Ask the Experts
Ask the Experts
- Are sprouted grains healthier than unsprouted grains?
- What is resveratrol?
- What are probiotics?
- Is organic milk healthier than non-organic?
- What is the influence of omega-3 fatty acids on risk of heart disease?
- What is the difference between “100% whole grain” and products that are “made with whole grain”?
- What is white whole wheat?
- Are energy drinks safe to consume?
- What are the benefits and risks of fish consumption?
- What are trans fats?
- Is it true that chocolate is healthy?
- What are phytochemicals?
- Are vitamin/ mineral supplements recommended?
- What are free radicals?
- What is an antioxidant?
- Is consumption of soy recommended?
- What counts as a serving of fruits and vegetable and how many servings do I need each day?
- What is the best way to eat produce: fresh, frozen, or canned?
Sprouted grains such as sprouted wheat, oats and corn, have been touted as a health food, but overall the nutritional benefits appear to be very small when compared to unsprouted grains. What we do know, based on research, is that sprouts can be slightly higher in some vitamins, like vitamin C and carotenoids, and may have higher quality protein compared to unsprouted grains. However, the difference is so small that it is unlikely that their consumption will improve the nutritional status of an individual. Another claim that is often made about sprouted grains is that their high enzyme activities provide an advantage for human health. While it is true that some sprouted grains may have higher enzyme activities, the biological significance of this is questionable. The function of the enzyme, phytase is to break down a compound called phytic acid. Since phytic acid binds with minerals and reduces their absorption in the small intestine, high phytase activity could potentially increase bioavailability of some minerals. However the difference in phytase activities is very small when compared to unsprouted grains. Another enzyme that can be elevated in sprouted grains is amylase. Amylases break down starches into sugars, which could increase digestibility.
Of utmost importance when considering adding sprouted grains to one’s diet are the numerous reports that raw sprouts have been linked to over 30 food-borne illness outbreaks in the last 15 years. The Food and Drug Administration recommends children, the elderly, pregnant women, and persons with weakened immune systems avoid eating raw sprouts.
Resveratrol is a polyphenol antioxidant. It is found in wine, grapes, grape juice, some berries, and peanuts. In cell culture and animal studies, it has been found to have beneficial cardiovascular effects and to inhibit growth of several types of cancer. More research is needed to determine if resveratrol has similar effects in humans.
Probiotics are foods or supplements that contain beneficial microorganisms in large enough amounts to provide a health benefit. Probiotics may be helpful in the treatment of diarrheal diseases and some gastrointestinal diseases and syndromes. Different strains of bacteria have different health benefits, and the quality and quantity of microorganisms in products may vary. No consensus exists on the frequency or amount that should be taken. Probiotic supplements are regulated as dietary supplements, and are not evaluated for safety or efficacy by the FDA.
At this time, the results from research are not conclusive. Some studies suggest that organic milk may be slightly higher in polyunsaturated fatty acids, compared to conventionally-produced milk, while others find it to be lower. Studies evaluating conjugated linoleic acid, carotenoids, and vitamin E in organic versus conventional milk have also had mixed results.
Omega-3 fatty acid consumption has been found to be associated with reduced risk of heart disease. There are a variety of mechanisms through which omega-3 fatty acids may act to reduce risk:
- Decreased production of certain kinds of inflammatory eicosanoids
- Reduction in serum triglycerides
- Lowering blood pressure
- Increasing vascular endothelial function
Because of the heart-healthy benefits of omega-3 fatty acids, the American Heart Association recommends eating two servings a week of fish, preferably fatty fish, each week.
Whole grains are grains that contain the entire seed kernel, including the bran, the germ, and the endosperm. The bran is the protective outer shell of the kernel, and contains fiber, some B vitamins, and small amounts of minerals. The germ is the nutrient-rich portion of the grain that provides nourishment for the seed. It contains B vitamins, vitamin E, and phytochemicals. The endosperm is the starchy portion of the grain that contains carbohydrate and protein. When we consume whole grains or products made with whole grains, we benefit from the nutrients provided by all parts of the grain. When a grain is milled or refined, such as in the case of polished white rice, it is stripped of the bran and germ, leaving only the carbohydrate-rich endosperm. This is why the 2005 Dietary Guidelines for Americans recommend consuming half our grains as whole grains.
