6 health benefits of grapes
Grapes have been around for thousands of years and are thought to have originated in what is known as the ‘Near East’. This is an area which generally encompasses western Asia.
Throughout history, grapes have most commonly been used in wine production, as their skins contain natural yeast which makes alcohol when it is fermented. Grapes are now a popular fruit in western culture and are still used widely to create wine.
They grow in bunches of 15 to 300 fruits, and come in a number of colours; green, red, black, and variants of these. There are thousands of grape varieties which all have slightly different characteristics, and are created either through natural selection of properties, or through man-made cultivation. Grape varieties are, in fact, officially called cultivars. This goes some way to explaining why there are so many different varieties of wine.
Grapes are often eaten fresh as a healthy snack, dried in the form of raisins, or as a drink either in the form of juice or wine. Although they are known to be healthy, their exact health benefits have not been well advertised. This article will discuss the nutritional benefits of grape consumption, and outline some specific health benefits which occur after eating grapes.
There are a number of grape species, but they are more or less the same in terms of nutritional information (any differences will be outlined where necessary).
100g of grapes contain 69 calories, zero fat or salt, just 6% RDA carbohydrates, and 4% RDA dietary fibre. They also contain 18% RDA Vitamin C and 18% Vitamin K.
Vitamin C is found in many fruits and vegetables, and it has a very important role in physical health. Also known as ascorbic acid, vitamin C is responsible for keeping cells healthy, as well as any connective tissues which support and provide structure for organs.
Furthermore, it is very important in wound healing as it is a cofactor of enzymes which make collagen. Without collagen, new skin would have no structure over which to form. Vitamin C is also an effective modulator of the immune system which can prevent wounds from becoming infected.
In a well-established study by Ringsdorf and Cheraskin (1982) it was found that 500mg+ doses of vitamin C administered to patients recovering from surgery led to a significantly higher quality of collagen in the healing wounds, showing that it has a strong, measurable impact on the quality of wound healing.
It is recommended that humans consume around 40mg of vitamin C per day (NHS, 2015) and this must be found in food as the body cannot synthesise the nutrient itself. A deficiency can lead to a condition called scurvy, which was common amongst sailors in the 18th century due to their very poor diet.
Vitamin K is most commonly found in green leafy vegetables and cereal grains, but some other foods, like grapes, have a surprising amount. Dietary requirements vary for individuals, but the general rule is that you require 0.001mg per kg of body weight.
For instance, if you weigh 65kg, you would require 0.065mg per day. The human body can store vitamin K so it is not needed in your diet every day, but not having enough readily available can cause some serious problems.
It is a very important nutrient for helping blood to clot – without this function, even small cuts could bleed for a very long time and it would be very difficult for wounds to heal.
There is also evidence that vitamin K is necessary for maintaining healthy bones. Booth et al (2003) found that vitamin K deficiency was associated with low bone mineral density, which could make the participants at risk for fractures and osteoporosis as they age.
The Health Benefits Of Eating Grapes
1. Resveratrol Helps Prevent Cancer
Approximately 14 million people worldwide are diagnosed with cancer each year, and it is one of the global leading causes of death, with over 8 million people having died from cancer in 2012 (WHO, 2014). What’s more, the number of new cases is expected to rise by up to 70% in the next 2 decades, and according to Cancer Research UK (2015), one in two people born after 1960 will be diagnosed with cancer at some point in their lives.
Although cancer is an extremely difficult disease to treat, it is also very preventable. In fact, the main causal factor of nearly a third of all cancers is lifestyle habits and behaviour, such as smoking, excessive alcohol consumption and poor diet (WHO, 2014).
Not eating enough fruit or vegetables is a significant risk factor for a number of cancers including gastrointestinal, colorectal and stomach cancer (WHO, 2015). Furthermore, research by Wallström et al (2000) has indicated that high fruit and vegetable consumption can actually mediate the effects of other risk factors. For instance, they suggest that the risk of cancer associated with low physical activity and a high fat diet may be worsened by low fruit and vegetable consumption.
