (kind of bad cholesterol)
2. causes small improvements in HDL (“good cholesterol)
3. small reduction in blood pressure
4. people with a history of heart attack, reduces the risk of non-fatal heart attack, fatal heart attack, sudden death and death due to any cause
5. reduces the risk of dangerous abnormal heart rhythms, and strokes in people with known cardiovascular disease
6. slows the buildup of atherosclerotic plaques (“hardening of the arteries”)

Too much of omega-3 fatty acids may have harmful effects, such as an increased risk of bleeding. It can increase LDL (bad cholesterol).

What about ALA? Scientific evidence regarding ALA is less compelling and beneficial effects may be less pronounced. Do not confuse ALA with omeg-6 fatty acids called Linoleic acid (LA).

In 2009, the American Heart Association advised the general public to make omega-6 part of heart-healthy eating. Omega-6 fatty acids are found in vegetable oils, nuts and seeds. Recommended daily servings of omega-6 depend on physical activity level, age and gender, but range from 12 to 22 grams per day.

PUFA (omega-3 and omega-6 fatty acids) are “essential” fats that your body needs but can’t produce, so you must get them from food. Observational studies showed that people who ate the most omega-6 fatty acids usually had the least heart diseases. Review of several trials by the American Heart Association indicated that replacing saturated fats with PUFA lowered risk for heart disease events by 24 percent.

Reports suggest that an average typical Western diet has omega-3 fatty acids found in fish to be about 150 mg per day. This is equivalent to eating about one fish meal every 10 days. This is not enough. The general recommendation is 650 mg per day of omega-3 fatty acids.

The American Heart Association recommends that people without coronary heart disease have two fish meals each week (at least 300 mg of omega-3 fatty acids daily), and they recommend that patients with documented coronary heart disease receive 1000 mg daily.

There are three sources of omega-3 fatty acids:

-the most important source is fish for DHA and EPA (salmon, tuna, and trout) and foods like eggs, dairy products and yogurt are fortified with omega-3 fatty acids.
-second source is plants for ALA and plant oils, including leafy vegetables, walnuts and flaxseed oil (which is made up of 50 per cent ALA)
-third source is commercially available salmon and flax seed oil pills. Fish oil capsule 1000 mg has 300 to 600 mg of DHA and EPA.

Finally, remember omega-3 fatty acids are not panacea for all kinds of health problems. . Regular exercise and healthy eating is important part of staying healthy.

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How Much Protein Does Your Body Need to Function Properly?

To function properly, all living cells in our body need protein. Protein also supplies fuel for meeting the body’s energy needs. Proteins are essential in the diet of animals for the growth and repair of tissue and can be obtained from foods such as meat, fish, eggs, milk, nuts, grains and legumes.

Proteins, like carbohydrates, contain four calories per gram as opposed to lipids which contain nine calories and alcohols contain seven calories.

There are about 20 amino acids used by humans in protein synthesis. There are 11 “nonessential” amino acids – that means our body can synthesize these amino acids in sufficient quantities. We do not have to rely on our food for these amino acids.

The nine essential amino acids cannot be synthesized by the body and must come from dietary sources. If you eat a balanced diet then you should be able to get all the essential amino acids your body needs.

The Recommended Dietary Allowance (RDA) is 0.8 grams of protein per kilogram (2.2 pounds) of body weight per day for an average size healthy person. Protein should provide about 15 per cent of a healthy person’s daily calories.

About eight ounces of chicken or six ounces of canned tuna should be enough. A vegetarian can get enough proteins from grains, nuts and legumes. Some vegetarians eat dairy products (lactovegetarians), egg products (ovovegetarians) or both (ovolactovegetarians).

What happens if you eat too much protein?

Studies have shown that excess dietary protein increases calcium loss in the urine, raising the risk for osteoporosis and kidney stones. Your weight goes up because you consume more calories than you need. You also increase the risk of cardiovascular disease if you consume protein high in saturated fats.

From time to time our body needs extra protein. For example: the RDA is higher during childhood, pregnancy, lactation and recovery from a serious illness, trauma, or major surgery. Very active people and athletes in training probably need more protein as well, but no special RDAs have been established for such individuals as there is no general agreement on this subject.

