Ingredients:

• 150g organic salad leaves (iceberg, romaine, Batavia, chard, etc)
• ½ mango (skin and stone removed)
• 1 carrot (peeled and grated)
• ½ organic pepper (diced)
• ½ cup sweetcorn
• 8 organic plum or cherry tomatoes (cut into quarters)
• A sprinkling of mixed seeds (pumpkin, sunflower, sesame, etc)

Method:

1. Wash all the salad leaves and cut the mango into cubes.
2. Combine all the salad ingredients in a bowl.
3. Cut up the red chilli so finely that it resembles a puree.
4. Combine all the dressing ingredients in a jug, blend and serve.

For the dressing:

• 60ml rapeseed oil
• 60ml water
• 1 tbsp mango puree
• 5ml white wine vinegar
• 5ml freshly squeezed lemon juice
• 1 tsp cornflour
• 2g red chilli

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We have thoroughly explained the meaning and functionality of macronutrients in our previous article. That article will enable you to understand diet ratios. Let us learn to combine foods that contain macronutrients which are carbohydrates, proteins, and fats with minerals and vitamins to enable our body system function efficiently

Choosing a Dieting Framework

Most people don’t organize or have a suitable plan for the food they consume, and they don’t maintain foods that have the suitable combination of macronutrients. Let us understand that people today have different nutrient requirements. One of the differentiating factor nutrient requirements is age and the environment. It has been found that the body tends to adopt a particular food consumed for a very long time. That is why the Eskimos can consume a special food for an every long period with noticing any deficiency in their body

Calculate your daily Maros with Macronutrient Calculator.

Macronutrients need to be taken in the right proportion. This will enable all the nutrients to function efficiently. There is no ideal diet for everyone. You need to understand your body system, so you know what food to take and at the right time. Some people naturally have high oxidation level. Therefore, they should not consume food made for people with low oxidation. The way to choose a diet framework in other to get proportional macronutrients in our body is very simple. Follow these tips;

• Have adequate knowledge of the average daily calories needed by your body
• Understand nutrition labels
• Eat the right combination of Cabs, protein and fats
• Stay disciplined to achieve your nutritional goals

You should understand that what is a good healthy food for a person might not work for the order. Therefore, you should figure out what is right for you, and you go for it. Your dieting framework should be adopted as soon as possible.

Calorie Intake

Understanding calories will help you maintain adequate macronutrient balance. Calories come from different sources which are carbohydrates, fat, and protein. To adjust your intake, you also understand their calorie values. Calorie intake should be vigorously maintained because the lack of it might cause problems for the body and the access to it will cause weight gain, once it is excess, it will put enough fat in your body

• A simple conversion of macronutrients to calories will give us
• A gram of protein is equivalent to four calories
• A gram of carbohydrates is also four calories, and one gram of fat is nine calories
• Regulating macronutrients for healthy living

The macronutrients composition of your diet should be your highest priority when you want to live healthily. Most people will suffer headaches, skin problems, and have potential liver issues when they consume too much protein because the body will be unable to break adequately down energy

Our Recommendation

We recommend the suitable macronutrient composition to be taken on a daily basis; we also include the calorie breakdown to be consumed for healthy living. This should be:

• Consume 50% Carbohydrates
• 30% food rich in protein
• 20% fatty foods

To achieve this, you need to interchange the sources of your proteins. Minimize your consumption of margarine it contains Trans fats. Foods with high levels of sugar should be avoided.

You will achieve good health when you regulate macronutrient consumption as recommended. Don’t forget to share this article about Macronutrients Ratio with your friends using the social media icons.

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Scientists and nutritionists have found that the body requires about 114 different nutrients every day for us to stay healthy. To achieve this, it is recommended that we combine the solid food we eat and nutritional supplements to be able to meet up with the full range of nutrients requires by our body:

• Macro-nutrients: Includes proteins, carbohydrates and fats
• Micro-nutrients: are the vitamins, minerals and trace elements
• Phyto-nutrients: are the plant-based nutrients

Note: You can calculate your daily Macronutrients need with this handy macro calculator

THE MACRO-NUTRIENTS

On a daily basis, the nutrients mentioned above need to be supplied to the body In a full range. This is why we recommend that proteins and carbohydrates should be included in our daily planned diet and also supplemented whenever possible.
Protein should not be consumed from any source. We recommend the following sources:
Lean Meat
Fish
Pulses (preferably grilled or steamed)
Because of some circumstances beyond the control of people and their ignorance, they find it difficult to eat sufficient quantities of the normal proteins in their daily routines.