Some examples of whole grain foods include oatmeal, brown rice, wild rice, 100% whole wheat, popcorn, corn tortillas, barley, and quinoa. In addition to consuming plenty of these and other 100% whole grain foods, we can also enjoy the nutritional benefits of whole grains by consuming products that are made with whole grains. These are foods that contain both whole grains and refined grains, such as sliced bread that is made with a combination of 100% whole wheat flour and enriched (refined) white flour. Even though such a product contains some refined grains, we can still benefit from the fiber, phytochemicals, and other nutrients provided by the whole grain portion of that product.
To determine whether a food contains whole grains, consumers should read the ingredients list on the package. Foods containing whole grains will list them in the ingredients list, such as “whole grain wheat”, “oats”, or “brown rice”. If a whole grain is listed first, that product contains a significant amount of whole grain. If the ingredients list only contains “wheat flour” or “enriched flour”, it probably does not contain whole grains.
In recent years, products have become available claiming to be made with 100% white whole wheat flour. This can be confusing because most people associate “white” flour with refined grains, not whole grains. As it turns out, there are different types of wheat. The majority of whole wheat bread is made from red wheat. There is, however, another variety of wheat called white wheat. It is sometimes referred to as albino wheat and tends to be milder in flavor than traditional red wheat. As long as this white wheat remains in the whole grain form – that is, it is not refined or milled – then it is 100% whole wheat. A few companies have begun making whole wheat bread with this white variety of wheat, which is why the bread is labeled as 100% white whole wheat bread. Again, the consumer should check the ingredients list for “whole white wheat flour”. Because it is a whole grain, white whole wheat flour provides the fiber, vitamins, minerals, and phytochemicals found in whole grains.
Energy drinks are beverages containing caffeine in combination with other ingredients. The caffeine content of a single serving ranges from 72 to 150 mg; however, many bottles contain 2 to 3 servings, raising the caffeine content to as high as 294 mg per bottle. In comparison, the caffeine content per serving of brewed coffee, tea, and cola ranges from 22 to 240 mg. Healthy adults can consume up to 400 mg of caffeine daily; however, women of reproductive age, adolescents, and children should limit their daily consumption of caffeine and consumption of energy drinks by these groups is not recommended. Caution is warranted even for healthy adults. Consumption of two or more energy drinks a day may lead to excessive caffeine intake and other stimulants such as guarana and ginseng are often added to energy beverages and can enhance the effects of caffeine. Adverse effects associated with excessive caffeine consumption include nervousness, irritability, sleeplessness, increased urination, abnormal heart rhythms (arrhythmia), decreased bone levels, and stomach upset.
Fish is a good source of protein, and fatty fish like salmon contain high amounts of omega-3 fatty acids. These kinds of fatty acids have been found to have a protective effect against heart disease. The American Heart Association recommends eating fish, particularly fatty fish at least twice a week to reduce risk of developing heart disease. However, some species of fish are high in mercury. Mercury can damage developing fetuses and children. For this reason, women who are pregnant or of childbearing age, and children under 18 should never eat swordfish, golden bass, king mackerel, or shark. They should also limit the amount of albacore tuna and tuna steaks or fillets to no more than 6 ounces per week.
Trans fats are unsaturated fatty acids that are used commercially in foods. They are made from regular cooking oils, such as soy oil, but they have been chemically changed to be more shelf-stable, and be able to withstand high cooking temperatures, such as those used in deep-frying. This change in chemical structure also has resulted in trans fats having negative health effects. Trans fats have been shown to lower high-density lipoprotein (HDL) cholesterol, aka “good” cholesterol, and raise low-density lipoprotein (LDL) cholesterol, aka “bad” cholesterol. As a result, they can raise a person´s risk for heart disease.