Some fruit and vegetables have better cancer-preventing properties than others; one such fruit are grapes. This is because they contain a compound called resveratrol. Red grapes have the highest concentration, but other varieties also contain the compound.
Resveratrol is a type of antioxidant called a polyphenol. They help the body to fight off free radicals; molecules which are missing an electron and so take them from other cells in the body. Sometimes the cells they take the electron from get damaged in this process, and when it happens to DNA, cancer can form.
Antioxidants can both prevent this damage from occurring by protecting cells and destroying free radicals, and they can also repair some damage once it has occurred.
Slowing, Beecher and Mehta (1997) investigated the impact of resveratrol on cancer cells, and found that it can inhibit tumour progression and initial development of tumours (through destruction of free radicals). It was also found that in mice models it can significantly inhibit tumour growth, and in some cases completely eradicate the tumours.
Although this study was conducted nearly 20 years ago, a recent review by Gescher (2008) supports these results, plus human studies have also found very positive results (e.g. Rotches-Ribalta et al, 2012).
A very recent animal study by Jones et al (2014) does even more to support the anti-cancer function of grapes. 344 rats were injected with Azoxymethane, a compound which can induce the growth of cancerous tumours in the colon. They were then administered a grape juice or raisins diet or a control substance which had similar nutritional content.
After 16 weeks, the colons were examined for cysts, which indicate precancerous activity. It was found that the rats on the grape juice diet had a significant reduction in cysts compared to the other two diets, and both grape juice and raisin diets had significantly fewer cysts than the control diet.
They also discovered a 2-3 fold increase in the glutathione S-transferase enzyme, which has antioxidant properties and can eliminate free radicals before they cause cancer-forming damage.
Over the past 20 years the research surrounding the cancer-preventative properties of grapes has been getting more and more support, and the evidence points towards very positive outcomes.
It is important to remember, however, that fresh grapes are much healthier than grapes in other forms, such as red wine. They are also much more likely to have cancer-protective affects, as the alcohol from red wine may counteract the goodness from the grapes.
2. Reduces The Risk Of Heart Disease
Heart disease is a general term for a number of conditions where heart or blood vessel function is affected. It is an extremely serious disease, and is in fact the number one killer in America (CDC, 2015), the UK (British Heart Foundation, 2015) and the world (WHO, 2015).
Heart disease is most commonly caused by atherosclerosis, which is the term for a build-up of fatty substances in the arteries. These narrow the blood vessels, restricting blood flow to and from the heart. There are a variety of risk factors for developing heart disease, many of which are entirely preventable such as being overweight, eating a poor diet low in fruit and vegetables, and not getting enough exercise.
Often there are no symptoms of heart disease until an event such as a heart attack or stroke occurs, so it is important to be aware of the lifestyle choices you make, and the risks they may pose for you before it is too late to prevent a cardiovascular event.
One way to reduce the risk of developing heart disease is to consume a healthy diet which is low in saturated fat and sodium, and high in fruits and vegetables. Wang et al (2014) explored the impact that fruit and vegetable consumption has on health by conducting a meta-analysis of 16 cohort studies.
A meta-analysis is a type of research where findings from many different studies are collated and analysed again together, in order to get a more accurate picture of a field of research. They are a gold-standard in scientific study, and are the best way to determine whether a scientific phenomenon is real.
In this particular study, data from over 833,000 participants was analysed. The results of the meta-analysis show that higher consumption of fruit and vegetables was significantly associated with a greatly reduced risk of death.
Each additional item led to a 5% decrease in mortality risk, with consumption of five items providing the greatest benefit (further consumption led to a plateau of effect). Furthermore, it was found that fruit and vegetable consumption was particularly effective against death by cardiovascular disease.
Some fruits and vegetables contain specific nutrients which make them particularly effective at fighting cardiovascular disease and reducing risk of developing the disease. Grapes come under this umbrella of specialised fruit because of the antioxidants they contain, including resveratrol mentioned above. Dohadwala and Vita (2009) conducted a clinical review of the research into grape products and cardiovascular disease.
