My mother in the 1940’s used to tell me when I was only a small child, never eat durians and drink alcohol at the same time or soon after that. She told me it will result in death. I was then very small when she told me this.
Today, I am a clinician, a nutritionist, a retired senior medical researcher, but above all - a medical and food toxicologist - formerly with the Massachusetts Institute of Technology working in collaboration with the Institute for Medical Research. I believe today I am in a much better position to speak on the scientific truth behind this traditional, social and cultural belief.
This deadly traditional belief has struck on for generations among most Malaysians. There were several reports I read in the newspaper and have also heard unconfirmed stories telling the same - of deaths resulting from the consumption of durian together with alcohol. Especially currently in the peak durian season we need to be careful with what we eat.
This paper is meant for all healthcare professionals, including medical doctors who have no clue on this traditional belief. Some doctors has even dismissed it as an “unscientific superstition”
Title: Durian and Alcohol - Biochemical Evidence Supporting a Traditional Malaysian Dietary Prohibition
Abstract
For generations, Malaysians have been cautioned against consuming durian together with alcohol, with traditional warnings ranging from severe illness to sudden death. Often dismissed as folklore, this belief has persisted across cultures and decades. This paper examines the biochemical basis of this traditional prohibition by analyzing the metabolism of ethanol in the human body and the inhibitory effects of sulphur-containing compounds found in durian on key hepatic enzymes. Evidence suggests that durian can significantly impair aldehyde dehydrogenase activity, leading to toxic acetaldehyde accumulation. While the claim of inevitable fatality is exaggerated, the combination poses genuine physiological risks, particularly in individuals with underlying metabolic or cardiovascular disease. This work demonstrates how traditional dietary wisdom may align closely with modern biochemical understanding.
Introduction
Durian (Durio zibethinus), revered as the “King of Fruits” in Southeast Asia, is cherished for its distinctive aroma, rich taste, and high nutritional value. Alongside its popularity, however, exists a long-standing traditional warning: durian should never be consumed together with alcohol. This belief was widely known in Malaysia as early as the first half of the twentieth century and was often conveyed with grave seriousness, sometimes invoking the possibility of death.
With advances in biochemistry, toxicology, and nutritional science, it is now possible to examine whether this traditional belief has a physiological basis. To do so, one must first understand the normal metabolic fate of ethanol in the human body.
Ethanol Metabolism: A Biochemical Overview
Absorption and Hepatic Processing
Ethanol is rapidly absorbed from the gastrointestinal tract into the bloodstream and transported to the liver, which serves as the primary organ for its metabolism. The detoxification of ethanol occurs via a tightly regulated two-step enzymatic pathway involving:
Alcohol dehydrogenase (ADH) and Aldehyde dehydrogenase (ALDH)
This system normally prevents the accumulation of toxic intermediates.
Step 1: Ethanol to Acetaldehyde (Alcohol Dehydrogenase)
The first step occurs in the cytoplasm of hepatocytes, where alcohol dehydrogenase (ADH) catalyzes the oxidation of ethanol into acetaldehyde:
Ethanol + NAD⁺ → Acetaldehyde + NADH + H⁺
Acetaldehyde is a highly toxic and carcinogenic compound, far more harmful than ethanol itself. It is responsible for many acute alcohol-related symptoms, including facial flushing, nausea, headache, tachycardia, and tissue injury. Therefore, rapid removal of acetaldehyde is essential for physiological safety.
Step 2: Acetaldehyde to Acetate (Aldehyde Dehydrogenase)
Acetaldehyde is promptly transported into the mitochondria, where aldehyde dehydrogenase (ALDH), particularly the mitochondrial isoenzyme ALDH2, oxidizes it into acetate:
Acetaldehyde + NAD⁺ + H₂O → Acetate + NADH + H⁺
This step is normally highly efficient, ensuring that circulating acetaldehyde levels remain extremely low.
Final Metabolic Fate
Acetate is relatively non-toxic and exits the liver to circulate to peripheral tissues such as muscle and brain. There, it is converted into acetyl-CoA, enters the citric acid (Krebs) cycle, and is fully oxidized to carbon dioxide and water, generating metabolic energy in the form of ATP.
