After 10 weeks the mice treated with either green tea extract had significantly lower fasting blood glucose levels compared with the control group (9.3mM±1.1 vs 14.7mM±1.8). The researchers found that green tea extract appeared to attenuate the death of beta cells - Beta cells store insulin and respond to spikes in blood glucose levels by releasing insulin which controls the level of glucose in the blood. It was suggested that green tea extract appears to exert its antidiabetic activity through a combination of reducing insulin resistance and increasing the glucose-induced insulin secretion via the preservation of functional beta cell mass. The green tea extract was also associated with increases in insulin content and with the preservation of pancreatic islet structure – Islets contain the hormone producing beta cells.

The researchers concluded: “this study demonstrates that a pharmacological dose of the green tea catechin, EGCG, possesses pronounced antidiabetic efficacy in vivo – comparable to the effect seen with rosiglitazone” and that the “total plasma EGCG levels shown to be efficacious in mice and rats can be reached by dietary supplementation of EGCG.” However, it should be noted that the amount of green tea extract used in this study was fairly high, making up 1% of the mice diet.

Summary of the effects of green tea extract

• Green tea extract enhanced glucose tolerance in pre-diabetic mice
• It reduced fasting blood glucose levels
• Reduced insulin resistance and increased glucose-induced insulin secretion
• Green tea extract appears to preserve functional beta cell mass and islet structure
• Green tea extract had pronounced antidiabetic effect comparable with rosiglitazone
• The amount of EGCG used in this study was fairly high making up 1% of the mice diet.

Reference

Ortsater H, Grankvist N, Wolfram S, Kuehn N and Sjoholm A (2012) Diet supplementation with green tea extract epigallocatechin gallate prevents progression to glucose intolerance in db/db mice. Nutrition & Metabolism 2012, 9:11

The research looked at EAA consumption amongst 27 healthy males (n=12) and females (n=15) (Age = 22 ± 3 yrs.; Weight = 71.7 ± 13.9 kg). EAA consumption was determined from a 3 day food record, averaged across the 3 days, and the amino acid profile was determined using a computer programme. The CAF level was determined using a total body DXA scan. 

The researchers found that both the quality of the protein consumed and the distribution of the protein consumption throughout the day, was an important factor in determining the level of central abdominal fat. The researchers also found a significant relationship between how many times the EAA threshold was reached per day and the percentage of CAF, with subjects who reached the EAA threshold more times having a tendency to have lower levels of CAF. The researchers did not find significant association between carbohydrate or fat consumption and CAF levels amongst this group of healthy subjects. They concluded that the results of their study “indicate that quality and distribution of protein may play an important role in regulating CAF, which is a strong independent marker for disease and mortality.”

Why are EAAs believed help to regulate body fat levels?

EAAs are known to increase the levels of muscle protein synthesis which can increase the quantity of lean muscle mass. Since, muscle mass is a significant contributor to the resting metabolic rate any increase in lean mass will also lead to increases in the resting metabolic rate. The results of this study will not come as a particular surprise to many in the fitness industry who have routinely taken protein supplements, particularly whey protein supplements, for both increasing lean mass and as an aid to reducing body fat levels.

How much EAAs are in whey protein?

The quantity varies depending on the protein concentration of the whey protein powder but typically you would need between 25g (whey protein consisting of 90% protein) and 30g (whey protein consisting of 70% protein) to achieve the EAA.

How many times a day should you take the whey protein to maximise results?

The results of this study suggest that the greatest benefits occur when you consume 10g of EAAs on two or more occasions daily. Therefore, you may benefit from consuming 30g of whey protein on 2-3 separate occasions daily. You should try to separate each serving by around 2-3 hours and try to take away from meals.

What are the nine essential amino acids

The nine essential amino acis are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

Some good natural sources of essential amino acids include: Eggs, chicken, turkey, beef, pork, soybeans, salmon and tuna.