The review cites studies such as Knekt, Jarvinen and Maatela (1996) who investigated the impact of dietary flavonoids (a type of antioxidant found in grapes) on coronary mortality. This was a cohort study which followed over 5100 Finnish men and women for over 20 years, which found that low intakes of flavonoids such as those found in grapes was significantly associated with a higher risk of death by heart disease.
They believe that this effect may partly be because the flavonoids can prevent free radicals from ‘oxidising’ LDL cholesterol. This can prevent heart disease because it stops the cholesterol from becoming inflamed and blocking arteries (the process of atherosclerosis). Not consuming enough flavonoids means that the LDL cholesterol becomes oxidised, and blood flow to the heart is significantly reduced.
The review also cites studies such as Hirvonen et al (2001) who investigated the impact of antioxidants called flavonols and flavones on coronary heart disease in over 25,000 male smokers, who are already at high risk. They found that consumption of these antioxidants was significantly related to a reduced risk of non-fatal heart attack, and to a slightly smaller extent, cardiac death.
Although these studies provide very compelling evidence for consuming these antioxidants to prevent heart disease, they did not study grape consumption specifically. Some researchers have done so however, such as Perez-Jimanes et al (2008) who investigated the effects of a product known as grape antioxidant dietary fibre on cardiovascular disease risk. The product is naturally derived from red grapes, and contains a large amount of dietary fibre and many antioxidants including phenolic acid, anthocyanidin and catechin.
They asked 34 non-smoking adults to consume 7.5g per day of grape antioxidant dietary fibre, and 9 participants were placed into a control group who consumed a product of similar nutritional value, but without the antioxidant and fibre content.
For 16 weeks these products were consumed alongside their normal diet, which is important as the results will be valid for the general population. Following the 16 week period a variety of measures were taken and compared to measures taken at baseline.
It was found that the participants who consumed the grape product had significantly lower total cholesterol, LDL cholesterol (the bad kind) and blood pressure levels compared to the control group.
These measures are all very strong risk factors for developing cardiovascular disease, and so this study shows that consumption of grape antioxidant dietary fibre for 16 weeks is a very effective preventative measure for reducing the risk of CDV.
Although there have been no long-term cohort studies to investigate effect of grape consumption on cardiovascular disease risk factors like there have been for specific antioxidants, Tome-Carnerio et al (2012) conducted a year-long investigation of 75 patients undergoing preventative treatments for CVD.
The participants were assigned to one of three groups; a placebo control group, a resveratrol-rich grape supplement group, or a standard grape supplement group.
All products were administered to the participants in the form of capsules, which they were expected to consume once daily for six months. For the next six months, the dosage was doubled to two capsules per day to investigate a dose-response effect (I.e. increased tolerance to the effects of the product).
The researchers were measuring the impact of the capsule consumption on the amount of highly sensitive c-reactive proteins (hs-CRP). Having a high level of proteins suggests that an individual has higher than normal inflammatory processes occurring, which can increase their risk of heart disease two to four-fold.
Blood samples and questionnaires on lifestyle habits, side-effects and consumption of other grape products were collected at baseline, 6 months, and 12 months. It was found that there was no effect of the placebo or standard grape supplement, but the resveratrol-rich supplement led to a significant decrease in hs-CRP.
It was also found that the resveratrol-rich supplement led to a significant decrease in tumour necrosis factor-α (which promotes an inflammatory response), plasminogen activator inhibitor type 1 (which can contribute to the formation of blood clots that can block the arteries), interleukin-6/interleukin-10 ratio (which can signal an inflammatory response) and a significant increase in interleukin-10 (which has anti-inflammatory effects).
In the placebo group it was found that the ratio of interlukin-6 and 10 increased regardless of the fact that medication (statins) was prescribed to these participants throughout the study.
All of these results suggest that resveratrol-enriched grape products are extremely effective at reducing the risk of CVD in high-risk patients. It is worth noting that a dose-effect was found, suggesting that an increased dose of grape resveratrol is required after a prolonged time period in order to benefit fully from the antioxidant’s effects.
