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Category: nutrition

Published on Leave a comment on Low Vitamin D Levels Linked to Aggressive Cancer

Two recent studies link low vitamin D levels with more aggressive cancers: aggressive prostate cancer in men and more aggressive breast cancers (in mice and women). Researchers generally advise people to take 1000 to 2000 international units per day of vitamin D3 to maintain normal blood levels of of more than 30 nanograms/milliliter. The best source of vitamin D is sunlight, which is why vitamin D is frequently called the sunshine vitamin.

From Science Daily:  Low vitamin D predicts aggressive prostate cancer

A new study provides a major link between low levels of vitamin D and aggressive prostate cancer. Northwestern Medicine research showed deficient vitamin D blood levels in men can predict aggressive prostate cancer identified at the time of surgery.

"Vitamin D deficiency may predict aggressive prostate cancer as a biomarker," said lead investigator Dr. Adam Murphy, an assistant professor of urology at Northwestern University Feinberg School of Medicine and a Northwestern Medicine urologist. "Men with dark skin, low vitamin D intake or low sun exposure should be tested for vitamin D deficiency when they are diagnosed with an elevated PSA or prostate cancer. Then a deficiency should be corrected with supplements."

Aggressive prostate cancer is defined by whether the cancer has migrated outside of the prostate and by a high Gleason score. A low Gleason score means the cancer tissue is similar to normal prostate tissue and less likely to spread; a high one means the cancer tissue is very different from normal and more likely to spread. The study was part of a larger ongoing study of 1,760 men in the Chicago area examining vitamin D and prostate cancer. The current study included 190 men, average age of 64, who underwent a radical prostatectomy to remove their prostate from 2009 to 2014.

Of that group, 87 men had aggressive prostate cancer. Those with aggressive cancer had a median level of 22.7 nanograms per milliliter of vitamin D, significantly below the normal level of more than 30 nanograms/milliliter. The average D level in Chicago during the winter is about 25 nanograms/milliliter, Murphy noted....The Institute of Medicine recommends 600 international units of D per day, but Murphy recommends Chicago residents get 1,000 to 2,000 international units per day.

From Medical Xpress:  Vitamin D deficiency contributes to spread of breast cancer in mice, study finds

Breast tumors in laboratory mice deficient in vitamin D grow faster and are more likely to metastasize than tumors in mice with adequate levels of vitamin D, according to a preliminary study by researchers at the Stanford University School of Medicine.The research highlights a direct link between circulating vitamin D levels and the expression of a gene called ID1, known to be associated with tumor growth and breast cancer metastasis.

The finding builds upon several previous studies suggesting that low levels of vitamin D not only increase a person's risk of developing breast cancer, but are also correlated with more-aggressive tumors and worse prognoses. Although the research was conducted primarily in mice and on mouse cells, the researchers found in a study of 34 breast cancer patients that levels of circulating vitamin D were inversely correlated with the expression levels of ID1 protein in their tumors, and they confirmed that a vitamin D metabolite directly controls the expression of the ID1 gene in a human breast cancer cell line.

Once ingested or made by the body, vitamin D is converted through a series of steps into its active form, calcitriol. Calcitriol binds to a protein in cells called the vitamin D receptor, which then enters the cell's nucleus to control the expression of a variety of genes, including those involved in calcium absorption and bone health.

In the new study, Williams and Aggarwal investigated whether vitamin D levels affected the metastatic ability of mouse breast cancer cells implanted into the mammary fat pad of laboratory mice. One group of 10 mice was first fed a diet lacking in the vitamin for 10 weeks; the other 10 received a normal dose in their food. Mice fed a diet deficient in vitamin D developed palpable tumors an average of seven days sooner than their peers, and after six weeks of growth those tumors were significantly larger in size than those in animals with adequate vitamin D levels.

Published on Leave a comment on What Are the Herbicide Levels In Your Food?

A very popular herbicide – currently the most widely applied pesticide in the world – is glyphosate, commonly known as Roundup. Global use was 1.65 billion pounds in 2014 , while overall use in the US was 276.4 million pounds in 2014. Glyphosate is a human carcinogen and linked to various health effects, and even though it is so extensively used, the FDA just announced in February 2016 that they will “soon” start testing for its presence and actual levels in food for the first time in the agency’s history.