Consumption of chocolate or cocoa has been associated with a variety of cardiovascular benefits. In one recent investigation, consumption of approximately 30 kcals of dark chocolate daily for eighteen weeks was associated with decreased blood pressure. However, calories from chocolate are still classified as “discretionary” (added fats and sugars) by the Dietary Guidelines for Americans 2005. These findings suggest that in light of current chocolate research, it may be beneficial to include a small piece of dark chocolate (equal to 30 kcals) as part of your daily diet.
Phytochemicals are a large group of plant-derived compounds hypothesized to be responsible for much of the disease protection conferred from diets high in fruits, vegetables, beans, cereals, and plant based beverages such as tea and wine.
The relationship between food and health is complex. By replacing foods with supplements, beneficial food components and important interactions between food components may be lost. It is important to recognize, however, that eating a well-balanced diet is not always feasible. The Dietary Guidelines, 2005, acknowledges that although consumption of a balanced diet is critical, use of dietary supplements is warranted when nutrients are not or can not be consumed in adequate amounts. The recommendations for specific populations are as follows:
- Individuals over 50: Consumption of Vitamin B12 in fortified foods or as a supplement (2.4 μg/ day from fortified food and/or supplements)
- Women who may become pregnant: Consumption of iron fortified foods with an enhancer such as vitamin C (27 mg/ day)
- Women who may become pregnant or are in their first trimester of pregnancy: Consumption of folic acid from fortified foods or supplements (400 μg/ day synthetic folic acid from fortified food and/or supplements)
- Older individuals and those with dark skin: Consumption of vitamin D in fortified foods or supplements (25 μg/ day from fortified food and/or supplements).
Free radicals are molecules that attack other molecules, such as those in our DNA or in the cell membrane. Damage by free radicals may be involved in the development of heart disease and cancer.
The body uses an elaborate system of compounds that act cooperatively to protect body cells from free radical-initiated damage. This is known as the antioxidant defense system. Each one works at different points dealing with different reactive molecules. This system includes enzymes, (dependent upon specific minerals for their action), vitamins (vitamin E, C) as well as non-enzymatic compounds such as glutathione and several phytochemicals.
Soy is a low-cost source of protein that has been consumed in Asian countries for many centuries. Regular intake of this food is thought to be partially responsible for the lower rates of heart disease, stroke, and cancer observed in Asian populations. Plant-based foods, such as soy, can provide the body with beneficial compounds including vitamins, minerals, fiber, and flavonoids. According to the American Heart Association and the U.S. Food and Drug Administration (FDA), soy products have beneficial nutrient profiles. Daily consumption of 25 grams or more of soy protein with isoflavones can help lower cholesterol levels in individuals at high risk for heart disease. An average serving of soy foods provides 6.25 grams of soy protein, so an individual who is trying to lower his or her cholesterol should aim for eating four servings of high-quality soy foods, not supplements, a day. High quality soy foods include edamame or soybeans, tofu, and soymilk. If a breast cancer patient, or a person who is at high risk for this disease, enjoys eating soy, occasional consumption does not appear to pose any risk; however, these individuals should consult their physicians before adding soy to their diets.
According to the Produce for Better Health Foundation, “For most fruits and vegetables, a serving is ½ cup. A serving of dried fruit is ¼ cup and a serving of lettuce is 1 cup.” Serving recommendations depend on gender, age, and activity level and range from 4 to 13 servings a day, or 2 ½ to 6 ½ cups. To find out personal serving recommendations visit http://myplate.gov/ .
Fresh and frozen produce can lose nutrients during storage and cooking while the nutrients in canned products are relatively stable after the initial heat treatment is completed (the amount of nutrient lost during heat treatment depends on the food). However, canned fruits and vegetable may be higher in sugar and sodium. It is important to remember that hundreds of nutrients, in varying amounts and with different biological functions, have been identified in produce. Furthermore, the biological importance of slight differences in the amounts of these nutrients has yet to be determined. Therefore, consuming a variety of plant-based foods helps to ensure that individuals receive the optimum benefits from the fruits and vegetables they eat. For these reasons, fresh, frozen, and canned fruits and vegetables should all be considered as good options for including a variety of produce in your diet.