3. Reduces Symptoms Of Diabetic Neuropathy
Over 9% of the global population suffer from diabetes (WHO, 2014) and diabetic neuropathy is an unfortunate side-effect of this condition which affects an estimated 60-70% of the diabetic population (National Institute of Health, 2013).
It is actually an umbrella term for a variety of nerve disorders caused by diabetes, which become more likely as the disease progresses and develops. Nerve damage can have no noticeable symptoms at all, or it can progress to the stage where pain, tingling or numbness is experienced in the limbs. There are also situations where nerves in organ systems can become damaged, such as those in the reproductive system or the cardiovascular system.
Symptoms are not limited to physical sensations (or lack thereof); other common signs of neuropathy include dizziness, diarrhoea or constipation, nausea, vomiting, and lack of response in the sexual organs (i.e. erectile dysfunction or vaginal dryness).
The causes of diabetic neuropathy are not always clear, although it is thought that different types of nerve disorder have different aetiologies. Some of the causes are thought to be metabolic, including having high blood glucose levels and having diabetes for a prolonged period of time. Other causes include autoimmune conditions, injury to nerves such as carpal tunnel syndrome, and the use of tobacco and alcohol.
Treatment for diabetic neuropathy occurs in stages. First of all it is important to lower blood glucose levels to prevent further damage to the nerves. This can be achieved through increasing physical activity, ensuring the diet is healthy and maintaining the correct diabetic medications and insulin levels. Pain relief measures will also be taken which may include tablets, topical lotions or therapies such as acupuncture and biofeedback.
Although diabetic neuropathy is a very serious condition which affects many diabetic patients, it can be prevented through maintaining healthy blood glucose levels. The pain from neuropathy has also shown to respond to antioxidant treatments.
Singh and Akhtar (2009) conducted a review of 75 studies in an attempt to discover the most effective therapies for diabetic neuropathy. They discuss research where diabetic mice have been treated with antioxidants and as a result markers in diabetic neuropathy have been reduced.
Furthermore, studies have found that the antioxidant resveratrol found in grapes is particularly effective. For instance, rats that had been treated with a compound called STZ to induce diabetes showed reductions in oxidative stress, DNA damage and nerve damage following treatment with resveratrol (Sharma et al, 2006; Kumar et al, 2007; in Singh and Akhtar, 2009).
Other antioxidants found in grapes can also prevent and improve diabetic neuropathy. Li et al (2008) investigated the impact of a ‘grape seed proanthocyanidin extract’ (GSPE; they do not specify which proanthocyanidins are present within the extract) on 60 rats that had been induced with STZ to give them diabetes.
The rats were divided into three groups; untreated diabetes, treated diabetes, and non-diabetic (i.e. not induced with STZ). The treated rats were given the GSPE for 24 weeks. After the experimental phase, the rats were examined for markers of diabetic neuropathy.
It was found that the rats showed many of the same features of diabetic neuropathy that human’s exhibit, and that the GSPE treatment was successful in reducing many of these symptoms. Specifically, there was up-regulation of complex I in diabetic rats, which was reduced in the rats treated with GSPE.
Complex I is a protein in the kidney which has a role in oxidation in areas of the body associated with diabetic neuropathy. What this result shows is that GSPE can reverse the up-regulation of complex 1 in areas associated with neuropathy, therefore reducing the symptoms of the disorder.
Similar results were found with other proteins. They did find, however, that some proteins associated with neuropathy were not responsive to GSPE treatment.
This suggests that they are either resistant to the antioxidants, or there is another mechanism by which these proteins cause neuropathy symptoms. Further research is required to determine the answer to this question.
4. Counteracts Negative Effects Of Ageing
Ageing is something we all have to deal with, and cannot be prevented. Alongside the aesthetic impacts of ageing (which I think we would all rather avoid), it is also associated with many health problems. These can range from mild cognitive impairments and a weakened immune response to those which severely limit quality of life and may even cause premature death, such as coronary heart disease, osteoporosis and diabetes.