What, it never occurred to them that the most widely used pesticide in the world would be found in food?  Of course they knew glyphosate residues were occurring in food because in 2013 the EPA raised "tolerance limits" for human exposure to glyphosate for certain foods, stating with "reasonable certainty that no harm will result" from human exposure to the chemical. This increase in tolerance levels came about from a request from Monsanto (the manufacturer of the glyphosate herbicide Roundup), and even though numerous groups protested the increase, the EPA went along with Monsanto's request. Some tolerances doubled.

But remember.... there are very strong industry pressures on the EPA, and so the EPA seems to keep its head firmly in the sand for all sorts of pesticide issues. Maybe their motto is: see no evil...hear no evil....

The reason that glyphosate tolerance limits needed to be increased in the USA is because Roundup Ready crops are now so extensively planted, and this has resulted in skyrocketing use of glyphosate in the last 20 years. Roundup Ready crops are genetically modified to tolerate repeated glyphosate spraying (against weeds)  during the growing season. However, the crops take up and accumulate  glyphosate, and so glyphosate residues are increasing in crops. Another reason for increased residue of glyphosate in crops is the current practice of applying an herbicide such as Roundup right at the time of harvest to non-GMO crops such as wheat, so that the crop dies at once and dries out (pre-harvest crop dessication), and which is called a "preharvest application" by Monsanto. Glyphosate is now off-patent so many other companies are also using glyphosate in their products throughout the world.

Private testing has already found glyphosate residues in breast milk, soybeans, corn, honey, cereal, wheat flour, soy sauce, and infant formula. It is currently unknown what glyphosate residues in food, which we then ingest, mean for human health. Several studies have linked glyphosate to human health ailments, including non-Hodgkin lymphoma and kidney and liver problems. Of special concern is that because glyphosate is so pervasive in the environment, even trace amounts might be harmful due to chronic exposure. Some people (including researchers) are even suggesting that much of "gluten sensitivity" or "gluten intolerance" that people complain of, may actually be sensitivity to glyphosate residues in food.

So where have glyphosate residues been found recently? In Germany's 14 most popular beers. German beer purity in question after environment group finds weed-killer traces And in feminine hygiene products in France. How to lower your daily intake of glyphosate? Eat organic foods as much as possible, including wheat, corn, oats, soybeans.

Some influential scientists and physicians just came out with a Statement of Concern regarding their serious concerns with glyphosate. The article summary (Abstract) from Environmental Health: Concerns over use of glyphosate-based herbicides and risks associated with exposures: a consensus statement

The broad-spectrum herbicide glyphosate (common trade name “Roundup”) was first sold to farmers in 1974. Since the late 1970s, the volume of glyphosate-based herbicides (GBHs) applied has increased approximately 100-fold. Further increases in the volume applied are likely due to more and higher rates of application in response to the widespread emergence of glyphosate-resistant weeds and new, pre-harvest, dessicant use patterns. GBHs were developed to replace or reduce reliance on herbicides causing well-documented problems associated with drift and crop damage, slipping efficacy, and human health risks. Initial industry toxicity testing suggested that GBHs posed relatively low risks to non-target species, including mammals, leading regulatory authorities worldwide to set high acceptable exposure limits. To accommodate changes in GBH use patterns associated with genetically engineered, herbicide-tolerant crops, regulators have dramatically increased tolerance levels in maize, oilseed (soybeans and canola), and alfalfa crops and related livestock feeds.

Animal and epidemiology studies published in the last decade, however, point to the need for a fresh look at glyphosate toxicity. Furthermore, the World Health Organization’s International Agency for Research on Cancer recently concluded that glyphosate is “probably carcinogenic to humans.” In response to changing GBH use patterns and advances in scientific understanding of their potential hazards, we have produced a Statement of Concern drawing on emerging science relevant to the safety of GBHs. Our Statement of Concern considers current published literature describing GBH uses, mechanisms of action, toxicity in laboratory animals, and epidemiological studies. It also examines the derivation of current human safety standards.

We conclude that: (1) GBHs are the most heavily applied herbicide in the world and usage continues to rise; (2) Worldwide, GBHs often contaminate drinking water sources, precipitation, and air, especially in agricultural regions; (3) The half-life of glyphosate in water and soil is longer than previously recognized; (4) Glyphosate and its metabolites are widely present in the global soybean supply; (5) Human exposures to GBHs are rising; (6) Glyphosate is now authoritatively classified as a probable human carcinogen; (7) Regulatory estimates of tolerable daily intakes for glyphosate in the United States and European Union are based on outdated science. We offer a series of recommendations related to the need for new investments in epidemiological studies, biomonitoring, and toxicology studies that draw on the principles of endocrinology to determine whether the effects of GBHs are due to endocrine disrupting activities. We suggest that common commercial formulations of GBHs should be prioritized for inclusion in government-led toxicology testing programs such as the U.S. National Toxicology Program, as well as for biomonitoring as conducted by the U.S. Centers for Disease Control and Prevention.