OUR CANDID SUGGESTION

We recommend the consumption of soy products. The best way to consume it is via meal replacement shakes. They are conveniently available as shakes and also affordable. Meal replacement shakes not only used for weight loss because recent research has shown that they are rich in protein and should be consumed more. Additionally, this method of supplementation also generates a host of health benefits that can lead to a reduction or even elimination of medication in curing some diseases. They are currently serving as a convenient shortcut to help provide optimally balanced nutrition for the entire family. Another attribute of the soy protein is that it contributes to lower the cholesterol level of the body.

The impact of the menopause can be reduced when you consistently consume the soy protein because it will help to eradicate some of those health concerns attributed to hormone replacement therapy such as breast cancer, heart disease or stroke. However, before you reduce medication for any condition, your medical physician must be consulted.

CARBOHYDRATES

This is considered as the most important component of the macronutrients. More carbohydrates should be proportionately consumed than anything else. Most people have the wrong information about carbohydrate consumption thinking that it is a threat to good health. We want to let you know that the consumption of carbohydrates is not the challenge. Our problem is only caused by the type of carbohydrates we choose to eat. Whenever you want to eat carbohydrates rich food, we suggest you go for dark grain, whole grain bread, rice and pasta.

FATS

The last group of macro-nutrients that is also important is fats. We need to have the right information before consuming fatty foods. Let us be informed that saturated fats: those that solidify at room temperature, should be consumed as minimal as possible because they contribute to Arteriosclerosis, the furring up of arteries, which can increase the chances of cardiovascular diseases. On the other hand, we recommend unsaturated fats. The best are those high in omega-3 fatty acids like flax oil, olive oil and fish oil. The consumption of the above mentioned fatty food should be done with moderation because of their high-calorie count.

In conclusion, we recommend that you should try as much as you can to eat fruit and vegetables because they are equally great for fiber. Our body needs 5 to 11 servings of fruit and vegetables every day. At least, women should have seven servings and men ought to have nine servings and above. Most people find it difficult to eat less than five serving of fruit per day. Therefore, in such cases, appropriate supplements needs to be introduced in their daily diet. However, none of the supplements can truly replace the benefits of eating fruits and vegetables.

The post Macronutrients: The truth About What Our Body Needs appeared first on Macronutrients.

What Are Macronutrients?

Essential elements and nutrients are imperative for our body to function efficiently. The normal consumption and combination of macronutrients are the secret of healthy living for plants, animals and humans. Through interactions and survey, we have found out that most people do not know the meaning of macronutrients, and that is why they cannot consume it proportionally to help them get the maximum benefits from it.

We need to educate you on the basics which you enable you to understand the subject matter.

You can calculate your daily Macronutrients need with Macro Calculator

The Real Definition of Nutrients

Nutrients can only be defined as constituents that are found in food which any organism, i.e., plants and animal, needs to survive and have adequate growth.

MACRONUTRIENTS

As the name implies, this can be defined as a compound or nutrients. In other words, it is nutrients in a bigger picture. Macronutrients are converted in the body to generate energy which the body uses in metabolism.

MICRONUTRIENTS

Micronutrients can be described as the necessary nutrients which the body needs in smaller amounts. They can also be described as cofactors required for metabolism, critical factor in the development and repair of tissues

Nutrient Assimilation in Plants

The understanding of plants intake of nutrients can be hard because it is a little be complex. The absorption or intake of nutrients occurs through two places in the plants. They are

• The roots and
• Leaves

The roots absorb nutrients from the soil which helps in the development of the plant. The leaves do the nutrient absorption from the atmosphere. The total growth and development of the plant are dependent on all these processes.

The digestive system of animals is designed in a way which helps it to digest macronutrients for energy. Micronutrients are used in the body of the animal for metabolism and anabolism.

We have thoroughly explained all the underlying facts about nutrients, macronutrients and micronutrients and we believe that our readers cannot be confused when we get to the complicated aspect of this subject matter.

