JustTheScience

What are the health effects of consuming food containing MSG?

Just The Science — Tue, 15 Jun 2010 22:52:40 +0000

Originally synthesized from kelp by Japanese researchers in 1908, Monosodium Glutamate (MSG) is now a major component of the food industry with 2009 global production levels estimated at 2 million tons (Sano 2009). ¹ The glutamate class of acids including MSG activates taste sensors that are responsible for the savory flavor, also called “umami,” which is considered to be a basic taste along with sweet, sour, salty, and bitter (Rolls 2009) (Kurihara 2009). ² ³ Americanized Chinese food is widely known for its MSG content, particularly due to the 1960′s MSG related phenomenon dubbed “Chinese Restaurant Syndrome (CRS).” Afflicted individuals with CRS exhibited symptoms including burning sensations, and facial and chest pain, following eating at Chinese restaurants that used MSG as a food additive (Schaumburg et al 1969). ⁴ Media coverage caused hyper-awareness of the syndrome, as is evident by a 1979 survey by Kerr et al (1979), in which 43% of respondents stated that they had suffered from CRS, despite only 2% of respondents reporting ever having symptoms matching those widely attributed to CRS.⁵

Although public awareness of the symptoms of Chinese Restaurant Syndrome is high, the question remains whether or not there is legitimate scientific evidence for this condition. A large double blind study by Geha et al (2000) of people who self reported a sensitivity to MSG found that some individuals exhibited reactions to direct ingestion of MSG. Results were neither consistent upon retesting nor were any of the effects persistent or serious.⁶ Rosenblum et al (1971) found no difference in symptoms between individuals ingesting MSG and a placebo (Sodium Chloride (table salt)) and no symptoms resulting from this study matched those of CRS.⁷ Tarasoff and Kelly (1993) found no difference between a placebo and MSG when the MSG was ingested with food, even at high concentrations. ⁸ Woods et al (1998) and Woessner et al (1999) found no link between MSG intake and asthma exasperation in asthmatics who self reported a sensitivity to MSG,⁹¹⁰ and Hawkins (2009) found that the blood/brain barrier is impermeable to glutamates.¹¹ Finally, Burrin and Stoll (2009) found that natural and artificial dietary glutamates are metabolized in the same manner and are both a major oxidative fuel for the gut, an important precursor for a key neurotransmitter (glutathione). ¹²

Key Points

MSG is a major component of the food industry; 2009 global production levels estimated at 2 million tons.¹³
MSG activates taste sensors responsible for the savory flavor (called “unami”).¹⁴ ¹⁵
MSG was attributed to a phenomenon called “Chinese Restaurant Syndrome.” Afflicted individuals exhibited symptoms including burning sensations, and facial and chest pain, following eat at Chinese restaurants that used MSG as a food additive.¹⁶
A 2000 study reported inconsistent results that were neither persistent or serious to direct ingestion of MSG.¹⁷
1971 study found no difference in symptoms between individuals ingesting MSG or Sodium Chloride (table salt).¹⁸
1993 study found no difference between individuals ingesting a MSG or a placebo with food or drink, even at high concentrations.¹⁹
1998 and 1999 studies found no link between MSG intake and asthma exasperation in asthmatics who self-reported a sensitivity to MSG.²⁰²¹
2009 study found blood/brain barrier is impermeable by glutamates (including MSG). ²²
2009 study found dietary glutamates are both a major oxidative fuel for the gut, and an important precursor for the neurotransmitter glutathione. ²³

Is Organic Produce Better for you?

Just The Science — Wed, 14 Apr 2010 21:58:42 +0000

The organic food industry has grown dramatically over the last several years, and it’s a natural assumption that eating organic foods is better for you. Organic foods are grown in an environment perceived to be free of harmful pesticides and herbicides, and in some instances are deemed to be more nutritional than those grown in a conventional manner. Are there any significant differences between organic and normally raised agricultural products?