Published on Leave a comment on Clear Differences Between Organic and Non-Organic Milk and Meat

Two new papers just published in the British Journal of Nutrition are analyses of existing studies that compare conventional vs organic milk, and conventional vs organic red meat. Both studies found clear differences between organic meat and milk compared to conventional milk and meat, with the organic milk and meat best health-wise, especially due to differences in fatty acids. The researchers stated: "organic bovine (cow) milk has a more desirable fatty acid composition than conventional milk".

Some of the differences may be due to organic milk and beef coming from cattle that graze on grass (organic farming standards require  grazing/forage-based diets), while most conventional milk and beef come from cows subsisting on grain. Beneficial omega-3 is much more prevalent in grass than in grain, which is why organic livestock and milk also contain higher levels, while omega-6 levels were lower in organic meat and dairy.

The researchers did not look at antioxidant, vitamin and mineral concentrations between the meat groups because there weren't enough studies to look at. Two years ago, Dr. Leifert led a similar review for fruits and vegetables that found organic produce had higher levels of some antioxidants and less pesticide residue than conventionally grown crops. From Medical Xpress:

New study finds clear differences between organic and non-organic milk and meat

In the largest study of its kind, an international team of experts led by Newcastle University, UK, has shown that both organic milk and meat contain around 50% more beneficial omega-3 fatty acids than conventionally produced products. Analyzing data from around the world, the team reviewed 196 papers on milk and 67 papers on meat and found clear differences between organic and conventional milk and meat, especially in terms of fatty acid composition, and the concentrations of certain essential minerals and antioxidants.  ...continue reading "Clear Differences Between Organic and Non-Organic Milk and Meat"

Published on Leave a comment on Eating An Egg Daily OK For Heart Health?

Remember all the medical advice for years about not eating eggs frequently (high cholesterol! heart disease!) and to instead eat egg white omelettes if one absolutely wanted to eat eggs? Remember the obsession with dietary cholesterol? Well, this recent research followed 1032 men for 21 years and found that a relatively high intake of dietary cholesterol, or eating one egg every day, was not associated with an elevated risk of incident coronary heart disease - not in the entire study population nor in those with the APOE4 phenotype. Also, the study did not establish a link between dietary cholesterol or eating eggs with thickening of the common carotid artery walls. Time to enjoy eggs again! From Science Daily:

High-cholesterol diet, eating eggs do not increase risk of heart attack, not even in persons genetically predisposed, study finds

A new study from the University of Eastern Finland shows that a relatively high intake of dietary cholesterol, or eating one egg every day, are not associated with an elevated risk of incident coronary heart disease. Furthermore, no association was found among those with the APOE4 phenotype, which affects cholesterol metabolism and is common among the Finnish population.

In the majority of population, dietary cholesterol affects serum cholesterol levels only a little, and few studies have linked the intake of dietary cholesterol to an elevated risk of cardiovascular diseases. Globally, many nutrition recommendations no longer set limitations to the intake of dietary cholesterol. However, in carriers of the apolipoprotein E type 4 allele -- which significantly impacts cholesterol metabolism -- the effect of dietary cholesterol on serum cholesterol levels is greater. In Finland, the prevalence of the APOE4 allele, which is a hereditary variant, is exceptionally high and approximately one third of the population are carriers.

The dietary habits of 1,032 men aged between 42 and 60 years and with no baseline diagnosis of a cardiovascular disease were assessed at the onset the Kuopio Ischaemic Heart Disease Risk Factor Study, KIHD, in 1984-1989 at the University of Eastern Finland. During a follow-up of 21 years, 230 men had a myocardial infarction, and 32.5 per cent of the study participants were carriers of APOE4.

Published on Leave a comment on The Effects of Low Fiber Diet Over Generations

A recent study using mice, and following them for 4 generations, has implications for Americans who typically eat a low-fiber diet (average of 15 grams daily). Note that current dietary guidelines recommend that women should eat around 25 grams and men 38 grams daily of fiber. The researchers found that low-fiber diets not only deplete the complex microbial ecosystems residing in the gut, but can cause an irreversible loss of diversity within those ecosystems in as few as three or four generations.