COMPOSITION OF FOOD

The food we consume is comprised of three macronutrients. Namely

• CARBOHYDRATES
• PROTEIN
• FATS

For the body to function properly, it needs the combination of the macronutrients and vitamins. We will not undermine the importance of the inorganic chemical compounds which are dietary minerals, water and oxygen. They play important roles in digestion and the body metabolism. To live a healthy life, you must be able to identify foods that contain the different types of macronutrients combining them with minerals and adequate consumption of water.

Among the three sources of macronutrients mentioned above, carbohydrates can be described as the most important because they help to produce and sustain us physically and mentally. Carbohydrates can further be divided into two type, namely;

• The Simple and
• Complex carbohydrates or sugar

The following can be described as simple sugars.

• Honey
• Brown Sugar
• Molasses
• Candies
• Cookies and
• Fruit juice

It’s been found that simple carbohydrates produce more energy than nutrients to the body. Complex carbohydrates which include whole grains, legumes, vegetables and nuts have more vitamins and minerals, and they provide the body with longer lasting energy.

A protein which is another important macronutrient is responsible for building and repairing muscles, tissues, hairs and the red blood cells. Proteins can further be divided into animal and plant proteins. Some of the sources of animal protein are poultry, beef, fish and dairy. The legumes and soy are excellent sources of proteins.

The human body cannot develop properly with fats. They protect the cells and organs and enable the body to absorb necessary vitamins like A, D, E and K.

This article has been developed to give you basic information about macronutrients, its compositions and functions. Don’t forget to share this article with your friends using the social media icons.

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Some evidence indicates that dietary and lifestyle habits may play a role in the development of depression.

Recently, a team of researchers examined how vitamin D supplements affect depressive symptoms. Below is a detailed summary of their results.

Background

Major depressive disorder is a severe form of depression, characterized by strong feelings of sadness and loss of interest in life.

For people with major depressive disorder, these feelings can be so persistent and pervasive that they interfere with activities of daily living.

According to some estimations, major depression affects about 20% of people at some point in their lives.

Although depression is linked with reduced levels of certain neurotransmitters in the brain, the underlying cause of major depressive disorder is unknown.

Depression has also been associated with elevated oxidant stress and vitamin D deficiency.

Several previous randomized controlled trials have examined the effects of vitamin D supplements on mood and depressive symptoms. Here is a summary of their findings from over the years:

• 1999: Taking a 100,000-IU dose of vitamin D improved depression in people with seasonal affective disorder.
• 2008: Supplementing with 20,000 IU or 40,000 IU of vitamin D for one year reduced symptoms of depression in overweight and obese people.
• 2011: A single dose of 500,000 IU of vitamin D every year for 3–5 years had no significant effects on mood in older women.
• 2013: Supplementing with 1,500 IU of vitamin D for 8 weeks had beneficial effects on depressive symptoms in patients with major depressive disorder.
• 2014: Supplementing with more than 800 IU of vitamin D per day is somewhat favorable in the treatment of depression.

Why supplementing with vitamin D may improve depressive symptoms is not entirely clear. Potentially, it may affect levels of neurotransmitters in the brain, reduce inflammation and promote nerve growth.

Article Reviewed

An Iranian research team examined how vitamin D supplements affected major depressive disorder patients’ symptoms.

Vitamin D Supplementation Affects the Beck Depression Inventory, Insulin Resistance, and Biomarkers of Oxidative Stress in Patients with Major Depressive Disorder: A Randomized, Controlled Clinical Trial.

Study Design

This 8-week, randomized controlled trial examined how vitamin D supplements affected depression symptoms of patients with major depressive disorder.

A total of 40 Iranian people, 18–65 years old, participated in the trial. The drop-out rate was low, or only 10%.

All participants had moderate depression, according to the Hamilton Depression Rating Scale. They were also deficient in vitamin D, with circulating levels less than 20 µg/L.

The participants were randomly assigned to one of two groups:

• Vitamin D: This group took one 50,000-IU vitamin D capsule each week for two months.
• Placebo: This group took a placebo capsule, containing no vitamin D.

At the start and end of the study, depression was assessed using the Beck Depression Inventory (BDI), a 21-question self-assessment of depressive symptoms.

