Can you really prevent Parkinson’s?
We take a look at the science behind claims that with diet and lifestyle changes you can prevent this incurable condition.
Parkinson’s is a degenerative condition that affects around 1 in 37 of us in our lifetime. Despite first being described over 100 years ago, today we have no cure and no preventative medicine. So why then if you search for Parkinson’s risk, can you find articles about how you can prevent the condition? Is there any science behind these claims, and if it’s so easy, why do over 7 million people have Parkinson’s worldwide?
Quick summary if you’re in a rush:
- Environmental factors that increase risk include exposure to pesticides and certain chemicals. Substances like caffeine and nicotine may decrease risk.
- Eating more vegetables, cooked in any way you fancy, is probably more beneficial than worrying about if they are organic, fresh and raw.
- The evidence behind taking vitamins and other supplements to prevent Parkinson’s is incomplete, although there is some interesting research into certain supplements like vitamin D.
- Claims that avoiding sugar, being on a specific diet, or getting more exercise can prevent Parkinson’s are too simplistic as these factors only reduce risk marginally, if at all. Many people living even the healthiest lifestyles develop Parkinson’s — the condition affects people indiscriminately.
Risk and Parkinson’s
There are many different lifestyle and environmental factors, as well as an ever-increasing list of genetic factors, that both increase and decrease the risk of getting Parkinson’s.
You may be more familiar with risk factors for diseases like cancer. For example, we know that smoking significantly increases the risk of a number cancers, and fatty foods can cause major problems for our heart health.
In Parkinson’s, one of the biggest risk factors is a family history of the condition, which could increase your risk by around 4 fold. But as both family and genetics are rather hard to change, in this blog we will consider the lifestyle and environmental risk factors that we have a little more control over.
Lifestyle and environmental risk factors
In Parkinson’s, most of the environmental and lifestyle factors that increase risk do so by less than 2 fold (as a comparison smoking increases risk of lung cancer by around 7 fold).
These risks include exposure to:
- pesticides, herbicides and fungicides,
- certain chemicals, such as trichloroethylene, used in cleaning solvents,
- and heavy metals including mercury,
You can read more about these risk factors by clicking on the links above, which will take you to some of our other blogs and news stories.
Calculating the risk
Scientists can work out the risk of these certain lifestyle or environmental factors by comparing the number of people diagnosed after being exposed to a risk factor with those with no or less exposure — we call these epidemiological studies.
But this style of study doesn’t take into account individual differences, or consider how susceptible individuals may be to certain types of risk factor — it just gives an average for the whole group. So these studies do not explain why some people can be exposed to risk factors at relatively high levels and never go on to develop Parkinson’s.
With the advent of genetic testing and the growth of computing power, we are now seeing that individual genetic differences can have a huge effect on the size of impact different risk factors have. We also believe that timing in the exposure to different factors may be important.
But when you consider that many different factors may play a role in both increasing and decreasing risk — and that the first symptoms of Parkinson’s may appear many years after changes start to happen in the brain — it’s likely we’ll never know exactly which risk factors are responsible for the onset Parkinson’s in most individuals.
Decreasing the risk of Parkinson’s
So now we’ve covered lifestyle and environmental factors that increase risk, let’s take a look at factors that have been suggested to reduce the risk of Parkinson’s.
It may sound strange, but substances in cigarettes and alcohol may actually have protective properties in Parkinson’s — although the effects are not sufficient to outweigh the negative health consequences that are part and parcel. You can read more about this in this blog:
Can Parkinson's risk be reduced?
What do nicotine, high cholesterol and caffeine have in common?
The answer, they may all reduce the risk of Parkinson’s…
Other factors people say can prevent Parkinson’s aren’t necessarily bad for your health, but are there any truth in the claims? We’ve rounded up some of the things that we hear time and time again, and investigated the science behind the claims.
1. Drink more green tea
This form of caffeinated beverage appears more often than drinks like black tea or coffee in lists of things that prevent Parkinson’s. This could be due to the healthy reputation that green tea has, as it contains “good” things like polyphenols, which purportedly reduce inflammation, and antioxidants, which play a detoxifying role inside cells. However, these substances are also present in ample quantities in coffee and black tea.
In fact, it’s the caffeine content of your hot drinks that researchers are probably more interested in. Some studies have suggested that people who consume more of this stimulant have a lower risk of Parkinson’s, and it may also have beneficial effects on some symptoms.
But, as caffeine is a widely consumed substance, we can probably assume that, even at very high doses, it cannot completely prevent people from ever developing Parkinson’s. So maybe there’s something else in green tea? Maybe something like EGCG, a substance known as a catechin that’s found in green tea but not in coffee.
Catechins are effective antioxidants, but research suggests that theaflavins, found in black tea, are equally as effective.
Studies looking at the neuroprotective properties of catechins highlighted their potential to target problematic proteins that build up in Parkinson’s. But despite this promising finding, one study of over 63,000 Chinese men and women found that black tea but not green tea reduced Parkinson’s risk.