One well known difference between organically and non-organically grown produce are the chemicals, or lack thereof, utilized during the growing process. Studies have found negative effects resulting from acute exposure to pesticides (Grandjean et al 2006) and herbicides (Kamel et al 2003) on farm workers and their children (if exposed prenatally).¹² For the consumers of produce from farms that utilize pesticides and herbicides, however, it’s been shown that actual exposure to these chemicals is relatively small. Leblac et al (2000) determined that an average person’s exposure to pesticides is 4% of an individual’s maximum recommended exposure. ³ Galal-Gorchev H. (1991) found that a person’s exposure to pesticide residue is well below established acceptable daily intake levels in the 21 western countries that supply data on the matter. ⁴ Juhler et al (1999) determined dietary exposure to pesticides does not affect male spermazoa,⁵ and Safe (1995) found an individual’s exposure to estrogenic compounds from organochlorine pesticides is 0.0000025% of the daily intake of estrogenic flavonoids in the diet.⁶ While organic farming has been shown to lower pesticide residues in food by 2/3, much organic produce is not pesticide free due to legacy contamination and drift from other fields (Baker et al 2002). ⁷

As far as differences in nutritional value between organic and conventionally grown produce, much of the current literature is suggesting a need for further research, although some slightly notable differences have been found. A review of 55 articles on the subject found conventionally produced crops had significantly highernitrogen content, and organically produced crops had significantlyhigher acidity and phosphorus content. These differences were attributed to the difference in production methods and none of them had a material impact on the food’s nutritional value (Dangour et al 2009) (Bourne and Prescott 2002). ⁸ ⁹ A study by Magkos et al (2003) found higher levels of ascorbic acid in organically grown leafy vegetables and potatoes and lower protein levels in some organic vegetables and cereals, but found this evidence to be inadequate to make a definitive argument. A study by Caris-Veyrat et al (2004) found that organic tomatoes had higher levels of antioxidants (vitamin C, carotenoids, and polyphenols) than conventionally grown tomatoes, but when both types of tomatoes were fed to people for 3 weeks, no difference was found in antioxidant levels in the bloodstream between those that consumed organic or conventional. ¹⁰ ¹¹ Similarly, Tarozzi et al (2005) found that organic red oranges have a greater total antioxidant activity than those grown conventionally, but did not investigate whether or not the organic oranges would alter antioxidant levels in the bloodstream ¹²

What are the best ways to train a dog?

Just The Science — Thu, 10 Dec 2009 07:01:37 +0000

Several methodologies and training tools exist to aid in training dogs. While several factors incorporate into the overall effectiveness of a training regiment (personality, age, consistency, etc), we will examine and summarize some recent studies that have exemplified both effective and non-effective measures. Please note that this is not a definitive summary of all available options, nor should this replace the advice of a professional.

A 2001 study by Pongrácz et al found that it is not necessary for the dogs’ owner to be the only individual conducting the training, and that a stranger can be equally effective at training, given equal skill.¹ Furthermore, a bond between dog and trainer (even if the trainer is a stranger) can grow in as little as 3 ten minute sessions (Gàcsi et al 2001). ² A study on different methods of training showed that there was a strong correlation between both use of rewards in training and resulting positive desired behaviors and use of punishment in training and resulting undesired negative behaviors (Hiby et al 2004). ³ Somewhat tangentially, McKinley and Young (2002) describe the Model-Rival method as a very effective training method, which rewards with positive social interaction instead of treats. ⁴ Increasing the amount of verbal communication between the trainer and the dog has been demonstrated to improve training effectiveness (Pongrácz et al 2004), while communication through physical demonstration is only effective if done in a consistent manner (Kubinyi et al 2003) (Pongrácz et al 2002). ⁵ ⁶ ⁷ Kubinyi et al (2003) found that it took over 30 independent repetitions for a dog to learn a task through demonstration and in some cases it took over 180. However, once it was imprinted it remained as a new behavior in the dog and proved durable. ⁸

The myriad available training tools have also been subjected to several recent studies. Schilder and van der Borg (2003) found that dogs trained using shock collars showed more signs of “stress signals” and lower ear positions than those trained without. ⁹ However, Schalke et al (2005 and 2006) found that stress resulting from shock collars can be reduced when utilized by those with advanced experience, specifically when the animal is made to understand that it can affect whether or not it is shocked. This particular association is difficult to cultivate, and therefore the authors suggest shock collar usage should be minimal. ¹⁰ ¹¹ Head collars or halters have been shown to be an effective, humane and non-physiologically stressing alternative to traditional and shock collars for training purposes (Ogburn et al 1998). ¹² Citronella spray collars that are marketed to deter barking behaviors have been shown to work in the short term but only if used intermittently (Wells 2001).¹³ Dogs tend to become accustom to these collars and the deterrent effects will diminish (Wells 2001). Scentless spray collars have been found to be less effective (Moffat et al 2003).¹⁴¹⁵

Does it matter when you eat?