The researchers also took blood samples, measuring fasting blood sugar, insulin, blood lipids, high-sensitivity C-reactive protein (hs-CRP) and oxidative stress.

Bottom Line: This was a randomized controlled trial examining the effects of vitamin D supplements on the symptoms of depression.

Finding 1: Vitamin D Reduced Symptoms of Depression

Supplementing with vitamin D did not improve depressive symptoms, according to raw data, although the improvement was on the verge of being statistically significant.

However, after statistically correcting for initial vitamin D levels, age and body mass index (BMI), supplementing with vitamin D improved depressive symptoms by 32%.

The main results are shown in the chart below:

Bottom Line: Supplementing with vitamin D reduced the symptoms of depression. However, the results were only significant after correcting for initial values of vitamin D, BMI and age.

Finding 2: Vitamin D Reduced Insulin Resistance

Supplementing with vitamin D reduced fasting insulin levels by 28%, whereas there was no significant change in the placebo group.

What’s more, the supplements improved insulin resistance by a significant 36%.

The function of the beta-cells — the pancreatic cells that produce and store insulin — appeared to improve significantly as well.

Insulin resistance and beta-cell function were estimated using homeostatic model assessment (HOMA-IR and HOMA-B), which is based on fasting values for glucose and insulin.

These results can be seen in the chart below:

However, insulin sensitivity, as estimated by quantitative insulin sensitivity check index (QUICKI), did not change in response to vitamin D supplements.

Previous studies have examined how vitamin D affects blood sugar control, but they have provided inconsistent results.

In pregnant women with diabetes, and insulin-resistant Asian women, vitamin D supplements may significantly improve blood sugar control.

Yet another study found that vitamin D supplements had no effects on insulin sensitivity in diabetic patients.

These inconsistencies might be explained by differences in study populations or study design.

Bottom Line: In the current study, vitamin D supplements reduced insulin levels and improved insulin resistance.

Finding 3: Vitamin D Improved Antioxidant Status

Vitamin D supplements also increased the amount of antioxidants in the blood.

Specifically, total antioxidant capacity (TAC) improved by 7% in the vitamin D group, but only by 3% in the placebo group.

Levels of glutathione — the body’s primary antioxidant — also increased by 24% in the supplement group, as shown in the chart below:

For example, vitamin D supplements did not affect oxidative stress in pregnant women with diabetes or in adults with non-alcoholic fatty liver disease.

The inconsistencies are probably due to differences in study designs and/or participant characteristics.

Additionally, in the present study, supplementing with vitamin D had no effects on the inflammatory marker hs-CRP or blood lipids.

Bottom Line: Vitamin D supplements improved the antioxidant status of the blood, including the levels of glutathione.

Limitations

The findings may not be generalized to all people with depression.

The participants in the current study did not get much sunlight exposure, and all of them were deficient in vitamin D at the start of the study.

It is likely that vitamin D supplements may only benefit those who are deficient.

Summary and Real-Life Application

In short, this study suggests that taking 50,000 IU of vitamin D per week, or about 7,000 IU each day, may improve depressive symptoms.

However, all of the participants were initially vitamin D-deficient.

Supplementing is likely ineffective for those who are already getting enough vitamin D, but further studies are needed.

The post Vitamin D Supplements May Help Fight Depression appeared first on Macronutrients.

For example, cow’s milk contains varying amounts of proteins known as A1 and A2 beta-caseins. For some people, A1 beta-caseins can cause adverse health effects.

Recently, researchers examined the digestive effects of A1 beta-casein in people with self-reported lactose intolerance. Here is a detailed summary of their results.

Background

Most cow’s milk contains both A1 and A2 beta-casein, but the proportions depend on the cow’s breed. A few years ago, a New Zealand corporation started marketing A2 milk, which contains only A2 beta-casein.

This is because A1 beta-casein has been associated with adverse health conditions, such as type 1 diabetes and heart disease.

Unlike A2 beta-casein, the A1 version releases an opioid peptide known as beta-casomorphin-7 (BCM-7) during digestion.

For this reason, A1 beta-casein has been under scrutiny in recent years. However, the evidence is far from conclusive and human studies are lacking.