An article in a sports medicine journal by Tipton and Witard (Clinics in Sports Medicine – January 2007) discusses the subject of protein requirements and recommendations for athletes.

The authors say that protein nutrition for athletes has long been a topic of interest. From the legendary Greek wrestler Milo – purported to eat copious amounts of beef during his five successive Olympic titles – to modern athletes consuming huge amounts of supplements including protein.

The subject is controversial. In general, scientific opinion on this controversy seems to divide itself into two camps – those who believe participation in exercise and sport increases the nutritional requirement for protein and those who believe protein requirements for athletes and exercising individuals are no different from the requirements for sedentary individuals.

The authors say that there seems to be evidence for both arguments but from a practical perspective, the requirement for protein may not be applicable to most athletes who consume a varied diet that contains complete protein foods and meets energy needs.

An athlete’s protein needs should be carefully assessed by the coach, physician and nutritionist. Risks and benefits of high protein diet and supplements should be discussed with the athlete. There is no reason to recommend protein supplements per se because there is no evidence that supplements work better than foods, say the authors.

Steak is a great source of protein but it is also a source of saturated fat.

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Scientific Evidence and the Role of Dietary Fats and Carbohydrates in Heart Disease

Dear Dr. B: In your Feb 1, 2011 article, you say that data indicate dietary cholesterol has little effect on blood serum cholesterol levels. I wonder if you could send me references for this. I’m having a debate with a friend and mentioned this, but he doesn’t believe it.

Answer: Finding a reference is not difficult these days. You just have to Google your question and you will find thousands of references. The difficult part is to know which reference is reliable. When I do my research, I generally look at several articles and find reliable scientific information from different sources.

You can find an excellent article on this subject in the American Journal of Clinical Nutrition (April 2011 vol. 93 no. 4 684-688) titled: The role of reducing intakes of saturated fat in the prevention of cardiovascular disease: where does the evidence stand in 2010?

The old hypothesis was that dietary fat raises blood cholesterol which eventually leads to atherosclerosis (hardening of the arteries) and coronary artery disease. This hypothesis was based on research done before we knew anything about the dangers of trans fats.

Now the research has confirmed that heart disease risk rises if there is a high concentration of bad cholesterol (LDL) in our blood and the risk is reduced if there is a high concentration of good cholesterol (HDL) in our blood. But what is poorly understood is the link between dietary fat and high blood cholesterol level.

What do we know about the role of dietary fats and carbohydrates?

-Eating saturated fats – SFs – (found in beef, pork, lamb, dairy products and tropical oils such as palm oil, palm kernel oil, and coconut oil) raises bad cholesterol (LDL) but also raises good cholesterol (HDL). One negative effect, one positive effect.

-Eating unsaturated fats – UFs – (MUFAs – monounsaturated fats – found in plant oils such as olive, canola, and peanut oil; PUFAs – polyunsaturated fats – found in plant oils such as safflower, sunflower, corn or soybean oil, fish with omega-3 fat) lowers the bad cholesterol (LDL) and lowers the good cholesterol (HDL). One positive effect, one negative effect.

-Eating industrially produced trans fats – TFs – (vegetables oils that have been chemically changed by a process called hydrogenation to make them solid at room temperature found in margarine, many fast foods, snack foods and fried or baked goods) is highly dangerous because it does two bad things – raises bad cholesterol (LDL) and lowers good cholesterol (HDL).

-Replacing saturated fats with carbohydrates (CHO) may actually increase cardiovascular risk unless carbohydrates come from whole-grain fibre-rich sources. Studies have shown that carbohydrates with high glycemic index –GI – (a measure of the effects of foods on blood-sugar levels) increase cardiovascular risk by 33 per cent.

Do you find all this confusing? You are not alone.

Next time you go to a grocery store, tell the helper (if you can find one) to give you some SFAs, PUFAs, MUFAs, no TFs, no LDL, lots of HDL, healthy CHOs and some low GI food. See what you get and surprise your family. Happy eating.

Start reading the preview of my book A Doctor's Journey for free on Amazon. Available on Kindle for $2.99!