Summary: More evidence from larger clinical trials is still needed to further understand the relationship between caffeine and Parkinson’s risk before recommending people increase their caffeine intake. But when it comes to what type of caffeinated beverage you choose, don’t be swayed by sites saying green tea is that much better — matcha isn’t going to prevent Parkinson’s.
2. Go gluten-free
A number of diets claim to help with Parkinson’s. But when it comes to preventing Parkinson’s, there’s little-to-no evidence that following most specific diets — such as gluten-free, ketogenic or calorie restriction diets — can reduce Parkinson’s risk.
Epidemiological studies have found that a high intake of fruits, vegetables, and fish was linked to a lower Parkinson’s risk. Of all the diets, a Mediterranean diet, high in vegetables, fruits, legumes, nuts, beans, cereals, grains, fish, and unsaturated fats such as olive oil, with a low intake of meat and dairy foods, is most associated with lower Parkinson’s risk.
Summary: Getting the right nutrition is vital but it’s also individual and will depend on a range of factors, including your weight, activity levels, any other health issues you have, and the medications you take. So it’s really important to speak to your doctor or nurse before making any significant changes to your diet.
3. Take probiotic supplements
Probiotics are an area of active research for Parkinson’s — the latest findings suggest that, for some, Parkinson’s may start in the gut and travel up the vagus nerve to the brain.
Recent studies have shown that the microbes that live in our guts, called the gut microbiota, can be altered in people with Parkinson’s. While most of the research into probiotics is focused on their use for treating Parkinson’s, including this clinical trial of an oral probiotic that is being funded by Parkinson’s UK, speculation is mounting than maintaining a healthy gut may also have a role in preventing Parkinson’s.
Certain diets, including high fibre diets, have been linked to potential gut related benefits, such as the promotion of potentially beneficial bacteria by a Mediterranean diet, or the inhibition of pathogenic bacteria such as E.coli in vegetarians. But not all diets may be beneficial — some can actually increase E.coli levels, and lower the levels of potentially beneficial bacteria.
There’s still much to learn about which microbes are good and which are bad, and more research is needed to fully understand if Parkinson’s can be prevented by altering gut microbiota.
Summary: Scientists are only just starting to learn about how the gut may be linked to Parkinson’s. We don’t yet know if it is possible to use probiotics to alter risk.
4. Avoid sugar
Sugar is on the list of things you might be told to avoid if you are looking to prevent Parkinson’s. This claim probably stems from research highlighting that people who are diabetic may be more likely to be diagnosed with Parkinson’s at some point in their lifetime (although again this is a very small increase in risk).
When we eat sugar, the level of glucose in our blood increases. Normally our bodies are fairly good at getting blood sugar levels under control. But if there are problems, brain cells can be exposed directly to high levels of glucose with no way to protect themselves. Exposing brain cells to higher than normal glucose levels may damage them and could start the changes that lead to the onset of Parkinson’s.
Further evidence on the link between diabetes and Parkinson’s comes from the fact that type 2 diabetes drugs, like exenatide, may help protect brain cells and have even entered clinical trials for Parkinson’s as a repurposed medication.
Exenatide works by targeting glucagon-like peptide-1 (GLP-1) receptors in the pancreas, which causes insulin to be released. GLP-1 receptors are also found in the brain. Lab-based experiments have suggested that activating GLP-1 receptors can boost dopamine-producing brain cells, have anti-inflammatory properties, improve energy production, and can switch on cell survival signals.
Summary: While we know that diabetes is linked to Parkinson’s, there’s little evidence that avoiding sugar completely would prevent the condition. Again a healthy and varied diet is probably the best way forward.
5. Take part in regular ‘cardio’ exercise
Aerobic exercise includes activities like brisk walking, swimming, running, or cycling and is often referred to as ‘cardio’ as it gets your heart rate going and increases cardiovascular fitness.
We know that, during aerobic exercise, the brain receives a greater supply of blood because the heart is beating faster — and this means more oxygen and nutrients to keep the tissue healthy and functioning well. Vigorous exercise can also stimulate the body to make molecules called growth factors — such as BDNF, which could help improve memory and thinking, and GDNF, which helps in healing and supports the development of brain cells.
Research in animal models of Parkinson’s shows that vigorous exercise seems to protect dopamine-producing brain cells, helping them work better and survive for longer. This could potentially slow down the progression of the condition — something no current treatment can do. But when it comes to preventing the condition, though some research has suggested that regular aerobic exercise might reduce the risk of Parkinson’s, more evidence is needed.
Summary: Exercise is certainly worthwhile for both people with and without Parkinson’s. If you want to know more about exercise when you have Parkinson’s, visit our website:
6. Go organic
We have already found out that certain pesticides and herbicides have been heavily implicated in causing Parkinson’s. However, the chemicals that are most associated, such as paraquat and organochlorines, are rarely used or are in fact banned outright.
In general, chemicals used in the growing of food today are much safer and there is limited data linking them to Parkinson’s. It’ also worth noting that organic foods are not necessarily chemical-free, although the use of chemical pesticides as well as synthetic fertilisers, antibiotics, and other substances are heavily restricted on organic farms.