There is also evidence suggesting that BCM-7 may cause digestive discomfort — bloating, gas and diarrhea — resembling lactose intolerance.

One trial showed that A1 milk may cause softer stools, compared to A2 milk, and animal studies indicate that A1 beta-casein may significantly increase intestinal inflammation.

Article Reviewed

A team of researchers from China and New Zealand compared the effects of A1 and A2 milk on people with self-reported lactose intolerance.

Effects of milk containing only A2 beta casein versus milk containing both A1 and A2 beta casein proteins on gastrointestinal physiology, symptoms of discomfort, and cognitive behavior of people with self-reported intolerance to traditional cow’s milk.

Study Design

This was a randomized controlled trial comparing the health effects of A1 beta-casein and A2 beta-casein on digestive symptoms, inflammation and mental processing.

A total of 45 Chinese adults, with self-reported lactose intolerance, participated in the study. None of them regularly consumed cow’s milk.

At the start of the study, all of the participants did not drink any milk for two weeks. Afterward, they were assigned to two groups in a random order:

• A1 milk group: For two weeks, the participants consumed 8.4 oz (250 ml) of conventional milk after two meals every day. This milk contained 40% A1 beta-casein and 60% A2 beta-casein.
• A2 milk group: For two weeks, the participants consumed 8.4 oz (250 ml) of A2 milk after two meals every day. The A2 milk contained only A2 beta-casein.

Both types of milk were provided by the a2 Milk Company in New Zealand. They were identical, apart from differences in the amounts of A1 and A2 beta-casein.

The participants were told not to consume any other dairy products during the study.

The study had a crossover design, which means that all participants were in both groups on separate study periods, separated by a 2-week washout period.

At the start and end of each of the two study periods, the researchers assessed digestive symptoms and collected blood and fecal samples.

Intestinal function was measured at the end of each study period using an electronic smart pill. Additionally, all participants took a Subtle Cognitive Impairment Test.

Bottom Line: This was a randomized, crossover trial in Chinese milk-sensitive individuals. It compared the effects of conventional milk and A2 milk on digestive symptoms, inflammation and cognitive function.

Finding 1: A2 Milk Did Not Affect Digestive Symptoms

This study suggests that A2 milk doesn’t worsen self-rated digestive symptoms — bloating, flatulence and stomach rumbling — in milk-sensitive individuals.

Conversely, symptoms tended to be greater when conventional milk was consumed.

Although the difference wasn’t significant overall, symptoms were significantly greater compared to the baseline at some of the lab visits.

Since the A2 milk contained the same amount of lactose as the A1 milk, the findings strongly suggest that A1 beta-casein may be responsible for increasing symptoms.

And, even though all of the participants thought they were lactose intolerant, only 51% of them actually turned out to be intolerant to lactose.

Interestingly, lactose-intolerant individuals seemed to be unaffected by the A2 milk. It didn’t significantly worsen symptoms, even though it contained substantial amounts of lactose. The reason for this paradox is unclear.

Bottom Line: Drinking conventional milk tended to worsen digestive symptoms, even in those who weren’t lactose intolerant. These findings suggest that A1 beta-casein may be responsible for digestive discomfort.

Finding 2: A1 Milk Impaired Mental Processing

Cognitive performance was evaluated using the Subtle Cognitive Impairment Test, which measures the speed and accuracy of mental information processing.

The study found that both cognitive speed and accuracy were slightly lower after drinking the A1 milk for two weeks, compared to the A2 milk.

The authors suggest these changes may be caused by worsened systemic inflammation. Similar effects have been observed in patients with untreated celiac disease.

Some researchers have also speculated that A1 beta-casein, or its breakdown product BCM-7, may be associated with mental problems.

This is the first study to show that A1 beta-casein may affect mental processing in healthy people. Further studies need to confirm these findings.

Bottom Line: Drinking conventional milk for 2 weeks slightly impaired mental performance, compared to A2 milk, in milk-sensitive people.

Finding 3: A1 Milk Increased Inflammation

Inflammation in the stomach and small intestines was evaluated by a gastroenterologist using images taken by an electronic smart pill.

This evaluation suggested that small bowel inflammation improved in 36% of the participants when they switched from the A1 milk to the A2 milk.