This is because fiber feeds the millions of microbes in the gut - and so a fiber-rich diet can nourish a wide variety of gut microbes, but a low-fiber diet can only sustain a narrower community. As the generations went by, the rodents’ guts became progressively less diverse, as more and more species were extinguished. If the fourth-generation mice switched to high-fiber meals, some of the missing microbes rebounded, but most did not. It took a fecal transplant (mice style) to get back the missing microbes. From Science Daily:

Low-fiber diet may cause irreversible depletion of gut bacteria over generations

A study by Stanford University School of Medicine investigators raises concerns that the lower-fiber diets typical in industrialized societies may produce internal deficiencies that get passed along to future generations. The study, conducted in mice, indicates that low-fiber diets not only deplete the complex microbial ecosystems residing in every mammalian gut, but can cause an irreversible loss of diversity within those ecosystems in as few as three or four generations.

Once an entire population has experienced the extinction of key bacterial species, simply "eating right" may no longer be enough to restore these lost species to the guts of individuals in that population, the study suggests. Those of us who live in advanced industrial societies may already be heading down that path.

Published on

This study found that greater intake of dietary nitrate and green leafy vegetables was associated with a 20 percent to 30 percent lower risk of primary open-angle glaucoma (POAG), which is the most common form of glaucoma. Glaucoma can lead to vision loss and even blindness (if left untreated).There is evidence that nitric oxide has a role in primary open-angle glaucoma, and that dietary intake of nitrates is beneficial. Green leafy vegetables (iceberg lettuce, romaine lettuce,  mustard, or chard, cooked spinach, and raw spinach) were found to be most beneficial, as well as kale and collard greens. Those who ate the most green leafy vegetables ate about 1.5 servings per day, versus .3 servings daily in the lowest intake group.

Dietary nitrate is predominately derived from green leafy vegetables, which contribute approximately 80% of nitrate intake. But they are found as well in other vegetables, such as beets and carrots. It should be pointed out that those who consumed the most dietary nitrate in this study also consumed more fruits and vegetables, and so also consumed more dietary carotenoids, vitamin C, vitamin E, flavonoids, folate, and vitamin A. Bottom line: try to eat fruits and vegetables daily, especially green leafy vegetables (e.g., a salad). From Science Daily:

Higher dietary nitrate, green leafy vegetable intake associated with lower risk of glaucoma

Greater intake of dietary nitrate and green leafy vegetables was associated with a 20 percent to 30 percent lower risk of primary open-angle glaucoma, according to a study published online by JAMA Ophthalmology.

Elevated intraocular pressure and impaired autoregulation of optic nerve blood flow are implicated in primary open-angle glaucoma (POAG; optic nerve damage from multiple possible causes that is chronic and progresses over time). Evidence suggests that nitrate or nitrite, precursors for nitric oxide, is beneficial for blood circulation. Jae H. Kang, Sc.D., of Brigham & Women's Hospital and Harvard Medical School, Boston, and colleagues evaluated the association between dietary nitrate intake, derived mainly from green leafy vegetables, and POAG. The researchers followed up participants biennially in the prospective cohorts of the Nurses' Health Study (63,893 women; 1984-2012) and the Health Professionals Follow-up Study (41,094 men; 1986-2012). Eligible participants were 40 years or older, were free of POAG, and reported eye examinations. Information on diet was updated with questionnaires.

During follow-up, 1,483 incident cases of POAG were identified. Participants were divided into quintiles (one of five groups) of dietary nitrate intake (quintile 5, approximately 240 mg/d; quintile 1, approximately 80 mg/d). The researchers found that greater intake of dietary nitrate and green leafy vegetables was associated with a 20 percent to 30 percent lower POAG risk; the association was particularly strong (40 percent-50 percent lower risk) for POAG with early paracentral visual field loss (a subtype of POAG linked to dysfunction in blood flow autoregulation). 

Published on Leave a comment on Eat More Berries, Less Erectile Dysfunction?

