In recent years, advances in genetic testing have led to increased attention being paid to nutritional management and dietary therapy based on an individual’s genetic characteristics. Unlike traditional “one-size-fits-all” nutritional guidelines, approaches that utilize genetic information make it possible to create dietary plans that are more suited to an individual’s constitution and health risks. This field is called “nutrigenomics” or “nutrigenetics,” and is the study of how specific genes affect nutrient metabolism and disease risk.
In this article, we explain the relationship between genes and nutrition and explore the potential of personalized dietary therapy based on the latest research.
2. The relationship between genes and nutrition
2.1 Nutrient metabolism influenced by genes
Our bodies metabolize, absorb, and excrete ingested nutrients through the actions of enzymes and proteins determined by our genes. Therefore, even if we eat the same food, there are individual differences in how it is digested, absorbed, and metabolized.
For example, the following genetic traits are known:
LCT gene (lactase) : Mutations in this gene affect the risk of lactose intolerance. If the activity of the enzyme lactase, which breaks down lactose, is low, people are more likely to experience indigestion and abdominal pain after consuming dairy products.
CYP1A2 gene (caffeine metabolism) : Differences in this gene affect the rate at which caffeine is broken down. People with a slower CYP1A2 gene are more susceptible to the effects of caffeine and may increase the risk of high blood pressure and heart disease.
FTO gene (associated with obesity) : People with certain variants of the FTO gene are more likely to have increased appetite and are at higher risk of obesity.
2.2 Effects of nutrients on gene expression
However, nutrients can also regulate gene function. This field of research is called “epigenetics,” and it has been shown that certain nutrients can regulate gene expression through DNA methylation and histone modifications.
Folic acid (vitamin B9): Involved in DNA methylation, intake during pregnancy is recommended to prevent neural tube defects in the fetus.
Polyphenols (green tea, red wine): Have antioxidant properties and may promote the expression of cancer-suppressing genes.
Omega-3 fatty acids (fish oil): Suppress the expression of inflammation-related genes and reduce the risk of cardiovascular disease.
3. Genetic characteristics and eating habits of Japanese people
In understanding the relationship between genes and diet, it is important to consider the genetic characteristics of each ethnic group. The following relationship can be seen between the genetic characteristics and eating habits of Japanese people.
3.1 Alcohol metabolism and the ALDH2 gene
It is known that about 40% of Japanese people have a mutation in the ALDH2 gene, which reduces their ability to break down alcohol. This means that even small amounts of alcohol can make their face turn red, and in the long term, this can increase the risk of esophageal cancer.
3.2 High-salt diet and risk of hypertension
Japanese people have traditionally had a high salt intake and are considered to be at high risk for hypertension. Genetic factors such as the ACE gene and salt sensitivity are involved, and some people can find it easier to control their blood pressure by limiting their salt intake.
3.3 DHA, EPA and lipid metabolism
Japanese people have a culture of eating a lot of fish, and their intake of DHA and EPA is said to be higher than that of Westerners. This is suggested to affect lipid metabolism and diabetes risk through interaction with the PPARG gene.
4. Individualized dietary therapy using genetic testing
By utilizing genetic testing, it becomes possible to adopt a diet that suits your constitution. Some possible personalized nutrition approaches include the following:
4.1 Obesity prevention and weight management
FTO Gene- Based Meal Plan: Control your appetite by regulating your carbohydrate intake and increasing your protein intake.
Lipid management according to the PPARG gene: Increase intake of omega-3 fatty acids and reduce animal fats.
4.2 Reducing the risk of diabetes
If you have a variant of the TCF7L2 gene, it is recommended that you follow a diet that strictly restricts carbohydrates and prevents sudden spikes in blood sugar levels.
A combination of exercise and diet improves insulin sensitivity.
4.3 Managing cardiovascular disease risk
If you have a variant of the CETP gene, eat more nuts and fish to increase your HDL cholesterol.
Adjusting salt intake according to ACE gene type.
4.4 Avoiding allergies and indigestion
Depending on your HLA gene type, you may be more susceptible to the effects of wheat gluten and may benefit from a gluten-free diet.
Dairy intake was adjusted based on LCT genes.
5. Future nutritional management using genetic information
The combination of genetic testing and nutritional science is making it possible to develop dietary therapy that is optimized for each individual. In the future , more precise nutritional management will become possible as meal plans are created using AI and research into the interactions between intestinal flora and genes progresses.