Similarly, stomach inflammation improved in 23% of the participants. There were also significant differences in inflammatory markers, according to blood tests.

Specifically, levels of the inflammatory markers IL-4, IgG, IgE and IgG1 were higher after 2 weeks of drinking the A1 milk, compared to the A2 milk.

The chart below shows the estimated difference between groups (A1-A2):

These findings are consistent with a few studies in mice showing that A1 beta-casein resulted in greater inflammatory responses in the intestinal tract.

Bottom Line: Drinking conventional milk for 2 weeks appeared to increase inflammation in the digestive tract, compared to A2 milk.

Finding 4: A1 Milk Changed Stool Form and Frequency

The participants rated their stool frequency and consistency every day using the Bristol Stool Chart. During lab visits, and at the start, middle and end of each study period, the participants also rated their digestive symptoms.

The study showed that drinking the A1 milk increased stool frequency and led to softer stools and diarrhea. Conversely, the A2 milk had no such effects.

These findings are supported by one previous study in humans linking A1 beta-casein with softer stools.

Possibly explaining these findings, the present study found that the A1 milk increased intestinal transit time, as well as intestinal inflammation.

Bottom Line: Drinking conventional milk for 2 weeks softened stools and increased stool frequency, compared to A2 milk.

Finding 5: A1 Milk Reduced Levels of Short-Chain Fatty Acids

Short-chain fatty acids are formed in the colon when beneficial bacteria ferment prebiotic fiber (17).

They reduce inflammation and are the main source of nutrition for the cells lining the colon, potentially improving colon health.

Fecal levels of short-chain fatty acids were significantly higher after drinking the A2 milk for two weeks, compared to the A1 milk. These included total short-chain fatty acids, as well as acetate and butyrate.

The estimated difference (A1-A2) in the levels of short-chain fatty acids are presented in the chart below:

The reason why conventional milk decreases short-chain fatty acids, and A2 milk does not, is unclear.

Bottom Line: Conventional milk reduced levels of short-chain fatty acids in the colon, compared to A2 milk.

Limitations

This study had several limitations. First, all of the participants had self-reported milk sensitivity, but only half of them turned out to be lactose intolerant.

A1 beta-casein may not have any adverse effects in people who are not lactose intolerant, or otherwise sensitive to milk. Further studies need to confirm these findings in people who are not milk-sensitive.

Second, in the abstract, the researchers claim to have detected elevated circulating levels of BCM-7 after the participants had consumed A1 milk for 2 weeks.

Yet these results are not presented or discussed anywhere in the article.

Finally, one of the main authors and designers of the study was an employee of the a2 Milk Company, which holds the patent for A2 milk. The study was also solely funded by the a2 Milk Company, creating a potential conflict of interest.

Bottom Line: The results of this study may not apply to people who are not milk-sensitive. Although there is no reason to suspect misconduct, the findings should be confirmed by an independent research group.

Summary and Real-Life Application

This study found that when milk-intolerant individuals consumed A2 milk for two weeks, they experienced no significant adverse effects.

On the other hand, conventional milk containing both A2 and A1 worsened digestive symptoms. It also increased inflammation, softened stools, reduced the levels of healthy short-chain fats in the colon and slightly impaired mental performance.

Taken together, these findings suggest that milk-intolerant individuals can safely drink A2 milk, without any adverse symptoms.

However, further studies need to confirm the findings.

The post Lactose intolerance: A2 Milk May Be Safe for Milk-Intolerant People appeared first on Macronutrients.

Recently, researchers used unpublished data from the ’60s and ’70s to test this theory. They also conducted a review and meta-analysis of more recent studies.

Here is a detailed summary of their results.

Background

According to the traditional diet-heart hypothesis, reducing circulating cholesterol by eating a diet high in omega-6 linoleic acid — rather than saturated fat — may reduce the risk of heart disease and death.

Pieces of this hypothesis are supported by randomized controlled trials. They showed that replacing saturated fat with linoleic acid reduced total circulating cholesterol, including LDL-cholesterol.

Observational studies have also shown that high levels of cholesterol are associated with an increased risk of heart disease and death.

However, association does not equal causation. And so far, no randomized controlled trials have shown that replacing saturated fat with linoleic acid reduces the risk of heart disease events or death.