Just The Science — Fri, 13 Nov 2009 06:45:17 +0000

There have been many different theories regarding when and how often an individual should eat, among them: including vs. skipping breakfast, not eating anything before bedtime, and eating several smaller meals vs. fewer concentrated meals. In this article, we intend to examine whether or not feeding timing and frequency is relevant to metabolism, and/or satiation.

Including breakfast in one’s day has been shown to have myriad effects. De Castro (2004) found those that skip breakfast are more likely to overeat later. ¹ Additionally, Schlundt et al (1992) and Stubbs et al (1996) found those that eat breakfast eat less fat throughout the day and are less prone to impulsive eating of familiar foods. ²³ However, multiple studies have found that feeding frequency and timing does not have an effect on metabolic performance (Wilhelmine et al 1998) (Dallosso et al 1982) ( Verboeket van de Venne and Westerterp 1998) (Wolfram et al 1987). ⁴ ⁵ ⁶ ⁷ In addition, Goldberg et al (1998) found that one’s metabolic rate while sleeping is roughly concurrent with one’s basal metabolic rate (BMR), which in combination with results from the previously mentioned studies suggests that there are no adverse metabolic effects from eating before sleeping.⁸ However, it is important if you are partaking in late night eating that you eat a prepared portion of food, as it’s been demonstrated that it’s common for individuals to overindulge late (Waller et al 2004). ⁹

Eating more frequent smaller meals has been shown to decrease future hunger more effectively than eating few highly concentrated meals (Speechly and Buffenstein 1999). Johnstone et al (2000) found similar results in their study, and also determined that the nutritional composition of these smaller meals (i.e. high in protein, fat, or carbohydrates) did not affect later decreased hunger, provided they contained a similar caloric composition¹⁰ ¹¹

Are there benefits to stretching before or after exercise?

Just The Science — Fri, 06 Nov 2009 03:35:58 +0000

Stretching prior to, and following exercise is a commonly recommended practice. Whether or not there are benefits in including this in one’s routine is a controversial subject. Studies exist that have found little to no benefit of including stretching as part of an athletic regimen (Thacker et al 2004). ¹ Other studies exist that have found stretching before or after athletic activity slightly reduces muscle, ligament, and tendon injuries as well as soreness (Jamtvedt et al 2009). ² In addition, Herbert and Gabriel (2002) found that stretching before or after exercising doesnot confer protection from muscle soreness and that stretching beforeexercising does not practically reduce the risk of injury.³ In this article, we intend to examine in more details whether or not there are benefits associated with incorporating the three major types of stretching (static, dynamic, and ballistic) as part of a regular exercise routine.

Static stretching takes place when an individual’s body is at rest, and one holds each stretch for thirty seconds to one minute. In individuals who are not yet fully involved in a committed athletic program, evidence exists that static stretching can help them ease into a new program without stressing the body (Kokkonen et al 2007).⁴ Static stretching also increases torque in concentric muscle movements (Cramer et al 2006), flexibility (O’Sullivan et al 2009), and range of motion over the long term (LaRoche and Connolly 2006). Static stretching has otherwise been found have no or negative effects on athletic performance, including a reduction in muscle power endurance, (Yamaguchi et al 2006) (Yamaguchi and Ishii 2005) (Nelson et al 2005) (Brandenburg 2006), sprinting and endurance running performance (Fletcher and Anness 2007) (Wilson et al 2008) (Heyes and Walker 2007), muscle activation (Cramer et al 2004), and jumping height (Holt and Lambourne 2008) (Bradly et al 2007). ⁵ ⁶ ⁷ ⁸⁹ ¹⁰ ¹¹ ¹² ¹³¹⁴ ¹⁵ ¹⁶ ¹⁷