The science of ageing has been more interesting to researchers over the past few years as conditions and statistics show that the population is getting older. According to the WHO (2015) the global population is rapidly ageing, and there will be double the number of people aged 65 or over by 2050.
This is a fantastic achievement for science as it shows that we are having great success with treating childhood diseases and in improving fertility control for women. It does have some negative side effects, however. Aside from the fact that the world is at risk of becoming extremely over-populated, an aging population means there is a greater strain on healthcare services due to diseases associated with the elderly.
Thankfully this strain can be significantly reduced if older members of society take responsibility for the maintenance of their own health. One very effective way to do this is to improve the diet.
Food is extremely important for health, as our bodies are composed of what we consume. The more nutritious our diet (e.g. the higher the number of vitamins and minerals and the better the balance between fats, carbohydrates and proteins) the healthier our bodies will become.
Eating a large amount of fruit and vegetables (at least 400g per day, WHO, 2015) is a very effective way of promoting physical health because fruits and vegetables contain high numbers of vitamins, minerals and antioxidants.
A study known as the Ageing and Diet Intervention Trial (ADIT) has been used to examine the impact of diet on ageing in a variety of ways. In 2009, Gibson et al recruited 83 healthy elderly volunteers aged 65 to 85 years old who normally followed a low-fruit and vegetable diet.
Half of the participants were asked to remain consuming their normal diet, whilst the other half were asked to increase their intake of fruit and vegetables to at least 5 portions a day. This lasted for 16 weeks. At the 12 week point, the volunteers were also injected with tetanus toxoid (TT) and pneumococcal capsular polysaccharide (PCP), which are vaccines against tetanus and pneumococcal infection respectively, and contain a small amount of the virus.
At the end of the experimental phase, the participants were tested on a range of immune markers to investigate the bodily response to the two injections.
What they found was that although fruit and vegetable consumption didn’t have an impact on the immune response to TT, there was a significant effect on PCP. Specifically, participants who consumed a high number of fruit and vegetables showed greater antibody activity for the PCP injection than those who consumed a low number of fruit and vegetables. Antibodies these are the compounds which bind to the antigens (e.g. the virus or bacteria) and attack it. This suggests that an increase in fruit and vegetables can improve the immune response to certain illnesses in elderly adults.
This research was supported by another ADIT study by Neville et al (2012). The same participants were again assigned to a group with low or high fruit and vegetable consumption (assignment was randomised, so the participants in each group may have been different to those in the first ADIT study). This time, the researchers were looking at whether consumption improved physical function and muscle strength, which when reduced can increase the risk of falls and injury.
It was found that after 16 weeks, the participants in the high-consumption group had a trend towards greater grip strength than those in the low-consumption group. There was no impact on physical function. The authors concluded that further research is needed into this phenomenon, although there is already a suggestion that fruit and vegetable consumption can improve muscular performance in the elderly.
One reason for the lack of firm evidence for the latter trial may be down to the types of fruit and vegetables included in the diets. Recent research suggests that some fruits are more effective than others at reducing the health impacts of ageing, and one such fruit is the grape.
Shukitt-Hale et al (2006) investigated the effect of 10% or 50% grape juice or a calorie matched placebo on cognitive and motor functioning in 344 elderly rats. The cognitive functioning was tested through the Morris water maze, and motor functioning by a battery of tests including tests of coordination, balance, muscle strength, prehensile reflex, stamina and fine-motor control.
A detailed description of the tests can be found here. Analysis of the test results revealed some very interesting results. For the cognitive parameters, grape juice at 10% led to the most positive effect; grape juice at 50% led to no significant improvements, just like the control substance. For the motor tests, however, results were as expected with 50% grape juice showing the greatest improvement, and 10% concentration leading to no difference compared with controls.
The researchers were unable to come up with an explanation for the unusual cognitive results, but it may be that there is an ideal amount of grape juice which improves cognitive performance, and anything following this may cause a decline.
In other words, there may really be ‘too much of a good thing’. It is also very important to remember that the rat brain and the human brain are very different and this may account for the unusual results. Despite these findings, however, the study does support the idea that grape juice can improve functioning in elderly individuals, and it is not the only study to do so.