In fact, evidence points to the opposite — that replacing saturated fat with linoleic acid may increase the risk of heart disease events and premature death.

Recently, researchers using previously unpublished data from the Sydney Diet Heart Study (1966–73) showed that replacing saturated fat with vegetable oil, rich in linoleic acid, increased the risk of death from heart disease.

Yet, for decades, one of the main cornerstones of official dietary guidelines has been to reduce saturated fat and replace it with unsaturated fat, such as linoleic acid.

These guidelines may have contributed to the high intake of linoleic acid in the US today. It’s quite high, at about 7% of total calorie intake, on average.

In comparison, linoleic acid intake has been estimated to have been around 2–3% of calories 100 years ago, when people ate minimal amounts of processed foods.

Article Reviewed

A group of researchers used unpublished data from the Minnesota Coronary Experiment to test the traditional diet-heart hypothesis.

Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968–73).

Study Design

This study was based on the Minnesota Coronary Experiment, a randomized controlled trial conducted from 1968–1973.

It tested whether replacing saturated fat with linoleic acid, a polyunsaturated omega-6 fat, would reduce the risk of coronary heart disease and death.

It’s the largest trial on the health effects of linoleic acid ever conducted, including a total of 9,570 people, aged 20–97. However, the current analysis used data for the 2,355 participants who received the experimental diets for a year or more.

The participants were patients in mental hospitals, but one nursing home was also included. The study length differed between participants, lasting for up to 56 months (4.7 years), depending on how long they were hospitalized.

Participants were randomly assigned to two diets:

• Linoleic acid: This diet increased linoleic acid intake (from corn oil) by 280%, from 3.4% to 13.2% of calories, on average. Saturated fat intake was reduced by 50%, from 18.5% to 9.2%, compared to the participants’ initial diets.
• Control diet: This diet did not change saturated fat intake, which was 18.5% of calories, on average. The linoleic acid content was increased by 38%, providing about 4.7% of calories.

The saturated fat and linoleic acid content of the two diets is presented below:

In addition to saturated fat, the control group’s diet contained considerable amounts of trans fat from margarine and shortening. The control diet was also 38% higher in linoleic acid, compared to the initial diet.

Using data from the start and end of the study, the researchers analyzed changes in circulating total cholesterol and the incidence of death.

They also used autopsies to detect heart disease. However, the researchers only managed to recover 51% of the 295 autopsy reports.

In addition to analyzing this data, the researchers did a systematic review and meta-analyses of all randomized controlled trials examining the health effects of lowering cholesterol by replacing saturated fat with linoleic acid.

Bottom Line: This study analyzed unpublished data from a large, randomized controlled trial examining how replacing saturated fat with linoleic acid affected cholesterol and the risk of death.

Finding 1: Linoleic Acid Reduced Cholesterol

A high-linoleic acid diet reduced total cholesterol by 13.8% or 31.2 mg/dL, on average. The control diet reduced total cholesterol only by 1% or 5 mg/dL.

When the participants were divided into subgroups based on age and gender, cholesterol reduced similarly within each of them.

Bottom Line: Increasing the dietary intake of linoleic acid significantly reduced the circulating levels of total cholesterol.

Finding 2: Linoleic Acid Did Not Reduce the Risk of Heart Disease

The study found no evidence that a diet high in linoleic acid reduced heart disease risk. In fact, excessive linoleic acid intake seems to have increased heart attacks.

According to autopsy reports, 41% of those who consumed high amounts of linoleic acid had signs of at least one heart attack, while only 22% of the control group did.

However, the incidence of clogged arteries was similar in both groups, and cholesterol reduction was not significantly associated with heart disease.

Additionally, only some of the autopsy reports were recovered in the current analysis.

Bottom Line: The study suggests that higher consumption of linoleic acid increased the risk of heart disease.

Finding 3: Cholesterol Reduction Was Linked With an Increased Risk of Death

The study showed that replacing saturated fat with linoleic acid was associated with an increased risk of death.

Specifically, each 30 mg/dL (0.78 mmol/L) reduction in total cholesterol led to a 22% higher risk of dying.

However, when age groups were analyzed separately, the association was only significant among those who were 65 years or older. In this subgroup, the risk of death increased by 35% for each 30 mg/dL reduction in total cholesterol.