Dynamic stretching utilizes momentum from form to propel the body beyond in an extended range of motion. This has been shown to have the greatest positive effect on a range of metrics, including improved muscular power (Yamaguchi and Ishii 2005), sprinting (Fletcher and Anness 2007), and high speed running performance (Little and Williams 2006).¹⁸ ¹⁹ ²⁰ A long-term dynamic stretching program has been positively correlated with sustained muscle power, strength, muscular endurance, anaerobic capacity, and agility performance enhancements (Herman and Smith 2008).²¹ However, it has not been shown to improve running economy (Heyes and Walker 2007). ²²

Ballistic stretching uses bouncing movements to force limbs into an extended range of motion when the muscle has not relaxed enough to enter it. Studies have shown the existence of some benefits, including improved vertical jump height (Woolstenhulme et al 2006) and general range of motion as a result of ballistic stretching (LaRoche and Connolly 2006).²³ ²⁴ Compared to the other two types, there is a dearth of research on ballistic stretching specifically comparisons between ballistic and dynamic stretching.

In short, due to the different benefits of the three types of stretching it is important to make sure that your stretching program will benefit your athletic regimen and not undermine it.

High Fructose Corn Syrup; good or bad?

Just The Science — Thu, 22 Oct 2009 16:14:14 +0000

As levels of diabetes, obesity, and other dietary issues increase (diabetes alone has increased 763% from 1935 to 1996 in the united states (Gross et al 2004)) studies have been conducted to investigate whether the 1,000% rise in the use of High Fructose Corn Syrup (HFCS) from 1967 to 2000 in the American food industry is a major contributor (Bray et al 2004).¹ ² In this article, we will examine whether or not HFCS is truly a factor in this significant increase.

Early studies found that there were possible clinical explanations for metabolic differences derived from HFCS ingestion and other sweeteners; primarily that it did not trigger insulin creation and thereby was thought to not trigger satiety signals (Reiser et al 1989) (Elliott et al 2002) (Bray et al 2004) (Teff et al 2004) .³ ⁴ ⁵ ⁶ However, more recent studies have found no difference in resulting satiety in men or women resulting from HFCS, sucrose, or milk, (Soenen and Westerterp-Plantenga 2007) (Melanson et al 2008) (Akhavan and Anderson 2007),⁷ ⁸ ⁹ and that HFCS yields similar metabolic responses to other caloric sweeteners. (Angelopoulos et al 2009),¹⁰ Stanhope et al 2008 and Melanson et al 2007 determined that sucrose and HFCS do not have significantly different short-term metabolic effects,¹¹ ¹² and moderate levels (~1.5 grams of fructose per kilogram of body mass) of HFCS intake does not cause ectopic lipid deposition or insulin resistance in healthy humans (Le et al 2006).¹³

Although HFCS is not itself responsible for the increase in dietary and metabolic disorders, other studies have demonstrated that increasing levels of excess energy consumption in general is a cause (Gross et al 2004).¹⁴ For thousands of years humans consumed fructose amounting to 16–20 grams per day, largely from fresh fruits (Gross et al 2004). ¹⁵ Westernization of diets has resulted in significant increases in food with added fructose, leading to typical daily consumptions amounting to 85–100 grams of fructose per day (Gross et al 2004). ¹⁶ For example, a 12 ounce Coke contains 39 grams of fructose and the USDA Recommended Daily Allowance allots for 32 grams of carbohydrates in a 2,000 calorie diet.¹⁷ A single 12 ounce Coke therefore contains significantly more than an individual’s entire excess dietary energy allowance for a day. Raben et al 2002 found that people have a very difficult time compensating for increased levels of calories associated with increased sugar intake by lowering caloric intake elsewhere.¹⁸ While moderate ingestion of HFCS will not specifically cause harm to oneself, it is advisable to monitor and limit consumption as much as possible.

What causes kidney stones and can you prevent them?