🔗 References and Latest Research Data For the latest research, please refer to the following links: ➡ Google Scholar – Nutrigenomics ➡ PubMed – Nutritional Genomics
6. Specific examples of use of dietary therapy based on genetic testing
The use of genetic testing has already been put into practice in many fields. Here we will introduce some specific examples of dietary therapy that utilize genetic testing.
6.1 Nutritional management for athletes
Athletes strictly manage their diet to improve their performance, but genetic testing can help them replenish their nutrients more efficiently.
ACTN3 gene (determines fast-twitch and slow-twitch muscle types）
Fast-twitch (RR) athletes can promote muscle development by consuming a high-protein diet.
Athletes with slow-twitch muscle fibers (XX type) should focus on a diet that emphasizes endurance (high in carbohydrates and healthy fats).
PPARGC1A gene (affects endurance and metabolism）
Depending on the type of gene mutation they have, endurance athletes can improve their performance by choosing a diet that promotes oxidative metabolism (foods rich in omega-3 fatty acids and polyphenols).
With this information, sports nutritionists and trainers can create individualized meal plans to help athletes maximize their potential.
6.2 Nutritional advice for pregnant women
For pregnant women, proper nutrition is crucial to the health of the fetus, and genetic testing can help provide optimal nutritional plans for both mother and fetus.
MTHFR gene (involved in folate metabolism）
Women with mutations in the MTHFR gene may have impaired folate metabolism, so they need to consume more folate than normal.
A deficiency in folic acid increases the risk of neural tube defects (NTDs), so women should actively take folic acid supplements, especially during the early stages of pregnancy.
GSTM1 gene (involved in detoxification ability）
Women with GSTM1 deletions have a reduced ability to metabolize antioxidants and are more susceptible to environmental toxins, so it is recommended that they consume foods rich in the antioxidant vitamins C and E (citrus fruits, nuts, and green and yellow vegetables).
In this way, by creating a nutritional plan based on genetic information, health risks to both the mother and fetus can be reduced.
6.3 Nutritional management for the elderly and dementia prevention
As we age, our metabolism and nutritional needs change. Dietary therapy using genetic testing is attracting attention, particularly in order to reduce the risk of dementia.
APOE gene (associated with risk of Alzheimer’s disease）
People with APOE4 are generally considered to be at higher risk of Alzheimer’s disease. People with this type are recommended to consume more seafood, which contains DHA and EPA, which have anti-inflammatory properties.
Avoiding a high-carbohydrate diet and adopting a ketogenic diet (such as coconut oil containing medium-chain fatty acids) can help replenish the brain’s energy supply.
BDNF gene (involved in brain plasticity）
Low expression of BDNF (brain-derived neurotrophic factor) reduces the growth and repair ability of nerve cells. Therefore, it is effective to consciously consume foods that promote the production of BDNF (blueberries, dark chocolate, walnuts, etc.).
It is also expected that gene-based nutritional therapy will be effective in managing the health of the elderly.
7. Current status and future prospects of genetic testing
7.1 Market expansion and penetration
In recent years, the cost of genetic testing has fallen significantly, and genetic testing services for general consumers have increased rapidly. For example, the following companies offer genetic testing for individuals:
23andMe (US）
It is possible to analyze health risks and ancestral roots.
MyCode (USA）
We partner with medical institutions to provide precise health risk analysis.
GeneLife（Japan）
We provide physical constitution, obesity risk, and nutritional analysis for Japanese people.
By using these services, even ordinary people can easily find out their own genetic information and use it in their lifestyle.
7.2 Advanced nutritional management in collaboration with AI
In recent years, there has been an increase in the use of AI (artificial intelligence) to create meal plans.
AI-powered diet analysis
By combining genetic information, blood test data, and intestinal flora analysis, we propose the optimal meal plan for each individual.
Integration with wearable devices
It works in conjunction with smartwatches and devices with blood glucose measuring functions to monitor nutritional status in real time.
Development of individualized supplements
A new service has been launched that provides optimal vitamin and mineral combinations based on genetic test results.
In this way, the combination of genetic testing and the latest technology is ushering in an era where more precise, individualized nutritional management can be carried out.
8. Latest research on genetic testing and dietary therapy
8.1 Effects of dieting based on genetic testing
In recent years, research into diet methods that utilize genetic testing has been progressing. In particular, research into the relationship between low-carbohydrate and low-fat diets and genetic characteristics has been attracting attention.
PPARG gene (involved in fat metabolism）
One study showed that people with a certain variant of the PPARG gene lost more weight on a low-carbohydrate diet than a low-fat diet .