In comparison, there was no significant association among those who were younger than 65 years.

In the early 1970s, these results conflicted with prevailing beliefs, probably explaining why the researchers decided not to publish the results.

Bottom Line: A reduction in cholesterol was associated with an increased risk of death.

What Do Observational Studies Say?

Observational studies are useful when randomized controlled trials are impractical or ethically unacceptable.

However, since they cannot identify causal relationships, their interpretation can often be misleading. For example, their findings may sometimes be opposite to the true causal association.

Observational studies have provided inconsistent results for the association of linoleic acid and heart disease.

A few studies have shown that self-reported intake of foods high in linoleic acid was associated with a lower risk of coronary heart disease.

Other studies found no significant associations.

Similarly, high circulating levels of linoleic acid have been linked with a lower risk of heart disease in some studies, but not all.

Bottom Line: Some observational studies suggest eating a lot of linoleic acid may reduce the risk of heart disease, whereas others found no link.

What Do Randomized Controlled Trials Say?

Randomized controlled trials are the only studies that can demonstrate a cause-and-effect relationship.

The systematic review identified only 5 randomized controlled trials that specifically examined the replacement of saturated fat with vegetable oils rich in linoleic acid.

All in all, these studies included a total of 10,808 participants. Compared to the control groups, a diet rich in linoleic acid reduced total cholesterol by 7.8% to 13.8%, on average.

When the results of these trials were combined in a meta-analysis, there was no evidence of any health benefits from consuming linoleic acid.

Bottom Line: Previous randomized controlled trials haven’t provided any evidence of benefits from increasing the intake of linoleic acid.

Why Doesn’t Linoleic Acid Have Benefits?

Linoleic acid is an essential amino acid that’s healthy in moderate amounts.

Since eating high amounts can reduce cholesterol, it may seem paradoxical that it doesn’t reduce the risk of heart disease in randomized controlled trials.

Although it is still not known why linoleic acid may be unhealthy in high amounts, there are a few ideas.

Higher linoleic acid intake increases the levels of oxidized linoleic acid in many body tissues. Oxidized linoleic acid has been associated with several chronic diseases, including heart disease.

However, high intake might only adversely affect those who have elevated linoleic acid oxidation — smokers, heavy drinkers, heart disease patients or elderly people — while not being as much of a concern for others.

Bottom Line: Why linoleic acid may be unhealthy in high amounts is not entirely clear, but it may increase oxidized linoleic acid levels for some.

Limitations

The Minnesota Coronary Experiment was designed well and is the largest study on the traditional diet-heart hypothesis. However, it also had a few limitations.

First, even though the current study used data from a randomized controlled trial, the findings linking cholesterol levels with death are observational.

Second, the study only measured total cholesterol. Other factors, such as LDL-cholesterol and HDL-cholesterol, are more closely associated with heart disease.

Third, the experimental diet contained twice as much linoleic acid as the average US diet. Only a small proportion of people reach the high levels examined in this study. It is unclear if lower amounts of linoleic acid have any adverse effects.

Additionally, the study was conducted in mental hospitals and nursing homes. The findings are not necessarily generalizable to healthy people.

Finally, this study and other previous studies have used concentrated vegetable oils high in linoleic acid. The results may not be generalized to nuts or other whole foods containing high amounts of linoleic acid.

Bottom Line: This study was well conducted but had a few limitations. The results may not necessarily be generalized to healthy people, normal intakes of linoleic acid or whole foods that are high in it.

Summary and Real-Life Application

In short, this study showed that replacing saturated fat with linoleic acid effectively lowered total cholesterol.

However, despite the significant cholesterol reduction, there was no evidence that linoleic acid reduced the risk of premature death.

The study even suggests that linoleic acid may increase the risk of death from heart disease for those who are 65 years of age or older.

Linoleic acid is an essential fatty acid and getting small amounts from the diet is healthy, but consuming too much of it is probably unhealthy. At the very least, replacing saturated fat with linoleic acid provides no health advantage.

If you wish to reduce the linoleic acid content of your diet, avoid vegetable oils high in linoleic acid. These include corn, soybean, sunflower, safflower and cottonseed oils.

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