Krikorian et al (2010) asked 12 elderly participants who were showing cognitive decline to consume either 100% grape juice or a placebo beverage for 12 weeks. They were then tested on a range of cognitive measures which were compared to baseline and between groups.
For verbal learning it was found that there was a significantly moderate improvement for participants who drank the grape juice compared to those who drank the placebo. Additionally, there was a trend (although non-significant) towards an improvement for verbal recall and spatial associations compared to the placebo group.
Again, there is some evidence here that grape juice can improve cognitive function in elderly individuals. One reason for the non-significant results in this study may be that it used an extremely small sample size (in fact, there were only 5 participants consuming grape juice for this study). A small sample size, therefore, may hide some of the effects of the juice.
In order to investigate the effect some more, Kriorian and others conducted more research in 2012. This time they scanned the brains of the participants and tested their cognitive functioning. They also enrolled a slightly larger sample of 21 participants, who consumed either grape fruit juice or a placebo for 16 weeks.
It was found that there was reduced semantic interference on memory tasks for participants who consumed the grape juice. This means that these participants were better able to identify previously learned material and ignore material designed to confuse them.
It was also found that the participants who consumed grape juice had greater activity in the right anterior and posterior cortical regions of the brain during the task, suggesting that these areas are associated with increased cognitive performance.
Despite some of the contradictions of the above research, most seem to suggest that adding more fruit and vegetables to your diet can help to counteract the negative effects of ageing. What’s more, fruits like grapes can lead to very specific benefits.
5. May Help Combat Migraines
A migraine is a neurological event which affects approximately 1 out of 5 women and 1 out of 15 men (NHS, 2014). Most often they are characterised by a severe throbbing headache which is generalised to one area, sensitivity to light and noise, and nausea.
There are three subtypes of migraine:
- Migraine with aura – with these sorts of migraines, there are warning signs in the form of an aura. These can occur as bright or flashing lights within the field of vision (sometimes they seem like blind spots), numbness or tingling in the hands, arms, face and mouth, dizziness and difficulty speaking. It is also possible to lose consciousness, but this is very rare.
- Migraine without aura – these types of migraines appear with no warning signs.
- Silent migraine – these are migraines where the aura is experienced, but no headache occurs. Other symptoms remain, however, and they can still be extremely debilitating.
The causes of migraines are not very clear, and tend to vary from person to person. There does seem to be a strong genetic component, however. It is thought that neuronal activity, chemicals and blood vessels in the brain are disrupted temporarily, but the reason for this is not known. Some common triggers include:
- Hormonal changes, such as a woman’s period
- Low blood sugar
- Dietary components (such as red wine, rich chocolates, cheese, caffeine and anything containing tyramine)
- Environmental triggers (such as bright or flashing lights, loud noises or changes to the climate like air pressure before a storm).
- Medicines (including HRT and some forms of the contraceptive pill).
This list is not exhaustive, and not all triggers will apply to all people.
Treatment for migraines, like symptoms, will vary from person to person but there are some basic groups. Painkillers are usually the first line of defence, and if taken early enough may be able to stave off the migraine completely.
For people who suffer from frequent and severe migraines however, they are not an ideal solution. Firstly, they may not be strong enough to tackle the pain. Secondly, taking them frequently means the patient will develop a tolerance for them. This will lead to them requiring stronger medication which may eventually become harmful, addictive or both.
Triptans are a type of medication prescribed by the GP for people who do not receive a benefit from painkillers. They attempt to reverse the migraine by narrowing the blood vessels around the brain, which are thought to dilate during a migraine.
Anti-sickness medications can sometimes be prescribed alongside triptans and painkillers, even for people who do not experience nausea and vomiting. They can help to reduce nausea in patients with that symptom, but can also speed up the effects of painkillers.
These treatments are all relatively common, but people who have very severe migraines or do not respond to treatment can visit a specialist where they may be given TMS (Transcranial Magnetic Stimulation). This treatment involves a magnetic pulse being delivered to your brain through the head, and is most effective when used at the beginning of a migraine attack.