Reference

Loenneke J P, Wilson J M, Manninen A H, Wray M E, Barnes J T and  Pujol T J (2012) Quality protein intake is inversely associated with abdominal fat. Nutrition & Metabolism 2012, 9:5

The researchers examined the effect of bioactive component grape seed proanthocyanidins on HNSCC cell invasion and looked at the molecular mechanisms underlying these effects.  They found that treatment with grape seed proanthocyanidins inhibited cell invasion by the cancer cells in a dose dependent manner. The inhibition of the cancer cells by grape seed proanthocyanidins was associated with a reduction in levels of epidermal growth factor receptor. The epidermal growth factor receptor (EGFR) signaling pathway helps to regulate cell growth, survival and proliferation. It is known that epidermal growth factor receptor (EGFR) is overexpressed in many types of cancers and therefore any reduction in levels of epidermal growth factor receptor levels may be beneficial to cancer patients. 

The inhibition of cell invasion by grape seed proanthocyanidins was associated with the inhibition of the phosphorylation of extracellular-signal-regulated kinases (p-ERK) and was associated with the reversal of the epithelial-to-mesenchymal transition (EMT) process. Previous research suggests that p-ERK plays a critical role in the cell proliferation of malignant disease whilst EMT has been associated with the increased aggressiveness, invasive and metastatic potential of cancer cells.

The researchers concluded that grape seed proanthocyanidins have the ability to inhibit the invasion of human Head and neck squamous cell carcinoma by targeting epidermal growth factor receptor expression and reversing the epithelial-to-mesenchymal transition process. The researchers stated: “These data suggest that GSPs can be developed as a complementary and alternative medicine for the prevention of invasion/metastasis of HNSCC cells.”

Grape seed Extract proanthocyanidins & HNSCC Summary:

• Grape seed proanthocyanidins (GSPs) inhibited cell invasion by cancer cells in a dose dependent manner
• Inhibition of cancer cells by GSPs was associated with a reduction of epidermal growth factor receptor
• The Inhibition of cell invasion by GSPs was associated with the inhibition of the phosphorylation of extracellular-signal-regulated kinases
• The inhibition was also associated with the reversal of the epithelial-to-mesenchymal transition (EMT) process

References:

Sun Q, Prasad R, Rosenthal E and Katiyar S K (2011) Grape seed proanthocyanidins inhibit the invasive potential of head and neck cutaneous squamous cell carcinoma cells by targeting EGFR expression and epithelial-to-mesenchymal transition. BMC Complementary and Alternative Medicine 2011, 11:134

Carbohydrates, BCAAs and Caffeine Enhance Endurance Exercise Performance

A recent study published in the Journal of the International Society of Sports Nutrition (Peltier et al., 2011) found that the consumption of a sports drink containing a combination of carbohydrates, branched chain amino acids (BCAAs) and Caffeine significantly increased running performance during a 2-hour treadmill run. The sports drink also helped to maintain glycemia (blood glucose) whilst significantly decreasing the rate of perceived exertion (RPE) and central fatigue compared with the placebo drink.

Why did the researchers look at the combined effects of Carbohydrates, Caffeine and BCAAs?

Previous studies have demonstrated that carbohydrate and caffeine ingestion can improve/prolong endurance exercise performance, and it has also been suggested that BCAA consumption may also have positive effects on endurance exercise performance. Both carbohydrate and caffeine consumption before and during exercise can help to preserve muscle glycogen levels, caffeine consumption can also increase fat metabolism and decrease central fatigue and the rate of perceived exertion (RPE), whilst BCAA consumption can decrease the rate of muscle breakdown, may preserve muscle glycogen, and has been postulated to reduce central fatigue. However, no previous studies have looked at the combined effects of carbohydrates, caffeine, and BCCAs on endurance exercise performance.

What Did The Researchers Find?