Just The Science — Thu, 15 Oct 2009 00:29:22 +0000

Kidney stones will effect around 5 percent of people in at some point in their life, and the rate is growing with time (Parmar 2004). ¹ Significant variation of occurrence exists between sexes; men develop stones twice as often as women at an average age of 30 while for women average age is bimodal with peaks at 35 and 55 (Parmar 2004).² Once you have had one, you also have a very high chance of having another one as there is a re-occurrence rate of 50% over five years (Borghi et al 1996).³ Although there is still somewhat of an evolving consensus around what the main cause is, literature points to treatment resistant micro-bacteria (Çiftçioglu et al 1999) that combines with urine supersaturated with calcium compounds and uric acid (contributed by an individual’s diet), creating the kidney stone (Kajander et al 2003). ⁴ ⁵

An individual’s weight and family history have both been demonstrated to have a positive correlation with his or her risk of getting kidney stones (Taylor et al 2005) (Curhan et al 1997). ⁶ ⁷ However, lack of daily water intake has been demonstrated to be the greatest risk factor, and increasing one’s daily water intake is an easily preventative measure one can take to avoid getting stone’s in the first place (Borghi et al 1996). ⁸ Drinking at least 2.5 liters of water per day has been shown to change the consistency of urine, lowering it’s saturation level of calcium compounds, thereby preventing supersaturation and it’s associated buildups (Borghi et al 1996).⁹ This alone has been found to reduce reoccurred rates of kidney stones from 50% to 20% over a five year period (Borghi et al 1996). ¹⁰

Intake of other fluids have also been found to decrease instances of kidney stones in both sexes. A study by Curhan et al (1998) found the following percentage of occurrence reductions in women for each 240-mL (8-oz) daily serving of the following fluids: caffeinated coffee – 10%, decaffeinated coffee – 9%, tea – 8%, and wine – 59%.¹¹ In contrast, a 44% increase in risk was seen for each 240-mL serving of grapefruit juice consumed daily (Curhan et al 1998). In men the risk of stone formation decreased by the following percentages for each 240-ml (8-oz) daily serving of the following fluids: caffeinated coffee 10%, decaffeinated coffee – 10%, tea – 14%, beer – 21%, and wine – 39%. In contrast, a risk increased 35% for comparable servings of apple juice and 37% for grapefruit juice (Curhan et al 1996).¹²

Reducing one’s consumption of animal protein to less than 52g per day has also been shown to lower one’s risk of specific types of kidney stones (Breslau et al 1988).¹³ Increasing dietary calcium has been shown to lower risk for kidney stones in women (Borghi et al 2002) and men (Curhan et al 1993) and lowering your salt intake to less than 800 mg per day combined with lower intake of animal protein lowers men’s risk of re-occurrence by 18% (Borghi et al 2002).¹⁴ Also, vitamin B6 in doses of >40mg/day has been found to reduce incidences of kidney stones in women (Curhan et al 1999).¹⁵¹⁶ A recent study by Taylor et al (2004) determined that in men: sodium phosphorus, sucrose, phytate, vitamin B6, vitamin D, and supplemental calcium were not independently associated with risk for first time instances, while magnesium intake decreases and total vitamin C intake seems to increase the risk of kidney stones (Taylor et al 2004).¹⁷ While this research may appear to contradict the previous study by Borghi et al (2002), this study examined the combination of reduced salt and animal protein, which suggests that reducing animal protein consumption is a more important dietary change to aid in reduced kidney stone risk.¹⁸

What are the effects of using energy drinks?

Just The Science — Tue, 13 Oct 2009 00:36:15 +0000

Energy drinks are a common way for individuals to presumably increase their energy level. In addition, more and more varieties of energy drinks with various ingredients are constantly appearing, all claiming to be the most effective. We intend to examine whether or not energy drinks are really physiologically effective, what ingredients increase energy levels most effectively, and whether or not there are any possibly harmful side effects.