Although NICE (2014) recently recommended the use of TMS for migraines, the evidence base is not particularly strong, and only suggests that it works for people who experience migraines with auras (NHS, 2014).
Although many of the treatments suggested above are effective, they are mostly (with the exception of triptans) helpful in preventing a migraine when an attack begins. For many people, this solution is not enough.
A migraine can occur at any time, and if it is not possible to take preventative medications they can be extremely debilitating and in some cases dangerous (imagine driving a car down a motorway when you suddenly experience an aura which disrupts your vision).
In order to reduce the likelihood of a migraine occurring, there are a few things which can be done. One solution is to work out what your triggers might be, and avoid these if possible. Keeping a migraine diary can be helpful with this. Rather than avoiding situations to avoid a migraine, however, it is possible to actively prevent them through the diet. Not only can the diet be a trigger for migraines, but it can also hold the key to preventing them.
A variety of studies have shown that missing meals can lead to a migraine, with one paper (Andress-Rothrock, King and Rothrock, 2010) reporting that over 39% of patients report this as a trigger. When we skip meals, we become dehydrated and the levels of nutrients in our bodies is significantly depleted.
Nutrients feed the brain and body, giving us energy, vitamins and minerals to allow our body to function. When we do not have enough, our body begins to suffer and migraines can occur. This suggests that ensuring we consume a high level of fruit and vegetables, which are extremely high in nutrients, can help to stave off migraine attacks.
In a review conducted by Sun-Edelstein and Mauskop (2008) they discuss the evidence for food as a supplement in migraine treatment. First of all they confirm some foods which are thought to be migraine triggers: phenylethylamine found in cocoa, tyramine found in cheeses and cured & smoked meats, aspartame which is an artificial sweetener, MSG which is a flavour enhancer, nitrates found in cured meats and fish, alcohol, particularly red wine & dark coloured alcoholic drinks, and caffeine.
They then go on to describe some of the types of food which can actually help migraines. Magnesium has been shown to be deficient during migraines, and research has found that magnesium supplements can help to prevent headaches.
CoQ10 (an enzyme found in organ meats, beef, peanuts, sardines and mackerel) can reduce migraines by 50%, and in paediatric cases is even more effective. Riboflavin (vitamin B2) can also reduce attacks by 50% and is perhaps one of the easier nutrients to find in everyday diets.
Grapes are a very good source of riboflavin, with 100g containing 4% RDA of the vitamin. 4% may not sound like very much, but 100g is a very small amount of grapes. In reality it’s more than likely you would eat double this amount.
Grapes are not only effective at preventing migraines because of their riboflavin, but they are also over 80% water. Dehydration can cause blood volume to drop, meaning the brain gets less blood than it requires. This can cause the blood vessels to dilate, which may lead to a migraine. This theory of dehydration as a cause for migraines has been supported in research.
Abu-Salameh, Plakht and Ifergane (2010) assessed migraines in practicing Muslims who must not eat or drink anything during daylight hours in the month of Ramadan. They found that, compared to a control month, migraine frequency increased threefold during Ramadan, and the migraines were longer in duration.
Two participants had to stop fasting as a direct result of their migraines. The researchers suggest that this increase happened as a result of severe dehydration during the day. In order to prevent this from happening in the future, it is suggested that Muslims drink a very large amount of water during the night-time hours, and for those with severe migraines they should consider medical intervention such as painkillers or other medicines.
Unfortunately there have not been any studies conducted on the benefits of grapes specifically for treating migraines, but they do contain components which are known to relieve migraine pain; riboflavin and dehydration. They are also included for treating migraine pain in Maheshwari et al’s (2013) review of the therapeutic benefits of grapes.
6. Fights Alzheimer’s Disease
Alzheimer’s disease is a progressive neurological condition caused by neurofibrillary tangles and amyloid plaques which build up in the brain and destroy the connections between neurons. This causes the neurons to die. It usually begins in an area of the brain called the hippocampus, which is responsible for transferring memories into and recalling memories from long-term storage.