Summary: There is a lack of evidence that suggests sticking to a solely organic diet can reduce the risk of Parkinson’s, or help those who already have the condition. Parkinson’s UK advises simply to eat a varied and healthy diet with five portions of fruit or vegetables a day.
7. Eat fresh, raw vegetables
Another claim is that eating fresh, raw vegetables can prevent Parkinson’s. This claim appears to based on the belief that the fresher the produce, the more vitamins it contains. Similarly, raw vegetables are reported to contain more vitamins, which may be lost in cooking.
So firstly, is it true that fresh and or raw vegetables contain more vitamins? And which vitamins are important?
Typically, the nutrient content of frozen vegetables is just as good, if not better than fresh vegetables. This is often because fresh vegetables are transported many miles, impacting on the quality and nutritional content by the time they reach you. Although, the process of preparing vegetables for freezing involves briefly cooking them (blanching), which may reduce the content of water-soluble vitamins such as vitamin B and C.
Cooking vegetables, in general, does alter their nutritional composition. Several studies have shown that while cooking can degrade some nutrients, it can enhance the availability of others such as fat-soluble compounds like vitamins A, D, E and K and antioxidants.
So if vitamins B and C may be lost during cooking and freezing, are they important for Parkinson’s? The answer is possibly…
There are two types of vitamin B that pop up in the research literature most often — B1 and B3 — but vitamin C has less evidence as to its value in preventing or helping treat Parkinson’s.
Vitamin B1, or thiamine, is found in many types of food. And as thiamine can’t be stored in the body, you need it in your diet every day. In Parkinson’s, thiamine supplements have been reported to help, but the studies have been very small scale (involving just 3 people).
Vitamin B3, also known as niacin, helps release energy from the foods we eat and keep the nervous system and skin healthy. Our cells convert vitamin B3 into NAD+, a chemical that’s vital in a range of processes inside cells. Studies have shown that levels of NAD+ decrease as we age, and are further reduced in people with Parkinson’s. And research has also shown that people who eat more foods containing niacin may have a slightly lower risk of developing the condition.
Summary: No one cooking method will conserve all different nutrients, although frying probably comes out worse, so why not try preparing vegetables in different ways by eating them raw, boiled, steamed or any other way you fancy. And with the minimal difference in the vitamin B content of vegetables that have been frozen compared with fresh, simply eating more vegetables would probably have a more beneficial effect. If you are considering supplements, always talk to a professional first as too much of some supplements can be dangerous.
8. Take omega-3 supplements
Some people claim that omega-3, a type of fatty acid important for the growth and development of brain cells, can help prevent Parkinson’s. Omega-3 is made in our bodies, but very slowly, so we mostly get it from our diet. Oily fish, such as mackerel, tuna, herring, and salmon, have high levels of omega-3.
In Parkinson’s, it’s not clear whether people have reduced levels of omega-3 inside the brain as lab studies have produced conflicting results. And currently, evidence of its protective effects to prevent Parkinson’s comes from animal studies with a lack of human-based research.
Looking at fatty acids more generally, saturated fats (the type in cheese, fatty meat and coconut oil) have borne the brunt of negative press in recent years — headlines have claimed they increase cholesterol and cause heart attacks. However, more recent research suggests that the reality is more complex than that and that saturated fats increase both the good cholesterol (HDL) as well as bad cholesterol (LDL).
Human studies have suggested a protective role of unsaturated fatty acids in Parkinson’s (the type in nuts, avocados, as well as fish), while saturated fatty acids were associated with increased risk of developing the condition. Researchers have also investigated the effect of statins on Parkinson’s risk. Although different studies have produced differing results over the last decade, the consensus is that statins may reduce Parkinson’s risk.
Summary: Overall, there is still much we don’t know about fatty acids, including omega-3. And with many questions on the role of cholesterol in Parkinson’s still left unanswered, making sure you include oily fish as part of a healthy, balanced diet is probably the best advice. If you are considering omega-3 supplements, always talk to a healthcare professional first as too much of some supplements can be dangerous.
9. Take vitamin D
Vitamin D helps regulate the amount of calcium and phosphate in the body. These nutrients are needed to keep bones, teeth and muscles healthy. The body makes vitamin D when the skin is exposed to direct sunlight, but there are small amounts present in certain foods.
A 2016 paper found that higher vitamin D levels are linked to a lower risk of Parkinson’s and that people with the condition tend to have lower vitamin D levels.
For those who already have the condition, studies have indicated that people with Parkinson’s who have higher vitamin D levels tend to have better mobility. And research in rats and mice indicates that vitamin D may have protective properties. In addition, studies of vitamin D supplements have shown some positive but variable effects on Parkinson’s symptoms.
Summary: While it is unlikely that vitamin D can completely prevent Parkinson’s, there does seem to be growing evidence that this vitamin plays a role in protecting brain cells and may be beneficial for some who have already developed the condition.
If you are considering supplements, always talk to a healthcare professional first as too much of some supplements can be dangerous. If you are interested in other supplements and Parkinson’s, we have another blog on the topic: