Categories
Prostate Health

Prostate Cancer and Diet & Lifestyle

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What is the prostateProstate cancer at a glance
ProteinInsulin
Dietary FatPhytochemicals
Minerals & VitaminsMeal Preparation
Heart Health & Exercise

Prostatic concerns and cancer have been well documented and observed over the centuries, earlier than one may initially think.

A plethora of medical treatments and surgeries to combat the disease have been researched, executed and pioneered over the years, however it’s been proven that one’s lifestyle, habits and diet can influence ones risk of developing prostate cancer as well as it’s progression in diagnosed patients. The main concern of most cancer survivors may simply be to lead a cancer-free life after the fact; however adopting a healthy diet and regular exercise are integral steps towards attempting to prevent other diseases that commonly occur with ageing.

What is the prostate…

The following article may help to shed light on an important topic that is still undergoing studies and trials. It may serve to inform readers affected by prostate cancer, of nutritional and lifestyle choices that could be potentially beneficial. Before diving in, it is important to have an idea of what the prostate is and its function.

The prostate is an organ that forms a part of the male reproductive system. It is located directly below the bladder, just above the muscles of the pelvic floor and directly in front of one’s rectum.

Due to its proximity to the rectum, doctors are able to examine/palpate the gland directly via ones rectum.

The diagram on the right depicts the prostate (Highlighted in red) being manually examined or palpated.

Upon examination a healthy prostate gland can be said to have a smooth, elastic feel to the touch. This is due to the fact that the prostate is surrounded by a capsule, which is made up of; connective tissue, elastic connective tissue and many smooth muscle fibres.

The prostate is generally found to weigh approximately 15-20 grams and to be the size of a walnut. Generally, ones prostate will measure between 3 and 4cm at it’s widest portion, between 4-6 cm in length, and between 2-3cm in thickness. (Tanagho & McAninch, 378)

The prostate encompasses the urethra which is the conduit between the bladder and the tip of the penis, through which urine and semen flows. Ducts from the prostate gland flow directly into the urethra.

The most important function of the prostate is to produce some of the components of seminal fluid. This fluid helps to nourish and transport sperm cells. During ejaculation, the muscles of the prostate contract and ensure that semen is forced into the urethra and expelled outwards.

The prostate is made up of three different “zones”, that form the entirety of the gland. Expand the sections below to see more on each zone…

Transition Zone

The smallest portion of the gland, the transition zone is at the centre of the organ and surrounds the urethra.


This zone tends to undergo benign (Noncancerous) growth in men of old age. This is medically referred to as Benign Prostatatic Hyperplasia (BPH). This tissue growth can result in the gland pressing up against the urethra or the bladder; often leading to difficulties with passing urine. 

Central Zone

This surrounds the transition zone and makes up about one quarter of the prostate’s mass.

Peripheral Zone

This surrounds the central zone and accounts for about 70% of the gland’s total tissue mass.


Where malignant (cancerous) growths normally occur.

Prostate Cancer at a Glance…

Prostate cancer is one of the most common types of cancer found in men. Ultimately prostate cancer is the result of changes in the DNA of “normal” prostate cells. 

Each and every cell in the human body contains groups of genes responsible for cellular functions. In regards to cancer, the two main groups of genes found within cells responsible for cellular division and apoptosis (programmed cell death) are called, Proto-Oncogenes & Tumour Suppressor genes.

When a mutation occurs within the Proto-Oncogenes of a cell, they then become what is known as Oncogenes. Lacking the required DNA to carry out the necessary cellular functions, oncogenes are responsible for abnormal, rapid cell division.

Tumour Suppressor genes are also responsible for functions that slow down cell division and regulate apoptosis (programmed cell death), but in addition they aid in the repair of possible DNA errors. An outcome of tumour suppressor gene mutation, is uncontrollable cellular growth. This in turn can lead to cancer. 

Protein

Proteins are a macronutrients comprised of amino acids.
Aside from providing the body with a source of fuel, the amino acids aid vital functions within the human body such as the growth and repair of muscle and bone, and the production of hormones and enzymes. 

Various studies and trials have ascertained a link between high intakes of certain sources of protein and an increased risk of developing cancer. Specifically animal (pork, beef and lamb) and dairy based sources of protein. 

This is not insinuating that protein needs to be eliminated from ones diet all together, in order to lower the risk of developing prostate cancer or its progression. Simply, one should ascertain how much protein their body needs and what the appropriate sources are for them as an individual.

An inverse relationship between protein consumption and age has been observed in men suffering from or predisposed to prostate cancer. Men 65 years and younger, who adhere to a low protein intake have a lower risk of cancer and overall mortality. Whereas, men 65 years and older, who have a low protein intake have a higher risk of cancer and overall mortality.

Animal Protein

For the sake of this article, animal protein refers specifically to meat products derived from animals and not their byproducts.

Various studies have found a link between red meat and an increased risk of developing prostate cancer and/or encouraging its growth. It has been observed that men who consume the highest quantities of red meat, are at least 2 times more at risk of developing prostate cancer when compared to men with the lowest intakes of red meat.

Research has shown that the carcinogenic properties of meat most likely stem from industry practices and the methods used to prepare food.

Industry Practice & Methods

Pesticide treated feed and supplements/hormones given to livestock can leave traces of residue in the meat that is intended for consumption.

Although healthier options aren’t always readily available nor the most affordable, it is recommended that when purchasing meat, opt for the following meat products where possible:

  • Organic
  • Grass-fed
  • Free range

Whether or not animal meat is processed after slaughter plays a vital role in the end products nutritional value. Processed meat can refer to a wide variety of products such as cured deli meats, sausages and bacon.
Studies have identified a link between regular consumption of processed meat products and an increased risk of chronic illness and disease.

A reason for this association may be due to the fact that, often processed meat products contain established N-nitroso compounds, nitrates, nitrites and added salt. All of which have properties linked to the promotion of cancer.

Meal Preparation

The way we choose to prepare our food can greatly impact the finished meal. Different cooking methods can imbue our foods with beneficial or harmful properties; cooking any animal meat at high temperatures, especially for extended periods releases carcinogenic compounds.

At approximately 100°C, Heterocyclic Amines (HCA’s) begin to form; this process accelerates significantly from 300°C and above. From temperatures 200°C and higher, Polycyclic Aromatic Hydrocarbons (PAH’s) begin to form; PAH’s are known to be cancer causing compounds.

Pre-clinical studies have found that HCA’s play a role in the increased occurrence of tumours in the following sites:
Prostate, lung, mammory, colon, oesophagus, stomach and pancreas.

Avoid fried foods and foods cooking at high temperatures for long periods of time; instead, opt for cooking methods such as steaming, boiling and roasting.

Plant Protein

Plant protein refers to the nutritional protein content found in plant sources.

It has been established that men with a greater over-all consumption of plant based foods, have a lower risk of developing prostate cancer and significantly more so for developing aggressive/fatal prostate cancer.

Sources of plant based protein:

  • Soybeans
  • Soybean derivatives: tofu, tempeh & edamame beans
  • Spelt & teff (ancient grains)
  • Hemp seeds
  • Quinoa
  • Chia seeds
  • Nuts & nut butters
  • Lentils
  • Beans
  • Nutritional yeast
  • Spirulina
  • Green peas
  • Oats
  • Wild rice
  • Seeds

A diet rich in cruciferous vegetables has also proven to be beneficial. Cruciferous vegetables are low-calorie and rich in folate, vitamins E, C & K and fibre.

Cruciferous vegetables contain anti-carcinogenic phytochemical compounds called sulforaphane and indole-3 carbinol.

Examples of cruciferous vegetables:

  • Broccoli
  • Bok choy
  • Brussel sprouts
  • Cabbage
  • Kale
  • Arugula
  • Cauliflower
  • Collard greens

Insulin

Insulin is naturally produced by the pancreas, which is a gland located in the abdomen, just behind the stomach. Two of insulin’s important functions are, to convert glucose into a readily available source of energy for the body and to store converted glucose as energy reserves in cells, fat, muscles and the liver.

It is a well known medical fact that cancer and sugar (glucose) go hand in hand; sugar facilitates the growth and proliferation of cancer cells. A physiologist by the name of Otto Warburg, established that tumour cells extract glucose from the body at a rate that is 20 to 50 times higher than that of normal cells.

According to scientist Lew Cantley, Ph.D., prostate cancer is no exception to this rule; however, results of their studies suggest that prostate cancer relies more on the amount of insulin present in the bloodstream.

It has been observed that individuals with prostate cancer, have elevated levels of Insulin-like Growth Factor and its receptors.

What is insulin-like growth factor 1? Insulin-like Growth Factor 1 or IGF-1 is a polypeptide hormone, that shares a structure similar to that of insulin. In conjunction with human Growth Hormone (GH), IGF-1 promotes anabolic (re: Anabolism – the building of tissues and organs) processes thus promoting tissue growth and development. Levels of IGF-1 and GH are much higher in children and adolescents, as they are still growing. As we begin to stop growing and continue to age, these levels drop and so do their subsequent signalling throughout our bodies; however, various conditions can cause IGF-1 and GH levels to increase.

Individuals diagnosed with the following: obesity (morbid or not), metabolic syndrome, and cancer, have detectably higher levels of IGF-1 and its receptors, present in their bodies.

As a prostate cancer patient, consult with your urologist/oncological team as how best to naturally reduce levels of IGF-1. Common suggestions include consistent low intensity exercise, caloric restriction or intermittent fasting.

Dietary Fat

There are four major groupings of dietary fat, and they are as follows: Saturated fats, transfats, monounsaturated fats and polyunsaturated fats.

Consistent evidence, proves time and time again that replacing saturated fat with unsaturated fat has significant health benefits.

Bad fats

  • Saturated fats
  • Transfats

Good/better fats

  • Polyunsaturated fats
  • Monounsaturated fats

Over the years, numerous studies have taken place to try and assess the impact of dietary fat intake on cancer patients/survivors, specifically more so prostate cancer patients/survivors. Earlier studies yielded mixed results, with no conclusive answers; however, this changed once Medical Professor, E. Giovannucci and his colleagues published their findings in 1993, from their prospective analysis of dietary fat on prostate cancer risk.

Using a semi-quantitive food frequency questionnaire to assess dietary fat intake of men, Giovannucci and his colleagues were able to determine that fat consumption as a whole was associated with advanced cancer risk. This paved the way for further research, since 1993 it has been established that animal fat and saturated fat poses the most threat to prostate cancer patients/survivors.

Interestingly enough, results from following studies and research were able to establish that dietary fat intake and circulating levels of IGF-1 in the body were positively associated. Ergo, as dietary fat intake increases so does the amount of IGF-1.

As of late, medical science is still trying to decipher the intricacies of all cancers. Research is still underway; for now, evidence points towards all stages of prostate cancer patient/survivor benefitting from a low intake of dietary fats. As a prostate cancer patient/survivor endeavour to limit saturated fats and trans fats in your diet.

Omega-3 Fatty Acid

Omega-3 fatty acids fall under the category of unsaturated fats. We obtain Omega-3 from sources such as fatty fish (Salmon for example), nuts and seeds, and plant oils.

Omega-3 is a beneficial dietary fat for heart health; additionally, it has been proven that consistent intake of Omega-3 fatty acids has been linked to a lower risk of aggressive/fatal prostate cancer and/or it’s recurrence. It is recommended that men consume omega-3 rich fish sources several times a week. Be sure to keep preparation methods in mind

Omega-3 supplementation is also an option for those who find fish to be unpalatable. Moderation is key, however; the recommended daily intake of Omega-3 is 250-500mg/day.

Dietary sources of Omega-3:

  • Salmon
  • Mackerel
  • Herring
  • Tuna
  • Sardines
  • Certain fortified foods
  • Flaxseed
  • Chia seeds
  • Walnuts
  • Soybean oil
  • Canola oil
  • Flaxseed oil

Phytochemical

Plants produce compounds called phytochemicals. (“phyto-” is derived from the greek word, “phytón”, which means “plant”)
Phytochemicals are found in; fruits, vegetables, grains, beans and other plants.

Certain phytochemical’s are believed to help protect our cells from cancer causing damage. The following information identifies which phytochemicals are believed to be beneficial and why.

Isoflavones

Isoflavones belong to a group of polyphenolic plant compounds that make up the Flavonoid family.

Isoflavones are considered to be phytoestrogens, the reason for this is due to the fact that it has both oestrogen-agonist and oestrogen-antagonist properties (For more information on this, follow this link).

The three main isoflavones are: daidzin, genistein and glycitein; of the three, genistein is the most prolific and plays the biggest role in prostate health. Genistein has an effect on various aspects of growth and proliferation mechanisms of prostate cancer cells, this includes epidermal growth factor (EGF) and IGF-1 metabolic pathways. In simple terms, genistein has been found to play a role in the inhibition of prostate cancer cell growth and metastasis.

The richest source of isoflavones are soybeans and it’s derivatives. Studies have linked the intake of non fermented soy products to a decreased risk of developing prostate cancer.

It is recommended that men include about two servings of soy based foods per day.

Dietary sources of isoflavones:

  • Soybeans (main source)
  • Mung beans
  • Black beans
  • Lentils
  • Lima beans
  • Peas

Sulforaphane & Indole-3 Carbinol

Sulforaphane and Indole-3 Carbinols are phytochemicals with known anti-carcinogenic properties.

Together, these nutrients induce the production of enzymes with antioxidant properties, which aids in protecting cells from oxidative stress and damage.

Apoptosis of damaged/cancerous cells is induced by sulforaphane; and animal studies have shown that indole-3 carbinol possess properties that help prevent the proliferation and metastasis of cancers.

Quercetin

Quercetin is another polyphenolic plant compound from the Flavonoid family.

Results regarding the efficacy of quercetin in prostate cancer and it’s risk are still unclear; however, quercetin compounds interest doctors due to their anti-inflammatory properties which have yielded some positive results for prostate cancer patients/survivors and those diagnosed with BPH.

Dietary sources of quercetin:

  • Citrus fruits
  • Apples
  • Onions
  • Parsley
  • Sage
  • Tea
  • Olive oil
  • Grapes
  • Dark cherries
  • Blueberries
  • Blackberries

Lycopenes

Lycopenes are considered to be a main dietary antioxidant. They are a part of the Carotenoid family. Carotenoids are a group of pigments found in plants.

Lycopene is responsible for the pigmentation of various red fruits and vegetables. As a powerful antioxidant, lycopene is attributed with the ability to protect our cells from damage.

Studies that focused on the impact of consistent dietary/supplemental lycopene intake in men diagnosed with prostate cancer, yielded favourable results. A decrease in risk and growth of prostate cancer cells, additionally they found that there was a reduction in PSA levels.

Lycopene has the ability to act on various pathways within the body, which contributes to its anti carcinogenic properties. Most notably are their ability to induce and initiate apoptosis. Be sure to include dietary/supplemental sources of lycopene in your diet.

Dietary sources of lycopene:

  • Tomato
  • Watermelon
  • Pink grapefruit
  • Pink guava
  • Papaya
  • Dried apricots
  • Pureed rosehip

Minerals & Vitamins

Minerals are naturally occurring elements found on Earth, and in food and water. Certain minerals aid our body’s development and help the body function.

Zinc

Zinc (Zn) is a naturally occurring mineral humans require for various functions within the body.

Due to the fact that humans do not produce or store zinc, it is considered to be an essential nutrient. Zinc is naturally found in a wide array of dietary sources which is why supplementation if often unnecessary. The recommended daily intake of zinc for adult men is only 11mg/day.

Zinc toxicity is often found in individuals who exceed recommended intake amounts. In order to avoid overconsumption, steer clear of high-dose supplements.

Studies have yet to yield definitive results regarding the role that zinc plays in prostate cancer patients/survivors. Evidence has suggested that zinc plays an important role in maintaining healthy prostate cell function.

Dietary sources of zinc:

  • Mushrooms
  • Spinach
  • Chicken
  • Oysters
  • Crab and lobster
  • Cocoa powder
  • Grass-fed beef
  • Kefir or yoghurt
  • Cashews
  • Oatmeal
  • Eggs
  • Tofu
  • Chickpeas
  • Pumpkin seeds

Selenium

Selenium (Se) is a mineral that the human body requires in very small amounts. Selenium plays roles in many bodily functions such as reproduction and the immune system.

Selenium is an essential trace element found in food sources, soil and water. Selenium has been attributed with many health benefits due to the role it plays in various bodily functions. One of the purported benefits of selenium is its cancer fighting properties; this is due to the antioxidant properties of selenium and the effect it has on the immune system, DNA repair, apoptosis, the endocrine system.

Various studies have sought to ascertain a definitive answer as to whether or not selenium reduces all risks regarding prostate cancer development, growth, proliferation and recurrence; unfortunately medical science has yet to yield conclusive answers as to whether or not selenium is beneficial for prostate cancer patients/survivors. For now, doctors advise that patients meet their selenium intake requirements but should not consider it to be a preventative/curative cancer therapy.

Calcium

Calcium is an element that is essential to humans and most living beings; of which our body’s require rather large quantities.

Our body’s require calcium for a host of different functions, the most notable being;

  • The development of strong healthy bones
  • Basic blood vessel, muscle and nerve functions
  • Sending signals from one cell to another
  • Releasing hormones

Adults between the ages of 19 and 64 generally require 700mg of calcium a day, many make the mistake of exceeding this amount thinking it’s beneficial to their health.

Although our bodies require large quantities of calcium, studies have shown that excess calcium intake can increase ones risk of proliferating and/or developing aggressive or even fatal prostate cancer. Studies linked high in-takes of calcium and dairy products to an increased risk of aggressive prostate cancer. Consistently exceeding ones daily intake requirement for calcium can result in the eventual formation of calcium oxalate kidney stones and in rare cases, calcium toxicity.

Unless your health care practitioner advises that you increase calcium intake by means of supplementation; it is advised that you meet your daily calcium intake requirements by eating a balanced, varied healthy diet.

Dietary sources of calcium:

  • Dairy products
  • Kale
  • Okra
  • Broccoli
  • Almonds
  • Beans & lentils
  • Whey protein
  • Fortified soya drinks
  • Fish containing bone (eg. Sardines)
  • Breads made with fortified flour
  • Fortified juices
  • Rhubarb
Age (years)Calcium (mg/day)
17-491000
50-701200
70+1200
Calcium requirements – Sources: Surgeon General’s Report on Bone Health and Osteoporosis and National Academy of Sciences.

Vitamin D

Vitamin D is a fat-soluble vitamin, produced naturally by the body as a response to sun exposure. Amongst many other biological effects, vitamin D is responsible for increasing intestinal absorption of calcium, magnesium and phosphate. In addition, it plays a role in the development of healthy bones and teeth.

Vitamin D is broken down in the human body to form a compound called calcitriol. Calcitriol is the active form of Vitamin D3 .

A study from 2009 showed a link between sun exposure and prostate cancer. The men with the least amount of sun exposure, almost invariably had more severe or aggressive prostate cancer when compared to men with higher amounts of sun exposure.

Another study from 2017 observed that men with the lowest levels of vitamin D had more aggressive prostate cancer as well as higher levels of inflammation than that of men with higher levels of vitamin D. Although supplementation won’t change the outcome of a cancer diagnosis; the anti-inflammatory properties of vitamin D suggest that it may prevent or slow down the growth of prostate cancer.

Sources of Vitamin D
  • Sun Exposure: it is recommended that 5-30 minutes of exposure during the brightest time of day is ideal. Over-exposure results in skin damage and can possibly lead to the development of skin cancer. Remember to always wear sun block.
  • Fortified dairy products
  • Fortified cereals
  • Lean meats
  • Nuts and seeds
Age (years)Vitamin D (mcg/day)
19-495
50-7010
70+15
Vitamin D requirements – Sources: Surgeon General’s Report on Bone Health and Osteoporosis and National Academy of Sciences.

Heart Health & Exercise

Heart health should be paramount for any individual concerned with living a healthy life. The number one cause of death in men is cardiovascular disease (CVD), which is responsible for more fatalities than any other cancer. Ones chances of surviving cancer, specifically prostate cancer, are significantly increased if patients make a conscientious effort to improve or maintain good heart health.

Factors to consider when keeping heart health a priority:

  • Monitor blood pressure
  • Monitor cholesterol
  • Low intensity/resistance weight lifting
  • Diverse intake of fruit and vegetables
  • Monitor or reduce sodium intake
  • Managing stress levels
  • Maintaining a healthy weight
  • Exercise and increased movement
  • Consume more fibre
  • Adopt healthy cooking methods
  • Monitor or reduce alcohol intake
  • Quit smoking!

Maintain a healthy weight

A healthy heart is not only determined by ones waist circumference, many other factors will come into play; however, we cannot escape the fact that being overweight (for reasons unrelated to a medical condition) is intrinsically linked to leading an unhealthy and/or sedentary lifestyle.

In the context of developing cancer, maintaining a healthy weight and lifestyle is your best preventative measure. The same can be said for those fighting cancer; this does not to imply that a healthy lifestyle and weight will cure a cancer diagnosis, however it does give your body the best fighting chance during and after treatment.

Overweight men are more prone to prostate cancer and other life threatening diseases. Subcutaneous (just below the skin) fat is less worrisome than visceral (internal) fat; subcutaneous fat is also easier to lose in comparison. Losing weight will incur many benefits, ranging from lower blood pressure to improved mood.

Categories
Renal Health

Guide to Kidney Stone Disease & Diet

At the helm of non-pharmacological preventative therapies for kidney stones; also known as renal calculi, nephrolithiasis, or urolothiasis (Mayoclinic.com, Kidney stones – Symptoms and causes, 2021), are dietary and lifestyle changes, as well as vitamin supplementation. 

Kidney stones can be defined as hardened masses that consist of crystallised minerals and salts, generated by concentrated urine. Stones too large to pass through the urinary system require medical treatment or intervention. Kidney stone disease is a common finding in today’s society, Studies show that, “It is estimated that one in ten people will have a kidney stone at some point in their lives.”(Kidney.org, Kidney Stones, 2021)

Kidney stones form due to various factors such as; obesity, genetics, lifestyle and certain medical conditions. A multitude of studies and trials have proven the link between the increased/decreased consumption or the exclusion of certain minerals/nutrients, and the reduced risk of kidney stone formation.

This article is based on the publication by, Ita P. Heilberg and David S. Goldfarb, titled Optimum Nutrition for Kidney Stone Disease. The following summarises their writings on the impact of certain dietary intake (Calcium, Oxalate, Protein, Sodium, Citrate & Potassium, Beverages, Phytate, and Calories & Fructose) on the risk of kidney-stone formation. Sharing their notes on the impact of the aforementioned factors on specific stone types, being; Calcium Oxalate Stones, Calcium Phosphate Stones, Uric Acid Stones, Cystine Stones, and Struvite Stones.

HealthyMeal
Photo by Ella Olsson on Pexels.com

Calcium

Description

Calcium (Ca) is one of the most important minerals required by the human body to maintain optimal performance of functions such as:

  • Growth and maintenance of healthy, strong bones.
  • Neurotransmission – maintaining healthy communication throughout the body.
  • Muscle movement. 
  • Cardiovascular movement. 

According to Heilberg and Goldfarb, calcium over-saturation of the urine is one of the biggest risk factors for calcium nephrolithiasis (Heilberg and Goldfarb, 2013). Calcium based stones account for up to 65-70% of kidney stones.

High levels of calcium present in the urine is referred to as hypercalciuria, and occurs in secondary and idiopathic incidences.

  • Secondary: Resulting as a side effect of another condition that causes excessive levels of calcium in the bloodstream.
  • Idiopathic: Occurring on its own, with normal levels of calcium present in the bloodstream. A complex primary metabolic alteration. At least half of calcium based stone formers are found to have idiopathic hypercalciuria.
  • An increase in active calcium transport by the intestines is observed in individuals with idiopathic hypercalciuria (IH). Seeing as; regardless of calcium intake, absorption of calcim is higher in IH patients. 
  • Commonly observed in IH patients:
    • A decrease in bone mineral density
    • High bone reabsorption
    • Reduced bone formation
  • Patients with IH excrete more calcium than was previously ingested when confronted with low calcium intake. The source of the excess calcium is most likely derived from bone.
  • Therefore, the entirety of effects decreasing calcium intake in IH stone forming patients has not yet been established.
  • Adversely to IH stone formers; decreasing dietary calcium intake in all other incident stone formers, reduces the risk of stone formation.
  • However, it has been widely observed that low calcium intake in young men, and younger and older women; can result in a 34% higher risk of developing kidney stones.
Sources of Calcium

  • Milk, cheese, cream and other dairy products.
  • Certain vareties of beans and lentilsLeafy vegetables eg. Spinach or kale
  • Fortified floursSeafoodSeeds eg. Sesame, poppy, chia and celery
  • Soya products, particularly those with added calcium.
  • Tofu

  • Oxalate

    Description

    Oxalate is a naturally occurring byproduct of metabolic activity, and derives from dietary sources. Excess urinary oxalate has the potential to collect in the kidneys and combine with other minerals present – leading to stone formation.


    • Urinary oxalate absorption is also dependant on calcium intake.
    • The malabsorption of fat is also responsible for increasing intestinal absorption of oxalate in conditions whereby reducing dietary fat might be considered.
    • It has been observed that in comparison to reducing oxalate intake, a more effective way of reducing urinary oxalate excretion is to increase calcium intake, especially if initial regular calcium intake is low.
    • The colonisation of Oxalobacter formigenes is another variable to factor into the consideration of the importance of dietary oxalate. Oxalobacter formigenes are obligate oxalate-degrading anaerobes [bacterium], found within the normal microbiome.
      • It’s presence in the colon is linked to a lower urinary oxalate excretion.
    • The significance of dietary oxalate restriction is yet to be determined in the overall prevention of stone formation. The exception being conditions such as bariatric surgery.
    • However, probiotic ingestion in patients characterised by high oxalate absorption resulted in the highest expectancy to experience clinically significant reductions in urinary oxalate. 
    • Which suggests that dietary oxalate plays a key role as a determinant of urinary oxalate excretion in response to the use of probiotic.
    Sources of Oxalate
    • Beans
    • Beer
    • Beets
    • Berries
    • Black tea
    • Chocolate
    • Cocoa powder
    • Coffee
    • Fizzy drinks/Soda
    • Green leafy vegetables
    • Nuts eg. Almonds and cashews
    • Okra
    • Oranges
    • Rhubarb
    • Soy beans & milk
    • Stevia sweetener
    • Sweet potato
    • Tofu
    • Wheat bran

    Protein

    Description

    Protein is a fundamentally essential nutrient the body requires. Two of the most important roles played by protein are; providing the body with a source of fuel; and facilitating healing and growth, as protein is one of the main constituents for the formation of bodily tissue. However, sources of protein derived from animals has been proven to have a prevalent effect on many urinary variables that lead to stone formation.


    • The combination of a low-calcium diet with a high-animal-protein diet induces a negative calcium balance which is exceptionally harmful.
    • High animal-protein intake places one at risk of developing calcium based stones as it is a contributing factor to hyperuricosuria.
      • Hyperuricosuria – excessive amounts of uric acid present in the urine. 
      • Hyperuricosuria can in turn lead to hypocitraturia
      • Hypocitraturia – abnormally low urinary citrate excretion.
    • The induction of hypercalciuria by animal-protein intake occurs as a result of higher bone resorption (The removal of calcium from the bones) and lower tubular calcium reabsorption (A higher loss of calcium in the urine because the kidneys reclaim less calcium from the urine.). 
    • Although, it has been established that the acid load accompanying high animal-protein intake is not responsible for hypercalciuria.
    • In patients with nephrolithiasis, a short-term reduction of animal-protein intake, for up to approximately two weeks has yielded a significant increase in citrate excretion and a reduction of urinary excretion of calcium, phosphate, hydroxyproline, uric acid, and oxalate.
    • In spite of the significant role increased animal-protein intake plays in adverse fluctuations in urine chemistry; thus increasing the risk of kidney stones – the only diet restricting animal-protein intake to effectively reduce stone risk, entailed higher calcium intake and a reduction of sodium intake.
    Sources of Protein
    • Animal products eg. Beef, pork, poultry and fish/seafood
    • Animal byproducts eg. Dairy products and eggs etc.
    • Beans
    • Legumes
    • Nuts
    • Seeds
    • Soy

    Sodium

    Description

    In order for our bodies to function properly and optimally, we require a relatively low intake of sodium (Na). Sodium is both mineral and electrolyte, playing roles in:

    • The regulation of the body’s water and electrolyte balances
    • Muscle function
    • Nerve function
    • Electrical impulses throughout the body
    • Regulation of blood pressure and volume

    • A diet consisting of high sodium intake in patients with reduced proximal sodium reabsorption, will lead to decreased kidney tubular calcium reabsorption. (The kidney’s ability to remove calcium from the urine.)
    • Considerable changes to dietary sodium intake reflected direct variations in daily urinary calcium excretion.
    • Stone-formation have been observed to experience a deleterious effect on calcium and bone loss.
    • It’s been observed that a higher calcium, and reduced sodium intake is linked to the reduction of calciuria. 
      • Calciuria: calcium presence in the urine.
    Sources of Sodium
    • Biscuits
    • Cheese
    • Chicken
    • Cured meats
    • Foods containing vegetable preservatives and additives
    • Multi-ingredient meals eg. Pizza, filled sandwiches, macaroni and cheese, and frozen meals
    • Popcorn
    • Salad dressing
    • Processed/refined snacks eg. Crisps/chips
    • Sauces/condiments

    Citrate & Potassium

    Description

    Citrate: is a key component of metabolism. Derived from the three carboxy groups of citric acid (Pubchem, 2021). Essentially, citrate is the salt form of citric acid. Citric acid/citrate play important roles throughout the body; however, in context of kidney function and stone disease – urinary citrate inhibits the growth of calcium oxalate stones, and increases the solubility of calcium salts in the kidneys. 

    Potassium: is a naturally occurring mineral the human body requires. Potassium is also classified as an electrolyte; due to the reaction that takes place when introduced to water, which is the production of positively charged ions. Potassium weighs in as one of the top three most abundant minerals found in the human body. Playing roles in: 

    • Fluid regulation
    • Regulation of muscle contraction and function
    • Neurotransmission

    The health benefits of a potassium-rich diet have been proven to be significant; potentially reducing blood pressure and alleviating water retention; also aiding in the prevention of stroke, osteoperosis and kidney stones.

    • Multiple factors plays a role in the regulation of kidney citrate excretion; however, acid-base variables were found to have the biggest impact.
      • Acid-base: refers to the reaction that takes place between an acid (low pH) and a base (high pH), which results in a salt (neutral pH)
    • Acid-loads and acidosis aid in reducing ones risk of uric acid and cystine-based calculi. Both increase urinary citrate excretion by increasing kidney tubule reabsorption of citrate. Thus, reducing calciuria.
    • Stone formers with increased/high animal protein intake, are encouraged to substitute this intake with fruits and vegetables.
    • An alternative nonpharmacological therapy to potassium citrate is an increased intake of citrus fruits such as:
      • Oranges
      • Lemons
      • Limes
      • Certain tangerines
    • Being sources of natural dietary citrate, the intake of these citrus fruits may aid the management of hypocitraturia and/or uric acid and cystine stones.
    • Citrate found in both orange and grapefruit have been noted to increase urinary pH.
    • Drinking freshly squeezed citrus fruit juice delivers a similar amount of dietary citrate whilst also increasing fluid intake and output. However, it is not advised to cosnume processed, commercial fruit juice in high quantities due to their often high; caloric, fructose and/or carbohydrate content.
      • However, it has been observed that orange juice is an exception, as it has no significant effect on the risk of stone formation.
    • Increased fluid intake = increased fluid output
    • By increasing ones fluid intake and in turn output, urine supersaturation is reduced. Thereby, reducing the risk of kidney stones.
    • Another alternate non-pharmacological therapy for hypocitraturic stone formers is the increased intake of non-citrus alkaline fruits such as melon.
    • Various melons provide high loads of; potassium, malate and citrate. The consumption of which can result in an increase of citrate excretion.
    • In contrast, observational studies indicated that a higher potassium intake is linked to incident stones in males and older women.
    Sources of Citrate
    • Beans
    • Berries
    • Citrus fruits and juice eg. Lemons and limes contain the most citric acid, then oranges & grapefruit.
    • Melon
    Sources of Potassium
    • Animal products eg. Beef, fish and poultry
    • Certain fruit and vegetable juices
    • Fruits eg. Bananas, oranges and apricots
    • Legumes
    • Nuts
    • Vegetables eg. Cooked spinach/broccoli, mushrooms, zucchini, cucumber and peas