The researchers found that the consumption of 2litres of sports drink (Energy = 1254kJ/l, Carbohydrate = 68.6 g/l, BCAAs = 4 g/l, and caffeine = 75 mg/L) before (250ml 15 minutes before exercise) and during exercise (250ml every 15 minutes of exercise) significantly improved performance (by 1.9%) compared with the consumption of 2litres of placebo drink (Energy = 50KJ/l). Whilst the 1.9% doesn’t sound like a significant difference it equated to an average difference of 410 meters over the 2 hours. Based on the distance covered by the two groups, 22.31 ± 1.85 km for the sports drink group vs. 21.90 ± 1.69 km for the placebo drink group, we can calculate that the placebo group were approximately 2 mins and 15 seconds behind the sports drink group. The researchers hypothesized that the improvement seen in the sports drink group may have been limited because the subjects were not fasted (overnight) and therefore initial muscle glycogen levels were high. However, by not fasting overnight the improvement is likely to more accurately reflect the beneficial effects of the sports drink over the placebo since most athletes will carbo-load prior to a prolonged endurance event to ensure muscle glycogen levels are maximized.

The researchers also found that the sports drink reduced central fatigue and RPE. However, it wasn’t possible for the researchers to establish the individual contribution of each of the main ingredients on central fatigue or RPE. Since it is already known that both carbohydrate and caffeine consumption can improve endurance it is not clear whether the addition of BCAA to sports drink further enhanced performance or reduced central fatigue beyond that of carbohydrate and caffeine consumption alone.

In Summary:

The consumption of sports drink containing carbohydrate, BCAAs and caffeine before and during exercise is beneficial to performance during prolonged endurance exercise. It wasn’t clear what the contribution of each was to the improved exercise performance. It is already established that both carbohydrate and caffeine can enhance endurance exercise performance but the effect of BCAAs is less clear. However, since BCAAs will not negatively impact performance and have been shown to reduce post exercise muscle breakdown it seems logical to include them in any sports drink either during training or competition.

Full Composition of The Sports Drink

Full Composition of The Sports Drink: maltodextrin 31.6g/l, dextrose 24.2 g/l, fructose 12.8g/l, BCAAs 4g/l, curcumin 250mg/l, piperine 2.6mg/l, caffeine 75mg/l, sodium 884mg/l, magnesium 100mg/l, zinc 5mg/l, Vitamin C 15mg/l, Vitamin E 5mg/l, Vitamin B1 0.7mg/l, Vitamin B2 0.4 mg/l, Vitamin B3 9mg/l.

Reference

Peltier S L, Vincent L, Millet G Y, Sirvent P, Morin J-B, Guerraz M, Geyssan A, Lescuyer J-F, Feasson L and Messonnier L. (2011) Effects of carbohydrates-BCAAs-caffeine ingestion on performance and neuromuscular function during a 2-h treadmill run: a randomized, double-blind, cross-over placebo-controlled study.Journal of the International Society of Sports Nutrition 2011, 8:22

Creatine Monohydrates Antioxidant Capacity

A recent research study provides further evidence to support creatine monohydrates antioxidant properties (Rahimi 2011). Previous studies have highlighted the antioxidant potential of creatine (Lawler et al., 2002; Royes et al., 2006; Sestili et al., 2011). In this study (Rahimi 2011) 27 resistance trained men were divided into either a creatine monohydrate group (taking 4x5g creatine monohydrate/ day) or a placebo group (taking 4x5g maltodextrin/day). The researchers looked at the effect of an acute resistance exercise protocol on oxidative stress response and oxidative DNA damage and whether creatine monohydrate supplementation (for 7 days) could protect against the oxidative stress.

The resistance exercise protocol consisted of 7 sets of four different exercises, using 60-90% 1RM in the flat pyramid loading pattern and was performed before and after the supplementation period. Oxidative stress was measured by analysing blood and urine samples taken before, immediately after, and 24-hour postexercise. Blood and urine samples were analysed for two key markers of oxidative stress: 1) Malondialdehyde (MDA) - a highly reactive naturally occurring organic compound that is a marker for oxidative stress and indicates lipid peroxidation, and 2) 8-hydroxy-2-deoxyguanosine (8-OHdG) - a widely used biomarker for oxidative stress and carcinogenesis. Before the start of the supplementation period the resistance exercises caused significant increases in urinary 8-OHdG excretion and plasma MDA levels. Creatine monohydrate supplementation was found to attenuate the increase in urinary 8-OHdG excretion and plasma MDA. The researcher concluded that the results indicate that creatine monohydrate supplementation appears to reduce oxidative DNA damage and lipid peroxidation induced by resistance exercises.