A study by Alford et al (2001) found that the intake of energy drinks is correlated with improved aerobic endurance and anaerobic performance, as well as significant improvements in choice reaction time, concentration, and memory.¹ Horne and Reyner (2001) found that energy drinks significantly improved the reaction time and reduced lane drifting of sleepy individuals when compared to a placebo, with the greatest improvement lasting an hour after ingestion.² Scholey and Kennedy (2004) determined that the combination of caffeine and sugar found in most energy drinks have a possibly synergistic relationship which results in improved secondary memory and speed of attention.³

Since it has been demonstrated that energy drinks do have a physiological effect on the body, it’s important to investigate which ingredients are contributing to this effect. The most common ingredients found in energy drinks are: sugar, caffeine, taurine, guarana, and ginseng. Studies on taurine’s impact on the body are predominantly inconclusive (Triebel et al 2006), although it has been noted that this free amino acid may play an important role in osmoregulation, immunomodulation, and bile salt formation (Bouckenooghe et al 2006), and consuming energy drinks with taurine increases taurine levels in the cerebellum (Roser et al 1998). ⁴ ⁵ ⁶ A separate study by Geiß et al (1994) found that energy drinks with taurine led to lower sustained levels of the hormones epinephrine and norepinephrine, which led to significantly longer endurance times in cyclists.⁷ Guarana and ginseng extract are believed to be stimulants that affect cognition (Kennedy et al 2004). ⁸ A study by Haskell et al 2007 determined that Guarana improves memory and general attentiveness,⁹ and Sorensen and Sonne (1996) reported that ginseng improved simple reaction performance as well as abstract thinking. Other studies have found ginseng supplementation has no effect on physical performance, psychomotor performance and cognitive function, immunmodulation, diabetes mellitus and herpes simplex type-II infection (Engels and Wirth 1997) (Vogler et al 1999) (Persson et al 2003). ¹⁰ ¹¹ ¹² ¹³

Despite all of the alleged beneficial properties of including the aforementioned ingredients in energy drinks, a study by Clauson et al (2008) found that popular energy drinks do not have high enough levels of Guarana, Taurine, or Ginseng to have any beneficial physiological or psychological effects, and that the only ingredients in high enough concentrations to have effects are caffeine and sugar (Clauson et al 2008). ¹⁴ Caffeine levels in energy drinks can range from 0mg per serving to 141.1mg which is almost a three fold increase over Coke which contains ~44.5mg per serving (McCusker et al 2006).¹⁵ Additionally, Candow et al 2009 found no improvement in physical endurance as a result of sugar free energy drinks.¹⁶

While the research around caffeine and sugar intakes will require articles of their own, some studies have been done regarding the risks of energy drinks themselves. Aside from the high level of sugar in energy drinks which could contribute to diabetes, studies have shown that people who have had prior psychiatric issues should avoid energy drinks as it may cause a relapse (Chelben et al 2008) and that the drinks have significant erosive effects on dental enamel (Kitchens et al 2007).¹⁷ ¹⁸ The effects of energy drinks and hypertension has had conflicting research and is as of this writing, unresolved (Hirata et al 2003) (Winkelmayer et al 2005).¹⁹ ²⁰

Is taking a daily multivitamin beneficial?

Just The Science — Tue, 06 Oct 2009 22:45:33 +0000

A study by Garland et al (2005) demonstrated that it is difficult for adults in America to get consistently adequate levels of micronutrients, especially those that come from more unconventional sources (i.e. Vitamin D, which comes from sunlight).¹ Several studies have determined specific demographics that are particularly susceptible to micronutrient deficiencies, including: women of child bearing age who may become pregnant (Olshan et al 2002),² people with deficiency inducing diseases such as type 2 diabetes (Barringer et al 2003),³ 40% of people over age 65 (Chandra 2001),⁴ 50% of postmenopausal women (Holick et al 2005), ⁵ and 100% of adolescents (Stang et al (2000)⁶. A common dietary supplement for these demographics, and those concerned about their daily intake of essential micronutrients are multivitamins. Extensive research has been conducted on the validity of this practice, with a major concern being whether multivitamins are as effective in delivering their content as natural sources. Earnest et al (2003) found that intake of multivitamins did in fact increase overall vitamin levels by studying the levels of vitamins B6, B12, and folic acid over the course of 24 week period and a study by Navarro et al (2003) found that the multivitamin disintegration properties due to physical make up (whole tablet, crushed tablet, powder) did not affect the delivery efficacy of micronutrients, and that multivitamins are an effective mechanism of micronutrient delivery. ⁷ ⁸