People with this gene can burn fat more efficiently by limiting carbohydrates and consuming healthy fats (such as olive oil, avocados, and nuts).
FTO gene (associated with obesity risk）
People with a mutation in the FTO gene are more likely to have increased appetite and become addicted to carbohydrates .
People with this type of diet can help suppress hunger by eating more high-protein foods (meat, fish, legumes) and choosing low-glycemic index foods that prevent blood sugar levels from rising too quickly.
These findings suggest that genetic testing may be used to improve diet success .
8.2 Relationship with the intestinal flora (microbiome)
In recent years, research on the interactions between the intestinal flora (microbiome) and genes has progressed. Our intestines are home to more than 100 trillion bacteria, which are involved in food digestion and nutrient absorption.
Interactions between gut bacteria and genes
One study has shown that different types of intestinal bacteria can affect the likelihood of becoming obese, even if you eat the same diet .
People with a higher proportion of Bifidobacterium and Akkermansia muciniphila are less likely to become obese.
Nutrients influenced by genes and gut bacteria
Short-chain fatty acids (SCFAs) : Produced by intestinal bacteria fermenting dietary fiber, they promote fat burning.
B vitamins : Intestinal bacteria synthesize B vitamins, but for people with genetically poor metabolism, it is important to obtain them through diet.
As this research field advances, it is expected that dietary therapy combining genetic testing and intestinal flora analysis will continue to evolve.
9. Genetic testing and risk management for specific diseases
9.1 Diabetes risk and diet
Diabetes is a disease that develops as a result of the interaction of genetic factors and lifestyle habits. People with certain gene mutations are at higher risk of developing diabetes, so prevention through dietary therapy is important.
TCF7L2 gene (risk of developing type 2 diabetes）
People with mutations in the TCF7L2 gene are prone to reduced insulin secretion.
People with this type of diet are advised to base their meals around low GI foods to prevent blood sugar levels from spiking.
People with low insulin secretion ability need to be creative with their diet.
By eating 5 to 6 small meals a day instead of 3 meals, you can expect to stabilize your blood sugar levels.
People at risk of developing diabetes can significantly reduce their risk of developing the disease by designing a diet based on their genetic information.
9.2 Relationship between cancer risk and diet
The development of cancer also involves interactions between genes and diet, and people with certain gene mutations may be able to reduce their risk by modifying their diet.
BRCA1/BRCA2 genes (breast and ovarian cancer risk）
People with mutations in these genes may be able to reduce their risk by eating more antioxidant-rich foods (berries, green leafy vegetables) .
GSTP1 gene (related to detoxification ability）
People with low GSTP1 function may have a reduced ability to metabolize harmful substances and be at higher risk of developing cancer .
Sulforaphane, found in cruciferous vegetables such as broccoli and cabbage, increases the activity of detoxifying enzymes , so it is recommended to actively consume them.
In this way, people at high risk of cancer can expect to reduce their risk by consciously consuming foods with antioxidant and detoxifying effects based on their genetic information.
Because genetic information is highly personal data, it must be managed with great care.
Protection of Personal Information
Genetic data must be strictly managed by medical institutions and companies.
Some countries have enacted the Genetic Information Nondiscrimination Act (GINA) , which prohibits discrimination on the basis of genetic information.
Issues with providing data to third parties
Some genetic testing companies provide users’ genetic information to third parties .
It is important for users to check the “Data Handling Policy” before taking the test.
10.2 Risk of misuse of genetic information
Genetic overlabeling
It is scientifically inaccurate to make a statement such as “If you have this gene, you will definitely become obese.”
Genes are merely a “risk factor,” and diet and exercise habits also have a large influence.
It is necessary to use genetic testing appropriately, taking into consideration such ethical issues.
11. Application of genetic testing and dietary therapy
The combination of genetic testing and nutritional management is being applied in a variety of fields. Here, we will introduce examples of its application in the fields of specific disease prevention, beauty, and anti-aging.
11.1 Mental health and diet
Research has also shown that genes and diet influence mental health conditions such as depression and anxiety.
COMT gene (involved in dopamine breakdown）
People with certain variants of the COMT gene have been found to have a lower tolerance to stress.
People with this type of condition may be able to improve their stress resistance by consuming more magnesium (nuts, spinach) and omega-3 fatty acids (oil-filled fish) .
BDNF gene (involved in neuroplasticity）
Individuals with low expression of BDNF may be at higher risk of depression.
It is believed that components contained in blueberries and turmeric promote the expression of BDNF, helping to alleviate symptoms of depression.