In summary, under normal conditions: ADH initiates ethanol metabolism. ALDH completes detoxification. Toxic intermediates do not accumulate.
ADH and ALDH: Distinct but Complementary Roles
Although ADH and ALDH function sequentially, their physiological roles differ profoundly. Alcohol dehydrogenase (ADH) converts ethanol into acetaldehyde
Cytoplasmic localization produces a highly toxic intermediate . Aldehyde dehydrogenase (ALDH) converts acetaldehyde into acetate
ALDH2 is predominantly mitochondrial. Detoxifies aldehydes and protects tissues
ALDH enzymes form a family of NAD(P)+-dependent enzymes responsible for oxidising a wide range of toxic endogenous and exogenous aldehydes. ALDH2 deficiency or inhibition leads to acetaldehyde accumulation, manifesting clinically as the alcohol flush reaction.
Crucially, ADH activity often exceeds that of ALDH. Therefore, any impairment of ALDH function rapidly results in acetaldehyde buildup and systemic toxicity.
Durian and Enzyme Inhibition
Sulphur Compounds in Durian
Durian contains several volatile sulfur-containing compounds responsible for its characteristic aroma. Among these, diethyl disulfide has been shown to significantly inhibit aldehyde dehydrogenase activity.
Experimental studies, including those from the University of Tsukuba (Japan), demonstrate that diethyl disulfide can reduce ALDH (particularly ALDH2) activity by up to 60–70%.
Biochemical Consequences of Co-Consumption
When alcohol is consumed together with durian. ADH continues to convert ethanol into acetaldehyde. ALDH activity is inhibited by durian sulfur compounds. Acetaldehyde like formaldehyde accumulates rapidly in the bloodstream and may even cause blindness. Other results in symptoms resembling severe alcohol intolerance like, intense facial flushing, severe nausea and vomiting, dizziness and headache, palpitations and chest discomfort and profound malaise and distress
Additional Metabolic and Cardiovascular Stress
Durian is also high in natural sugars, calorically dense, and capable of transiently increasing blood pressure and heart rate
Alcohol contributes further physiological strain through vasodilation, dehydration, and sympathetic activation. In individuals with diabetes mellitus, hypertension, coronary artery disease, or cardiac arrhythmias, this combined metabolic burden may precipitate serious adverse events, including hypertensive crises, arrhythmias, or myocardial ischemia.
This provides a plausible explanation for rare but credible reports of collapse or death following durian–alcohol co-consumption.
Discussion: Tradition Anticipating Science
The traditional Malaysian warning against consuming durian with alcohol is not merely cultural superstition. While claims of inevitable or immediate death are exaggerated, modern biochemistry clearly demonstrates that the combination is physiologically hazardous, particularly in vulnerable individuals.
This case exemplifies how empirical cultural wisdom, transmitted across generations, can precede and is in line in the same frequency with scientific discovery.
The consumption of durian together with alcohol disrupts normal ethanol metabolism by inhibiting aldehyde dehydrogenase, leading to toxic acetaldehyde accumulation. While not universally fatal, the combination can cause severe adverse reactions and may be dangerous in individuals with underlying medical conditions.
Accordingly, avoidance of alcohol for several hours before or after durian consumption is strongly advisable. In this instance, traditional dietary guidance stands validated by modern biochemical science.
Selected References
1. Zakhari, S. (2006). Overview: How is alcohol metabolized by the body? Alcohol Research & Health, 29(4), 245–254.
2. Edenberg, H. J. (2007). The genetics of alcohol metabolism. Alcohol Research & Health, 30(1), 5–13.
3. Yokoyama, A., et al. (2010). Alcohol flushing, alcohol and aldehyde dehydrogenase genotypes, and risk for esophageal cancer. Alcohol, 44(2), 123–130.
4. Maninang, J. S., et al. (2009). Inhibition of aldehyde dehydrogenase by sulfur compounds in durian. Journal of Agricultural and Food Chemistry, 57(21), 10342–10347.
5. Lieber, C. S. (1997). Ethanol metabolism, cirrhosis and alcoholism. Clinical Chimica Acta, 257(1), 59–84.
1. thanol + NAD
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