Numerous studies have found correlations between taking daily multivitamins and a number of health benefits. These include: increased cognitive functions in the elderly (Chandra 2001), ⁹ lower instances of colorectal cancer (Jacobs et al 2003),¹⁰ lower instances of heart disease (Holmquist et al 2003), ¹¹ improved immune system in people over 59 years of age (Bogden et al 1994), ¹² and increased in bone density in postmenopausal women (Morton et al 2001).¹³ Separate studies have determined multivitamin intake during pregnancy decreased levels of childhood cancers (Olshan et al 2002) ¹⁴, lowers instances of birth defects (Botto et al 2004),¹⁵ and lowers instances of childhood anemia (Geltman et al 2004).¹⁶

It is important to note that excess ingestion of all vitamins is not beneficial. In some instances, vitamin intake above a certain level will have no effect. For example, Levin et al (1996) found that doses of Vitamin C over 400 mg per day had no physiological effect, and any amount over 1,000 mg is simply excreted not utilized.¹⁷ In other instances, overdosage can be detrimental. A study by Graat et al (2002) found that taking Vitamin E in supplement form worsens acute respiratory tract infections in well nourished people over the age of 60,¹⁸ and Omenn et al (1996) found correlations between taking Vitamin A in supplement form and increased lung cancer rates and cardiovascular disease in smokers.¹⁹ Wooltorton (2003) examined micronutrient overdosage effects that exist for all individuals, and found: overdosage of magnesium and phosphorus can cause diarrhea; overdosage of iron can cause constipation, nausea, vomiting, and reduced zinc uptake; overdosage of zinc can cause nausea, vomiting, immunosuppression, and impaired copper uptake; and overdsoage of selenium can cause brittle hair and nails, peripheral neuropathies, and gastrointestinal upset.²⁰ A study by Lawson et al (2007) found that high doses of multivitamins correlates with increased levels of advanced and fatal prostate cancer.²¹

Based on these studies, it is reasonable to state that multivitamins are a beneficial supplement to one’s daily diet, provided that a recommended dosage is taken. If one feels they are in a demographic that could be affected negatively by this supplementation, contact a physician before starting.

Are amalgam fillings harmful?

Just The Science — Thu, 01 Oct 2009 19:42:30 +0000

Amalgam fillings, commonly used for the last century, are an alloy of approximately 50% mercury, 35% silver with other trace elements (Hahn et al 1989)¹. Mercury is a versatile element, and is utilized in both organic and inorganic forms; both of which are toxic (Langford and Ferner 1999).² A study by Nylander et al (1987) demonstrated a statistical correlation between number of amalgam fillings and amount of accumulated inorganic mercury in an individuals body. ³ Hahn et al (1989) found mercury vapor is released into the mouth by chewing action, and activities that increase this activity such as chewing gum and brushing teeth increase the level of mercury released. Likely routes of uptakes of released vapors suggested in this study include inhalation, swallowing, and absorption through bone, tooth, and gum tissues in the mouth. However, the actual amount of mercury absorbed into body tissue was undetermined, and the authors suggest more research is required to determine this. ⁴ The results of this study suggest that there is an increase in mercury exposure in individuals with amalgam fillings, however, it is necessary to ascertain both how much mercury is actually absorbed, as well as the effect this mercury has on an individual.

Myriad results have been found in regards to determining the effects of absorbed mercury from amalgam fillings. Sandborgh-Englund et al (1996) and Bates (2006) found no evidence of renal toxicity, chronic fatigue syndrome, reproductive, or other chronic diseases from mercury absorbed from amalgams, but a evidence of susceptibility to Alzheimer’s, Multiple Sclerosis, and Parkinson’s from mercury absorbed from amalgams. ⁵ ⁶ In addition, Grandjean et al (1997) found that individuals treated for self reported amalgam related psychotic disorders responded equally to a mercury purging drug in both treatment and placebo groups, while those in the treatment group actually expelled much higher levels of mercury in their urine.⁷ Further study is required for a more definitive answer to whether or not amalgam fillings should be considered a health threat, however, the aforementioned studies have demonstrated that chronic physiological disorders are not associated with amalgams while neurological disorders can be.