This study showed an association of eating lots of flavonoid rich foods (strawberries, blueberries, cherries, blackberries, red wine, apples, pears, and citrus products) and lower rates of erectile dysfunction. A higher intake of several flavonoids also reduces diabetes and cardiovascular disease risk. Keep in mind that erectile dysfunction is thought to be of vascular etiology (the cause) and so shares risk factors (such as hypertension, obesity, and smoking) with cardiovascular disease. Studies have shown that lifestyle factors such as plenty of exercise, being of normal weight, and a Mediterranean style diet rich in whole grains, fruit, vegetables, nuts, legumes, and olive oil was associated with both lower rates of erectile dysfunction and an improvement in erectile function in men. So don't focus just on the flavonoids, but on the whole lifestyle package. From Science Daily:

Blueberries, citrus fruits, red wine associated with reduced erectile dysfunction

Flavonoid-rich foods are associated with a reduced risk of erectile dysfunction -- according to a new collaborative study from the University of East Anglia (UEA) and Harvard University. Research published in The American Journal of Clinical Nutrition reveals that eating foods rich in certain flavonoids is associated with a reduced risk of erectile dysfunction in men, with the greatest benefit in those under 70. Of all the different flavonoids, Anthocyanins (found in blueberries, cherries, blackberries, radishes and blackcurrant), flavanones and flavones (found in citrus fruits) were found to offer the greatest benefits in preventing the condition.

It is already known that increased exercise can improve erectile function, but this research shows that eating a flavonoid-rich diet is as good for erectile function as briskly walking for up to five hours a week. The study also showed that a higher total fruit intake was associated with a 14 per cent reduction in the risk of erectile dysfunction. And that a combination of consuming flavonoid-rich foods with exercise can reduce the risk by 21 per cent.

More than 50,000 middle aged men were included in this large population based study. They were asked about their ability to have and maintain an erection sufficient for intercourse -- dating back to 1986. Data on dietary intake was also collected every four years.....More than one third of the men surveyed reported suffering new onset erectile dysfunction. But those who consumed a diet rich in anthocyanins, flavones and flavanones were less likely to suffer the condition.

Prof Cassidy said: "The top sources of anthocyanins, flavones and flavanones consumed in the US are strawberries, blueberries, red wine, apples, pears, and citrus products.""We also found that the benefits were strongest among younger men," she added. The team also looked at other lifestyle factors and found that men who consumed a high intake of anthocyanins and flavanones and who were also physically active had the lowest risk of erectile dysfunction.

Published on Leave a comment on Sugar in Western Diet and Breast Cancer

This study was done in mice, but...it may apply to humans. The researchers found that sugar intake in mice comparable with levels in Western diets (in humans) led to increased breast tumor growth and metastasis.They specifically found that table sugar and high fructose corn syrup "was responsible for facilitating lung metastasis and 12-HETE production in breast tumors" in mice. So, at the very least, think about eliminating high fructose corn syrup from the diet - read labels and definitely eliminate soda (a huge source of added high fructose corn syrup).From Science Daily:

Sugars in Western diets increase risk for breast cancer tumors and metastasis

The high amounts of dietary sugar in the typical Western diet may increase the risk of breast cancer and metastasis to the lungs, according to a study at The University of Texas MD Anderson Cancer Center.The findings, published in the Jan. 1, 2016 online issue of Cancer Research, demonstrated dietary sugar's effect on an enzymatic signaling pathway known as 12-LOX (12-lipoxygenase).

"We found that sucrose intake in mice comparable to levels of Western diets led to increased tumor growth and metastasis, when compared to a non-sugar starch diet," said Peiying Yang, Ph.D., assistant professor of Palliative, Rehabilitation, and Integrative Medicine. "This was due, in part, to increased expression of 12-LOX and a related fatty acid called 12-HETE." Previous epidemiological studies have shown that dietary sugar intake has an impact on breast cancer development, with inflammation thought to play a role.

"The current study investigated the impact of dietary sugar on mammary gland tumor development in multiple mouse models, along with mechanisms that may be involved," said co-author Lorenzo Cohen, Ph.D., professor of Palliative, Rehabilitation, and Integrative Medicine. "We determined that it was specifically fructose, in table sugar and high-fructose corn syrup, ubiquitous within our food system, which was responsible for facilitating lung metastasis and 12-HETE production in breast tumors." Cohen added that the data suggested that dietary sugar induces 12-LOX signaling to increase risks for breast cancer development and metastasis.

Identifying risk factors for breast cancer is a public health priority, say the authors. The researchers state that moderate sugar consumption is critical, given that the per capita consumption of sugar in the U.S. has surged to over 100 lbs. per year and an increase in consumption of sugar-sweetened beverages has been identified as a significant contributor to an epidemic of obesity, heart disease and cancer worldwide.

The MD Anderson team conducted four different studies in which mice were randomized to different diet groups and fed one of four diets. At six months of age, 30 percent of mice on a starch-control diet had measurable tumors, whereas 50 to 58 percent of the mice on sucrose-enriched diets had developed mammary tumors. The study also showed that numbers of lung metastases were significantly higher in mice on a sucrose- or a fructose-enriched diet, versus mice on a starch-control diet.