This is why Alzheimer’s disease is characterised by memory loss. It currently affects approximately 46.8 million people worldwide (Alzheimer’s Disease International, 2015) and by 2050 it is projected that 131.5 million people will have the disease. Despite its prevalence, however, its cause is still unknown. It is an extremely debilitating condition for which there is no cure and it will eventually become fatal.
Age is the highest risk factor for Alzheimer’s with the risk doubling after the age of 65 (NHS, 2014), but there is also a genetic component. Despite these two factors being out of our control, there are ways to reduce the risk of developing the disorder. For instance, it is known that having cardiovascular disease is a risk factor for developing the condition. By ensuring you have a healthy heart, you can reduce your likelihood of getting Alzheimer’s disease.
Eating a healthy diet can also protect you against the condition. In a review conducted by Solfrizzi et al (2011), there is a small amount of strong evidence suggesting that eating a diet high in fruits and vegetables can be protective against cognitive decline, dementia and Alzheimer’s disease.
Furthermore, they recommend that eating a diet which can protect against heart disease and the consumption of fruits with a low GI. GI, or glycaemic index, refers to how much a food product raises blood sugar levels. The scale ranges from 1 (little or no effect) to 100 (pure sugar). Grapes have a GI of 9, making them an ideal candidate.
Eskelinen et al (2011) have supported this review in a study where they assessed the diet of 385 middle-aged participants. A healthy diet was assessed using a questionnaire which assigned points to unhealthy foods. Therefore, participants who scored lower points on the questionnaire in total had healthier diets. 14 years after the initial assessment, the participants were assessed for Alzheimer’s disease. It was found that participants who consumed a healthy diet were at significantly lower risk of developing dementia or Alzheimer’s disease.
There are some specific foods which are particularly beneficial for reducing the risk of Alzheimer’s disease. Resveratrol, an antioxidant found in grapes, can trigger sirtuin proteins which have been shown to be protective against cardiovascular problems, cancer, ageing, and Alzheimer’s disease. They can, for instance, protect against toxicity from amyloid plaques which destroy synapses between neurons (Anekonda, 2006).
Furthermore, wine consumption has been associated with a lower risk of Alzheimer’s disease in a study by Lindsay et al (2002). This was a 5 year long prospective cohort study, where participants were initially assessed for cognitive decline and were all declared healthy.
Reassessment 5 years later revealed that nearly 200 of the sample (4615 participants) had developed Alzheimer’s disease. The researchers then assessed conditions which may have affected the risk of developing the disease. They found that use of anti-inflammatory drugs, high levels of physical activity, consumption of coffee and consumption of wine were all protective factors.
Wine has long been thought to have some health benefits when consumed in moderation, but it is suggested that it is not the alcohol which has the effect. Tredici et al (1999) support the idea that it is other components of wine which are protective, and that resveratrol is particularly effective.
This has been supported by Joseph, Shukitt-Hale and Willis (2009) who claim that grape juice can improve memory performance in both animal models and human trials. The studies they reviewed were conducted on participants who had shown cognitive decline but not Alzheimer’s disease, suggesting that grapes may be able to prevent or delay the onset of the condition.
Some Things You Should be Aware of
As with all healthy foods, although there are many benefits there are also some things to be cautious of. Although there does not appear to be any risk factors associated with eating fresh grapes, dried grapes (in the form of raisins) can be dangerous when eaten in large amounts.
This is because when fruit is dried it becomes much smaller. Therefore, consumption is more likely to be high because they do not fill you up as well as grapes would. As all fruit contains sugar, it is important to be cautious when eating them in dried forms, because it is quite easy to consume a lot more sugar than you realise.
An even more likely risk from adding grapes to your diet is if it is done in the form of red wine. Although there is a lot of research suggesting that red wine has many health benefits, this is only when consumed in moderate amounts (i.e. no more than 2 units a day according to the BBC).
Furthermore, these health benefits only tend to make a significant difference to people at greater risk for the development of health conditions. In other words, younger people will not reap the benefits from red wine consumption, but they may well suffer the damage associated with alcohol consumption.