Understanding more about the relationship between mental health and nutrition could lead to advances in genetically based dietary approaches to prevent mental illness.
11.2 Prevention of skin aging and genetic testing
In the fields of beauty and anti-aging, skin care and dietary management that utilizes genetic testing are becoming more common.
MMP1 gene (involved in collagen breakdown）
It is known that people with a mutation in the MMP1 gene are more susceptible to UV-induced skin aging.
Consuming foods rich in vitamin C and collagen can help slow down the aging of your skin.
SOD2 gene (related to antioxidant enzymes）
People with low SOD2 activity are more susceptible to cell damage caused by active oxygen, and are more likely to develop wrinkles and sagging skin .
Consuming a lot of polyphenols, found in green tea and red wine, may help reduce skin damage through their antioxidant effects.
By utilizing genetic information, it will be possible to suggest skin care and dietary treatments that are optimal for each individual’s skin type.
11.3 Management of allergy risks
Genes also play a role in allergic diseases such as food allergies and hay fever.
HLA genes (involved in autoimmune diseases and allergic reactions）
It has been found that people with certain HLA variants are more likely to develop allergies to wheat and dairy products.
By utilizing genetic testing to identify possible allergies in advance, it becomes possible to take measures to avoid high-risk foods.
IL13 gene (involved in the strength of allergic reactions）
People with certain variants of IL13 are at increased risk of atopic dermatitis and hay fever .
Including fermented foods (yogurt, natto) in your diet may improve your intestinal environment and reduce allergy symptoms.
In this way, by understanding the genetic factors behind allergic diseases, more effective preventive measures can be taken.
Based on genetic information, it can be applied to improve not only diet but also exercise and sleep.
12.1 Improving athletic performance
Athletic ability varies genetically from person to person, and genetic testing can help select appropriate training methods.
ACTN3 gene (determines muscle type）
Fast-twitch muscle (RR) people are suited to explosive activities such as sprinting and weightlifting.
People with slow-twitch muscle types (XX type) are suited to endurance exercise such as marathons and cycling.
PPARGC1A gene (involved in energy metabolism）
People with this gene mutation need to optimize their carbohydrate intake to improve endurance.
By utilizing genetic information, it will be possible to create optimal exercise programs for each individual and train efficiently.
12.2 The relationship between sleep quality and genes
Sleep is also a genetic factor, and appropriate sleep habits vary depending on an individual’s genetic type.
PER3 gene (involved in circadian rhythm）
The PER3 variant determines whether you are a morning or evening type .
Morning people are more likely to improve the quality of their sleep by limiting their caffeine intake in the evening.
ADA gene (affects length of sleep）
People with the ADA gene mutation are more likely to stay healthy even with short sleep periods .
However, it’s important to get adequate rest to avoid accumulating sleep debt.
By utilizing genetic information, it is possible to establish optimal sleep habits that are tailored to each individual and maintain good health.
13. The future of personalized nutrition using genetic testing
13.1 Gene editing technology and the potential of dietary therapy
Advances in gene editing technologies such as CRISPR-Cas9 may in the future enable us to directly modify genetic makeup and enable more effective nutritional management.
Example: Eliminating lactose intolerance through gene editing
Research is underway to use gene editing to restore lactase expression in people who are unable to break down lactose due to a mutation in the LCT gene.
Example: Development of individualized supplements adapted to diet
If fully individualized supplements based on genetic information become widespread, it will be possible to effectively supplement specific nutrient deficiencies.
13.2 Linking genetic data with wearable devices
In recent years, real-time health management using wearable devices has become more common. By monitoring an individual’s metabolic and nutritional status based on the results of genetic testing, it becomes easier to maintain optimal diet, exercise, and sleep habits.
Blood glucose monitoring in conjunction with a smartwatch
Systems are being developed that combine genetic test results with real-time blood glucose data to optimally manage diabetes risk.
Personalized nutritional guidance using AI
Services that use AI to suggest optimal menus based on genetic data and food records may become widespread.
In this way, by combining genetic testing with the latest technology, we can expect to see a future where more precise personalized nutrition will be realized.
Summary
The combination of genetic testing and dietary therapy has made it possible to provide optimal nutritional management according to each individual’s constitution and health risks. By utilizing genetic information, a wide range of health issues can be addressed, including obesity, diabetes, cancer, mental health, and skin aging. In addition, real-time health management is also evolving through collaboration with AI and wearable devices. In the future, with the development of gene editing technology, personalized nutrition is expected to become even more precise and contribute to extending healthy lifespans.