In Summary:

In addition to the research proven benefits of creatine monohydrate on sporting performance it also appears to provide protection against the oxidative stress and oxidative damage induced by resistance exercise.

References

Lawler JM, Barnes WS, Wu G, Song W, Demaree S. (2002) Direct antioxidant properties of creatine. Biochemical and Biophysical Research Communications. 2002;290:47–52.

Rahimi R. (2011) Creatine supplementation decreases oxidative DNA damage and lipid peroxidation induced by a single bout of resistance exercise. J Strength Cond Res. 2011 Dec;25(12):3448-55.

Royes LF, Fighera MR, Furian AF, Oliveira MS, Myskiw Jde C, Fiorenza NG, Petry JC, Coelho RC, Mello CF. (2006) Effectiveness of creatine monohydrate on seizures and oxidative damage induced by methylmalonate. Pharmacol Biochem Behav. 2006 Jan;83(1):136-44. Epub 2006 Feb 15.

Sestili P, Martinelli C, Colombo E, Barbieri E, Potenza L, Sartini S, Fimognari C. (2011) Creatine as an antioxidant. Amino Acids. 2011 May;40(5):1385-96. Epub 2011 Mar 15.

Caffeine Consumption Improves 5,000m Time Trial Performance

A recent study found that the consumption of caffeine, in the form of caffeine anhydrous, improved 5,000m time trial performance by an average of 51 seconds (Marangon and Mendes 2011). The subjects, 9 male triathletes aged between 18 and 35, completed two 5,000m time trials which were separated by an average of 7 days. Prior to one of the time trials the subjects took a capsule containing caffeine anhydrous (5mg/kg - this equates to 350mg for a 70kg athlete) and for the other time trial they took a placebo capsule.

Caffeine supplementation had no significant effect on either Blood lactate or glucose levels before or after either treatment. However, the mean time to complete the time trial was significantly quicker for the caffeine group (20.48±3.15 min) than the placebo group (21.39±3.1 min) with a mean improvement in time of 51±3.2 seconds.

Caffeine and Endurance Exercise Performance

Caffeine is known to enhance exercise performance through a number of different pathways including activation of the central and sympathetic nervous system, the cardiovascular system as well as neuro-muscular activation. The combined effects of these lead to increased muscle recruitment, enhanced aerobic and anaerobic metabolism, and a delay in fatigue levels by a reduction in the athlete’s perception of fatigue/effort.

The researchers concluded that caffeine is a powerful ergogenic that shows beneficial effects on aerobic performance.

Reference:

Mendes P HM (2011) Caffeine influence on the performance of the 5000m race. Journal of the International Society of Sports Nutrition 2011, 8(Suppl 1):P12

High Fibre Consumption Lowers Colon Cancer Risk

Researchers from the Imperial College London have found that the risk of colon/bowel cancer can be reduced by 10% for every 10g/day of dietary fibre and cereal fibre consumed (Aune et al., 2011a). The researchers also found that there was a 20% reduction in risk when three servings (approximately 90g/day) of whole grain was consumed daily. Interestingly, they observed further reductions in risk with higher intakes of whole grain and dietary fibre suggesting that bowel cancer rates appeared to decreased linearly with increased consumption. The research was carried out by performing a meta analysis of 25 previous research studies that involved a total of 1.9 million people.

The results are particularly important since Colon cancer accounts for 9.7% of all cancer cases worldwide and is the third most common type of cancer. It is believed that a number of dietary and lifestyle play a role in increasing the risk of bowel cancer including: consumption of red meats and processed meats, excessive alcohol consumption, leading a sedentary lifestyle and/or sitting down for prolonged periods per day.

The analysis suggests that the greatest benefit came when the consumption of cereal fibre and whole grain was increased. In addition to the reduced risk of colon/bowel cancer an increase in the consumption of dietary fibre and whole grains is believed to have a number of other health benefits including:  a reduce the risk of cardiovascular disease, reduced risk of type 2 diabetes, benefits for weight management/weight loss, and possibly a general reduction in overall mortality. Good sources of whole grains include: whole grain breads, whole grain wraps, cereals, brown pasta, brown rice, porridge, and oatmeal.

The researchers were unable to find any association between the intake of fibre from fruit, vegetables, or legumes and a reduction in risk of colon cancer. However, the authors pointed out that in a previous study they had found a reduction in risk with high intakes of fruit and vegetables  (Aune et al., 2011b). The authors commented that the previous results suggested that there was a “potential role of components other than fibre in fruits and vegetables in explaining this result”. In fact, most current research has found that the main beneficial components that contribute to improved health and reduced cancer risk, from fruit and vegetables are the antioxidant molecules – most fruits and vegetables contain relatively high levels of antioxidants which act to protect cells from the damaging effects of free radicals.

References:

Aune D, Lau R, Chan DS, Vieira R, Greenwood DC, Kampman E, et al. (2011a) Nonlinear reduction in risk for colorectal cancer by fruit and vegetable intake based on meta-analysis of prospective studies. Gastroenterology .141:106-18.

Aune, D., Chan D. S., Lau, R., Vieira, R., Greenwood, D. C., Kampman, E. and Norat, T. (2011b) Dietary fibre, whole grains, and risk of colorectal cancer: systematic review and dose-response meta-analysis of prospective studies. BMJ 2011;343:bmj.d6617

Whey Protein Delays the Age Related Decline in Muscle Mass

It is well known that aging is associated with a gradual decline in muscle size and mass. This gradual loss of muscle size/mass, known as sarcopenia, is accompanied with a gradual loss in muscular strength. It is this loss in muscle strength that often makes everyday tasks more difficult for the elderly and can eventually lead to increased mobility problems and may eventually lead to disabilities.

In order to prevent or slow this gradual loss of muscle mass and strength, exercise and dietary interventions are often employed. A recent review of current dietary and exercise interventions has highlighted that the elderly may have a blunted response to lower doses of protein and appear to benefit from dietary plans including at least 20g of high quality protein per meal, and may even require as much as 30g of high quality protein per meal (Breen & Philips, 2011). The researchers suggested that high quality protein, in particular whey protein, is likely to be of particularly importance when attempting to maintain muscle mass in the elderly. The researchers highlighted that the high quality protein should provide sufficient essential amino acids (~10g), and in particular leucine (~2g).

The researchers also advise the use of resistance exercise programs for the elderly in order increase their muscle mass. This should be carefully monitored to ensure they are working within safe limits. The researchers stated that: “In older adults who are not restricted by physical disability, frequent high intensity weight lifting will increase lean muscle mass. Alternatively, low-intensity high volume weight lifting may also promote an adaptive response in the elderly”. The high intensity weight lifting would typically involve 2-3 repeated sets of around 12 repetitions per muscle group – the weight should be sufficient that they struggle to complete the final set of 12. A low intensity high volume approach would typically involve 2-3 repeated sets of around 20-25 repetitions per muscle group – again the weight should be sufficient that they struggle to complete the final set.

The researchers found the optimal response to resistance training in the elderly appears to occur when resistance training is combined with protein ingestion. When protein is consumed post exercise (ideally within 2 hours of exercise completion) it appears that the elderly may require more protein (~40g) than younger individuals (~20g). It is not clear at this point whether it is the extra quantity of protein or the higher levels of EAA’s and Leucine that are the reason why the elderly appear to benefit from the increased protein intake.

Summary of The Benefits of Whey Protein For Seniors:

• Increased consumption of high quality protein appears to help to delay the age-related decline in muscle mass
• The elderly should consume around 20-30g of high quality protein per meal
• Whey protein appears to be the best source of protein for the elderly, it should be high in EAAs and Leucine in particular
• Carefully monitored resistance training will also be of benefit to the elderly and should help to increase muscle mass
• Optimal results are obtained when resistance training is combined with protein consumption
• The elderly may require up to 40g of protein post exercise compared with 20g for younger individuals

Reference:

Breen L, and Phillips, S. M. (2011). Skeletal muscle protein metabolism in the elderly: Interventions to counteract the 'anabolic resistance' of ageing. Nutrition & Metabolism. 8:68

Protective Effect of Vitamin C & E Against Damage from Tobacco Smoke

Recent research has demonstrated that the administration of vitamin E and/or vitamin C reduces the pro-inflammatory response in Blood Brain Barrier (BBB) caused by tobacco smoke exposure (Hossain et al 2011).

It is well known that tobacco smoke contains many highly reactive oxygen species (such as hydrogen peroxide) which cause oxidative damage to any tissue that they come into contact with. The free radicals in tobacco smoke cause significant damage to vascular tissue (arteries, veins etc) and may eventually lead to damage to the blood brain barrier. It is already known that tobacco smoke can lead to significantly decreased levels of vitamin E and vitamin C in the blood plasma of smokers due to increased anti-oxidative responses to the elevated levels of reactive oxygen species.

The researchers found that pre-treatment with the antioxidant vitamins E & C can help to reduce some of the pro-inflammatory response caused by the reactive oxygen species found in tobacco smoke. The researchers suggested that “it very likely that higher concentrations and/or a sustained supplementation of vitamin C are necessary to maintain a protective effect for a longer period of time.” – possibly around 200mg/day for smokers.

It was also demonstrated that vitamin C’s protective effect was significantly enhanced, both in efficacy and duration, when combined with vitamin E. The researchers concluded that “These antioxidant vitamins may act synergistically in preventing oxidative damage and pro-inflammatory stimulation induced by tobacco smoking exposure, thereby reducing TS toxicity at the BBB level.”

Reference

Hossain M , Mazzone P, Tierney W and CuculloIn L (2011) Vitro Assessment of Tobacco Smoke Toxicity at the BBB: Do Antioxidant Supplements Have a Protective Role? BMC Neuroscience 2011, 12:92

Effect of Leucine-Protein Supplement on Endurance Recovery

Researchers have found that the consumption of a Leucine-Protein supplement improves recovery, as measured by the cyclists performance in subsequent bouts of interval training. The cyclists performed 2 – 2.5 hour interval training bouts on three consecutive evenings.  Following each interval training session the cyclists consumed either a leucine-protein high carbohydrate supplement or an isocaloric control consisting of protein, high carbohydrate, and fat. Below is the composition of the leucine-protein high carbohydrate supplement and isocaloric control:

Leucine-Protein Drink – Leucine (0.1g/kg/hour), Protein (0.4g/kg/hour), Carbohydrate (1.2g/kg/hour), and Fat (0.2g/kg/hour). This equates to a  70 kg athlete 10.5g of leucine, 42g of protein, 126g of carbohydrate, and 21g of fat in the 90 minutes after training.

Isocaloric Control – Protein (0.06g/kg/hour), Carbohydrate (1.6g/kg/hour), and Fat (0.2g/kg/hr). This Equates to a 70kg athlete consuming 6.3g of protein, 168g of carbohydrate, and 21g of fat in the 90 minutes after training.

What did the researchers find?

Following 39 h of recovery the cyclists performed a repeat-sprint performance test to see whether the Leucine-Protein consumption had enhanced their recovery. The researchers found that the postexercise consumption of leucine-protein improved the cyclists mean sprint power by 2.5% and reduced their perceived overall tiredness during the sprints by 13%.  The cyclists perceptions of leg tiredness and soreness were unaffected by the Leucine-protein consumption. The researchers also found that the Creatine-kinase (CK) concentration was lowered by 19% - the concentration of CK can indicate the level of muscle breakdown. The researchers concluded: “The ingestion of a leucine-protein supplement along with other high-carbohydrate food following intense training on consecutive days enhances subsequent high-intensity endurance performance and may attenuate muscle membrane disruption in well-trained male cyclists.”

Reference:

Thomson JS, Ali A, Rowlands DS (2011). Leucine-protein supplemented recovery feeding enhances subsequent cycling performance in well-trained men. Appl Physiol Nutr Metab. 2011 Apr;36(2):242-53.

Effect of Whey Protein on Protein Synthesis and Cardiovascular Health

A recent review of the effects of whey protein supplements on metabolism (Graf et al. 2011) highlighted the positive effects that whey protein appears to have on both glucose metabolism and muscle protein synthesis. A number of previous studies have looked at how a range of milk and dairy products are associated with reduced risk of cardiovascular disease and some metabolic disorders. The researchers stated that “In particular, whey protein seems to induce these effects because of bioactive compounds such as lactoferrin, immunoglobulins, glutamine and lactalbumin. In addition, it is an excellent source of branch chained amino acids.”

The researchers looked at 25 recently published trials that were examining  the effects of whey protein supplementation on measures of cardiovascular health (lipid and glucose metabolism, blood pressure, and vascular function) and on the musculoskeletal system. The researchers found that “Whey protein appears to have a blood glucose and/or insulin lowering effect” and “protein may increase muscle protein synthesis”.

The review provides further support for the use of Whey Protein by bodybuilders as part of a balanced nutritional approach. It is particular promising to note that the as well as the apparent increased muscle protein synthesis, whey protein also has a number of beneficial effects on cardiovascular health and function.

Whey Protein Benefits Reference

Graf S, Egert S, Heer M (2011). Effects of whey protein supplements on metabolism: evidence from human intervention studies. Curr Opin Clin Nutr Metab Care.

Effect of Vitamin B Supplement on Mild Cognitive Impairment

Researchers from the University of Oxford and the University of Oslo, Norway, looking at the effect of a high dose Vitamin B supplement on Mild Cognitive Impairment (MCI) found that subjects receiving the high dose vitamin B supplements showed improvements in cognitive function compared with those taking a placebo (dummy) drug. This has important implications since 10% of all individuals with MCI develop dementia per year - approximately 50% will develop dementia within 5 years of initial MCI diagnosis – and any improvement in cognitive function could help to slow the rate of development of dementia. The research supports previous research where subjects receiving a high dose vitamin B supplemented experienced 30% less brain atrophy (shrinkage) when compared with those who only received a placebo drug.

How might B Vitamins help to reduce the rate of dementia?

It is believed that individuals who have low levels of B vitamins (either from poor diet or poor absorption of B vitamins) are at increased risk of cognitive impairment possibly due to elevated homocysteine levels in their blood – homocysteine has previously been found in higher levels in patients with Alzheimer’s. It is believed that a high dose Vitamin B supplement can help to lower homocystein levels, improve cognitive function and possibly delay the progression from MCI to dementia.

What dose of B Vitamins was used in the research?

The high dose Vitamin B supplement consisted of 20mg of Vitamin B6 (1000% RDA), 0.5mg of Vitamin B12 (50,000%), 0.8mg of Folic Acid (400%).

What did the researchers find?

• The high dose Vitamin B supplement had homocysteine levels that were 30% lower (on average) compared with those receiving just a placebo drug.
• Those who received the Vitamin B supplement tended to do better in a test that looked at their ability to plan and execute a task correctly.
• The B vitamin supplement tended to be more beneficial to those individuals with higher levels of homocysteine.

Effect of High Antioxidant Consumption on Body Fat Distribution

New research indicates a link between total dietary antioxidant consumption, body fat distribution and antioxidant status in healthy young people. The researchers found an inverse relationship between the consumption of dietary antioxidants and body fat distribution – in other words the greater the consumption of antioxidants the lower the distribution of bodyfat, and the higher their antioxidant status. The researchers also found that dietary antioxidant consumption was inversely associated with glucose biomarkers – an indicator of insulin resistance.

The researchers found an association between higher dietary antioxidant consumption and lower level of specific lipid biomarkers. The researchers stated that: “an increased consumption of antioxidant-rich foods, such as fruits, vegetables, olive oil, nuts, red wine, seafood and legumes, has resulted in an improvement in the lipid profile, with increased HDL-c and decreased LDL-c and triglycerides concentrations in some intervention trial studies” – HDL is the good cholesterol and LDL is the bad cholesterol. The researchers also commented that: “polyphenols and carotenoids have the ability to reduce cholesterol absorption, to increase cholesterol and fecal bile excretion, to inhibit cholesterol synthesis and to stimulate the expression and activity of the LDL receptors”.

Summary of the research

The key findings from this research was that subjects with a higher consumption of dietary antioxidants tended to have reduced central adiposity (fat stored around the stomach) lower levels of glucose and lipid biomarkers. The link between antioxidant consuption and reduced central adiposity is particularly important since it is well known that Central adiposity carries an increased risk of type II diabetes, heart disease, hypertension and death, and is closely related to insulin resistance. Of particular importance was how this research highlighted the potential health benefits of a high intake of antioxidants even amongst a group of healthy young adults.

References

Hermana, et al. (2011) Dietary total antioxidant capacity is inversely related to central adiposity as well as to metabolic and oxidative stress markers in healthy young adults. Nutrition & Metabolism 2011, 8:59

Walnut Consumption and the Risk of Breast Cancer

New research confirms that a daily intake of just a handful of walnuts can help to significantly reduce the risk of breast cancer. The research led by Elaine Hardman, Ph.D., of Marshall's Joan C. Edwards School of Medicine looked at the effect of a diet containing walnuts and breast cancer risk in mice that were genetically programmed to develop cancer at higher rates. The researchers compared the effects of a typical diet and a diet that also contained walnuts across the lifespan of the mice: through the mother (during pregnancy and through weaning), and when eating the food directly. The amount of walnut used in the test research equates to about 2 ounces a day for humans - 2 ounces = 28 halves which supplies around 370 calories (18.5% of a 2,000 calorie diet). 

They reearchers found that the group whose diet included walnut throughout their lifecycle had a 50% reduction in the rate of breast cancer development compared with the group that ate a typical diet. In addition, the mice in the walnut fed group developed tumours at a lower rate, and the number of tumours and the size of tumours were significantly smaller than the typical diet group. The researchers stated that: "These reductions are particularly important when you consider that the mice were genetically programmed to develop cancer at a high rate,".

The anticancer properties of walnuts

Antioxidants – 2oz of walnuts contain nearly double the recommended intake of antioxidants. In fact walnuts contain nearly twice the amount of antioxidants of any other commonly consumed nut. In addition the quality of the antioxidants present in walnuts is also the highest among nuts - antioxidants in walnuts have been found to be 2-15 times as potent as vitamin E.

Ellagic Acid - Ellagic acid appears to have some anti-cancer properties. It works as an anti-oxidant, and can cause cell death in cancer cells in the laboratory. It also appears to reduce the effect of estrogen in promoting the growth of breast cancer cells in tissue cultures.

Gallic acid - Gallic acid is a powerful antioxidant found in walnuts. It is believed to be beneficial to people suffering with neural disorders or who are at risk of certain cancers. Gallic acid is believed to be toxic to cancer cells, while having no negative effect on healthy cells.

Melatonin - melatonin modulates the transcriptional proliferation of human breast cancer cells.

Omega 3 – 2 oz of walnuts will give you nearly 200% of your daily recommended amounts of Omega 3. Omega 3 has a number of health benefits including helping to maintain a healthy heart and circulation, brain health, joint health, and may help to reduce the risk of certain cancers including breast and colon cancer.

Phytosterols - these are specific compound that resemble cholesterol and are found exclusively in plants. Phytosterols are believed to enhance our bodies own antitumor responses and directly inhibit tumor growth.

Additional considerations:

Although there are many health benefits to be gained by the addition of 2 ounces of walnuts to your diet, you should carefully adjust your daily calorific intake to accommodate the extra 300+ calories in the walnuts.