Published on

Two recent studies found health problems associated with low levels of vitamin D: higher risk of stress fractures and also increased severity of IBS (Irritable Bowel Syndrome) symptoms. From Science Daily:

Low levels of vitamin D may increase risk of stress fractures in active individuals

Vitamin D plays a crucial role in ensuring appropriate bone density. Active individuals who enjoy participating in higher impact activities may need to maintain higher vitamin D levels to reduce their risk of stress fractures, report investigators in The Journal of Foot & Ankle Surgery.

The role of vitamin D in the body has recently become a subject of increasing interest owing to its many physiologic effects throughout multiple organ systems. Vitamin D is an essential nutrient that can behave as a hormone. It is obtained through diet and through the skin when exposed to the sun's rays. It is essential for bone development and remodeling to ensure appropriate bone mass density. Low levels of vitamin D can lead to osteoporosis, osteomalacia, decreased bone mineral density, and risk of acute fracture.

Investigators tested the serum concentration of 25(OH)D, which is used to determine vitamin D status, in patients with confirmed stress fractures....Using the standards recommended by the Vitamin D Council (sufficient range 40 to 80 ng/mL), more than 80% of these patients would have been classified as having insufficient or deficient vitamin D levels. According to the standards set by the Endocrine Society (sufficient range 30 to 100 ng/mL), over 50% had insufficient levels.

"Based on these findings, we recommend a serum vitamin D level of at least 40 ng/mL to protect against stress fractures, especially for active individuals who enjoy participating in higher impact activities," explained Dr. Miller. "This correlates with an earlier study of 600 female Navy recruits who were found to have a twofold greater risk of stress fractures of the tibia and fibula with a vitamin D level of less than 20 ng/mL compared with females with concentrations above 40 ng/mL.

From Science Daily: Large proportion of IBS sufferers are vitamin D deficient

A large proportion of people living with Irritable Bowel Syndrome (IBS) are vitamin D deficient, a new study has found. Researchers from the University of Sheffield discovered a significant association between a patient's vitamin D levels and the severity of their IBS symptoms, particularly the extent to which IBS affects their quality of life.

The study, which is the first of its kind, found that out of 51 IBS patients tested 82 per cent exhibited insufficient vitamin D levels....IBS is a chronic and debilitating functional disorder of the gastrointestinal (GI) tract which affects around 10-15 per cent of the western population. Little is known about why and how the condition develops, although it is known that diet and stress can make symptoms worse. 

Published on Leave a comment on Drinking Coffee May Improve Athletic Endurance and Performance

A University of Georgia review study of the research literature shows that drinking coffee (instead of a caffeine supplement) improves athletic endurance performance. Also, that caffeine from coffee has ergogenic benefits—that it enhances physical performance. More beneficial effects of coffee! From Medical Xpress:

Coffee may improve athletic endurance performance, review finds

The caffeine in a morning cup of coffee could help improve athletic endurance, according to a new University of Georgia review study....To research the issue, Higgins reviewed more than 600 scholarly articles and screened them for those that focused only on caffeinated-coffee conditions, measured the caffeine dose and measured an endurance performance. Of these, nine randomized control trials specifically used coffee to improve endurance."Previous research has focused on caffeine itself as an aid to improve endurance," Higgins said.

 Looking at the nine trials, Higgins found that between 3 and 7 milligrams per kilogram of body weight of caffeine from coffee increased endurance performance by an average of 24 percent. The amount of caffeine in a cup of coffee can vary from 75 mg to more than 150, depending on the variety and how it's roasted and brewed. 

In the nine trials, participants either cycled or ran after drinking coffee. They then exercised vigorously and the results were measured. In a majority of cases, endurance was noticeably improved after the use of coffee.When researching the effects of caffeine from coffee, Higgins found two important discoveries: that caffeine from coffee has ergogenic benefits—that it enhances physical performance—and that more research is needed on the use of caffeine from coffee versus pure caffeine use.

"While there is a lack of high-quality research on coffee as a source of caffeine, there is an abundance of research on pure caffeine," he said. "It's surprising how little we know about caffeine from coffee when its endurance effects could be just as beneficial as pure caffeine."

Higgins said that coffee shouldn't be dismissed as less beneficial for endurance. He found that coffee appears to be just as helpful as taking caffeine in the form of powder or tablets.... Higgins says that more research is needed before giving official recommendations to athletes, especially since the amount of caffeine in a cup of coffee can vary depending on how it's prepared.