    Other Beverages


    • Increasing water intake to ensure a urinary output volume of approximately 2.5 litres per day, is associated with reduced risk of stone reccurance.
    • Although the previous point advocating the consumption of water in stone formers, is tried and true; certain variables may be reasons to be concerned about the, “effect of water hardness on kidney stone incidence.” Consuming inordinate/excessive amounts of water can have adverse effects on the kidneys.
      • Water “hardness”, merely refers to the mineral content of the water. Noteably calcium and magnesium. The “harder” the water, the higher this mineral content is.
    • The ingestion of mineral waters that deliver loads of bicarbonate and magnesium may reduce ones risk of of uric acid percipitation as the minerals may result in;
      • Favourable changes in urine pH.
      • Favourable changes in magnesium and citrate excretion.
      • Favourable changes to inhibitors of calcium oxalate stone formation.
      • Favourable changes to counterbalancing increased calcium excretion.
    • Caffeinated as well as decaffeinated tea and coffee have been observed to reduce the risk of stone formation.
    • (In moderation) Alcohol (specifically beer) has been associated with the reduced risk of kidney stone formation. Possibly as a result of decreased urinary concentration due to alcohols ability to inhibit the secretion of antidiuretic hormone (ADH). Leading to an increased need to urinate.

    Phytate

    Description

    Phytate or insitol hexaphosphate, inhibits calcium salt crystallisation and stone growth (specifically in vitro).


    • Many phytate rich foods (Such as; beans, cereal, whole grains and rice) are rich in oxalate content too.
    • It is possible that phytate alleviates/nullifies oxalate content – “induced lithogenic potential.”
    • Although only roughly 5% of ingested phytate appears in urinary output (implying that phytate is mostly nonabsorpable), the increased consumption of dietary phytate is strongly associated with increases in urinary excretion. Thus decreasing ones risk of kidney stone formation.
    Sources of Phytate
    • Beans
    • Grains
    • Legumes
    • Nuts
    • Seeds

    Calories & Fructose

    The caloric content (amount of calories) of a food or meal refers to the amount of energy the food delivers to the body. A calories is characterised by its ability to raise the temperature 1 gram of water by 1° Celsius, and is defined by the amount of energy this requires. Regular high calorie intake, exceeding ones needs will result in weight gain, as the body stores excess calories as fat. Fat is a readily available source of fuel and energy reserved in the body, one of the reasons why a certain percentage of body fat; appropriate to ones heigh, weight and age, is integral in the body’s ability to function optimally. A lower caloric intake can result in weight loss as the body will burn fat in order to replace the fuel it’s not getting from dietary caloric intake. 

    Fructose is a simple sugar that the liver converts into glucose, which is another main source of fuel for the body. Fructose makes up 50% of table sugar, which is why high fructose intake can result in abnormal metabolic activity.Vegetables and sweet fruits (and fruit in general) contain relatively low amounts of dietary fructose.


    • Many observational and epidemiological studies link, obesity, weight gain, insulin resistance, metabolic syndrome and diabetes with an increased prevalence of kidney stones.
    • A higher body mass index (BMI) is associated with:
      • Lower urine pH and increased risk of uric acid stones.
      • Increased excretion of urinary oxalate.
    • Ergo, obesity (one of the causes for a high BMI) has been linked to calcium oxalate stone formation.
    • Uric acid stone formers have been known to have an increased net-acid excretion and a decreased urine pH, compared to non-uric acid stone formers at any given level of urine sulphate excretion. 
    • This in turn means that another nonpharmacological treatment known as a process called alkalinisation (the neutralisation of an acid) has been observed to fail in uric acid stone formers.
    • Weight loss has been associated with reduced risk of formation of all compositions of stone.
    • Stone formers are recommended to avoid diets that combine intakes of high animal-protein with low- carbohydrate, such as the Atkins diet. Due to the following:
      • Reduced urine pH
      • Reduced citrate excretion
      • Increased uric acid excretion
    • Instead, stone formers are encouraged to follow a DASH diet, which stands for Dietary Approaches to Stop Hypertension. A low calorie DASH-style diet is rich in fruits and vegetables.
    • Although the consumption of fructose is not definitively linked to kidney stone formation, it has been observed that high fructose intake is associated with an increased risk of incident kidney stone formation.

    The Take Away

    The following summary is directly quoted from the source document; Optimum Nutrition for Kidney Stone Disease, written by Ita P. Heilberg and David S. Goldfarb

    Calcium Oxalate Stones

    “Idiopathic oxalate stone-formers are advised to reduce animal protein, oxalate and sodium in their diets as well as maintain adequate intake of calcium and increasing their consumption of citrate and potassium.”

    Calcium Phosphate Stones

    “Reduce their sodium intake to reduce calcium excretion.”

    Uric Acid Stones

    “The mainstay of therapy is weight loss and urinary alkalinisation, provided by a more vegetarian diet, leading to an increase in urine citrate content and pH. Reduction in animal protein intake may further reduce purine ingestion and uric acid excretion.”

    Cystine Stones

    “Restrict animal protein to reduce cystine methionine ingestion, and restrict sodium intake to further reduce excretion and supersaturation of cystine. Ingestion of vegetables high in content of organic anions, such as citrate, should be associated with higher urine pH.”

    Struvite Stones

    “Because of their infectious origin, diet has no definitive role for Struvite stones.”